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Highest Power on 4" Refractor

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#1 brentknight

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Posted 23 February 2020 - 06:16 PM

I'm looking for some advice on an eyepiece that will give me the highest useful magnification with my AT102ED.  I recently purchased the 4.5mm Morpheus and I'm very happy with it.  I'd like to go a bit higher, but I don't want to get something that might be usable once or twice a year.  I'd like to keep it under $300 but would consider cheaper alternatives (I'd love another Morphie, but they don't make any that short).  My thoughts are the following:

 

DeLite 3mm   This seems to me too much magnification

DeLite 4mm   This seems more reasonable, but it's close to what I already get with the 4.5mm

Paradigm 3.2mm   I know these are good, just wonder how they compare to the more premium DeLite's.

 

I've considered a barlow, but I think that would still just give me a single useful extra power so no real cost savings there.  Plus all the extra hassle of dealing with another device in the focuser...



#2 areyoukiddingme

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Posted 23 February 2020 - 06:21 PM

A used Nagler 3-6 zoom is typically about $300. 

 

I usually find somewhere around 150-160x is about my maximum for planets in a 4", but if you are doing doubles you will most likely want the ability to go higher.


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#3 starcam

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Posted 23 February 2020 - 06:23 PM

Pentax 3.5XW


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#4 SeattleScott

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Posted 23 February 2020 - 06:31 PM

Vixen HR 3.4 or TOE 3.3 would be a nice increment. Whether or not your seeing conditions or scope can make good use of these eyepieces, I cannot say. I have the 3.4 HR and I use it in my ED103S but I have pretty good seeing, and the ED103S is on a little different level than an AT102. Maybe others with your scope can advise on their highest useful magnification. But those are a couple good options if you determine you want to push it that far.

In general paradigm get good reviews, but it is all relative. They are fantastic eyepieces, compared to plossls, but not sure how close they come to a Delite. It seems like I heard the weakest ones are the 3.2 and the 25, but you should verify that. It somewhat makes sense as the design is probably getting stretched at these extremes.

If you want wide AFOV, the Vixen SSW series have been getting rave reviews recently for planetary. I believe they have a 3.5. Someone preferred the 7mm over a Tak 7.5 LE. Sure they have SEAP, but not a problem at short focal lengths.

Scott

Edited by SeattleScott, 23 February 2020 - 06:37 PM.

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#5 sg6

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Posted 23 February 2020 - 06:34 PM

Paradigms are good for the cost but don't compare to a Delos. If you can find one to borrow might be fun but unsure.

3mm is likely a bit too far and as you say a 4mm is close to the 4.5mm.

 

Leave I suppose Starcams idea of a Pentax 3.5.

Don't know of any other option, but I stop at 4mm and yes I do have a 3.2mm Paradigm, but really to maintain a full set. And it has nice purple rings.

 

Not sure of Vixen offerings, they line up seems to change aften here.

Odd but maybe - anything in the ES 52 degree range?

Think 4mm is their shortest.


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#6 vtornado

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Posted 23 February 2020 - 06:42 PM

For planetary, I usually use a .7 - 1mm exit pupil, which is a 7-5 mm for your scope.

Under .7mm and I can see floaters, and the image starts getting so dim that color is muted,

and low contrast details become hard to pick out.

 

Doubles because you aren't trying to see detail, just separate the stars can stand a lot more power.

 

Your atmosphere has a lot to say about your ultimate high power.  In the upper mid west most nights are

about 180 - 220x no matter how large your scope is.  Superb rare nights are 300x.

 

Do you have a tracking mount?  If so wide fields are not as necessary for high power views.

Some think that televue plossls are some of the best planetary eyepieces.


Edited by vtornado, 23 February 2020 - 06:43 PM.

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#7 barbie

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Posted 23 February 2020 - 06:48 PM

I have a TOE 3.3mm that I've used on both my 3" Taks but only on a few nights per year when seeing and transparency allow.  The Tak TOE's are tops on their class but you will only use them on a few occasions at best.


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#8 brentknight

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Posted 23 February 2020 - 06:52 PM

Great advice, quick responses. I guess I should have said this would be more for doubles. That Pentax sounds very good - I had not considered those....

#9 Redbetter

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Posted 23 February 2020 - 08:11 PM

It is hard to beat a 3-6 TV zoom for high power in refractors of this aperture and focal length.  A single eyepiece covers the magnification range.  

 

For my eye with that scope I would expect it top out at ~200x or a little more for planetary/lunar, although I might go even higher for some doubles to see elongation or notching of the airy disk, or a snowman pattern.   I find a 2x Barlow covers the extremes for doubles.   


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#10 dusty99

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Posted 23 February 2020 - 08:26 PM

I was in the same place (w/the AT102 plus SW 120ED) and chose a 3.5mm Olivon 70*.  It’s a fine eyepiece for the price, but seeing almost never allows me to use it.  Turns out my Meade SWA 5.5mm is about as short as I can usually go, and for the really special nights I have an HD-60 4.5mm and an old ortho 4mm.  I put my money into my wide-med. eyepieces since they get the huge majority of my time.  Things might be different if I didn’t live on the side of a mountain. cool.gif


Edited by dusty99, 23 February 2020 - 08:27 PM.

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#11 MrRoberts

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Posted 23 February 2020 - 08:36 PM

Just added the 3.5 Delos to my stable, but yet to use it in my 120 (840/F7) and of course in my 80 (400/F5) is sweet. Also have yet to use any with my 2.5 PM.


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#12 brentknight

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Posted 23 February 2020 - 09:02 PM

Just added the 3.5 Delos to my stable, but yet to use it in my 120 (840/F7) and of course in my 80 (400/F5) is sweet. Also have yet to use any with my 2.5 PM.


I really love my Delos, but I just can't see spending that much on an piece that I know will only work in one of my scopes, and only on the best nights.

I really don't want to go cheap, and then think that if I only got the better one that I could see that little star.

#13 brentknight

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Posted 23 February 2020 - 10:12 PM

I see the Pentax XW are on sale now for $30 off.  That puts them in line with the Morpheus.  I know they don't offer that FL, but how would they compare?  Or how would they compare to the Delos/DeLite?

 

The idea of the zoom is appealing (a little pricey though).  How do they compare to individual FL's in this class?  What do you feel are the major disadvantages to the zoom?

 

A little background for my interest in these eyepieces.  I haven't done much double star observing, but I'm getting more interested.  My main obsession right now is trying to see the F star in the Trapezium.  I can usually pick out the E, but not quite the F.  Apparently doubles like this are at the cutting edge of what the AT102ED can do.  I'm pretty sure they would help with planets and the moon as well - although that's not my primary interest right now... 



#14 areyoukiddingme

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Posted 23 February 2020 - 10:50 PM

I see the Pentax XW are on sale now for $30 off.  That puts them in line with the Morpheus.  I know they don't offer that FL, but how would they compare?  Or how would they compare to the Delos/DeLite?

 

The idea of the zoom is appealing (a little pricey though).  How do they compare to individual FL's in this class?  What do you feel are the major disadvantages to the zoom?

 

A little background for my interest in these eyepieces.  I haven't done much double star observing, but I'm getting more interested.  My main obsession right now is trying to see the F star in the Trapezium.  I can usually pick out the E, but not quite the F.  Apparently doubles like this are at the cutting edge of what the AT102ED can do.  I'm pretty sure they would help with planets and the moon as well - although that's not my primary interest right now... 

 

That's a good deal on the XWs. The performance of the lower focal lengths of the XWs are going to be more alike to the Morpheus and Delos than different. The main differences are somewhat less apparent field, and different housing. People seem to prefer one line or the other for personal reasons.

 

The Nagler zoom is a very sharp eyepiece, but it is a 50 degree apparent field. So noticeably less than the others you are looking at. However, you appear to have an equatorial mount, so the apparent field shouldn't be a major issue for you. You can expect the Nagler zoom to be as sharp as these others.

 

In fact, I've compared my Nagler zoom with Takahashi ortho 6mm and Takahashi TOE 4mm. The zoom beat the orthos, and I can't separate it from the TOE.


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#15 brentknight

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Posted 23 February 2020 - 11:08 PM

The problem is, they all seem like good choices.  You are correct Scott, tracking with the LX70 isn't much of an issue - it's pretty solid when focusing too.  It sounds like the zoom would allow me to tailor the view to the sky conditions instead of just being stuck with either not enough or too much.  I've never used a zoom before - is the range of FL's continuous or does it only allow 3, 4, 5, 6?  Is the 50° constant or does it get smaller at the longer FL's? 


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#16 SeattleScott

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Posted 23 February 2020 - 11:56 PM

From what I understand the AFOV is constant and I believe it is even parfocal. I think there are click stops at 3, 4, 5 and 6 but of course you can stop anywhere between. Of course you already have a good 4.5 so you would really only be using the 3-4mm range, unless it usurps your 4.5.

Scott
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#17 Redbetter

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Posted 24 February 2020 - 12:07 AM

The problem is, they all seem like good choices.  You are correct Scott, tracking with the LX70 isn't much of an issue - it's pretty solid when focusing too.  It sounds like the zoom would allow me to tailor the view to the sky conditions instead of just being stuck with either not enough or too much.  I've never used a zoom before - is the range of FL's continuous or does it only allow 3, 4, 5, 6?  Is the 50° constant or does it get smaller at the longer FL's? 

The zoom is continuous with detents for 3,4,5,6.  It is generally most convenient to use the detents, but at times I find the optimum is somewhere in between.  With my 110ED f/7 I employ 4mm most decent/good nights, but on better nights I have found the sweet spot to be a bit more than that.  I had the impression it wasn't quite 3.5, but I added a 3.5T6 anyway.  The 3.5 proved to be a little too much, until I tweaked the collimation of the scope which was a little off. 

 

The apparent field is constant across the range from what I have seen.


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#18 brentknight

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Posted 24 February 2020 - 12:14 AM

From what I understand the AFOV is constant and I believe it is even parfocal. I think there are click stops at 3, 4, 5 and 6 but of course you can stop anywhere between. Of course you already have a good 4.5 so you would really only be using the 3-4mm range, unless it usurps your 4.5.

Scott

I was afraid of this, especially since I just got it and it's a very nice EP.  I suppose I could justify keeping it for the much larger apparent field at that FL.



#19 brentknight

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Posted 24 February 2020 - 12:24 AM

I see a pair of Radians just came up on CN for $125 each.  Would these be good options?



#20 areyoukiddingme

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Posted 24 February 2020 - 12:28 AM

Another possibility given you have an Ethos 8 and Delos 6 is a good quality barlow. A 2x would get you 3 and 4.


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#21 Allan Wade

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Posted 24 February 2020 - 12:29 AM

If it's only for use in your AT102, do you feel like you're missing something with the lineup you already have? You seem to have a nice, complete set of eyepieces. If you are looking for a bit more magnification to specialise in doubles, the 4mm Tak TOE offers a nice step up in quality over the wide fields with a bit more mag than your 4.5 Morpheus.



#22 Allan Wade

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Posted 24 February 2020 - 12:38 AM

I see a pair of Radians just came up on CN for $125 each.  Would these be good options?

The Radians are good eyepieces. I don't have any in my case given the modern options available now. But the thing is, if they are only $125, go and buy one and try it out. If you don't like it, go and sell it for $125. I've bought and sold so many eyepieces that way and gained a lot of experience for free. I wouldn't have 'my' perfect 50 eyepiece lineup without having tried out many times that number of eyepieces.


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#23 brentknight

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Posted 24 February 2020 - 12:41 AM

The Radians are good eyepieces. I don't have any in my case given the modern options available now. But the thing is, if they are only $125, go and buy one and try it out. If you don't like it, go and sell it for $125. I've bought and sold so many eyepieces that way and gained a lot of experience for free. I wouldn't have 'my' perfect 50 eyepiece lineup without having tried out many times that number of eyepieces.

That is a darn good suggestion...

 

EDIT...

I just went to grab one, and apparently the ad was pulled.


Edited by brentknight, 24 February 2020 - 12:44 AM.


#24 brentknight

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Posted 24 February 2020 - 12:53 AM

If it's only for use in your AT102, do you feel like you're missing something with the lineup you already have? You seem to have a nice, complete set of eyepieces. If you are looking for a bit more magnification to specialise in doubles, the 4mm Tak TOE offers a nice step up in quality over the wide fields with a bit more mag than your 4.5 Morpheus.

Yeah...I'm happy with the lineup, but I'd just like a little more on the high end.  I know I'm not going to be using it that much so I don't want to spend a whole bunch.  The TAK looks nice, but it's a little more than I want to spend.  The TV zoom is a bit more too, but it's like getting a bunch of eyepieces in that range.  In my twisted logic, I can convince myself that makes sense...

 

I think it's down to the Pentax 3.5mm or the TeleVue Zoom (if I can find one used...).



#25 brentknight

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Posted 24 February 2020 - 12:58 AM

Another possibility given you have an Ethos 8 and Delos 6 is a good quality barlow. A 2x would get you 3 and 4.

I think to be able to use a barlow type device with the Ethos I'd need a Powermate.  That would mean the 2.5x/1.25" or the 2x/2".  Neither option sounds very practical with the refractor for basically one (maybe two) new FL's.




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