Astrophotography scope

[rlh7928]

Really at a tosser between the ZENITHSTAR 61 APO or the Altair 70mm EDT-F Triplet APO. This will be going on a ioptron cem 40 and using a qhy183c camera. Any input on the two scope would be great. Thanks

[Elp]

I've got a z61, awesome scope. Has done everything within its focal length and aperture well, visual and photographic, planetary, lunar, solar (white light and ha both with respective filters) and deep sky imaging.

Increase in aperture will usually give you greater benefit though.

[rlh7928]

Thank you for it is a hard line between 60 or 70mm as I've only used a 6inch reflector 

[bosun21]

I would go for the 70mm triplet over the 60mm. The Zenithstar is a proven scope so if I were you I would garner some feedback on the optical quality of the 70mm triplet before pulling the trigger. Good luck with whatever you choose.

[Adam J]

16 minutes ago, rlh7928 said:

Really at a tosser between the ZENITHSTAR 61 APO or the Altair 70mm EDT-F Triplet APO. This will be going on a ioptron cem 40 and using a qhy183c camera. Any input on the two scope would be great. Thanks

Can't find the edt-f model at 70mm on their website. Perhaps a link would help. 

Adam

[rlh7928]

Here's the link Adam https://landseaskyco.com/products/altair-70-ed-triplet-apo-refractor-telescope

[Adam J]

2 hours ago, rlh7928 said:

Here's the link Adam https://landseaskyco.com/products/altair-70-ed-triplet-apo-refractor-telescope

Honestly with the small pixel camera my feeling is that you will want to get a triplet as a minimim and if it was me a quad like this:

https://www.firstlightoptics.com/askar-telescopes/askar-fra300-60mm-f5-petzval-astrograph.html

The reason for that being that the doublet is not likely to fully exploit the small pixels of your 183mc.

If you go with the linked scope you will be imaging at F5 (better as your at a disadvantage in terms of SNR with the small pixels in any case) and the spot diagram for that scope is really excerlent.

Adam

Edited March 13, 2023 by Adam J

[IDM]

I have recently bout an Altair 70 EDQ-R:

Altair 70 EDQ-R F5 Quad APO Astrograph (altairastro.com)

Still early days but it seems truly excellent and I find myself selecting over my Esprit100 due to its relative lightness making setup very easy. 

I was tossing up between William Optics 70 + flattener versus the Altair scope. One of the main reasons I chose the Altair was the inbuilt flattener that doesn't require completely accurate back focus distance (just focus and start imaging). So in my setup I have a filter draw where I only sometimes need a filter. This means that whatever the situation, filter or no filter, I can get precise focus (as you probably know the filter thickness affects back focus distance). It is so much easier than my Esprit 100 with flattener, where I am constantly wondering if I should try different shims to try and more precisely nail focus. Certainly on my limited use so far the Altair is producing tighter stars with routinely lower star FWHM values (as determined by Sharpcap). At F5 the scope is also fast.

I know that I am encouraging you to spend more money but if you were thinking of getting a flattener as well as the scope then the price difference becomes less pronounced. The only issue I am aware of with the EDQ-R is tat it doesn't lend itself well to visual astronomy. Though I understand it may be possible, I certainly haven't tried.

Good luck with your decision making.

Ian

[iantaylor2uk]

Another vote for the ASKAR FRA 300 Pro - I am using this with an APS-C sized sensor (ZWO 071 MC Pro) and get a field of view of 4.5 x 3 degrees (at 3.3" per pixel)

A recent (large) photo I took with this combination, which is best viewed on a computer screen rather than on a phone, is available at: https://drive.google.com/file/d/1ekx3ibz3QnfTha3xX3PBIaGB36Vh1LLn/view?usp=sharing

If you have a 183mc camera, the field of view would be 2.5 x 1.7 degrees with 1.65" per pixel

The only downside of this scope is that it is mainly aimed at astrophotographers, and I think you need a special diagonal from ASKAR if you want to use it for visual.