Tuesday, February 22, 2011

The Samyang 85mm f/1.4 Aspherical IF for Portrait with the Optix V5 AF Confirm Chip

Samyang/Rokinon 85mm F/1.4 Aspherical IF
A few weeks back I took the opportunity to use my Samyang/Rokinon 85mm F/1.4 Aspherical IF lens for an actor's headshot session. I'm not going to write this as a review of the lens as there's plenty of good reviews out there. This is going to be just an account of my experiences of using this in the field rather than testing it on charts and brick walls. For specifications on this lens, follow this link and a great review here.

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
My copy is a canon mount, and ever since the digital age of cameras, the need for the old style focusing screens have pretty much gone extinct. However you can purchase various types of focusing screens from third party sources, plus some select brand name one. Focusing aids are very important with a lens that has a shallow depth of field like the 85 F/1.4 (at the widest aperture I have approximately 1 1/2 inch forward and 1 1/2 inch back) however the draw back to using a focusing aid is that it makes an already dark viewfinder, darker. It is not recommended to use lenses slower than F/2.8 with a focusing screen as it becomes very difficult to see through the viewfinder.

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.

12 comments:

  1. The focal length of 85mm has been a favorite of mine for many years now, be it on full frame or APS sizes sensor, that is until I fell in love with my 105mm F2 DC...

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  2. Hi Terrance,

    Thanks for clarifying the DOF table question. Great help!

    I walked into Henry's. Picked up the 135mm F2 DC that I ordered. I've been waiting for a while. I was somewhat worried that it may be discontinued especially the current diasater that Japan is experiencing. Decided to try out the 85mm as well in the store. The image I had on the D700 was 'beautiful'.... And.... I walked out of Henry's with 2 lenses.

    I love this 85mm!!! It has a clarity that's difficult to describe in words. I'm just an amateur. No pressure about taking my 'time' to shoot. One of my friends complained that she 'posed' the longest time since I had to fiddle with manual focus. I don't want fuzzy pics especially at 1.4 or 2! I cannot rely on the 'dot' indicator. On my camera sample, the focus is dead on when the indicator oscillates between 'left arrow' and 'lit'.

    Love the contrast and clarity. $300 Cdn (plus taxes sadly) I think it's a good investment....
    Frankly I prefer this to 135 f2. Am I crazy??

    LOL. Mark.

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    Replies
    1. Hi terrence,
      I have picked up a rokinon 85 mm 1.4 canon mount, and would like to insert the optix v5+ chip. However, the link provided by you does not have just the chip, but an adaptor as well. I dont mind, picking one of those, but dont see a rokinon to canon eos adaptor with chip shown.
      Can you please guide me which one should i buy?

      Thanks
      Chinmay

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    2. Hi there Chinmay.

      The link I provided is a seller that will sell you the chips directly. Just contact him through ebay mail and he'll provide you with a paypal order to do so.

      The chips do come with double sided tape, so you can align them first and test to make sure you did it right, then you use two part epoxy to make it a permanent installation.

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    3. Terrance,
      Picked up an v6 chip but sadly cudnt getit to work on 5d3? Contacted optixpcb but found no answer. Does the chip work on 5d2?Did you get a chance to try it?

      Thanks
      Chinmay

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    4. Chinmay, it might be a misalignment but that said, I do know the V5 works on the 5Dmk2. I don't have a V6 so I can't comment on whether it works, but I will assume that since the V6 is a newer generation that it should work.

      I would keep trying to contact the seller and hopefully you'll get an answer.

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  3. Do take the time and be patient with it, and even stopped down to F/2, it's still has bokeh but more of your subject is in focus. Be patient with it for sure. All 1.4 lenses can be a little tricky to master.

    Enjoy both of those lenses!

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  4. Nikon has the 105mm f/2.5 ais MF witch is really wonderfull. Beautifull smooth bokeh, good sharpness wide open and a build in metal lens hood. You can get them very cheap these days.

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  5. Hi there, I just bought and tested that lens today after reading this article. I love it. I just have a little question about that chip, on eBay I can only see chips for Nikon, Leica, M42 and Contax and I'm not too sure which one to pick for my Canon body. Could you clarify which one you ordered?

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    Replies
    1. The chips usually only come in Canon adapters, so when they say the other camera models it must mean adapters as well for the respective lenses. The chips usually aren't sold separately, I buy my chips from a person who puts the adapters together. Here's his online store and you can contact him directly to see if he'll sell you just the chips alone: http://stores.ebay.ca/Shamino123s-Store-for-Photography?_rdc=1

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  6. Hi Terrance, have you ever used the EG-S focusing screen? It does darken the frame, but not by much. I use it for Tilt-and-shift and very fast lenses and it really helps in focusing, even without confirmation. --dmg

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    1. Yes I did, but for me the problem was when I wanted to stop down. I eventually stopped using the screens because it was annoying me that way. But wide open it works excellent. The EG-S screens are a great recommendation for manual focusing lenses, but I always add the caveat as long as you don't stop it down.

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