?: Focus with Nikon 85mm f/1.4 D wide open

Discussion in 'Nikon' started by rick_pascale|1, Feb 17, 2019.

  1. Hello,

    I hope everyone is doing well!

    I recently shot some portraits of our daughter with my old 85mm f/1.4 D lens and normally I use this lens in the f/3.2-f/5.6 range. The results have been excellent.

    For this particular photo shoot I wanted to open the lens up to f/1.4 and see if we could get some interesting shots. When I did this and left my D850 in AF-S, and even on a monopod with legs, I noticed that the focus was not nearly as good as I was getting while hand holding at a more stopped down aperture. I took many images side by side first at 1.4 then switched to 3.2 and the consistent difference was really noticeable.

    After trying a few different techniques I decided to give Manual focus a try and wow, what a difference! The results were much, much better while focusing manually.

    I was wondering if you folks have noticed this with any of your lenses wide open and if you opt to shoot in Manual when opening up the aperture to the max.

    Thanks so much for your time and hope to hear from you.

    best always,

    Rick
     
  2. I find it difficult to consistently nail perfect focus at very shallow DOF settings (85mm@1.4) with manual focus, even AF is not always perfect with the D810 and other Nikon equipment I have. The D810 seems more consistent with nailing shallow DOF focus than the D800 I had previously, and I would expect the D850 to be better yet. I remember thinking that the D3 I used to have was the easiest to manual focus, but possibly the 12MP was a little more forgiving.

    You might want to try AF-C vs AF-S(ingle). With super thin DOF, just a little movement by subject or photog (or both) is enough to get less than perfect results. I have found that AF-C can compensate for this movement. I don't have an 85/1.4D, but my AF hit rate is pretty good with a 105/2DC and 85/1.8G. Recently, I was surprised that I did pretty well shooting a pretty tight head shot manually focusing with a 180/2.8 AIS, maybe the 2.8 max aperture is a little more compatible with the screen in the D810. My understanding is that the screens in DSLR's are optimized for 2.8 or slower lenses.
     
    Last edited: Feb 17, 2019
    rick_pascale|1 likes this.
  3. Thanks so much Robert!
    Appreciate your input very much!
    Yes, I have tried AF-C with Single Point and I still am finding that Im getting better results with Manual at 1.4 vs. AF at 1.4 on both my D850 and D3.
    I read a report recently that stated that this particular lens has its best focus in the 4-6 f/stop range and only about 50% as good wide open. Just one report but it contained some pretty believable data. I will try to find it and post it here.
    Thanks again for responding!
     
  4. As a follow up to the above...
    Here is an article that states that the lens is sharp at f1.4. Now, I never like to criticize anyones work, in fact I respect every photographer I know, even if I disagree with their style, results etc. I can learn a lot from any photographer Im sure. With that said, take a look at the images in this article illustrating the sharpness of the lens. The images don't look sharp to me, do they to you?

    Nikon 85mm f/1.4 D AF Review - Bokeh, Autofocus, Handling

    thanks,
    Rick
     
  5. After I wrote the post, I remembered that I tested two 50/1.4 lenses (K type and older AI'd S-C) against my 50/1.8G last week. The lenses were fine, but I found that my focusing was all over the place. Thinking about it, I don't do very well with the 28/2 and 55/1.2 AI'd lenses I have, either. I did fairly well with a 105/2.5 and 100/2.8 yesterday, and the 180/2.8 a few weeks ago. Maybe the D810 screen is better with slower lenses. It was easy to focus precisely with the zoom feature in my now dead Sony A7, so I plan to get another mirrorless camera to use with the manual focus glass I have. But basically, I have about given up with manual focus lenses on the DSLR's I have.

    Edit: Just quickly read the link article you posted, there was a sentence in there about modern focusing screens and f/2.8, lol. Also, I have used an 85/1.4D a while back. I always stopped down to f/2ish when using that lens.
     
    Last edited: Feb 17, 2019
  6. Since the focus is off only when using autofocus and a shallow DOF, perhaps the lens/camera combination needs Autofocus Fine Tuning. I ran a few figures through a DOF calculator. for an 85mm lens at f/1.4 and a camera to subject distance of 10 feet, the DOF is approximately 0.35 feet (4.2 inches almost equally divided tin front and rear). At f/3.2 the DOF is approximately 0.78 feet (9.36 inches) a considerable difference. If your lens was front focusing by say 3 inches, it would look off at f/1.4 but good at f/3.2.

    Since you have a single focal length lens and you are shooting portraits at approximately the same range, you should be able to use the Auto Focus fine tune on the D850 (see pages 164 - 168 in the D850 Menu Guide).
     
  7. I used to have this lens and to be honest, it was one of my favorites. I didn't use it at f/1.4, but from f/1.8 to f/3.5 typically. At f/1.4 the focus just wasn't quite precise enough. AF fine tune may help improve things, though. My recommendation would be not to open up further than f/1.8 with this lens, if you are demanding on the sharpness and focus. But still, when I look at the results I got with this lens, I have to say it is a great lens although it has this limitation. The image rendering is lively and beautiful. The 1.4G has more precise AF and somewhat different color rendering.
     
  8. Some lenses, particularly older ones with partially uncorrected aberrations, have been known to confuse the AF system - they may prioritise a wavelength that's not a good approximation to the overall focal plane. But absolutely trying AF fine tune first would be a good idea. Honestly, I never entirely trust f/1.4 autofocus - I wish Nikon's stacking mode included a focus bracketing option.
     
  9. That article is fairly old, and uses a D700, so of course it's not going to look as sharp as a D850.

    I was recently looking at some of my pictures taken with a D700, and thinking, 'crikey they're really soft', but that was par for the course in those days of 12 megapixels.

    Having said that, I think the sharpness shown in those examples is exactly what I'd expect from that lens and camera combo.

    Anyhow. No f/1.4 lens from the time of the 85mm D was really sharp wide open, and most modern wide-aperture lenses still struggle to convince at f/1.4. Not unless you've paid a four-figure sum for them!

    WRT your AF problem. Not unusual with f1.4 lenses used wide open IME. AF fine-tune might help.

    Most of my f/1.4 lenses are manual focus anyway, and tend to fool the focus-confirmation dot into back focussing. My simple work around is to pull focus from close-to-far, and stop just as the focus dot starts to flicker. That seems to nail the best focus most of the time. YMMV.
     
  10. Try AF in LV. Contrast Detect AF should show you what the lens is like when 'accurately' focused.

    I never really got on with mine as I just didn't think it was ever sharp enough wide open.

    The AA filter on the D700 is pretty strong for assessing focus....:(
     
    Andrew Garrard likes this.
  11. +1 for Focus Fine Tune
     
  12. The down side is how long focus takes (on pre-Z devices). On my wish list is "take the shot after contrast-detect AF, then do a live view fine-tune", which should be good enough for many of the cases when I'm shooting relatively static people in the dark.

    Tru dat. I never really had AF accuracy issues despite shooting wide open on my D700. I doubt it was actually much better than my D8x0 bodies - but I see a lot more optical aberrations and focus misses. It's taken a lot of glass upgrades to get me to the point where I'll consider shooting at f/1.4 on my D850!
     

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