D700 focus challenges

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bluesfox
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p.1 #1 · D700 focus challenges

Seems that my photos are generally lacking a tack sharp quality to them since purchasing the D700 about 8 months ago. This could also be a perception issue, so I'm seeking your assistance and suggestions.

After recently attempting to use the lens align to calibrate the lenses, it became difficult acquire tack sharp focus, even when using a tripod and remote trigger. Here are a few images from the calibration attempt with a 50mm 1.4g prime and a 24-70mm @50mm:

d700 - 50mm 1.4g - @6ft dist. - 1/30s - f/2.8

This image is copyrighted by the owner

d700 - 50mm 1.4g prime - @3.5ft dist. - 1/40s - f/2.8 - ISO 200

This image is copyrighted by the owner

d700 - 50mm 1.4g prime - @6ft dist. - 1/30s - f/2.8 - ISO 200

This image is copyrighted by the owner

Here are a couple of handheld shots, one where the focus turned out decent, and another shot where I expected the focus to be much better @5.6.

d700 -left eye - 24-70mm @66mm - 1/320s - f/4 - iso200

This image is copyrighted by the owner

d700 - 4 'dots' to upper left of head - 24-70mm @70mm 1/250s f/5.6 - ISO 200

This image is copyrighted by the owner

All photos were shot in .NEF 14 bit lossless, and converted to jpg using CNX2. Also of note is that the liveview appears to give slightly better impression of sharp focus, but when zoomed in with liveview, the pixelation is pretty nasty. (Nothing nearly as sharp as the lens align videos.)

I've also recently attempted to use an 85mm 1.4af with the D700 with great anticipation, and finding that the images don't seem to be tack sharp at any aperature using my D700 (1.4 through f4+).

Maybe I'm expecting too much sharpness, but any help or thoughts would be appreciated. Not sure if the camera /lens should be sent in for service, or just accept the current results. And the skills for holding the camera could use major improvement (just an amateur looking to improve), but expected the tripod remote trigger shots to be in better focus.

(updated to show crop photos instead of full images)

Edited on Jun 19, 2009 at 03:50 PM · View previous versions

Jun 19, 2009 at 04:53 AM

James R
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p.1 #2 · D700 focus challenges

It doesn't seem to be back or front focusing, even though the gauge is pretty small in the pic. A crop would be easier to see, or, get closer to the target; unless 6' is the recommended target distance? The dog looks sharp to me. The peacock pic looks fine, though I can't figure out what was the focus point--very busy pic with too much DOF.

The LensAlign seems to be a little off center. Could that screw up the test?

I

Jun 19, 2009 at 05:32 AM

R. Francois
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p.1 #3 · D700 focus challenges

Those look fine to me. What screen are you watching them? do you have a sample which shows sharpness like you want it or what you expect?

Jun 19, 2009 at 06:41 AM

Ivo Heshusius
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p.1 #4 · D700 focus challenges

+1 on R. Francois

besides that: use the old rule that your speed should be equal to or faster than 1/focal length of your lens

Jun 19, 2009 at 07:25 AM

Mocca
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p.1 #5 · D700 focus challenges

I see no problems either - perhaps you've become accustomed to viewing images online, with more than fortunate sharpening ?

Or perhaps you've had Canon equipment before. Canon images are sharper out the gate

Jun 19, 2009 at 10:24 AM

rjk55425
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p.1 #6 · D700 focus challenges

Looks fine to me. Seems like a lot of mirror vibration with the d700 at slow speeds, try mirror lock up and timer.

Jun 19, 2009 at 10:53 AM

bluesfox
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p.1 #7 · D700 focus challenges

Thanks to everyone for your input!

The 6' is for the 25x distance that is recommended to perform the focus test. The difficulty was that there was not enough resolution or sharpness to clearly see when the ruler was tack sharp.

Francois, I'll post a couple of images later today that show sharpness that I thought was more representative of the D700. Good suggestion.

lol Mocca, yes I did transition from Canon

But I'm a happy Nikon user for the useability of the controls. Your comment about the images online with post processing may be on track. Might be used to seeing great images that have been juiced up with sharpening effects, giving the impression that the images straight from the camera are not as sharp.

I'll try with the mirror lockup later to see the potential of the body/lens combo.

Will update the initial images to show crops instead of the full shot.

Jun 19, 2009 at 03:49 PM

jmcfadden
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p.1 #8 · D700 focus challenges

really need to control the variables better so that conclusions can be drawn on them

weigh down the tripod , get that shutter speed up to at least 2x FL , use a cable release and mirror lock up. then you can start to make assumptions from the data

J

Jun 19, 2009 at 03:58 PM

Genes Home
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p.1 #9 · D700 focus challenges

I agree with above comments on shutter speed...........trying to determine sharpness on anything with very low shutter speeds (1/60 and below) is almost impossible....camera shake, shutter shake, mirror bounce, just three factors that get magnified when you are down slow.

If you have to shot slow for a focus test, you need to sandbag the camera/tripod combo and lock the mirror up and use a wireless release.

ALSO.................except for the ever-shrinking number of us ole fogies who came out of the film world (and thus remain truly amazed at how sharp the digital blowups are)..........many people are expecting FAR TOO MUCH sharpness out of their camera and lens rigs. With the D700 you have a native file size of about 13x19 or so.....once you enlarge past that reality you are looking beyond the actual performance of the camera and lens combination.....which is why we have photoshop to work with.

Jun 19, 2009 at 04:18 PM

tomb18
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p.1 #10 · D700 focus challenges

The 50mm 1.4 at f3.5 seems to have an awfull lot of CA to me. I would not be happy with that.

Jun 19, 2009 at 04:59 PM

Len Shepherd
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p.1 #11 · D700 focus challenges

This Nikon link advises you what types of AF targets to avoid as they can sometimes result in a camera taking pictures even though the subject is not in focus
http://nikoneurope-en.custhelp.com/app/answers/detail/a_id/4585
The detail in the dogs fur and the peacocks feathers are in category 6 of the Nikon link so a soft image is likely to demonstrate AF is not infallible and not to be evidence of front or back focus.
Good though the lens align is relative to some other test targets the central target area consists of geometric patterns - the Nikon link (category 3) points out geometric patterns can result in pictures being taken even though the subject is not in focus.
A second issue is whether depth of field on the 45 degree measure should be equal both sides, or more behind than in front, as the point of sharpest focus within the depth of field available varies with shooting conditions. This means front or back focus (or how much) cannot be accurately determined by looking solely at the scale.
Looking at your "evidence" I cannot see that it confirms any front or back focus.

Jun 19, 2009 at 05:11 PM

bluesfox
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p.1 #12 · D700 focus challenges

(sorry for the delay in following up)

I've been using a faster minimum shutter speed based on your suggestions (around 1/125th on auto ISO). The number of sharp images has increased since using the faster shutter, so it was probably not so optimal technique that was leading to the sharpness issues.

And the comment about getting used to seeing PP sharpness is true as well.

Thanks for the input and the great suggestion to go with the faster default shutter speed.

Nov 01, 2009 at 08:59 AM

cputeq
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p.1 #13 · D700 focus challenges

The dog looks good to me, unsure on the peacock.

If you havne't sharpened anything, that's your "problem" if you want to call it that - lots of pictures posted online have some sharpening done to them, and I know (at least with the D300) the strong AA filter on some of the newer Nikons requires are greatly helped with just a touch of sharpening.

Nov 01, 2009 at 10:40 AM


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