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Equipment Discussions >> Eyepieces

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Bob S.
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Leica ASPH Zoom in a Fast Newtonian
      #5466183 - 10/11/12 11:56 PM

I am totally beat as this is my second observing session today. The morning session was dedicated to playing with my Baader Mark V's in my 16.5" f/3.65 Lockwood/Starmaster with tracking from 1:30a.m. until about 5:30a.m. Today, I received my Leica ASPH zoom with 2" adapter. It appears that Andreas, Bill P., Doug C., and others are really onto something quite interesting. I used both my Paracorr II and 2x Powermate to look at a bunch of objects tonight with the Leica. In the Paracorr II, the Leica prefers the "A" setting and requires just a bit more infocus than my 17mm Ethos. Objects of interest tonight were M22, M57, Double Double, October Salt/Pepper, M31, Alberio and a few others that I am too tired to remember.

The Leica zoom is without a doubt the finest zoom that I have ever used. In fact, it doesn't feel like a zoom in terms of the expected degraded images I have gotten in zooms so often. With the Paracorr II and/or TV 2x Powermate, the stars are extremely tight and very pleasing in terms of color/light transmission.

I was recently diagnosed with a form of cataracts known as cortical spokes and so there are some self-induced abberations that I have been able to compensate for but notice the spokes with a defocused intrafocal position and thus some of my observations are less reliable than someone without my current but soon to be remedied medical condition.

I tried to use the Leica with my 2x Powermate on the Ring Nebula to catch the central star and could not make it out tonight even though I kept zooming in and out. The double double was a hoot with the zoom and the 2x Powermate. Comparisons between the views with the Leica ASPH and my 17mm Ethos in the relatively same mag were somewhat equivocal with the Leica tending to show a darker background and slightly tighter star points.

I cannot wait to do some further testing both in my fast Newtonians and my slow refractor. I missed the VP debate tonight but figured that playing with a Leica ASPH zoom had to be more fun than listening to politicians Bob


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sixela
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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: Bob S.]
      #5466365 - 10/12/12 05:41 AM

What, you want _even more_ entertainment value from Joe Biden? Whatever you think of the man, I don't think you can accuse him of being 'no fun'.

Clouds here and I was back from a tango milonga, so I watched 'your' debate.


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Bob S.
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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: sixela]
      #5470101 - 10/14/12 04:16 PM

Just got back from the Peach State Star party at Deerlick observation field (what a great bunch of astronomers!) and have now had the Leica ASPH zoom which has a 60-80 FOV and zoom range of 8.9 to 17.8mm range in a 16.5" f/3.65 Lockwood/Starmaster; 16" f/4.5 Spooner/Home Built; and a 28" f/3.7 Kennedy/Webster. The eyepiece was placed in Paracorr I's for the homebuilt and Webster and a Paracorr II with the Starmaster.

The results were uniformally well received and wowed all who looked through it. In numerous comparos with 10mm and 13mm Ethos ep's, the Leica reliably showed tighter star points and darker backgrounds (more contrast) in all three scopes. The ability to zoom to the best magnification for a given seeing moment won great favor as well as the fact that you can set the zoom to frame the object that most aesthically pleases you.

Markus Ludes reported that another new zoom he will be selling seemed to be a bit sharper than the Leica (Meopta) in a f/5 Newtonian. I am not sure how this could be because the stars were pretty pinpoint to the edge in all three Newtonians. I am wondering if Ludes' recommendations are based on tests where the Leica was used exclusively in Newts with a Paracorr in place? Certainly, the scopes I tested it in really benefit from the use of a coma corrector. The stars were a bit more bloated in the 28" on M13 and I suspect that it was related to the owner using a Paracorr I rather than the newer Paracorr II that is designed for sub f/4 Newts. The 28" was also not tracking when we were doing the tests and the 16" homebuilt was also not a tracking telescope.

The ep is close to being parfocal when you zoom but you do have to fine focus when you stop at another zoom setting. It seems that when you zoom it to the highest mag (8.9mm),
the sharpness of the image may be slightly degraded at the end-stop and backing off the zoom with a slight twist of the rubber zoom ring seems to produce a slightly sharper image that stays that way all the way up to its least mag at 17.8mm). This phenomena was noted by another astronomer and has not been realiably tested to ascertain if this performance observation is accurate?

As I mentioned to Andreas, I have yet to compare the Leica ASPH with my ZAOII's, Baader GAO's fast Newts. I can say that it is one of the finest ep purchases I have made in the last decade in terms of its surprising and almost logic defying performance. I have yet to get it into my 6.2" Apo refractor and some other fast scopes. Bob

Edited by Bob S. (10/14/12 04:26 PM)


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: Bob S.]
      #5470202 - 10/14/12 05:21 PM

Quote:

In numerous comparos with 10mm and 13mm Ethos ep's, the Leica reliably showed tighter star points and darker backgrounds (more contrast) in all three scopes.



I noticed the same thing in my friend's SCT. Stars in the Ethos were slightly bloated when compared to 2 other premium wide-field eyepieces.

Quote:

The ep is close to being parfocal when you zoom but you do have to fine focus when you stop at another zoom setting.



I require two minor tweaks on the micro-focuser. Tweaking the main focus knob induces too much of a focus change...so the Leica is very nearly parfocal for me too. Thanks for your report.


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sixela
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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: Bob S.]
      #5470306 - 10/14/12 06:17 PM

Quote:

Just got back from the Peach State Star party at Deerlick observation field (what a great bunch of astronomers!) and have now had the Leica ASPH zoom which has a 60-80 FOV and zoom range of 8.9 to 17.8mm range in a 16.5" f/3.65 Lockwood/Starmaster; 16" f/4.5 Spooner/Home Built; and a 28" f/3.7 Kennedy/Webster. The eyepiece was placed in Paracorr I's for the homebuilt and Webster and a Paracorr II with the Starmaster.

The results were uniformally well received and wowed all who looked through it.




I'm very surprised. Even in my 'mundane' f/4.5 scope with Paracorr II, the edge of field astigmatism that the Leica produces is hard to ignore until I use it with a 1.6x barlow.


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Bob S.
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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: sixela]
      #5470389 - 10/14/12 07:26 PM

Quote:

Quote:

Just got back from the Peach State Star party at Deerlick observation field (what a great bunch of astronomers!) and have now had the Leica ASPH zoom which has a 60-80 FOV and zoom range of 8.9 to 17.8mm range in a 16.5" f/3.65 Lockwood/Starmaster; 16" f/4.5 Spooner/Home Built; and a 28" f/3.7 Kennedy/Webster. The eyepiece was placed in Paracorr I's for the homebuilt and Webster and a Paracorr II with the Starmaster.

The results were uniformally well received and wowed all who looked through it.




I'm very surprised. Even in my 'mundane' f/4.5 scope with Paracorr II, the edge of field astigmatism that the Leica produces is hard to ignore until I use it with a 1.6x barlow.




That is kind of wild. I nor anybody else commented or was seeing astigmatic stars? Could it be that your scope is astigmatic? Or is it possible that your eye is producing some stig? We looked at globular clusters, planetary nebula, open clusters, nebula, planets and did not experience any stig? Bob

Edited by Bob S. (10/14/12 08:41 PM)


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sixela
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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: Bob S.]
      #5470982 - 10/15/12 04:19 AM

Quote:


That is kind of wild. I nor anybody else commented or was seeing astigmatic stars?




Tangential/sagittal eyepiece astigmatism only in the edge of the eyepiece, and disappearing when you use other eyepieces? Not that likely, I think.

Plus I'm not the only one to have reported that. In addition to what Markus Ludes said in the thread in which he announced the Meopta zoom, Doug Culbertson, BWAZ, Bill Paolini and I think Andreas and Tammy all reported similar things - an edge of field which isn't as well corrected as the centre of the field.

Quote:

Or is it possible that your eye is producing some stig?



At all exit pupils, and again only at the edge, with the orientation different at different parts of the edge?

Quote:

and did not experience any stig? Bob




Uhm...I have yet to see _any_ eyepiece that does not produce at least some edge of field astigmatism (i.e. enough to make it obvious in a star out of focus, even though the best eyepieces tend to make it inobtrusive in focus). "Not any" is not in my vocabulary.

Now I do use the eyepiece unbarlowed in my f/5 travelscope, and bear it with a grin. I feel no need to rationalise away what is clearly there: the eyepiece is fine and is not perfect. Yes, it's a lot more practical than fixed focal length eyepieces and the centre of the field is so nice (and stays nice for a field that's so wide) that you'll excuse the defects at the outer edge.

I think what we're looking at, as far as our different appreciations are, is a difference in observing style: I quite frequently keep my scope pointed in the exact same point and look throughout the entire field; others don't tend to use the entire field as often and reposition their scopes more readily to look at another corner of an object or group.

Given many people ask me for an opinion about an eyepiece/scope combo, I've also developed the bad habit of instinctively star testing the entire field (including the edge) while focusing, i.e. being aware of the shape of the diffraction patterns throughout the field while I run through focus a couple of times to determine where I'll focus (it does help me to avoid too many problems with field curvature, since on some eyepieces I'll instinctively end up focusing something else than the centre).

But you've convinced me to give my barlowless Leica another chance, though.


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johnnyha
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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: sixela]
      #5470984 - 10/15/12 04:31 AM

Markus himself said the Leica ASPH zoom "sucks a bit" in newtonians. I'm pretty sure he was referring to just the edge of the field.

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Bob S.
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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: johnnyha]
      #5471004 - 10/15/12 05:46 AM

Alexis, I can see that you are analyzing the eyepiece at a level that I am not interested in paying attention to for several reasons. The first is that the Leica to me represents a very convenient package that presents stars as good at least as a TV Ethos (and likely Pentax XW's although I have not compared them yet) with a lot less hassle in terms of changing eyepieces to get different mags. Secondly, my aging eyes an some current medical eye challenges are causing me to be less critical in both my expectations and capabilities to discern some subtle aberrations. Thirdly, with the zooms capability, I and others were using it to frame the object of interest and so stars beyond the framed area have likely not been as critically analyzed as the framed area of interest which is where the zoom seems to "shine". Even with those caveats, there was still no significant noticeable astigmatism that caused my eye or others to comment or experience edges of the FOV that were problematic. I suspect that in playing with this new eyepiece, I and the others that were using it were not holding it up to the most critical of analyses.

When I see where you are coming from with the level of your analysis, I do not doubt that there are some minor aberrations that can be discerned if you are looking for them. Unlike tight FOV's like are presented in orthos, I guess my expectations for an overall presentation of tight stars in the FOV were adequately met and the sense that the edges presented astigmatic stars was not apparent to me or others at the relatively simplistic level that we were assessing the eyepiece. Bob


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sixela
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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: Bob S.]
      #5471069 - 10/15/12 08:04 AM

Oh, another point: how did you manage to get the eyepiece to focus when you weren't using a barlow?

In my scope with a SIPS Paracorr, there's simply no way to focus the eyepiece (with a SIPS in place there's really no way to focus anything that requires more than 3mm more focuser in-travel than a 17mm Ethos). I'm not missing much, but I am missing something (obviously, putting the SIPS a bit too close to the telescope would fix that, but at the expense of some of the coma correction).

I assume you were using a 'regular' Type 2 Paracorr with tunable top fully turned in and then still had to rack in the focuser some more?


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Bob S.
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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: sixela]
      #5471166 - 10/15/12 09:49 AM

Quote:

Oh, another point: how did you manage to get the eyepiece to focus when you weren't using a barlow?

In my scope with a SIPS Paracorr, there's simply no way to focus the eyepiece (with a SIPS in place there's really no way to focus anything that requires more than 3mm more focuser in-travel than a 17mm Ethos). I'm not missing much, but I am missing something (obviously, putting the SIPS a bit too close to the telescope would fix that, but at the expense of some of the coma correction).

I assume you were using a 'regular' Type 2 Paracorr with tunable top fully turned in and then still had to rack in the focuser some more?




No problems focusing at all with either the Paracorr 1 or 2. They are both in the A or full-in position. I am using it with the 2" adapter supplied by APM and have no focus issues yet in anyone's Newt.

Edited by Bob S. (10/15/12 07:22 PM)


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Bob S.
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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: Bob S.]
      #5476064 - 10/17/12 11:12 PM

Quote:

Quote:

Oh, another point: how did you manage to get the eyepiece to focus when you weren't using a barlow?

In my scope with a SIPS Paracorr, there's simply no way to focus the eyepiece (with a SIPS in place there's really no way to focus anything that requires more than 3mm more focuser in-travel than a 17mm Ethos). I'm not missing much, but I am missing something (obviously, putting the SIPS a bit too close to the telescope would fix that, but at the expense of some of the coma correction).

I assume you were using a 'regular' Type 2 Paracorr with tunable top fully turned in and then still had to rack in the focuser some more?




No problems focusing at all with either the Paracorr 1 or 2. They are both in the A or full-in position. I am using it with the 2" adapter supplied by APM and have no focus issues yet in anyone's Newt.




I had a colleague over tonight with his two grandchildren and proceeded to show them a bunch of eye candy with a IIE image intensifier with and without an Ha filter (M22, M20, M8, M16, M17, M31, M57, Veil. They left and the night was full of promise with transparency about 8/10 and seeing about 7-8/10. I had my Pentax XW's out and also played with a 16mm Brandon, 16mm ZAO II, 18mm Baader GAO and the Leica ASPH zoom on Alberio. The ZAO II and the Leica showed the tightest star points in my 16.5" f/3.65 Lockwood/Starmaster with either a Paracorr II in the "A" setting or a 2x TV Powermate. I also tried the ASPH without anything other than the ep in the focuser and had absolutely no problem having everything come to focus.

It's funny but I slightly preferred the views for a while with the Leica ASPH over the Zeiss Abbe Ortho because I could zoom the mag to the exact place where I started to get some image softness. Both were absolutely beautiful. I also had to zoom around with the Leica to M15 and enjoyed that beautiful globular cluster while zooming at different mags. The 60-80 degree AFOV with the excellent eye relief makes this a wonder of an eyepiece. I had forgotten that I had it until about 2/3 of the way through viewing this evening. Sheesh, I didn't think it would fit into the lineup that quietly As others have remarked, the Leica ASPH zoom is just an all around wonderful ep and it works very well in a fast Newtonian in spite of a brief negative remark by Markus Ludes who sells them but has possibly found and even better performing zoom with a 66 degree AFOV. Bob Schilling


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sixela
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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: Bob S.]
      #5478424 - 10/19/12 09:14 AM

Quote:

I also tried the ASPH without anything other than the ep in the focuser and had absolutely no problem having everything come to focus.




Quite. As I said, the only note I wanted to make is that without a barlow, it wants slighly more focuser in-travel than a 17mm Ethos, which creates problems _for a SIPS Paracorr_ (and only that) so I'd advise people to get a regular Paracorr Type 2 instead if they want to use that zoom unbarlowed.

Quote:


It's funny but I slightly preferred the views for a while with the Leica ASPH over the Zeiss Abbe Ortho because I could zoom the mag to the exact place where I started to get some image softness.




Mirrors my experience with the Leica vs. the Pentax XO. When the best view in the Leica is at an effective 5mm (with Zeiss barlow), the Pentax XO delivers a slightly cripsier view.

But if other focal lengths are required for the best view, that XO doesn't change focal length...

I'm sure I could tweak a longer ZAO-II plus a Zeiss barlow and variable length between the two to "always" beat the Leica, but I'd be spending my time screwing and unscrewing T2-rings instead of observing, and I'd hate to think of the moments of good seing missed...


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johnnyha
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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: sixela]
      #5479167 - 10/19/12 05:27 PM

The newer model Zeiss barlow does have maybe 1/2" "tweakability" built in to the 1.25" clicklock eyepiece holder. Not a lot but you can definitely get a bit more mag with the helical feature.

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sixela
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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: johnnyha]
      #5479174 - 10/19/12 05:31 PM

But that's extremely cumbersome --been there, done that-- and hardly makes a lot of difference, given the barlow focal length (measured from the principal plane, not the flange) is roughly 68mm. Even a 15mm T2-extension only changes the barlow factor by 0.22.

Now that shiny 40mm Baader T2-tube, _that_changes things ;-).


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johnnyha
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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: sixela]
      #5479176 - 10/19/12 05:33 PM

How about the Baader T2 helical variable length extension? 41-56mm and you won't have to screw it on and off like the T2 tube...

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sixela
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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: johnnyha]
      #5479200 - 10/19/12 05:47 PM

Actually, two Baader #24 "Schiebe-focussierer" are even better for that. Allow you to go from 55mm to 77mm very rapidly.

And there's the #25V 29-46 Varilock, and two of these go from 58mm to 92mm but they're more than a bit more difficult to handle rapidly.

If you're thinking 'helical', screwing on T2-rings is usually faster.


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johnnyha
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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: sixela]
      #5479209 - 10/19/12 05:51 PM

Oh that is cool thanks!

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johnnyha
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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: johnnyha]
      #5479362 - 10/19/12 07:32 PM

So as far as barlowing the Leica ASPH zoom can I just screw say a Barcon element onto the bottom of the 2" adapter or what? I have the short 1.6X Antares barlow but I'd prefer an even shorter overall length.

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sixela
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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: johnnyha]
      #5479955 - 10/20/12 06:37 AM

Yes, you can. I personally use a Baader Zeiss in that exact same manner you describe, and alternatively a Baader VIP in a Baader T2-#12 adapter screwed into the 2" barrel (since that allows me to place the element closer and get a smaller barlow factor).

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RAKing
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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: johnnyha]
      #5480061 - 10/20/12 09:10 AM

Quote:

So as far as barlowing the Leica ASPH zoom can I just screw say a Barcon element onto the bottom of the 2" adapter or what? I have the short 1.6X Antares barlow but I'd prefer an even shorter overall length.




Johnny,

You can screw the Barcon directly to the two inch Leica adapter ---- But a word of WARNING: The top lens element of the Barcon will contact the bottom of the Leica with about 1/4 - 1/2 turn to go.

Personally, this is way too close for me, so I inserted an empty filter ring between the two. This only adds a total of 7mm distance and your magnification will still be a puny 1.2x set up like this.

I am now using a couple of A-P CCD spacers between my Leica and the Barcon because I want a bit more magnification. These spacers are 0.5" each and you can stack them as needed. With my refractor, I have settled on a comfortable 1.45 - 1.5x setup and this allows me to use the full range of the Leica. My effective focal lengths go from a nominal 12mm to 6mm with the zoom. If I need more mag, I pop in the XW 5.

I have been using my Leica for a couple of weeks now. It performed poorly in my C8 Edge SCT with no barlow - but it works like a champ in my refractor with the Barcon.

I am not planning to sell my ZAO-II set, nor do I plan to sell my Pentax XW collection, yet. But after moving the Leica to my refractor, I definitely understand the enthusiasm for this eyepiece. I like to view double stars and I also do variable star estimates for AAVSO. The Leica is now an indispensible piece of gear for both activities.

Cheers,

Ron


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Bob S.
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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: RAKing]
      #5480081 - 10/20/12 09:33 AM

Quote:

Quote:

So as far as barlowing the Leica ASPH zoom can I just screw say a Barcon element onto the bottom of the 2" adapter or what? I have the short 1.6X Antares barlow but I'd prefer an even shorter overall length.




Johnny,

You can screw the Barcon directly to the two inch Leica adapter ---- But a word of WARNING: The top lens element of the Barcon will contact the bottom of the Leica with about 1/4 - 1/2 turn to go.

Personally, this is way too close for me, so I inserted an empty filter ring between the two. This only adds a total of 7mm distance and your magnification will still be a puny 1.2x set up like this.

I am now using a couple of A-P CCD spacers between my Leica and the Barcon because I want a bit more magnification. These spacers are 0.5" each and you can stack them as needed. With my refractor, I have settled on a comfortable 1.45 - 1.5x setup and this allows me to use the full range of the Leica. My effective focal lengths go from a nominal 12mm to 6mm with the zoom. If I need more mag, I pop in the XW 5.

I have been using my Leica for a couple of weeks now. It performed poorly in my C8 Edge SCT with no barlow - but it works like a champ in my refractor with the Barcon.

I am not planning to sell my ZAO-II set, nor do I plan to sell my Pentax XW collection, yet. But after moving the Leica to my refractor, I definitely understand the enthusiasm for this eyepiece. I like to view double stars and I also do variable star estimates for AAVSO. The Leica is now an indispensible piece of gear for both activities.

Cheers,

Ron




Ron,
I measured the depth of the Barcon barlow piece from the glass to the end of the threads and it measured just a hair under 5mm. I measured the APM supplied 2" adapter for the Leica and the threads extend down to the top of the bottom part of the eyepiece element 5mm. So your recommendation to not fully screw down the Barcon piece is warranted.

Like you, I do not plan to sell my ZAO II's, Pentax XW's, Brandons, TV Ethos or Baader GAO's anytime soon but the Leica is extremely versatile. This morning I used it placed in a TV 2" 2x Powermate in a 12.5" f/5 Newt with power ranging ranging from 178x-356x primarily on Jupiter. My most steady/reliable views were at slightly past the 30x marking at about 230x. In this scope the markings translated to 25x=178 30x=216, 40x=283 and50x=356x. The seeing really did not reliably allow more than the 40x seeting at 283x with the overall best views at 230x. The eyepiece is simply amazing in that you can precisely dial in the magnification that affords the absolutely best views. Can't do that with any of my fixed focal length ep's.


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: Bob S.]
      #5480137 - 10/20/12 10:26 AM

Quote:

Ron,
I measured the depth of the Barcon barlow piece from the glass to the end of the threads and it measured just a hair under 5mm. I measured the APM supplied 2" adapter for the Leica and the threads extend down to the top of the bottom part of the eyepiece element 5mm. So your recommendation to not fully screw down the Barcon piece is warranted.

Like you, I do not plan to sell my ZAO II's, Pentax XW's, Brandons, TV Ethos or Baader GAO's anytime soon but the Leica is extremely versatile. This morning I used it placed in a TV 2" 2x Powermate in a 12.5" f/5 Newt with power ranging ranging from 178x-356x primarily on Jupiter. My most steady/reliable views were at slightly past the 30x marking at about 230x. In this scope the markings translated to 25x=178 30x=216, 40x=283 and50x=356x. The seeing really did not reliably allow more than the 40x seeting at 283x with the overall best views at 230x. The eyepiece is simply amazing in that you can precisely dial in the magnification that affords the absolutely best views. Can't do that with any of my fixed focal length ep's.




Bob,

Thanks for confirming my fears! I measured these pieces several times and hoped I was wrong, but my math kept coming up, "too close for comfort." And my very gentle attempt to mate the two was halted by contact.

I want to be able to use as much of the Leica's range as possible and this is the reason for my experiments. I have my zoom set up so it's more in the sweet spot for my needs. I have the 12T4 Nagler (and others) for finding my target stars and I have the 5mm Pentax (and others) if I really need to get close. The Leica is performing perfectly in between these two.

It's way too cool to be able twist the Leica until the view is "just right".

Ron


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: RAKing]
      #5480282 - 10/20/12 12:09 PM

Quote:

I have been using my Leica for a couple of weeks now. It performed poorly in my C8 Edge SCT with no barlow - but it works like a champ in my refractor with the Barcon.





Ron, could you describe more on your experience with the zoom in the Edge? What aspect of performance wasn't good? Planetary, DSO, field performance?

The rave reviews I keep hearing about the zooms would suggest they should be as good as anything on axis (as good as the ZAO's I've heard commented...). Just wondering what would be different with the Edge.

Thanks,


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: Gord]
      #5480416 - 10/20/12 01:41 PM

At the risk of hijacking this thread, the Leica vignetted badly in the C8 SCT from the 30x position down to the 25x position. Possibly the baffle tube? Going the other way, the exit pupil dropped too quickly for me and I couldn't use it much beyond the 40x position.

For those who don't own these, there is a tiny focal shift as you zoom in and I couldn't adjust in the C8 as I can in my refractor. So I was left with decent views from 30x to 40x and that's not good enough for me.

Caveat - I only had one opportunity with the C8 and will try again. I could also have been victimized by poor seeing at the higher end.

Another Caveat - These are my impressions through my eyes, with my scopes, under my skies. YMMV!

Cheers,

Ron


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: RAKing]
      #5480615 - 10/20/12 03:48 PM

I would say someone who pays the price of the ASPH wants just the best, and therefore will only be happy with the barlow permanent on it That is my case anyway.
On axis it is good without barlow, but on-axis is usually used for planets, and planet mags usually go from 10mm to 3.5mm.
Also I find a zoom is more important in the high mag range to dial mag according to seeing.
So I use the ASPH permanmently barlowed. The unbarlowed low mag vignetting just sucks and the high mag edge is not pefect. Barlowed all is perfect. As simple as that.

Please note I don't use it with fast scopes, only f/7 to f/10.

Edited by pbsastro (10/20/12 03:50 PM)


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: pbsastro]
      #5481491 - 10/21/12 06:59 AM

Quote:

I would say someone who pays the price of the ASPH wants just the best, and therefore will only be happy with the barlow permanent on it That is my case anyway.
On axis it is good without barlow, but on-axis is usually used for planets, and planet mags usually go from 10mm to 3.5mm.
Also I find a zoom is more important in the high mag range to dial mag according to seeing.
So I use the ASPH permanmently barlowed. The unbarlowed low mag vignetting just sucks and the high mag edge is not pefect. Barlowed all is perfect. As simple as that.

Please note I don't use it with fast scopes, only f/7 to f/10.




Pedro, You and Ron's suggestion concerning barlowing the Leica ASPH with a Paracorr II in a fast 16.5" f/3.65 Newtonian worked very well. I had been using the Leica with its 2" adapter in a Paracorr II and the views were very pleasant. However, when I placed the front element of a Astro-Physics Barcon on the Leica, the star points got tighter yet and I was seeing the I star (mag 15) and the G star(mag 14.5) periodically. I checked a chart or two to see what I was able to see and am quite freaked out by what the ASPH and my 16.5" were able to see. In my 11 years in the hobby having owned up to 28" scopes, I have never seen the I and G stars with a conventional eyepiece. I have seen them and the H1 and H2 stars just outside the Trapezium with my image intensifying eyepieces with good seeing once or twice but have NEVER, EVER, seen them visually before this morning. WOW!!!! The Barcon barlow added a very positive effect to the performance of the ASPH. Thanks for the suggestion from you and and Ron. I am totally blown away right now. I started viewing at 1 a.m EDT and the seeing went from spectacular to average then back to spectacular and then back to below average and then average by sunrise. I spent the entire night only viewing M42 and Jupiter. I would have to take breaks from Jupiter looking at the Orionids to get my night vision back. Bob

Edited by Bob S. (10/21/12 07:43 AM)


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: Bob S.]
      #5481526 - 10/21/12 08:01 AM

Great report, Bob! Wow - G and I in the Trap, I can only dream about those in my little scopes.

My Barcon will never leave the Leica. I need good edge performance in order to do accurate VSO estimates. With the Barcon, I was able to zoom in on some 12+ mag comp stars the other night and still see them clearly. I consider that to be excellent performance with my little 5 inch refractor.

My next order of business is to use this setup in my C8 SCT and see if that fixes my original issues.

Cheers,

Ron


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: RAKing]
      #5481537 - 10/21/12 08:15 AM

Thanks for the answers on the Barcon. I am still a little confused as to what magnification is being achieved by people. Ron said even with a 7mm spacer it's still only 1.2x - so was this enough to clean up the edge? And Ron you stacked some spacers to achieve 1.5X, which would be perfect for my scopes - what is the length between the Leica's 2" adapter and the Barcon element for 1.5X?

Also, Alexis, it is not entirely clear to me how you are screwing the Baader Zeiss barlow (I assume you are talking about the familiar 1.25" Baader Zeiss barlow) onto the 2" adapter, and what magnification that would achieve?

I am very seriously considering getting this eyepiece and streamlining my kit down to a 31T5, Leica Zoom, and then my MkV binos and collection of ortho pairs.


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: johnnyha]
      #5481571 - 10/21/12 09:04 AM

Johnny,

Lots of questions - let's see if I can provide some answers.

To start, I used Andreas' formula and worked the numbers backward to come up with a 97mm focal length for my Barcon. (The Barcon is advertised to be 1.7x with the standard eyepiece holder.) Then you can just go on and use his formula to compute any magnification you wish, given your available spacers.

For me to hit 1.5x, I add three A-P CCD spacers to the Leica's two inch adapter. It comes up to 1.52x.

My personal preference is to use two A-P spacers and one empty filter ring for 1.46x.

I have not tried the Barcon with just the filter ring, yet. That only gives me 1.2x and it's not enough in my refractor. I'll try that combo in the SCT next time out and see if it clears up the vignetting and soft edges.

The Barcon will screw right on to the Leica two inch adapter, but mine hits the lens just before the end. You could slide the two inch adapter out a millimeter or so and use it that way. My calculations show that achieves 1.14x magnification increase.

Cheers,

Ron


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: RAKing]
      #5481589 - 10/21/12 09:13 AM

Thanks Ron. I have a Televue 2" barrel extension (1.25" long) and I am thinking that might work perfectly with the Leica Zoom and Barcon for pretty close to 1.5X. At an effective fl of 12mm to 6mm that would be absolutely perfect for my two scopes and my viewing habits. Wow - two eyepieces to cover my full range of monoviewing. Very enticing.

Update: In stock. Paypal sent.


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: johnnyha]
      #5481729 - 10/21/12 10:58 AM

I think that will work out to the same length I'm using. 12mm to 6mm is also my sweet spot and I think you will enjoy that, too.

Cheers,

Ron


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: johnnyha]
      #5481749 - 10/21/12 11:12 AM

I screw in the Baader Zeiss in a zero height M48x0.75 to T2 adapter and then screw that into the 2" adapter (Markus's adapter has 2" filter threads over its entire length, but the smallest barlow factor is around 1.95x since the element of the Zeiss is at the end of a fairly long 1.25" barrel.

The Baader VIP element can be put a lot closer (in a Baader T2-#12 with a T2->M48x0.75 adapter), but that still yields a factor of 1.6x (1.5x is possible but the edge then suffers from astigmatism).


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: sixela]
      #5481932 - 10/21/12 01:21 PM

Quote:

..

The Baader VIP element can be put a lot closer (in a Baader T2-#12 with a T2->M48x0.75 adapter), but that still yields a factor of 1.6x (1.5x is possible but the edge then suffers from astigmatism).




I am using the TMB 1.8 ED barlow in a special housing. Thanks to its long focal lenght I can get 1.5 x without astigmatism at the edge. It is a great combination,
for details see here:

http://www.cloudynights.com/ubbthreads/showflat.php/Cat/1,2,3,4,5,6,7,8,9,10,11/Number/5329647/Main/5325399

best regards

Thomas


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: sixela]
      #5482006 - 10/21/12 02:05 PM

Quote:

The Baader VIP element can be put a lot closer (in a Baader T2-#12 with a T2->M48x0.75 adapter), but that still yields a factor of 1.6x (1.5x is possible but the edge then suffers from astigmatism).



That's my experience as well.

For serious 1.5x barlowing of the Leica I've already suggested (in the review) using the Barcon:
"The Baader VIP barlow lens has a focal length of approximately -64mm. Using it in the 1.5x configuration places it quite near to the field lens of the zoom which introduces slight astigmatism near the edge of the field. If this barlow factor is very important a longer focal length barlow lens like the Antares 1.6x or the AP Barcon should be considered to reduce the astigmatism. On the other hand, for me the 1.5x with its up to 43' true field of view (framing nicely the double cluster at 83x) is too useful to reject it for some edge astigmatism. And zooming in up to 165x and still maintaining a true field of view of 30' (framing one or the other of both clusters) with even less astigmatism is very attractive."

Andreas


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: andydj5xp]
      #5482198 - 10/21/12 04:13 PM

What I'm missing is which adapter people are using to get such small barlow factors with a Barcon or Baradv, given those can't actually go inside a 2" adapter's barrel.

My adapter from Markus is 42.5mm long beyond the shoulder of the Leica, and if I'd use a Baradv at the end of it (-102mm focal length, principal plane 12mm inside the housing) I'd get a factor of 1.58x.

Are you using the StarLight Instruments adapter, and is it that much shorter?


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: sixela]
      #5482240 - 10/21/12 04:35 PM Attachment (6 downloads)

Quote:

What I'm missing is which adapter people are using to get small barlow factors with a Barconor Baradv.

My adapter from Markus is 42.5mm long beyond the shoulder of the Leica, and if I'd use a Baradv at the end of it (-102mm focal length, principal plane 12mm inside the housing) I'd get a factor of 1.58x.

Are you using the StarLight Instruments adapter, and is it that much shorter?




My DIY-adapter made from a Baader T2 #16 is only 28mm long from the zoom's shoulder (including the 2"/T2-thread adapter #29, see pic) thus enabling barlow factors as low as 1.5x with the VIP barlow.

Andreas


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: andydj5xp]
      #5482284 - 10/21/12 04:52 PM

Yes, I know about yours, but even that will yield a factor of 1.43x with a BarAdv (4,5mm from focal plane to shoulder, 28mm for your adapter, and 12mm from the threads of the BarAdv to its principal plane, the sum divided by 102mm, and then +1).

And yours is shorter than the commercial ones I know. I'm simply puzzled by what RAKing and Bob S. are doing.

If I remember the Barcon element well, it doesn't fit inside a 2" barrel, so it's bound to end up a lot further from the eyepiece's focal plane. Or does it have different housings, one of which is more narrow than a 2" barrel andallows it to go into Markus's 2" adapter?


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: sixela]
      #5482326 - 10/21/12 05:04 PM

The adapter I got from Markus is only 25mm long overall and the field lens of the Leica is less than 10mm from the bottom.

My math might not be correct, but the views I'm getting seem to indicate my Barlow factors with the Barcon are close to what I think they should be. If nothing else, I can stick the regular holder onto the Barcon and start at 1.7. I know if I go shorter, I am going down in magnification.

Cheers,

Ron


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: sixela]
      #5482345 - 10/21/12 05:13 PM

If the Barcon *just barely*contacts the Leica field lens when screwing it into the 2" adapter, there is obviously no way it could go inside the adapter. So Alexis your Leica has a longer adapter? Sorry I'm a bit confused here.

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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: sixela]
      #5482386 - 10/21/12 05:34 PM

Quote:

Yes, I know about yours, but even that will yield a factor of 1.43x with a BarAdv (4,5mm from focal plane to shoulder, 28mm for your adapter, and 12mm from the threads of the BarAdv to its principal plane, the sum divided by 102mm, and then +1).

And yours is shorter than the commercial ones I know. I'm simply puzzled by what RAKing and Bob S. are doing.

If I remember the Barcon element well, it doesn't fit inside a 2" barrel, so it's bound to end up a lot further from the eyepiece's focal plane. Or does it have different housings, one of which is more narrow than a 2" barrel andallows it to go into Markus's 2" adapter?




Reading this again, it looks like I went the wrong way with one of my measurements.

Recalculating............. Now the math gives me 116mm as the focal length for the Barcon and if you screw the Barcon directly to the base of my adapter, it calculates to 1.2x.

If I add up the components for my current spacers, I now get 1.52x - which is still good for me.

Hope this helps,

Ron


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: RAKing]
      #5482417 - 10/21/12 05:48 PM

Which adapter is it? As I said, mine is 42.5mm long so if the 2" BarAdv is simply at the end of it, it's quite far from the Leica's focal plane.

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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: sixela]
      #5482436 - 10/21/12 06:01 PM

Quote:

Which adapter is it? As I said, mine is 42.5mm long so if the 2" BarAdv is simply at the end of it, it's quite far from the Leica's focal plane.




I don't know. It's the one that Markus supplied with the eyepiece. It's a nice unit, with three long grub screws, and it is much shorter than the one you have. You are closer to him, I suggest you give him a shout and see if you can get one.

The Barcon will not fit all the way into this adapter -- but you must keep in mind that the lens of the Barcon is set about 5mm before the threads end. Thus, it is possible to screw the Barcon partially into this adapter and that is where the close proximity issue between the Barcon and the Leica's field lens retainer occurs.

So if I ran my numbers: 4.5mm to focal plane + 25mm adapter - (minus) 5mm to principal plane divided by 116mm focal length, I get 0.211. Add 1 for 1.21x. Does this sound correct?

Cheers,

Ron


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: sixela]
      #5482446 - 10/21/12 06:05 PM

Astro Buds, I had done some sky meter readings this morning when I bagged the 15th magnitude I star in the trap. The SQM reading on my sky meter was 20.92 that Cruxis translated into a Naked Eye Limiting Magnitude of 6.4 and Telescope Limiting Magnitude of 15.2 mag. The Leica ASPH coupled with a superb Lockwood primary/secondary was able to present a point of light that was only .2 below its theoretical limit. This boggles my mind because I am currenlty fighting a healthy dose of cataract problems with my eyes that was recently diagnosed and yet my eye was able to discern this faint point of light with the help of superb optics and very pleasant eye relief. Andreas observations about this eyepiece being as good as a Zeiss Abbe Ortho II is certainly gaining credence in my book<g>. I was, during parts of this observing session, using a pair of 16mm ZAO II's in a Baader Mark V and the views were brilliantly neutral renditions of the planet with a light blue festoon and tons of white ovals linked in one of the equatorial bands. I don't think they will be going anywhere because unlike Tammy, there is no way that my IPD would allow for binoviewing ASPH's. Bob

Edited by Bob S. (10/21/12 06:27 PM)


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: Bob S.]
      #5482449 - 10/21/12 06:07 PM

My wallet will not allow binoviewing with ASPHs.

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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: Bob S.]
      #5482459 - 10/21/12 06:12 PM

Naked eye = 6.4? I can only wish!

I alert the media when I get 4.8.

I am sitting here holding my zoom because of the calculations and it would be awesome to bino a pair of these.

I have the cataracts, plus I have a condition called "asteroid hyalosis", yet I was able to pick out a mag. 12.5 comp star with my 130mm refractor the other night using this eyepiece. I was very happy with its performance.

Cheers,

Ron


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: RAKing]
      #5482481 - 10/21/12 06:28 PM

Yes, if your adapter is 2cm shorter and if the Barcon's M48 thread is that long that explains a lot.

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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: Bob S.]
      #5483071 - 10/22/12 04:13 AM

Quote:

Astro Buds, I had done some sky meter readings this morning when I bagged the 15th magnitude I star in the trap. The SQM reading on my sky meter was 20.92 that Cruxis translated into a Naked Eye Limiting Magnitude of 6.4 and Telescope Limiting Magnitude of 15.2 mag. The Leica ASPH coupled with a superb Lockwood primary/secondary was able to present a point of light that was only .2 below its theoretical limit. This boggles my mind because I am currenlty fighting a healthy dose of cataract problems with my eyes that was recently diagnosed and yet my eye was able to discern this faint point of light with the help of superb optics and very pleasant eye relief. Andreas observations about this eyepiece being as good as a Zeiss Abbe Ortho II is certainly gaining credence in my book<g>. I was, during parts of this observing session, using a pair of 16mm ZAO II's in a Baader Mark V and the views were brilliantly neutral renditions of the planet with a light blue festoon and tons of white ovals linked in one of the equatorial bands. I don't think they will be going anywhere because unlike Tammy, there is no way that my IPD would allow for binoviewing ASPH's. Bob




Thanks for the beautiful reports, Bob.

How about starting another thread labeled "Leica ASPH Zoom in a TEC 160FL"? This combo will be as close to perfection as possible.

Andreas


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: andydj5xp]
      #5483074 - 10/22/12 04:16 AM

Is the Leica ASPH zoom suitable for use with eyeglasses ? What is the eye relief stated as ?

That's a deal breaker for me. Gotta be able to use it easily with glasses on.

Cheers


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: ausastronomer]
      #5483077 - 10/22/12 04:24 AM

ER is stated as 18mm.

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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: ausastronomer]
      #5483096 - 10/22/12 04:53 AM

Quote:

Is the Leica ASPH zoom suitable for use with eyeglasses ? What is the eye relief stated as ?

That's a deal breaker for me. Gotta be able to use it easily with glasses on.

Cheers




I've measured the eye relief to be between 19mm to 17mm. See here

But there are also measurement results obtained by BillP to be between 16mm and 13mm (scroll up the link).

Therefore, it's still a bit mysterious.

Andreas


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: andydj5xp]
      #5483144 - 10/22/12 06:26 AM

Quote:

Quote:

Astro Buds, I had done some sky meter readings this morning when I bagged the 15th magnitude I star in the trap. The SQM reading on my sky meter was 20.92 that Cruxis translated into a Naked Eye Limiting Magnitude of 6.4 and Telescope Limiting Magnitude of 15.2 mag. The Leica ASPH coupled with a superb Lockwood primary/secondary was able to present a point of light that was only .2 below its theoretical limit. This boggles my mind because I am currenlty fighting a healthy dose of cataract problems with my eyes that was recently diagnosed and yet my eye was able to discern this faint point of light with the help of superb optics and very pleasant eye relief. Andreas observations about this eyepiece being as good as a Zeiss Abbe Ortho II is certainly gaining credence in my book<g>. I was, during parts of this observing session, using a pair of 16mm ZAO II's in a Baader Mark V and the views were brilliantly neutral renditions of the planet with a light blue festoon and tons of white ovals linked in one of the equatorial bands. I don't think they will be going anywhere because unlike Tammy, there is no way that my IPD would allow for binoviewing ASPH's. Bob




Thanks for the beautiful reports, Bob.

How about starting another thread labeled "Leica ASPH Zoom in a TEC 160FL"? This combo will be as close to perfection as possible.

Andreas




Andreas, I have yet to put the ASPH in my TEC 160FL. With 16.5" of aperture vs. 6.2", it is sometimes difficult to carry the refractor down from my study and mount it. However, I need to see the magic of the ASPH in the TEC for sure! I have not compared the ASPH monocularly with the Zeiss because I have been playing so hard with e Baader Mark V's. For lunar/planetary observation, I am finding that what I give up in light throughput and sheer monocular resolution is made up for and then some on the planets/Moon with binovision. I promise in the weeks to come to get that beautiful Leica into my beautiful refractor. Bob


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: sixela]
      #5483723 - 10/22/12 01:59 PM Attachment (29 downloads)

Folks,

Sixela asked me to take a picture of my Leica zoom with the adapter and I think it might help clarify things if I go ahead and post the picture.

It shows the Leica Zoom with the 25mm adapter, plus I included the A-P Barcon in the shot.

The inner threads on the Barcon are T2 and the outer threads are M48. The Barlow lens inside the barcon sits about 5mm "up" from where the M48 threads end at the main body.

It's also worth noting that the Leica field lens is only about 5mm "up" from the bottom of the adapter. It's possible to get the Barcon and the Leica in very close proximity.

Hope this helps explain things in this thread.

Cheers,

Ron


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: RAKing]
      #5484013 - 10/22/12 05:05 PM

Thanks Ron!

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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: johnnyha]
      #5487498 - 10/24/12 07:10 PM

I received my used AP Barcon today, still waiting on the Leica Zoom. However I though it was worth noting, the AP Barcon barlow element does not jive with the Televue 2" barrel extender's "universal filter threads". I can screw it in one revolution and then it sticks. This jives with my other Televue stuff, it is not actually universal and appears to be proprietary to TV filters, etc idea of what filter threads are. The Barcon is usable on the TV barrel extender but I suspect the same will be true when I get the Leica, the barrel extender will undoubtedly not screw into the Leica's filter threads fully, since it is slightly different. I'll probably just get a T2 extension and adapt it to the Leica filter threads or use the Leica Zoom in the native 1.7X AP Barcon. Unfortunately though while the length is perfect, I am not satisfied with the TV 2" barrel extender as a way to achieve 1.5X with the Leica Zoom.

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sixela
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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: johnnyha]
      #5487562 - 10/24/12 08:00 PM

Got a short adapter from Markus.

If anyone wants an unused longer one, PM me.


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: sixela]
      #5487713 - 10/24/12 09:49 PM

How does an outsider obtain the shorter 25mm Markus adaptor?

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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: ohioalfa64]
      #5488047 - 10/25/12 04:24 AM

You just buy it. It's listed on his web site for €60 (and less for people who don't pay VAT).

Markus tells me he no longer makes the long adapter (I have one to sell to anyone interested; if you don't plan to screw on a barlow it's a bit better to register the eyepiece in the focuser, as the new adapter is frighteningly short for such a large eyepiece; but of course extending that small barrel is trivial while taking a saw to the old longer one is more frightening).


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Re: Leica ASPH Zoom in a Fast Newtonian *DELETED* new [Re: ohioalfa64]
      #5488050 - 10/25/12 04:28 AM

Post deleted by sixela

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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: sixela]
      #5488059 - 10/25/12 04:59 AM

I have a question - does the current 2" adapter have just standard 48mm filter threads or does it have a T2 thread as well?

Arg - OK I see Markus offers two separate 2" adapters, 48mm and T2. I did not specify so I bet i got the 48mm. Shoulda got the T2.


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: johnnyha]
      #5488081 - 10/25/12 05:47 AM

Quote:

I have a question - does the current 2" adapter have just standard 48mm filter threads or does it have a T2 thread as well?

Arg - OK I see Markus offers two separate 2" adapters, 48mm and T2. I did not specify so I bet i got the 48mm. Shoulda got the T2.




No problem. Just get the Baader T2 part #29 (see here ) to convert your 48mm thread into a female T2 thread.

Andreas


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: andydj5xp]
      #5488086 - 10/25/12 05:56 AM

Thanks Andreas. I went ahead and ordered the whole Baader Spacer Tube set from Agena, that has part 29 and the whole kit is sweet, I can achieve any mag with the Leica and the Barcon. This kit will work with my MkV T2 system as well, and my 31T5, and Paracorr - Oh, and I can use my 2X Baader/Zeiss Abbe Barlow with the T2 nosepiece! - lotsa fun stuff!

So anyone tried the 2X Baader/Zeiss Abbe Barlow (removing the clicklock and screwing the T2 nosepiece into the adapter) and does it vignette? Alexis?


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: johnnyha]
      #5488125 - 10/25/12 07:20 AM

Can you please post a link to the correct adaptor, or list the right part number? Sorry to be so slow.

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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: ohioalfa64]
      #5488145 - 10/25/12 07:40 AM

http://www.apm-telescopes.net/de/Okulare/Okular-Zubehoer/Adapter-2-fuer-Leica-89-178-Zoomokular-M48.html

There's also one with T2-threads instead, but that's more limited (it's easier to go to T2-threads from M48 than the reverse).


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: johnnyha]
      #5488167 - 10/25/12 07:57 AM

Quote:

Thanks Andreas. I went ahead and ordered the whole Baader Spacer Tube set from Agena, that has part 29 and the whole kit is sweet, I can achieve any mag with the Leica and the Barcon. This kit will work with my MkV T2 system as well, and my 31T5, and Paracorr - Oh, and I can use my 2X Baader/Zeiss Abbe Barlow with the T2 nosepiece! - lotsa fun stuff!

So anyone tried the 2X Baader/Zeiss Abbe Barlow (removing the clicklock and screwing the T2 nosepiece into the adapter) and does it vignette? Alexis?





That's way too cool, Johnny!

I am using all these parts, but I just "collected" them over the years and had them rattling around in my junk box.

The Hyperion tuning rings will also jam in the 2 inch adapter - but they screw in far enough to be safely used. If you go with the T2 threads, you should be fine.

Cheers,

Ron


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: RAKing]
      #5488280 - 10/25/12 09:49 AM

Haven't tried the Zeiss very close to the Leica. In my old adapter it didn't vignette, but then the barlow factor was quite large (given the Zeiss barlow element sticks out a lot on its private 1.25" barrel, it's far from the Zeiss, and IIRC I couldn't get much less than 2.2x-2.3x).

With my new adapter I can have smaller barlow factors and I should try it before I comment. It might just vignette a bit, I'm less sure it doesn't.


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: sixela]
      #5490779 - 10/26/12 07:47 PM Attachment (19 downloads)

OK here is the Baader Spacer tube set! 28mm extension, 15mm extension, T2 to 48mm expanding ring (part 29), and 7.5mm T2 extension. The 28mm and 15mm extensions are 48mm (2" filter thread).

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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: johnnyha]
      #5490783 - 10/26/12 07:52 PM Attachment (14 downloads)

Here is the Baader/Zeiss 2X Abbe barlow with the clicklock removed and the 7.5mm T2 extension installed + the T2-48mm expanding ring (part 29). So this would be able to be screwed into the bottom of the Leica adapter or any barrel with 2" filter threads. Looks like this might work with my 13E, there is just enough clearance for the protruding 1.25" barrel. I'm not sure what mag this will give with the Leica ASPH Zoom but it should be a little over 2X. I'll need to use the Barcon to achieve less than 2X. 1.6x-1.7x should be a real sweet spot for my scopes and replace the 10-7-5 XWs.

I expect to get the Leica ASPH Zoom around Halloween.


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: johnnyha]
      #5490971 - 10/26/12 10:24 PM Attachment (11 downloads)

So the Barcon filter threads do not match the Hyperion spacers' filter threads either, same experience as the Televue barrel extender. I only get a revolution and a half before the Barcon jams - the TV extension I get one revolution. The T2-29 expander threads into the filter threads of the extension pieces well though, and the T2 side works perfectly with the Barcon... So anyway, the Barcon's 48mm filter threads are not 100% universal. The Barcon does work well with my AP Maxbright diagonal nosepiece and my Baader prism diagonal nosepiece though.

Oh and here is the Baader/Zeiss 2x Abbe Barlow as before but without the 7.5mm T2 extension, this just has the T2-48mm expander part 29 ... this should be close to exactly 2X with the Leica Zoom.


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: johnnyha]
      #5491941 - 10/27/12 05:13 PM Attachment (12 downloads)

Woah!!!

Five days from Germany? This was ordered last Sunday, sent out Monday, and I received it today, Saturday, in SoCal. OK that's pretty amazing.


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: johnnyha]
      #5492828 - 10/28/12 09:54 AM

A whole lot of fiddling and finessing going on here to coax good performance out of a $1000 eyepiece.

Anyone else see the irony in this? Is the Emperor wearing clothes?

Or is the Fox just assuming the grapes must be sour?


Mike


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: Sarkikos]
      #5492839 - 10/28/12 09:59 AM

Last night I was reviewing in my mind which eyepieces - and telescopes! - I should sell to cover the purchase of a Leica ASPH Zoom, but after perusing this thread I'm reconsidering the whole idea.


Mike


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: Sarkikos]
      #5493041 - 10/28/12 12:14 PM

You seem easily swayed by Jedi mind tricks.

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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: sixela]
      #5493063 - 10/28/12 12:24 PM

No, not at all. I'm equally aware of the persuasive powers of both the Light and Dark sides of the Force ... and of the Pentax Buddha and of the Bradonistas.

Ever the skeptic, never the cynic. A skeptic is eager to learn. A cynic refuses to.

Mike


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: Sarkikos]
      #5493225 - 10/28/12 03:13 PM

What I mean is that it looks more complicated in these threads than it is (just like collimation; we routinely see similar comments from people saying "if it's that complicated I'll just buy a refractor instead").

And it's not something confined to the Leica, it's simply related to barlows in general and more in particular eyepieces that require lots of focuser in-travel; who hasn't had issues about finding out exactly what barlow factor a barlow would yield or how much focuser travel he'd need when using it?

I can tell you my TMB 1.8x barlow gave me much greater headaches in a Paracorred scope than this thing does, not to mention the BinoViewer in Newtonians monster when it rears its ugly head.


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: sixela]
      #5493282 - 10/28/12 03:51 PM

I've mastered collimation in Newts - if anyone can legitimately say that - and binoviewing is a walk in the park. The Paracorr is still a bit of a challenge, but only because I don't use it constantly like some observers.

But to make a long story - or a long thread - short, I have a fast Newtonian, so IF I go for the Leica ASPH, what do I really need to make it work optimally in my setup? It's a Celestron 10NGT OTA, a 10" f/4.8 Newt with an after-market Dob mount and a Crayford focuser, but not a low-profile.

Like most Newts, if I stack a filter wheel or binoviewer or eyepiece turret between the focuser and the eyepiece, I will need an OCA or Barlow to allow enough in-focus. A Leica ASPH would take the place of my Baader Hyperion Zoom, which I often use stacked with a filter wheel of DSO filters at a dark site. So having to screw on an OCA or Barlow lens cell would be par for the course whether or not I use a Leica Zoom.

Often when I stack my Baader Zoom with a filter wheel, I just screw a Burgess OCA onto the neck of the wheel. This gives me about 100-300x, which I find to be a nice range for many DSO, including galaxies, planetaries and moderately-sized bright nebulae.

Would something as humble as a Burgess OCA give me decent results in the Leica ASPH?

Mike


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: Sarkikos]
      #5493462 - 10/28/12 06:04 PM

Quote:

Would something as humble as a Burgess OCA give me decent results in the Leica ASPH?



I think so Mike. I had a chance to check my new Leica ASPH Zoom out last night in my f8 APO refractor with average seeing in suberbia. As reported, the edge correction of the Zoom in native mode is not so good, in fact there was quite a bit of CA in my setup in the outer, say, 15% or so. Other than the edge CA, the views of the full Moon were, however, phenomenal. As for the different barlow combinations well, that's half the fun Mike! I tried the Leica zoom with my 1.6X Antares, my 1.7X Barcon, my 2X Baader/Zeiss Abbe Barlow, and also in different combinations with the Barcon element and spacers. The Moon was exquisite with the barlows attached, extremely sharp and clear. There was still a tiny amount of CA on the very edge even using the barlows but this could be my setup.

My only negative to report was that this zoom has some internal reflections on very bright Jupiter. I compared this to my 13 Ethos and the 13E also had a lot of internal reflections on Jupiter, and my XWs had some internal reflection but not as much as the Leica zoom. Anyway, I checked and ALL my eyepieces had internal reflections on Jupiter last night, even a small amount on the Brandons and ZAO-IIs, so the internal reflections I saw in the zoom were not unique. I panned over to the Double Cluster and the Leica Zoom presented a beautiful view with pinpoint stars that went on and on.

The performance of the Leica ASPH zoom was similar with all the barlows, with the 2X Abbe barlow being my favorite. There was no vignetting on any of the barlows, even with the 1.25" Abbe barlow attached directly to the bottom of the Leica zoom. I did not see any of the vignetting at the 17.9mm setting either as some have reported, the field stop was sharp all the way from 17.9mm to 8.8mm with or without a barlow.

Those are some of my initial impressions, I hope I get a chance to use this in better seeing conditions and with darker skies soon. I will also check it out in my f4.5 dob soon. This is a very crisp, sharp eyepiece that has terrific apparent contrast, and performance on the Moon was pretty spectacular. I suspect performance on globs, DSO's and doubles should be spectacular as well. Used with a barlow, the entire field was crisp and sharp at every setting. The zoom was not parfocal, I did need to tweak the focuser whenever changing the zoom power. Fit and finish was beautiful with excellent mechanical performance, it was a pleasure to use the zoom feature.

The only real surprise I got was the amount of CA on the edge in native mode - I am curious to see if my dob gives the same results.


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: johnnyha]
      #5493510 - 10/28/12 06:39 PM

Yes, an OCA will work. But particularly the small factor ones are sometimes also meant to compensate for the chromatic error introduced by some length of BK7 glass in the converging beams, so a regular barlow with an element you can unscrew from its holder should be better.

If you don't have a Paracorr, you don't care that much. Even the unbarlowed Leica needs only 3-4mm more focuser in-travel than a 17mm Ethos.

If you have a regular Type 2 Paracorr, it's also not a problem unless you insist you want the Paracorr placed optimally (where it corrects coma best). If you don't, you can just rack in those few millimeters while using the Leica.

With a Type 1 Paracorr, though, you'd better have some focuser in-travel left for 'regular' eyepieces since even the 17mm Ethos wants some and the Leica will want more.

With a SIPS you do want a barlow, because the setup is intolerant of eyepieces that want more focuser in-travel than a 17mm Ethos. The focal plane is 56mm from the Paracorr lens top and 10mm above the fully racked in focuser, and you just run out of focuser in-travel, although Andreas's self-hacked adapter might just work (since it allows you to insert the Leica deeper).

The Leica's not alone with that issue with the SIPS, some Speers-Walers and anything in the TV 2"-1.25" adapter in a TMB 1.8x barlow are even worse. But you don't have a SIPS, so you don't care.

For you, that leaves the barlow mainly to get a clean edge in a fast scope, or to get the magnification range you want. There's no magic recipe for someone else to decide what's right in your stead with respect to those two, of course.

The Baader VIP works quite well and can be screwed in very close to the Leica (or further, so you can pick the range fairly easily).

The Baader/Zeiss also works very well, but the barlow factor is always fairly large.

The Barcon also works well and cleanly but its long focal length means you're not going to make it Paracorr-perfect (or SIPS-friendly), because if you place it close it wont't really have a large barlow factor and if you place it further it'll stick out so much that you'll have to watch out for hitting the Paracorr. Unless you simply use it as a regular barlow (with its holder) and stick with that barlow factor.

Same for the Antares 1.6x barlow; that should just about work even with Paracorrs, with the top set low.

The BarAdv (with a focal length of -102mm instead of -127mm) is a bit better if you want to use it as a screw-on barlow, be able to tweak the focal lemgth range and still make it Paracorr-friendly.


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: sixela]
      #5493520 - 10/28/12 06:45 PM

By the way, for me the zoom is parfocal.

But whether it is for you depends on whether you are short- or nearsighted and even on what distance you find natural to focus your eyes on when looking through an eyepiece and focusing the scope (not everyone sets the focuser for an afocal scope plus eyepiece system and then looks at infinity with his eyes).

It's impossible to make it exactly parfocal for everyone.


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: sixela]
      #5493525 - 10/28/12 06:49 PM

Quote:

By the way, for me the zoom is parfocal.

But whether it is for you depends on whether you are short- or nearsighted and even on what distance you find natural to focus your eyes on when looking through an eyepiece and focusing the scope (not everyone sets the focuser for an afocal scope plus eyepiece system and then looks at infinity with his eyes).

It's impossible to make it exactly parfocal for everyone.




Thanks for that info. I generally have to tweak the fine focus knob a little as I zoom in, but sometimes the focus stays good all the way in. Now I know it's my eyes and not the zoom.

Cheers,

Ron


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: sixela]
      #5493537 - 10/28/12 06:57 PM

By the way, for me the zoom is parfocal.

But whether it is for you depends on whether you are short- or nearsighted and even on what distance you find natural to focus your eyes on when looking through an eyepiece and focusing the scope (not everyone fouses the eyepiece for an afocal scope plus eyepiece system and then look at infinity with their eyes).

It's impossible to make it exactly parfocal for everyone.


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: johnnyha]
      #5493538 - 10/28/12 06:57 PM

Yes, an OCA will work. But particularly the small factor ones are sometimes also meant to compensate for the chromatic error introduced by some length of BK7 glass in the converging beams, so a regular barlow with an element you can unscrew from its holder should be better.

If you don't have a Paracorr, you don't care that much. Even the unbarlowed Leica needs only 3-4mm more focuser in-travel than a 17mm Ethos.

If you have a regular Type 2 Paracorr, it's also not a problem unless you insist you want the Paracorr placed optimally (where it corrects coma best). If you don't, you can just rack in those few millimeters while using the Leica.

With a Type 1 Paracorr, though, you'd better have some focuser in-travel left for 'regular' eyepieces since even the 17mm Ethos wants some and the Leica will want more.

With a SIPS you do want a barlow, because the setup is intolerant of eyepieces that want more focuser in-travel than a 17mm Ethos. The focal plane is 56mm from the Paracorr lens top and 10mm above the fully racked in focuser, and you just run out of focuser in-travel, although Andreas's self-hacked adapter might just work (since it allows you to insert the Leica deeper).

The Leica's not alone with that issue with the SIPS, some Speers-Walers and anything in the TV 2"-1.25" adapter in a TMB 1.8x barlow are even worse. But you don't have a SIPS, so you don't care.

For you, that leaves the barlow mainly to get a clean edge in a fast scope, or to get the magnification range you want. There's no magic recipe for someone else to decide what's right in your stead with respect to those two, of course.

The Baader VIP works quite well and can be screwed in very close to the Leica (or further, so you can pick the range fairly easily).

The Baader/Zeiss also works very well, but the barlow factor is always fairly large.

The Barcon also works well and cleanly but its long focal length means you're not going to make it Paracorr-perfect (or SIPS-friendly), because if you place it close it wont't really have a large barlow factor and if you place it further it'll stick out so much that you'll have to watch out for hitting the Paracorr. Unless you simply use it as a regular barlow (with its holder) and stick with that barlow factor.

Same for the Antares 1.6x barlow; that should just about work even with Paracorrs, with the top set low.

The BarAdv (with a focal length of -102mm instead of -127mm) is a bit better if you want to use it as a screw-on barlow.


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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: sixela]
      #5495227 - 10/29/12 07:59 PM

I had another short session with the Leica ASPH Zoom last night in the FS152, with the Moon and later Jupiter as the targets. I was able to confirm on Jupiter that yes, even the Brandons and ZAO-IIs showed a little internal reflection as I had also reported with the Leica Zoom, although the orthos show less. But jupiter is so bright and shiny now that it defies all of my eyepieces as far as that goes. However the good news - it was the best seeing conditions I have seen from my backyard in L.A. this year, Jupiter was stunning and looked like a photograph on up past 240X. I tried the Leica ASPH Zoom with the 1.7X Barcon which I estimate was around 120X-240X and the image was breathtaking, very very crisp and clear with loads of details seen in the belts and even near the poles, at all mags. I switched later to the binoviewers but I was very impressed with the performance of the Leica.

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johnnyha
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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: johnnyha]
      #5495553 - 10/29/12 11:38 PM

Oh and I did catch the very slight vignetting or whatever you might call it right at the very end of the lowest mag setting - it's very subtle. Its just a very slight softening of the field stop, right at the last little twist.

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Taeyoung
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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: Bob S.]
      #5520463 - 11/15/12 01:31 AM

Hello Bob^^
Exept for FOV, this ASPH is better than old Leica 20x-60x zoom?
I'm considering to buy Leica's zoom now. My club member said that this ASPH has large FOV but the old one is better sharpness and contrast^^
Is it right?
For me, narrow FOV is not problem. I'm a sincere planet observer^^ My main target is Planet and Moon^^
I use ball lens eyepiece which made by myself and ultra narrow fov(about 10 degree) is no problem to me.
I want more sharp and more contrasty one^^
My precious line-up is this
Ball lens 4.4mm, 5.9mm, 7.3mm
XO 5mm
Circle V celestron 7mm ortho(this one is really sharp^^)
Brandon 8 & Televue Plossle 8


My plan is,
If old Leica is same quality with ASPH except FOV, buy 2 of it and use it with my Nikon binoviewer^^


Which one is suitable for me?


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sixela
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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: Taeyoung]
      #5520508 - 11/15/12 02:58 AM

I wouldn't buy an ASPH if I already had the other one except for the FOV. You only 'gain' a more narrow range if you don't care about the AFOV.

But then, I don't think 'the old one is better with respect to sharpness and contrast' either.


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andydj5xp
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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: Taeyoung]
      #5520516 - 11/15/12 03:16 AM

Quote:

Hello Bob^^
Exept for FOV, this ASPH is better than old Leica 20x-60x zoom?
I'm considering to buy Leica's zoom now. My club member said that this ASPH has large FOV but the old one is better sharpness and contrast^^
Is it right?
For me, narrow FOV is not problem. I'm a sincere planet observer^^ My main target is Planet and Moon^^
I use ball lens eyepiece which made by myself and ultra narrow fov(about 10 degree) is no problem to me.
I want more sharp and more contrasty one^^
My precious line-up is this
Ball lens 4.4mm, 5.9mm, 7.3mm
XO 5mm
Circle V celestron 7mm ortho(this one is really sharp^^)
Brandon 8 & Televue Plossle 8


My plan is,
If old Leica is same quality with ASPH except FOV, buy 2 of it and use it with my Nikon binoviewer^^


Which one is suitable for me?




If you are intending binoviewing the 20x-60x Leica zoom definitely is the better choice. Only 53mm outer diameter as compared to the 59mm of the ASPH. Besides the narrower field of view the "old" zoom is optically as good as the ASPH.

Your club member's opinion ".... that this ASPH has large FOV but the old one is better sharpness and contrast" should be taken with a grain of salt. I've used the 22-7.3mm Leica for seven years and the ASPH zoom now for almost four years: as far as contrast, definition, and lack of stray light is concerned both are equal and equally top notch.

Andreas


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Bob S.
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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: andydj5xp]
      #5618888 - 01/12/13 11:38 AM

Andreas, I posted the performance of the Leica ASPH on the reflectors forum this morning pertaining to the Leica ASPH's phenomenal performance. "The coyotes were literally howling, the owls were hooting and a Leica ASPH vario zoom 8.9-17.8mm with 80-60 degree AFOV got an intense workout tonight in my 20" f/3 Lockwood/JP Astrocraft. The NELM was just under mag 6 tonight as measured by my Sky Quality Meter and the seeing was quite steady. Earlier experiments tonight with the fans on Jupiter and Rigel showed that the (Comprehensive Boundary Layer Mitigation System) is working superbly. I tuned the SIPS to perfection on Jupiter using a 5x magnifying loupe and checked collimation of the scope after it had been cooling with the CBLMS running at full speed for about 1.5 hours. I was looking at Jupiter with the Leica ASPH and was finding that 194x was not even making the eyepiece or the scope breathe deeply. I popped the Leica ASPH into my 2x TV powermate and now was running views of the planet between 194x-389x. Still the views were showing that I could use more power. In goes the 4x TV Powermate coupled to the Leica ASPH for views between 389x-777x. Predominantly, the views at about 389x to about 600x showed periods where the planet looked like a CCD image. The orb of Jupiter seemed suspended in black space. The contrast of atmospheric features against a jet black background was jaw dropping. Now, for the first time since this past years WSP in the Florida Keys, I was able to view comfortably at over 550x. With the ASPH in the 4x Powermate and a 2" OIII filter, I had the scope go over to the Eskimo Planetary Nebula in Gemini which is an object on good nights that can take a lot of power. The Eskimo was not to disappoint either then or hours later at ridiculously high mags. I am used to viewing it with my former 28" f/3.5 Lockwood/Starmaster and so noticed that the brightness was way down with the OIII filter and only 20" of aperture compared to the views I would get with the 28". Now, I had not had a chance to see the Horsehead and Flame Nebulas with my new scope. I put a 2" H-Beta filter into the bottom of my ASPH and was zooming in and out on the Horsehead and Flame Nebulas. I actually like the view better in my Leica at 17.8mm with 60 degree AFOV than my 21mm Ethos or 17mm Ethos with the h-b filter and their 100 degree AFOV.

Of course, in the high mag mode, I had to see the Pup in Sirius. Sirius was a superb pinpoint of a star and I used it for further high-mag testing of the primary mirror. I did a test of the fans on this object and each time I turned off the CBLMS, the star would get more flairs. The tightest views were with the CBLMS running and so it was left on all night. Back to Jupiter with the 389x-777x eyepiece arrangement and Jupiter was strutting the GRS along with beautiful festoons and white ovals and a dark barge or two in the NEB. The amount of different colors I was seeing in the GRS, festoons, ovals, barges and belts was very impressive. At between 550x-777x, I was able to make out reliable but faint albedo markings on Ganymede in what I think was the Southern half of the Jovian Moon. This is only the third time that I have been able to do that and it was best seen when I moved Jupiter out of the FOV. I forgot to mention that I used the ASPH with the 4x Powermate on M42 and was seeing the A-I stars (not the H-stars). The G and I stars were only intermittently seen with averted vision. This is only the second time that I have seen the I and G stars without my image intensifying eyepiece. BTW, I tried my Micro IIE Gen 3 image intensifier and was unable to get it to come to focus with the SIPS system in place. I was lacking just a bit of infocus. I finished off the session tonight first returning to the Eskimo and seeing his face briefly with a full parka surrounding his face and nose. I then went back for a last look at Jupiter and the seeing was getting a bit soft even at a lowly 389x. It was time to wrap it up and glow in the aftermath of my best viewing session to date with my new telescope. It also represented the best magnification I was able to successfully deploy in the past year here in North Florida. For some reason, obtaining 1000x plus nights like we used to get have been very difficult for the past two years. I did some high-power testing of the mirror on Sirius and Betelgeuse and the mirror is superb! Mike, I found that the Leica showed pinpoint stars to the edge with tighter star points when it was in either the 2x or 4x Powermates with those items behind the SIPS. Without a barlow, the stars were a bit less tight and not so uniform across the FOV with just the Leica ASPH and the SIPS. The views were not bad but just not perfect like they were with barlowing. I am including a picture of the setup. You will note that all focusing was done with my 3" Feathertouch optional focuser wheel which made focusing a dream. I cannot say enough good things about this 3" focuser wheel for critical focusing at high-mags. To say that I am pleased with the scope and the performance of the Leica ASPH with the TV Powermates would be an incredible understatement. I am frankly ecstatic! I am very much questioning if I need all of my fine Ethos ep's (I have the whole set). As some know, I had done comparisons of the Leica ASPH with my Zeiss Abbe Ortho II's along with a host of other orthos and ep's and the Leica was a good as or at times better than the Zeiss glass in a 6.3" f/7 fluorite Apo and this is no small accomplishment. It's performance on Jupiter was so convincing tonight and the fact that it was being used in a f/3 scope with a Starlight Instruments Paracorr System (SIPS) that made the AFOV perform like an f/12 scope leads me to wonder how much glass I need? I am forever indebted to John Pratte for making such a stout scope with an ultra-stout focuser board/UTA that easily handled all of the weight placed on it. This is without a doubt, the finest 20" scope I have ever been priviledged to be the steward of." Bob

Edited by Bob S. (01/12/13 09:32 PM)


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andydj5xp
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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: Bob S.]
      #5619142 - 01/12/13 02:06 PM

Bob, thanks for your enthusiastic report. I'm very glad my recommendation for the Leica ASPH zoom turned out being the right one for you. And remember: my main recommendation was for using it with your f/7 160FL. The better if it's also that powerful - in particular together with the powermates - in a fast Newtonion.

I've no affiliation whatsoever with Leica but as a German engineer I'm glad - may be proud even - that this famous name of German optics history has managed to survive into the 21st century. Unfortunately this is not the case for many other also famous names from the past.

Enjoy your fantastic gear.

Andreas


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Bob S.
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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: andydj5xp]
      #5619384 - 01/12/13 04:24 PM

Quote:

Bob, thanks for your enthusiastic report. I'm very glad my recommendation for the Leica ASPH zoom turned out being the right one for you. And remember: my main recommendation was for using it with your f/7 160FL. The better if it's also that powerful - in particular together with the powermates - in a fast Newtonion.

I've no affiliation whatsoever with Leica but as a German engineer I'm glad - may be proud even - that this famous name of German optics history has managed to survive into the 21st century. Unfortunately this is not the case for many other also famous names from the past.

Enjoy your fantastic gear.

Andreas




Thanks Andreas. I updated my original post here and mentioned that the testing had been done with my TEC 160FL. It is a lot slower than my f/3 Newt. Thankfully, I think that the SIPS system mitigates the ultra-steep lightcone and the star images were exceptionally pleasing last night. Not as tight as with my refractor but the extra 14" of aperture minus the 5" secondary so actually 9", didn't hurt. Come to think of it, I did not have as high of expectations for the Leica zoom in my Newtonian but last night definetly proved that the Leica flat performs even in very fast scopes if properly tamed with the best coma correction that can be implemented. Bob

Edited by Bob S. (01/12/13 04:26 PM)


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johnnyha
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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: Bob S.]
      #5619494 - 01/12/13 05:29 PM

Quote:

I actually like the view better in my Leica at 17.8mm with 80 degree AFOV than my 21mm Ethos or 17mm Ethos with the h-b filter and their 100 degree AFOV.



Remarkable especially since the Leica is actually 60 degrees at 17.8mm. Thanks for the great report Bob, I posted a few days ago in another thread I had excellent results with the Leica ASPH zoom unbarlowed in my f4.65 with a Paracorr 1.


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Bob S.
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Re: Leica ASPH Zoom in a Fast Newtonian new [Re: johnnyha]
      #5619745 - 01/12/13 08:06 PM

Quote:

Quote:

I actually like the view better in my Leica at 17.8mm with 80 degree AFOV than my 21mm Ethos or 17mm Ethos with the h-b filter and their 100 degree AFOV.



Remarkable especially since the Leica is actually 60 degrees at 17.8mm. Thanks for the great report Bob, I posted a few days ago in another thread I had excellent results with the Leica ASPH zoom unbarlowed in my f4.65 with a Paracorr 1.




Thanks Johnny, I always get the numbers backward on the AFOV of this thing Johnny, I had to take the Leica out with my Apo and get the FOV issues squared away empirically for myself. The reason is that when I zoom to higher powers, it appears that I am losing FOV which is sort of true based on increase mag but when I was looking through the ASPH tonight and zooming it, I did in fact notice maybe for the first time solidly that the zoom AFOV gets smaller at lower power and larger at the higher powers of the zoom. Quite counterintuitive but absolutely correct. Thanks for helping me to understand my zoom better. Bob

Edited by Bob S. (01/12/13 09:28 PM)


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