Battle of the Fisheye's - Sigma 15 vs. 8-15L vs. Rokinon 12mm

Bassat wrote in post #17829926
Ok, I'll try to set something up. I expect significant DOF differences, though. Will start with f/5.6 focused at 6'.

Ya just for your sanity... do both at 5.6 then at 4 then at 2.8 then you can compare.

I bet you'll find it interesting.

I tried f/5.6 with target at 6', focused at 3'. The Rokinon covers that with DOF. The Sigma does not. Or one of their DOF scales is WAY off. I need a better test. This comparison is not fair. I think perhaps a similarly framed brick wall shot at f/8 would be a better test of corner performance.

Bassat wrote in post #17829944
I tried f/5.6 with target at 6', focused at 3'. The Rokinon covers that with DOF. The Sigma does not. Or one of their DOF scales is WAY off. I need a better test. This comparison is not fair. I think perhaps a similarly framed brick wall shot at f/8 would be a better test of corner performance.

just Liveview it and goto 10x zoom and match focus on center object on both.

Talley wrote in post #17829950
just Liveview it and goto 10x zoom and match focus on center object on both.

But the DOF is vastly different for these lenses. If you still own both, look at the DOF scales. On top of that, what is in the corners of the 12mm shot won't even be visible in the 15mm shot. How do you compare that?

Bassat wrote in post #17829969
But the DOF is vastly different for these lenses. If you still own both, look at the DOF scales. On top of that, what is in the corners of the 12mm shot won't even be visible in the 15mm shot. How do you compare that?

by not being so critical. I don't use the DOF scales... I will dial in with live view at 10x to ensure accuracy. I also know there is differences in field curvature so most of the time I just compare to other items that are in focus in the general area.

it doesn't have to be so exact.... just analyze various parts of the image. I don't make it so critical. I just do some quick glances and mostly at 50% crop too. 1:1 some... but mostly 50%.

We use these lenses differently. I had a Rok 14 and never focused it. I shut off the AF on my Sigma and liked it a lot better. I don't see ever focusing the Rok 12. I bought these lenses for the REALLY HUGE DOF. If I am shooting landscapes/buildings, I select f/8-16, depending on distance extremes, and set focus by the markings on the barrel: 2' for close objects, 4-5' for everything else. The first day I shot my Rok 14, I was on the Indiana University South Bend campus. I was out for about 3 hours and never touched the focus ring. The 12mm should be even better.

Bassat wrote in post #17830044
We use these lenses differently. I had a Rok 14 and never focused it. I shut off the AF on my Sigma and liked it a lot better. I don't see ever focusing the Rok 12. I bought these lenses for the REALLY HUGE DOF. If I am shooting landscapes/buildings, I select f/8-16, depending on distance extremes, and set focus by the markings on the barrel: 2' for close objects, 4-5' for everything else. The first day I shot my Rok 14, I was on the Indiana University South Bend campus. I was out for about 3 hours and never touched the focus ring. The 12mm should be even better.

My 12 is a much better focus ring than my 14 was. Even at F8 vs F8 the 12 bested the sigma.

Mine was/is the opposite. The 14 was silky-smooth. The 12 feels like it has a small piece of grit in it. It is getting better as I use it. I agree about the Roks being better than the Sigma. I intend to use the 12 when I want wide & DOF, the sigma when I want hilarious distortion. Definitely keeping both of them. I already sold the 14.

JTPhotography33 wrote in post #17848080
Cool thread, glad I found it. I have the Rok 12 and love it. I was thinking of moving to the Sig 15 for the AF and since it also covers 180 deg, but wasn't sure if the coverage was less due to the extra 3mm. I can see from you pics that the Rok is wider. Still not sure how that works, diff focal length but same 180 coverage? I will post some sample pics soon.

Take a look at this. Three different FE lenses; three different views. Doesn't really explain it, but it is interesting.

https://www.slrlounge.​com …venture-photography-lens/

JTPhotography33 wrote in post #17848080
Cool thread, glad I found it. I have the Rok 12 and love it. I was thinking of moving to the Sig 15 for the AF and since it also covers 180 deg, but wasn't sure if the coverage was less due to the extra 3mm. I can see from you pics that the Rok is wider. Still not sure how that works, diff focal length but same 180 coverage? I will post some sample pics soon.

at infinity the diagonals on both are 180. It's just the stereographic projection of the 12mm allows way more into the frame edges in the top/bottom center and sides center than the sigma/canon 15s

Talley,

Please go tho this thread, and convince the OP to get the Samyang 12mm: https://photography-on-the.net …/showthread.php​?t=1450017

anscochrome wrote in post #17851485
Talley,

Please go tho this thread, and convince the OP to get the Samyang 12mm: https://photography-on-the.net …/showthread.php​?t=1450017

hi ! that is my thread and samyang looks better then vizitar 16mm
thanks !