11 replies to this topic

[sunistar]

I've been a binocular observer for 20 years (Canon 10x42 and 15x50). I recently purchased an AT60ED for the simple purpose of being able to take a closer look at the DSOs I've come to know (and to be able to give friends passable views of Jupiter, Saturn, and the Moon.) G&G was a high priority, as was simplicity. I purchased a Baader AMICI in order to have views that match my binos. I purchased an APM Super Zoom to minimize eyepiece swapping, and put a lens cell from a GSO 2x Barlow on, for 1.5x. This gives me roughly 35x to 70x. I have astigmatism, so I use a DioptRx.

Unfortunately I have come to see that the eye relief of the Super Zoom is simply insufficient.

So I plan to sell the APM Super Zoom. I want to purchase two eyepieces with outstanding eye relief, one that gives me about 70x (a 4mm or a Barlowed 8) and one that gives me about 35x.

What would you choose?  And are these the approximate powers you'd want? If not, what would you choose and why?

Again, I'm going for simplicity, minimal eyepiece swapping. I wish the APM SUper Zoom had worked out, but the eye relieve is simply insufficient, especially with the DIptRx.

Thank you.

 

[KWB]

As to focal length you are going to need a 10mm eyepiece for 36X and if you don't use a barlow, a 5mm eyepiece for 72X.

 

You didn't state a desire as to preferred AFOV capability in the design. The Pentax XW and TV Delos both have a stated 20mm of eye relief and are 70 and 72 degree AFOV designs, respectively. You can start from there. I have no experience with either design but the popularity of these two eyepiece designs have been well documented on this forum.

 

Since you asked, I can't function with only 2 eyepieces and extract what this telescope is capable of. I need 4 eyepieces and a 2X barlow. That covers the ground from 13X and a 5.29 TFOV for binocular type scanning of the sky to 103X and a 0.66 degree TFOV for splitting double stars and served me well for viewing Jupiter this Fall. A 7mm, 8.8mm, 13mm and 28mm eyepieces and a TV 2X barlow work nicely for me.

[sunistar]

Thank you. I should have mentioned that my preference is to obtain the 35x and 70x (ish) with Barlows, which should increase ER, and would then give me 4 different magnifications.

Yes, the Delos has a fine reputation, as does the Baader Hyperion, both with long ER.

[csphere.d]

I use both Delos and XWs; and they are great matches for the AT60.  The wider field negates the need for a finder, and the eye relief is excellent for eyeglass wearers.

 

I usually think more in terms of FOV and exit pupil when choosing eyepieces for the night.  I have astigmatism as well, so I try to keep the exit pupil around 3mm or below. 

 

My first choice at a dark sky spot is usually my 17.3 Delos, which gives 21x and close to 3.5 degree FOV.  Then I usually go with my 10XW for 36x or perhaps my 7XW for 51x, depending on targets.  

 

At home in heavy light pollution, I usually go with my 12 Delos for 30x and a 2.4 FOV.  If I am just after a quick view of the planets, I use my 5XW for 72x.

 

I try sometimes to think in terms of a minimalist set of eyepieces, but it never really works for me.  So I would have a difficult time just choosing two!  

[penguinx64]

I have an 80mm f7.5 refractor.  I mostly use an 8-24mm zoom eyepiece with it.  It's not a high end scope, so the zoom eyepiece works about as good as anything else.  

[csphere.d]

Thank you. I should have mentioned that my preference is to obtain the 35x and 70x (ish) with Barlows, which should increase ER, and would then give me 4 different magnifications.

Yes, the Delos has a fine reputation, as does the Baader Hyperion, both with long ER.

What other two magnifications are you after?  You could get a 14mm, a 10mm, and a 2x barlow and pretty much have it covered.

[RichA]

I've been a binocular observer for 20 years (Canon 10x42 and 15x50). I recently purchased an AT60ED for the simple purpose of being able to take a closer look at the DSOs I've come to know (and to be able to give friends passable views of Jupiter, Saturn, and the Moon.) G&G was a high priority, as was simplicity. I purchased a Baader AMICI in order to have views that match my binos. I purchased an APM Super Zoom to minimize eyepiece swapping, and put a lens cell from a GSO 2x Barlow on, for 1.5x. This gives me roughly 35x to 70x. I have astigmatism, so I use a DioptRx.

Unfortunately I have come to see that the eye relief of the Super Zoom is simply insufficient.

So I plan to sell the APM Super Zoom. I want to purchase two eyepieces with outstanding eye relief, one that gives me about 70x (a 4mm or a Barlowed 8) and one that gives me about 35x.

What would you choose?  And are these the approximate powers you'd want? If not, what would you choose and why?

Again, I'm going for simplicity, minimal eyepiece swapping. I wish the APM SUper Zoom had worked out, but the eye relieve is simply insufficient, especially with the DIptRx.

Thank you.

A 60mm refractor is capable of supporting 60x per inch of aperture.  The problem is running out of light.  Only the brighter objects can benefit from the power.  A 4.5mm - 5mm eyepiece would be good. 

[sevenofnine]

The Baader Mark lV 24-8mm zoom has an ER of 19-16mm. It works very well in on my AT80 ED. Many times it's all I ever use with that scope fitted with an AT2D  

[sunistar]

I had debated between the Baader and the APM zooms. Went for the APM because I felt I didn't really need any mag lower than the 15.4x of the APM. But again, the issue would be the ER of the Baader. Am I wrong to conclude that the only way I can get truly long ER is to go with fixed? Like a couple Delite or Hyperions? Plus a Barlow, for 4 magnifications? 4 should be enough for my purposes.

[csphere.d]

I have no experience with the zooms.  However, I can vouch for the Delites, Delos, and XWs....they have ample eye relief for eyeglass wearers.

[Second Time Around]

How are you fixing the Dioptrx to the APM zoom? Apologies if you already know this, but it may be useful to others.  I've found the best way is to attach a 43mm to 42mm step down ring to the 43mm thread under the eyecup. The Dioptrx then fits securely. The alternative is a 43mm extender, but this isn't quite such a good fit, but is better if you put a 42mm X 2mm O-ring over the threads.

Everyone's facial features are different, but if you can't see the full FOV with the APM zoom then you'll have the same problem with the Baader zoom at the higher powers. You'll be able to see all the FOV at the lower powers, but there of course the FOV is considerably less than the APM anyway.

I can't quite see the full FOV with the APM, nor the Baader from about 12mm down, but I'm happy enough to put up with this to get the benefits of a zoom. My choice is the APM, partly because, unlike the Baader, the top of the eyepiece doesn't rotate when adjusting the Dioptrx.

Turning to fixed focal length eyepieces, the Hyperion isn't usually recommended for f/6 scopes.

Other alternatives are the Delite and Delos ranges, plus the Pentax XW series, and one with an even wider FOV, the Baader Morpheus range. All these have a nominal 20mm eye relief, although I'll leave it to others to post whether this is likely to be enough with a Dioptrx. The shape of the eye lens and how far it's recessed will make a difference here.

The Delite and the Delos of course take a Dioptrx natively. Both the XW and the Morpheus have 43mm threads under the eyecup so can be fitted with a Dioptrx, again preferably using a 42mm X 2mm O-ring on the threads.

Edited by Second Time Around, 03 December 2022 - 09:50 AM.

[sunistar]

Hi--This link has four pics labeled 1-4, showing

 

*APM zoom

*APM zoom with ring removed

*APM zoom with step down ring installed

*APM zoom with DioptRx

 

https://drive.google...?usp=share_link

 

Can you confirm that this is the setup you have recommended?  Unfortunately it just doesn't provide sufficient eye relief. I must admit...I have deep set eyes.

I don't see that there's any way to get the DioptRx lens any closer.

 

I'm coming to the conclusion that my only option is a couple Delites, as they natively take the DioptRx. Can I assume that that would give the max possible ER of any eyepiece with a DioptRx?

 

As always, thank you.