85/1.8G and 851.4/G accuracy

<p>I used to shoot Nikon in film era, that was F90. At present I am not so versed with newer Nikon equipment. Here is my question - how accurate is those lenses wide open with D610 camera when you shoot headshots, half-lenght portrait, etc. <br />Here is another question - what resolution does the good 85/1.8G give when you shoot full-lengh wide open.<br />It is what everybody knows and it is proved by the practice - Canon (EOS 5D mk2) with its 85/1.8 <em>is not</em> accurate wide open and the number of misses is huge.<br />What would you say in this regard?</p>

<p>mm QUestion about accuracy ( i guess this is about AF..) .<br>

Question is : How accurate is the AF of the camera used...<br>

Recently read in a wel known & respected german magazine a comparison obout AF accuracy between three different camera's : Canon 70D ( i think) using DUal Pixel / pixel comparison AF , Nikon d7000, and an Olympus EM-5 ( i think it was),<br>

The Canon Dual Pixel method scored a 93%<br>

The Olympus scored a 73% accuracy<br>

The Nikon scored around 49% accuracy<br>

All measured with a quality F/2.8 lens and in different circumstances using proffesional measuring equipment...<br>

Now Accuracy is not the only aspect of a camera, otherwise everybody would move to a Canon 7oD i guess..<br>

Apart from that, using a 85mm F/1,8 lens wide open for portraiting is asking for trouble since no model sits perfectly stil, DOF is paperthin, and at portrait distance the AF sensor used covers more than the size of a human eye.....</p>

 

<p>I've had good luck autofocusing the 85/1.4G AF-S on the eye even with the subject wearing glasses (assuming a head and shoulders shot). With the previous D version of that lens it would hunt and grab the rim of the glasses most of the time, being unsure of the contrast in the eye itself. However, most of the time I shoot head and shoulders at around f/3.5 to f/4, not at f/1.4. In the wintertime I sometimes combine f/1.4 in these shots with monitor light to give office shots some realistic mood and at least some ambient light. However, I use cameras with Multi-CAM 3500 AF module, the D610 has a different system that may have a different performance in this application.</p>

<p>To use the dual pixel AF in the 70D, I believe you need to shoot using live view, not the viewfinder, which at least to me would be awkward when shooting portraits (how exactly do you keep the camera steady that way, using a telephoto lens?). I don't think for portraits you really need that kind of system to get good results. And if your subject is moving in low light then the dedicated AF modules of DSLRs track the movement better than AF systems relying on the main imaging sensor for AF information, or at least that is my experience with those mirrorless cameras I've used.</p>

<p>Plus the AF in the 5D Mk. 2 is a quite different unit than what the 70D has. And the D610 should be improved (at least somewhat) over the D7000, though how that affects it accuracy, I dare not tell.<br>

For the resolution of the 85 f/1.8G: here are <a href="http://www.photozone.de/nikon_ff/717-nikkorafs8518ff?start=1">test results on 24MP</a> full frame. It's pretty stunning good. </p>

<p>Ilkka, I expect your stopping down to 3.5 for head and shoulder shots is for the same reason as mine. It is where a 3/4 head pose consistently gives me both eyes in focus. I will shoot at 1.4 but only when 1 eye out of focus is acceptable or eyes are on the same plane. </p>

When barbers give a guy a bad haircut, do they blame the scissors? All three of the lenses you discussed are fine lenses,

it always helps to a) know how to use your camera and lens and b) it's never a bad idea to use a camera's AF micro

adjust to tune a camera's AF system to the lens you are using.

<p><em>"The Olympus scored a 73% accuracy</em><br /><em>The Nikon scored around 49% accuracy"</em><br>

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I have owned and used the OMD EM5 and D7000 and both exhibited extremely consistent and accurate AF. I also owned and used the EOS 5D and EOS 5D mk2 and both were extremely accurate in their auto focus as well. Operator error/poor technique is typically at fault for AF issues.<br>

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I have owned entry level Nikon DSLR bodies and Pro level - and they have all focuses with near perfect accuracy. Again, operator error/poor technique is typically at fault for AF issues.</p>

<p>My last sentence should read "and they have all focused with perfect accuracy nearly all of the time".<br>

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In fact, in almost every shot that I may have had that was out of focus, the error was more often than not mine.</p>

<p>AF accuracy with the 600/610 will depend on the light to some degree. the d750 is reportedly far better in dim light.</p>

<p><br />Eric, you make a good point, and adding to that IMHO the AF point selected really becomes important in more difficult lighting conditions - I always only use the cross-type AF points which I think it critical for accurate AF with any Nikon body and becomes even more important with the D600/D610 bodies, especially in low light because of its AF module (not that it is bad but it is not Nikon's best for extreme shooting conditions).</p>

<p>I have used the 85mm f1.8 for dozens of shots. I never have had any focusing problems. I use a single focus point, half depress the shutter, and recompose. Old fashioned but old habits are hard to break - and it works. :) The Nikon D610 has many focus modes and some can absolutely lead to missed focus.</p>

<p>bingo, steve bingham. i do the same and get spectacular results from the $500 wonder that is the 85/1.8 for portrait work. never use a tripod, never use live view. hell, i've shot sports with the 85/1.8. it's that fast. it's that accurate.</p>

<p>D7000, AF-C, 15-point. this kid is coming right for me. second shot is him running past as i'm panning and banging off a quick burst of three frames. look at that sharpness, from a $1K consumer camera and a $500 consumer lens!</p>

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<p> also owned and used the EOS 5D and EOS 5D mk2 and both were extremely accurate in their auto focus as well. </p>

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<p>Elliott, I have spoken to several pros working in fashion and weddings and have read scores of articles and lots of reviews, tried it myself, with Canon 85/1.8 shooting <strong><em>wide open</em></strong> the EOS-5 D Mk2 is <strong><em>not</em> </strong>accurate - in portraits you will be lucky to get 40-60 % perfectly focused (on the eye) not nose, eyebrow, etc. </p>

<p>In this regard I do hope the Nikon to be better.</p>

<p>How on earth does a contrast-detect AF system (the Olympus) score less than 100%, at least on a static subject? And on that note, there's always live view.</p>

<p>Ruslan, using a lens like the 85mm wide open poses many challenges and requires exceptionally good technique and knowledge of the camera's AF performance to get it 'right'. Keep in mind that the AF points in the viewfinder and not necessarily EXACTLY where the AF point is located.</p>

<p>Without proper care, I can understand why many would think the lens/camera combo is not working properly. Many using far less critical combinations have similar issues and often blame the equipment. </p>

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<p>Elliott, I have spoken to several pros working in fashion and weddings</p>

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<p>Not really my experience I have to say. Depends on which AF spot you are using in low light, if that is what they mean.</p>