This is an intriguing thread as a friend of mine has expressed similar concerns about his 85mm. He's going to loan it to me as I'm interested in acquiring this lens. The problem is that I have no idea how to fine tune it, and I need to learn about front vs. back focusing. I'm sure I can pick up the education here and through a couple of other photography sites but I still don't know how to tune a lens.
I don't want to hijack this thread but if anyone can offer me some tips as a good starting point for my education, I'd be grateful.
I want this lens to work for me as I intend to use it for indoor portraiture among other applications.
The images of the black women with the D 800 and D 700 even show the texture of the skin on their foreheads when magnified. And these were all taken between f/1.8 and f/2.2 so the DOF is not that large.
Your 3rd copy looks better than the original 85mm. Maybe you should have sprung for the Sigma Art lens or really sprung for the Otus.
I guess the resolution on the modern digital cameras is really critical on images as I don't remember having problems with my old film SLR's. There was no micro tuning on them. Sometimes you missed focus, but when you got the focus right they seemed very sharp.
I notice that you moved from d800 to D810, is it possible that was the problem, not the lens? Though given the comments here and my own experience, I think the 85 1.8 is not consistent in AF
Fivesense wrote:
This is an intriguing thread as a friend of mine has expressed similar concerns about his 85mm. He's going to loan it to me as I'm interested in acquiring this lens. The problem is that I have no idea how to fine tune it, and I need to learn about front vs. back focusing. I'm sure I can pick up the education here and through a couple of other photography sites but I still don't know how to tune a lens.
I don't want to hijack this thread but if anyone can offer me some tips as a good starting point for my education, I'd be grateful.
I want this lens to work for me as I intend to use it for indoor portraiture among other applications.
There are some good articles out there on the ins and outs of auto focus fine tuning. If I recall correctly, lensrentals.com has a good article on the subject. In any case, search around if you care to learn a ton about how auto focus works and what fine-tuning it can accomplish.
If you want to jump into a free and relatively easy way to test for AF fine tuning, I'd recommend starting with snapsy's Dot-Tune method, here: https://www.fredmiranda.com/forum/topic/1187638
I prefer FoCal (software) for measuring, but Dot-Tune is perfectly capable.
jeff gude wrote:
I notice that you moved from d800 to D810, is it possible that was the problem, not the lens? Though given the comments here and my own experience, I think the 85 1.8 is not consistent in AF
The switch to the D810 certainly could have been the "fix." It's one of those things where my other lenses had no issues on my D800, and everyone else's Nikon 85mm 1.8G worked perfectly on their bodies, so perhaps it was just a bad combo with that specific copy (actually two copies) of the lens and my copy of the D800. This third copy of the lens with my new D810 is fantastic!
Oh and for those interested in the AF fine tune numbers according to Focal...
My first copy of the lens, paired with my D800, was so far off Focal recommended +32 or some such crazy number (I don't recall for sure, but it was well outside the +-20 range.
My second copy of the lens, also paired with my D800, was between +14 at near focusing to +18 in the middle, then beyond +20 for far focusing. It was this copy that prompted my original post in this thread and all samples posted except my most recent samples were taken with this copy.
My third copy of the lens, paired with my new D810, is between -1 and +2. This is a far smaller range than my other copies, and my hit rate is way better. My hunch is, the more AF fine tune required, the harder the focusing system has to work to acquire/lock focus. So, AF fine tune set to +1 will focus more consistently than +18. I have no info to back this up, but it's my hunch. My latest post with sample images is using this third copy and I am completely satisfied with its sharpness.
