|Samyang/Rokinon 85mm F/1.4 Aspherical IF|
Being that this is a completely manual lens, it does seem a little risky to use it for a commercial shoot, but I also came from an era of film where I never used autofocus. However not to take the chance of missing shots, I put an autofocus confirm chip onto the back of the lens.
|The Optix V5 programmable chip|
Another issue with using a focusing screen with the Samyang (or any manual focus lens) is that no matter how fast the aperture is, if you need to stop it down for more depth of field, your viewfinder will also get dark.
In my case, I decided to use an autofocus confirm chip called the Optix V5. These are generally easily available from ebay in china. I buy them from a seller by the name of shamino124 click on this link to find his products. The chip is programmable, so I can tell the camera I'm using an 85mm F/1.4 lens. It also gives me some ability to change the F stop so I can match what I'm using on the physical ring, but when I don't have the time to screw around, I leave it on the widest setting. What this chip does is it tricks the camera into thinking it still has a valid autofocusing lens on it. When I focus, my AF points light up when I'm in focus. Very handy when you don't have a split prism focusing aid. It's accuracy is still a little rough, but as long as you know that, take multiple shots to ensure you get critical focus.
In this session I used my Canon EOS 7D to shoot my models as my 5DmkII was out for servicing. Probably not the most ideal camera for this lens I'll admit, and part of the reason is the difference in depth of field flexibility and framing options. The difference between using my 5DmkII and the 7D is an inch of difference front and back which means focusing errors are going to be less likely to happen on the 5D than it will on the 7D. Something to consider for sure when you're using a manual lens this fast.
Another thing to consider with any fast primes is the fact that they can suffer from something called Longitudinal Chromatic Aberrations or LoCA for short. This is pretty normal with most fast primes and can be somewhat corrected with an APO element. But for the most part, most people won't identify it easily unless you have high contrast scenes and are slightly out of focus (most of these kinds of issues result from poor exposure). Regardless, it's always good to be aware of your background and to give some reasonable distance for your subject to give a nice smooth background.
During this session I also used a Lastolite Professional Ezbox softbox lit by a 580EX. I was mostly using natural lighting (overcast day), but brought in some extra light to fill in any harsh shadows on the faces.
Using flash with a manual lens was not problem either, even though the metering was off, it was easy to calculate real quick in my head what I needed to adjust. I did bring a light meter with me and took some reading, but all told, it was much faster to just take a shot, review and adjust.
All in all it wasn't a bad experience out in the field. The lens performed very well and upon review of my images, about 70-80% of my images were useable, with about 50% nailed perfectly. I will say that this combination is not for the inexperienced shooter if you hope to use it for commercial applications, it's not an easy lens to use. However, it doesn't mean I don't recommend it. Considering the alternatives are twice or four times as much, this lens produces spectacular images that frankly my 85 F/1.8 couldn't touch, or the extra expense of the 85 F/1.2 just doesn't seem like something to tote around if I don't use it enough.
Because this session involved 4 guys, I was really pressed for time. If I had a little more time I think my percentages would have been much better. Is it possible to do this without a focusing aid? Yes it is, but you better have eagle eyes and frankly my eyes aren't the worst, but having the aid really kept my numbers high.
Would I do this again? Absolutely. I learned some things to consider the next time and with the 5Dmk2 I will have a far wider margin for error. Do I recommend this? That's a tough question to answer absolutely.
The following week I shot the same models with a 135mm F/2 lens and my Canon 5Dmk2. I found that this was a far easier portrait session, with 100% of the shots in focus and approximately 90% that were useable. Based on these kinds of numbers it's very hard to say that it makes sense to use the 85 F/1.4 over the 135mm F/2. Certainly I would not use this lens combination for event shooting, but in a controlled studio situation, it's a great lens to use.
Even in a studio or controlled shoot, you have to ask yourself do you need to spend more time with directing the models, or have plenty of time to compose. Because these actors are not trained models, it was a little more work to get them to pose right so there was more work required. Having not to worry about whether I'm in focus is something you need to carefully consider. One thing is certain, I would be very wary of choosing this lens if you didn't have some sort of focusing aid.