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If the Pentax XW 30mm & 40mm came back, would you buy?....

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#51 RAKing

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Posted 01 August 2019 - 08:23 AM

I could, using your approach, just see the whole FOV on the 41 Pan, but compared to the ease of my 35, expecting the 41 to be easier still, was disappointing.   

 

With any new ES92, the big XWs are what I hope 2020 will bring to me.

 

Do the 30 & 40 Barlow well? -  

Yes.  I used a 2x Powermate with both of them when I used my old Mak, Then just carried a 10XW and covered a lot of focal lengths with only three eyepieces.

 

Cheers,

 

Ron


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#52 25585

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Posted 01 August 2019 - 12:05 PM

Yes.  I used a 2x Powermate with both of them when I used my old Mak, Then just carried a 10XW and covered a lot of focal lengths with only three eyepieces.

 

Cheers,

 

Ron

That would be a 14 & 20 XW not needed then.


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#53 RAKing

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Posted 01 August 2019 - 12:09 PM

True - and if you also carried an XW7, you could cover the whole line with four eyepieces and the Powermate.

 

Cheers,

 

Ron


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#54 Sarkikos

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Posted 01 August 2019 - 12:19 PM

Or you could eliminate some of those eyepieces with a Baader or Leica Zoom.  wink.gif 

 

Mike


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#55 Pezdragon

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Posted 01 August 2019 - 12:33 PM

If the 40 mm XW had better edge correction in my F6.4 Newtonian than my 42mm Vixen LVW, I’d go for it. 



#56 areyoukiddingme

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Posted 01 August 2019 - 12:54 PM

The 40 XW is far superior to the 42 LVW.


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#57 25585

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Posted 01 August 2019 - 01:46 PM

I have reserved a place in my case for the XW40. 



#58 areyoukiddingme

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Posted 01 August 2019 - 02:07 PM

I have reserved a place in my case for the XW40. 

Of the two, the 40 to me is the keeper. Optically it is a little better to my eye--I see less astigmatism and lateral color.

 

The 40 also maximizes a 2" aperture, whereas the 30 has some stiff competition from the 31 Nagler and 30 APM.

 

(and as I have said in the past, I think the 30 APM is optically better than the 30 XW; though I still prefer the XW for it's comfort factor and sharper field stop for my eye).

 

People report field curvature in both, but it is mild, and my 46 year old eyes can accommodate it. It's nothing like the FC found in the 14 and 20mm.

 

The weight of the 40XW compared to the 40 ES and 41 Pan is also attractive. Both the XWs come in at a similar weight to the 30 APM (measured by the highly accurate "pick them up and jiggle them about test").

 

My final though on these XWs is that they are best matched to slower scopes. When I had a 6" F8 refractor, the performace of all the XWs was fantastic. In my 80mm F6 and Televue 101, not so much.

 

They also perform quite well in my 12.5" F5 once the paracorr is in place. The paracorr performs the magical feat of decreasing the FC in the 14 and 20, without adding any I can see in the other focal lengths.

 

Though the 40 Vignettes badly in my P2 (which I strongly suspect of having issues; works great in the P1 though).

 

(I'm hoping to find someone else with a P2 tonight to compare.)


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#59 25585

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Posted 02 August 2019 - 08:34 AM

Using a P2, I will be interested in what you find. Does either 30 or 40 have a matching letter for setting on the tunable top?



#60 Oscar56

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Posted 02 August 2019 - 12:59 PM

I have a nearly complete set of XWs other than the 30 and 40. If I was to buy either it would probably mean giving up my 35 Pan.

#61 earlyriser

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Posted 02 August 2019 - 03:31 PM

On a serious note, I think the XW 40 makes sense with a scope having a focal ratio greater than f/6, such as a refractor or SCT with or without a focal reducer. But if you have a Dobsonian at f/5 or less, the Nagler 31 makes more sense as it provides a widest field without the exit pupil exceeding the diameter of the observer's pupil. This kind of boxes out the 40 and 30mm XW eyepieces for this Dobsonian owner.


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#62 Jon Isaacs

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Posted 02 August 2019 - 05:34 PM

On a serious note, I think the XW 40 makes sense with a scope having a focal ratio greater than f/6, such as a refractor or SCT with or without a focal reducer. But if you have a Dobsonian at f/5 or less, the Nagler 31 makes more sense as it provides a widest field without the exit pupil exceeding the diameter of the observer's pupil. This kind of boxes out the 40 and 30mm XW eyepieces for this Dobsonian owner.

There are those whose eyes dilate to 7mm and greater.  But even so, at F/5, the 31mm Nagler, 35mm and 41mm Panoptics make more sense, they're just so well corrected in a fast scope.

 

Jon


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#63 25585

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Posted 02 August 2019 - 05:45 PM

I have the 35 Pan & 30 APM. Have to do more comparison, also to include 30mm Vixen LV & NLVW, perhaps 32mm Erfle as well. APM is as easy as an Erfle, why I like it so much. Tougher competition for an XW 30.



#64 Jon Isaacs

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Posted 02 August 2019 - 06:16 PM

I have the 35 Pan & 30 APM. Have to do more comparison, also to include 30mm Vixen LV & NLVW, perhaps 32mm Erfle as well. APM is as easy as an Erfle, why I like it so much. Tougher competition for an XW 30.

 

It's always the glasses.. 

 

I am just glad that for whatever reasons, eye placement is not an issue for me and I can concentrate on the quality of the view itself.

 

Jon



#65 25585

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Posted 03 August 2019 - 07:19 AM

It's always the glasses.. 

 

I am just glad that for whatever reasons, eye placement is not an issue for me and I can concentrate on the quality of the view itself.

 

Jon

You are lucky Jon. So am I, and those like me, that there is such an assortment of excellent optics that we are not tied to a particular brand or optical design.

 

In a way, the general unsuitability of Tele Vue eyepiece optical designs for me (excluding Delites maybe), has broadened my experience, and made my discovery journey and interest more diverse, no partisanship here smile.gif. The big XWs have eluded me until hopefully the near future, TV Widefields are another if I should come across any 30mm+ ones.

 

You mentioned quality of view. Optical quality can only be truly enjoyed and fully appreciated if its accessible and relaxed. My 4 TV eyepieces allow that, most TV I have tried do not. But, I have a large number of others that have both excellent quality of view and high comfort in use.

 

Happy viewing!


Edited by 25585, 03 August 2019 - 07:34 AM.


#66 dscarpa

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Posted 03 August 2019 - 02:55 PM

 I'm glad they're coming back!  I've got and am happy with a 30 ES 82 but the 40 would give me extra FOV in my C9.25 and IM715D mak. I've already got the 7 and 10 and their among my favorite eyepieces. David


Edited by dscarpa, 03 August 2019 - 02:55 PM.


#67 nicoledoula

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Posted 03 August 2019 - 06:38 PM

I'd rather own the 35mm Pan than BOTH the 30 and 40XW. The grass is NOT always greener on the other side of the fence. 


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#68 areyoukiddingme

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Posted 03 August 2019 - 06:55 PM

Using a P2, I will be interested in what you find. Does either 30 or 40 have a matching letter for setting on the tunable top?

Well, I did of course forget to bring the XW . . . though I did learn that my Nikon 17 HW which vignettes in the Paracorr 2 is not just caused by my P2. Seems it is a common effect.

 

I compared with P1 which works about as well as the P2 does with 17 Ethos (i.e., very mild vignetting).

 

Which I bring up because . . . the 40 XW vignettes like crazy in my P2, but not in a P1.

 

So I'd suggest that those interested in using a 40XW in a Paracorr 2 consider their options.



#69 25585

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Posted 04 August 2019 - 12:51 AM

Well, I did of course forget to bring the XW . . . though I did learn that my Nikon 17 HW which vignettes in the Paracorr 2 is not just caused by my P2. Seems it is a common effect.

 

I compared with P1 which works about as well as the P2 does with 17 Ethos (i.e., very mild vignetting).

 

Which I bring up because . . . the 40 XW vignettes like crazy in my P2, but not in a P1.

 

So I'd suggest that those interested in using a 40XW in a Paracorr 2 consider their options.

I wonder what makes the difference? I would use the 40 with refractors mainly, but 30 with Newts as well.



#70 25585

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Posted 04 August 2019 - 12:53 AM

I'd rather own the 35mm Pan than BOTH the 30 and 40XW. The grass is NOT always greener on the other side of the fence. 

Is this strong emotion from personal experience?



#71 Sarkikos

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Posted 04 August 2019 - 01:45 PM

I would use the 40 XW as a lighter-weight alternative to the 41 Pan when viewing large nebulae through deep sky filters, particularly the OIII or H-Beta.  I would do this for my f/4.8 10" Dob, or slower refractors or Cats.

 

Mike


Edited by Sarkikos, 04 August 2019 - 01:46 PM.

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#72 junomike

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Posted 04 August 2019 - 11:27 PM

I would use the 40 XW as a lighter-weight alternative to the 41 Pan when viewing large nebulae through deep sky filters, particularly the OIII or H-Beta.  I would do this for my f/4.8 10" Dob, or slower refractors or Cats.

 

Mike

I found the 40mm Paragon just as good off-axis and a little better on-axis.


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#73 Sarkikos

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Posted 05 August 2019 - 06:22 AM

I already have a 40 Titan-II ED.  So I don't need a 40 XW? :thinking:

 

Mike



#74 yowser

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Posted 05 August 2019 - 07:39 AM

I already have a 40 Titan-II ED.  So I don't need a 40 XW? thinking1.gif

 

Mike

I don't think you do.  Several years ago I was looking for a wide field eyepiece.  I already had the 40 Pentax XL.  I bought the 40 Titan-II ED based on recommendations here.  I then got a good deal on a 40 Pentax XW before they were discontinued.  But all of my other eyepieces were the heavier ES 100's and balancing was an issue.  Then ES came out with the 30mm 82* which was heavy enough to balance with my other ES 100's and gave me basically the same field of view.  All of the above were fine eyepieces and difficult to discern differences optically so it came down to weight.  The 30 ES 82 won out and also gave a blacker background, greater magnification, and almost as much field of view as the 40 Pentax XW.  The 40 Titan-II was an absolute steal at its price point.  Only reason I didn't keep it was that it was too light, as was the 40 Pentax XL.  It was also a bonus that I got a very good price for the 40 Pentax XW.  No doubt that it's a fine eyepiece, but there are others that are right up there.


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#75 Sarkikos

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Posted 05 August 2019 - 12:50 PM

So far, I've never let an eyepiece go because it was too light or too heavy. 

 

For a lighter eyepiece in a Dob, you can put a magnetic weight on the OTA near the eyepiece to compensate, or use an Equalizer as the 1.25"-2" adapter. 

 

For a telescope on a dovetail, often you can move the dovetail backward or forward to compensate.  For a telescope in rings, you can move the OTA backward or forward in the rings.

 

The only times I did not use an eyepiece in a telescope due to the weight of the eyepiece, was in small refractors on grab-n-go alt-az mounts.  In those cases, an eyepiece like a 41 Pan or 31 T5 is just so heavy that you can't move the OTA far enough forward to compensate for the weight of the eyepiece.  Maybe you can rig up a counterweight on the sky-end of the dovetail.  But adding even more weight so you can use a heavy weight eyepiece tends to negate the grab-n-go advantage of the setup.  That just never made much sense to me.

 

And I don't like clamping down with a death-like grip on the altitude knob to keep a telescope "balanced."

 

So the end result is there are some eyepieces so heavy I almost never use them in small grab-n-go scopes.  But I have other scopes I can use the heavy eyepieces in, so I'm not letting them go.

 

Mike


Edited by Sarkikos, 05 August 2019 - 12:53 PM.

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