Samyang 135mm f/2

[AdamJL]

Does anyone have one?
How good is this little lens? Pretty cheap for a fast prime. Yes, there's no autofocus and there's a manual aperture ring (cool!) but this thing is so sharp in the corners. Here's a current sub in the top right hand corner at f/4, 100% crop.

I'm going to open her up to f/2 in a bit but even at f/4, it's a worthy astro lens.

Also sold in some parts of the world under the Rokinon branding.

[Camelopardalis (Dunk)]

I had one…but it wasn’t a good copy unfortunately, so it went back and I didn’t risk it a second time. Not only we’re the stars not round in the corners when using an ASI1600 (not a big chip!), but it had terrible CA too.

Looks like you’ve got a good one

[AdamJL]

Cheers, Dunk. Yes it's a pretty good sample. I opened it up to f/2 and did notice some CA, but nothing major. I'll probably stop down to f/2.8 or f/4 in future and use the lens there.

With your issues, it does sound odd that the 1600 gave you a poor field. Are you sure the backspacing was correct?

[Luke125 (Luke)]

Does this lens support upto APSC?

[AdamJL]

It supports APS-C yes.
I also use it on my Canon R6 which is full frame

[ChrisV (Chris)]

Great lens. I use it at f2.8 with my 450d or asi071 (aps-c). Critical to get the backspacing correct. Was straightforward with the 450d but had to muck around with spacers on the 071 to get rid of CA.

Is it still good with full frame Adam?

[Camelopardalis (Dunk)]

Originally Posted by AdamJL

Cheers, Dunk. Yes it's a pretty good sample. I opened it up to f/2 and did notice some CA, but nothing major. I'll probably stop down to f/2.8 or f/4 in future and use the lens there.

With your issues, it does sound odd that the 1600 gave you a poor field. Are you sure the backspacing was correct?

Yeah the spacing was correct - I’d tried setting it at a spread of values to get it right, but even then there was bad tilt.

I just put it down to getting a bad one. Potentially great, and I would have paid extra for a good one …I just don’t have the budget for a Sigma.

[AdamJL]

Originally Posted by ChrisV

Great lens. I use it at f2.8 with my 450d or asi071 (aps-c). Critical to get the backspacing correct. Was straightforward with the 450d but had to muck around with spacers on the 071 to get rid of CA.

Is it still good with full frame Adam?

Hi Chris

I haven’t used it for astro work on Full Frame (my astro camera is APS-C) but for a few portraits of the kids it’s a fantastic performer on the R6… if I can keep the kids still because it’s manual focus
I do have to dial in some micro focus though but that should be easy

Have you got any images to share with this lens of astro stuff at all?

Originally Posted by Camelopardalis

Yeah the spacing was correct - I’d tried setting it at a spread of values to get it right, but even then there was bad tilt.

I just put it down to getting a bad one. Potentially great, and I would have paid extra for a good one …I just don’t have the budget for a Sigma.

Ha yeah fair enough. Sigma makes some great stuff but this lens has a lot of support in the community for astrophotography. All the kits you can buy to pair a ZWO EAF for instance. Or the 3D printed rings etc as well.
I haven’t seen that for Sigma

[Retrograde (Pete)]

Hi Adam,

I've had mine since 2017. Great bit of glass (as long as you get a good copy).

I use mine with an astro-modded DSLR. Might work out how to attach it to the ZWO one day when I have the time.

My most recent image with the Pentax/Samyang combo:
Lagoon Region - Samyang 135

[ChrisV (Chris)]

Here's one I did nearly 3 years ago with my astro-camera
https://www.astrobin.com/401364/

I've just started using it for a portable setup with a 450d and my modded EQ5. No computer or guiding, just an intervalometer and Goto via my mobile phone. Here's a shot, its not fully processed yet.

[AdamJL]

Originally Posted by Retrograde

Hi Adam,

I've had mine since 2017. Great bit of glass (as long as you get a good copy).

I use mine with an astro-modded DSLR. Might work out how to attach it to the ZWO one day when I have the time.

My most recent image with the Pentax/Samyang combo:
Lagoon Region - Samyang 135

Wow, Pete, that's a beauty! I tried the same nebula a week ago for 2 hours and got nothing but just a hint. That nebula is made for this lens. Thanks for sharing

Originally Posted by ChrisV

Here's one I did nearly 3 years ago with my astro-camera
https://www.astrobin.com/401364/

I've just started using it for a portable setup with a 450d and my modded EQ5. No computer or guiding, just an intervalometer and Goto via my mobile phone. Here's a shot, its not fully processed yet.

Brilliant. Would love to see the final result. Barnards Loop would look amazing through this lens.