8 replies to this topic

[Egorrokita]

Hello!

Please help me choosing my first setup for widefield astrophotography.

What i have now is star adventure gti mount, asiair and zwo 30mm f4 guide scope + asi120mm guide camera.

I'm thinking about buying a manual 135mm Samyang lens and asi2600mm mono(I have good mirrorless camera, so i dont want to go with second color camera, and a live under a very light poluted sky). Is it a good idea, maybe a can buy something better? (i considered redcat 51, but it is too heavy for my mount)

 

Also i have some questions about samyang, If I stop at it, I'll choose the canon ef version.

 

Do I understand correctly that rokinon 135mm and samyang 135mm are technically the same?

 

And i heard about tilt problems, do I understand correctly that i can fix them with zwo tilt plate?

 

What else (besides camera, tilt plate and astrodymium mounting rings) will I need to buy? I also know that I need a filter wheel, will I be able to achieve the correct backfocus distance with it and tilt plate?

Edited by Egorrokita, 02 June 2025 - 03:54 PM.

[photoracer18]

You are correct they are essentially the same optics sometimes with just a name change and sometimes with small changes. You will also need the adapter that goes from the camera to the lens. Camera lenses, at least DSLR ones, use a T-adapter to camera with 55mm back spacing designed many decades ago to accommodate  using different brand lenses with different brand SLR film cameras. Which also worked with DSLRs later. Not so with MILC cameras or astro cameras.

[klangwolke]

“Do I understand correctly that rokinon 135mm and samyang 135mm are technically the same?”

Yes, they are the same as far as I know. Generally the 135mm is a great setup for wide field and that is a good camera combination.

[Egorrokita]

Thanks for response! And about backfocusing, would i be able to achieve the correct backfocus with filter wheel?

[soojooko]

@Egorrokita

 

What mount are you currently using?

 

Also, you should maybe consider the Askar FMA series scopes. The FMA180 pro is well regarded. It depends on the price you are willing to pay for the Samyang.

[dedo]

ZWO makes three different Canon adapters: a standard one, a filter drawer integrated one and a thin one designed to be paired with the ZWO EFW. I don't know about tilt adjustmens.

[Egorrokita]

@Egorrokita

 

What mount are you currently using?

 

Also, you should maybe consider the Askar FMA series scopes. The FMA180 pro is well regarded. It depends on the price you are willing to pay for the Samyang.

My mount is star adventure gti, I can buy samyang for 370$, thanks for the advice, I'll consider askar

[Egorrokita]

ZWO makes three different Canon adapters: a standard one, a filter drawer integrated one and a thin one designed to be paired with the ZWO EFW. I don't know about tilt adjustmens.

If i understand correctly, a need 44.5 backfocus 

so i can use 12mm adapter maximum(12.5 in camera + 20 in efw + 12 = 44.5)

Is there an adapter of 12 or less mm?

[dedo]

Here's the product page, seems like it should work just out of the box when paired to a Canon EF lens and the ZWO EFW:

 

https://www.zwoastro...dapter-for-efw/

 

Enquiry ZWO directly for added security