Thoughts on the Samyang 135mm f1.8?

Samyang AF 135mm f/1.8 Equipment Buying Advice
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Claudio Boicu avatar
Claudio Boicu avatar
Hello everybody,
so ive been slowly putting together a wide field rig for Milky Way shots, but I also would like to have a 135mm lens that I can pair up with my Sony a7ii astro modified camera.
now I thought about going with the famous rokinon 135mm f2 lens, but ive been looking around and found a cheap samyang AF 135mm F1.8 that I could pick up. my question now is, is it any good for astrophotography? I mean, do I rather go the safe route with the rokinon f2? because on astrobin and on the internet I have found very little to no information on how this lens actually performs for astro. I found 2-3 reviews but they don't really go as in depth as I would like them to be. do any of y'all have this lens or have seen pictures taken with it?
Markus Selbach avatar
Markus Selbach avatar
I used that lense for one year with a sony a7r and a sony a7r2 before upgrading to a redcat51. I never got really satisfied with the results. I had a strong focus tilt because I didn‘t find a solution to mount it directly to my mount. And this lense is big and heavy. Sharpness was pleasend when stopped down to 2.8.
The nice feature Astro-Focus-Hold button was more or less useless because compared to any other lense I used so far, this one had little focus stability and needed fine adjustments every hour, which is annoying. Another problem that drove me mad was that even when in manual focus mode there was a short autofocus adjustment whenever my camera was turned off and on. So when you had to turn it off to change batteries, you had to refocus again. But this may be a special problem with sony.
After all I sold mine and can not recommend it to you.
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Claudio Boicu avatar
Claudio Boicu avatar
Markus Selbach:
I used that lense for one year with a sony a7r and a sony a7r2 before upgrading to a redcat51. I never got really satisfied with the results. I had a strong focus tilt because I didn‘t find a solution to mount it directly to my mount. And this lense is big and heavy. Sharpness was pleasend when stopped down to 2.8.
The nice feature Astro-Focus-Hold button was more or less useless because compared to any other lense I used so far, this one had little focus stability and needed fine adjustments every hour, which is annoying. Another problem that drove me mad was that even when in manual focus mode there was a short autofocus adjustment whenever my camera was turned off and on. So when you had to turn it off to change batteries, you had to refocus again. But this may be a special problem with sony.
After all I sold mine and can not recommend it to you.

thats doesn't sound fun, thank you tho for your input, I probably go with the rokinon then.
Markus Selbach avatar
Markus Selbach avatar
Yes, there are so many happy colleagues with that lense, that it might be a better choice. Should be cheaper and lighter anyway. Would buy the F2 too if I some day want to so more widefield again.
Jens avatar
Jens avatar
Claudio Boicu:
Markus Selbach:
I used that lense for one year with a sony a7r and a sony a7r2 before upgrading to a redcat51. I never got really satisfied with the results. I had a strong focus tilt because I didn‘t find a solution to mount it directly to my mount. And this lense is big and heavy. Sharpness was pleasend when stopped down to 2.8.
The nice feature Astro-Focus-Hold button was more or less useless because compared to any other lense I used so far, this one had little focus stability and needed fine adjustments every hour, which is annoying. Another problem that drove me mad was that even when in manual focus mode there was a short autofocus adjustment whenever my camera was turned off and on. So when you had to turn it off to change batteries, you had to refocus again. But this may be a special problem with sony.
After all I sold mine and can not recommend it to you.

thats doesn't sound fun, thank you tho for your input, I probably go with the rokinon then.

The Rokinon is the same lens, just a different name. Maybe it matters on the copy you'll get. it's possbible that some are sharper than other since the quality control isn't as thorough as with more expensive lenses. I've heard so many good things about it though
Pariah avatar
Pariah avatar
Just to throw a spanner in.. I have the f2, it is terribly decentered. Fantastic lens over about a quarter of the field though!  ;)  Unfortunately it was too late to return when I found out..

Check any copy carefully
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Tom Victor avatar
Tom Victor avatar
I also have the 135mm f2 and are extremely happy with it. No telescope I have owned has given so much fun for the bucks. Prices as low as €300-400 on Amazon when on offer. Together with the astrodymium kit, EAF and ASIAIR you have the ultimate short fl travel setup, or a very capable beginner kit, just add any mount.
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Markus Selbach avatar
Markus Selbach avatar
Jens:
Claudio Boicu:
Markus Selbach:
I used that lense for one year with a sony a7r and a sony a7r2 before upgrading to a redcat51. I never got really satisfied with the results. I had a strong focus tilt because I didn‘t find a solution to mount it directly to my mount. And this lense is big and heavy. Sharpness was pleasend when stopped down to 2.8.
The nice feature Astro-Focus-Hold button was more or less useless because compared to any other lense I used so far, this one had little focus stability and needed fine adjustments every hour, which is annoying. Another problem that drove me mad was that even when in manual focus mode there was a short autofocus adjustment whenever my camera was turned off and on. So when you had to turn it off to change batteries, you had to refocus again. But this may be a special problem with sony.
After all I sold mine and can not recommend it to you.

thats doesn't sound fun, thank you tho for your input, I probably go with the rokinon then.

The Rokinon is the same lens, just a different name. Maybe it matters on the copy you'll get. it's possbible that some are sharper than other since the quality control isn't as thorough as with more expensive lenses. I've heard so many good things about it though


claudio asked for the samyang/ rokinon 135mm F1.8 not the F2 version. But of course you could be right and I got a bad copy of the F1.8. That‘s allways the risk
Mau_Bard avatar
Mau_Bard avatar
My 2 cents: while weighting the possibilities, consider the Sigma 135mm f/1.8 ART, optically superior to the Samyang f/2, in my experience. One point in favor of the Samyang is that there are commercial ready 3D printed mounting systems (including the motor focusser belt and housing), that a few months ago were not available for the Sigma.
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Chris Beere avatar
Chris Beere avatar
As Mau said, the Art 135 is a better lens, you can shoot it at f/2.0 and not have to deal with the aperture vignetting diffraction pattern on brighter stars that you get on the Samyang wide open.

However, it doesnt have the hardware support of the Samyang so getting a decent rig up and running is a lot more hassle.
Ali Alhawas avatar
Ali Alhawas avatar
I got the Samyang F2 ED UMC and I am very happy with it.. Stars are good all over the field even when using f2.
Ethan Sweet avatar
Ethan Sweet avatar
My 2 cents: while weighting the possibilities, consider the Sigma 135mm f/1.8 ART, optically superior to the Samyang f/2, in my experience. One point in favor of the Samyang is that there are commercial ready 3D printed mounting systems (including the motor focusser belt and housing), that a few months ago were not available for the Sigma.

It better be optically superior. It's nearly $1k used lol
Michael Lev avatar
Michael Lev avatar
I have the Samyang f2, Im not very happy, at f2 it is very decentered, and stars look pretty bad.
This gets pretty good at f2.8, and I'll probably keep it for now.
But i am using it with a small IMX585 sensor, and can see a little aberrations in the corners (especially at f2)

Haven't tried the sigma or the samy f1.8, though i have also considered them in the past.
I didn't go with the samy 1.8 because i wanted more back focus to put filters.
And didn't go with the sigma for the price.
Plus i got the f2 for dirt cheap.
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