Help Finding Field Flattener

andrea tasselli:
Why would you do that as there is no need, it's a guide scope after all. Not to mention that the WO isn't any better than the lowly stuff, identical for all the practical aspects, that you can get through the usual channels (eBay...) for much less moolah.

I was thinking of using it for wide field imaging. I looked at EvoGuide 50 by SkyWatcher and UniGuide 50 by WO. How bad of an idea is it?

andrea tasselli:

Alien_Enthusiast:
I was thinking of using it for wide field imaging. I looked at EvoGuide 50 by SkyWatcher and UniGuide 50 by WO. How bad of an idea is it?

Pretty bad in my book. For one, there is no field flattener for 1.25" barrels, AFAIK. Secondly, it's 1.25" so not really wide. Thirdly, it's a cemented doublet achromat at f/4 and I cannot think of anything worse for imaging purpose, except for singlets. You want wide field, get a camera lens. Way safer, better optically and effective choice, especially if you buy used.

Ok got it! Which camera lens would you reccomend to use with ZWO 585MC camera for big targets like M31, M42, M45 etc?

85mm - 135mm are great with this camera 585MC.

If you want similar focal length to your guide scope, you could get an Askar FMA180.

I looked at FMA180, it looks very appealing to me. Portable and not too expensive. If I were to choose between FMA180 and F2 135mm Samyang - which would be better?

Thanks!

Alien_Enthusiast:

If you want similar focal length to your guide scope, you could get an Askar FMA180.

I looked at FMA180, it looks very appealing to me. Portable and not too expensive. If I were to choose between FMA180 and F2 135mm Samyang - which would be better?

Thanks!

I have seen some very nice pictures made with the Samyang, but I have never worked with one, just the Askar. They are about the same weight, the Askar has the longer focal length, the Samyang is light stronger f2 versus f4.5. @andrea tasselli , have you used both?

Alien_Enthusiast:

If you want similar focal length to your guide scope, you could get an Askar FMA180.

I looked at FMA180, it looks very appealing to me. Portable and not too expensive. If I were to choose between FMA180 and F2 135mm Samyang - which would be better?

Thanks!

I have seen some very nice pictures made with the Samynag, but I have never worked with one, just the Askar. They are about the same weight, the Askar has the longer focal length, the Samyang is light stronger f2 versus f4.5. @andrea tasselli , have you used both?

Looking at the FMA180PRO which replaces the FMA180 that I have you now get a rotator, you can easily plug in 2” filters and it comes with a vixen dovetail now.

I would search here for pictures made of the same object with those lenses and preferably your camera. That should give you a better idea than either Andrea or I can tell you, as we both only have experience with one of the two.

FMA180 with 585 camera: https://www.astrobin.com/search/?q=&d=i&subject=&telescope=Fma180&camera=585&date_published_min=2011-11-09&date_published_max=2024-02-26&sort=

Samyang 135 with 585 camera: https://www.astrobin.com/search/?q=&d=i&subject=&telescope=Samyang+135&camera=585&date_published_min=2011-11-09&date_published_max=2024-02-26&sort=

Alien_Enthusiast:

FMA180 with 585 camera: https://www.astrobin.com/search/?q=&d=i&subject=&telescope=Fma180&camera=585&date_published_min=2011-11-09&date_published_max=2024-02-26&sort=

Samyang 135 with 585 camera: https://www.astrobin.com/search/?q=&d=i&subject=&telescope=Samyang+135&camera=585&date_published_min=2011-11-09&date_published_max=2024-02-26&sort=

I looked at those images, and it seems like Samyang 135 is a bit more crispy!

To me or for me it is not, FMA180 is crispier, or better to say, better quality and dynamic than Samyang 135, it is just that 135 is wider, i want to see the comparison between Samyang/Rokinon 135mm and Askar 135 then we can judge better.