I know that the left AF issue on the D800 has been discussed ad nauseam here, but I have a question I haven't seen (and I read a bunch of the threads on this issue). I picked up a D800 from a local shop today, and when I tried following Thom Hogan's test setup to test for the AF issue, I find that the left AF shots are inconsistent. On some of them, they look just as sharp as the phase-detect center pictures, but on others they look out of focus. I tried going over my setup multiple times to make sure it wasn't user-error: I'm about 6 feet from the wall with the targets, and the camera is in parallel with the wall on a tripod. I used a 10 second delay, and a 3 second shutter-delay to make sure there were no vibration issues.
Is this the symptom of the standard left AF issue, or if I can get ANY sharp pictures out of my left AF point does it mean that this is user error?
If it's any consolation, I get the left AF issue but only with the 85mm f1.4G and like you, it is inconsistent. I'd say about half the time the left AF is ok, the other half not ok. All my other lenses are fine for left AF and these include:
14-24 f2.8, 16-35 f4 VR, 24-70 f2.7, 70-200 f2.8 VRII, 35mm f2.4G, 105 f2.8 Micro, 300 f2.8 VRII 500 f4 VR.
At this point in time, I can live with it as it is not really a concern for me.
Thanks, Lance. I only have one FF lens right now, the Tamron 28-75/2.8, so I can't test other lenses. Based on what you said, does that mean this is just another form of the left AF issue?
I've seen inconsistent D800 AF results when tuning was required, where the center point was fine but the peripheral points were affected. I'd tune the lens so that both the center/right AF points are consistent, then repeat your left AF point test.
recdaco wrote:
Thanks, Lance. I only have one FF lens right now, the Tamron 28-75/2.8, so I can't test other lenses. Based on what you said, does that mean this is just another form of the left AF issue?
It seems to only manifest itself on the fast lenses, like the 1.4's as far as I can tell, not one of my "slower" lenses has suffered from the left AF issue. Also, I never get the AF issue on the 85mm f1.4G when I shoot at f2.8 or narrower, like f2.8, f4, f5.6 etc. It is definitely not DOF masking the back focus, but that the AF is sometimes missing the correct AF spot. This is why i can live with it as I can manual focus under f2.8 if I really need to.
I tried exchanging the d800 and the second camera looks almost identical to the first. Now I'm trying to figure out if the focus variability is just within the margin of error and I'm being overly sensitive, or if it's the same issue again. Here's a quick example of two consecutive shots from the left-most AF point. The paper is the test pattern that overlaps the left AF point (yes, the laser printer I used needs more toner). Those shots look close, but clearly not the same. The masking tape with handwriting is below the center target. There you can clearly see a much greater variance.
Am I going nuts, or is this the dreaded left AF issue on a second camera in a row? I can post center and live view photos too if anybody would like.
Months ago when this first appeared, the left AF issue was never described as a sometimes thing. People were experiencing an issue with every shot. And the issue was glaring.
I know that the left AF issue on the D800 has been discussed ad nauseam here, but I have a question I haven't seen (and I read a bunch of the threads on this issue). I picked up a D800 from a local shop today, and when I tried following Thom Hogan's test setup to test for the AF issue, I find that the left AF shots are inconsistent. On some of them, they look just as sharp as the phase-detect center pictures, but on others they look out of focus. I tried going over my setup multiple times to make sure it wasn't user-error: I'm about 6 feet from the wall with the targets, and the camera is in parallel with the wall on a tripod. I used a 10 second delay, and a 3 second shutter-delay to make sure there were no vibration issues.
Is this the symptom of the standard left AF issue, or if I can get ANY sharp pictures out of my left AF point does it mean that this is user error?
James -- I have a hard time buying something as high-end as a D800 and immediately sending it to Nikon in the hopes that they can fix it. Either the camera is good, and I'll keep it, or it goes back to the store.
Guari -- I used a 2s mirror up-delay, but I didn't have a remote. So I used the self-timer set to 10s. I figured 10s should dampen out any shake from me starting the shutter.
recdaco wrote:
James -- I have a hard time buying something as high-end as a D800 and immediately sending it to Nikon in the hopes that they can fix it. Either the camera is good, and I'll keep it, or it goes back to the store.
Guari -- I used a 2s mirror up-delay, but I didn't have a remote. So I used the self-timer set to 10s. I figured 10s should dampen out any shake from me starting the shutter.
I agree with you, I didn't know about the issue until I could no longer return to the store. I'm usually a focus and recompose shooter. I'm actually glad that I didn't know about this early, because Nikon struggled with this, finally got their engineers busy and came up with a fix. I love the camera!
Lance B wrote:
It seems to only manifest itself on the fast lenses, like the 1.4's as far as I can tell, not one of my "slower" lenses has suffered from the left AF issue. Also, I never get the AF issue on the 85mm f1.4G when I shoot at f2.8 or narrower, like f2.8, f4, f5.6 etc. It is definitely not DOF masking the back focus, but that the AF is sometimes missing the correct AF spot. This is why i can live with it as I can manual focus under f2.8 if I really need to.
I agree my 1.8 50mm shows it before I sent to Nikon.
Bruce Sawle wrote:
Compare it to the right. If they are the same then your camera is fine. The outer AF points will never be as consistent as the center.
I agree! and ussually the left AF issue is a total blur at 100%
I think this may be an inherent issue with the high resolution. In my opinion, it seems like the AF system is not "up to date" with the high megapixel count so it at 100%, the left and right accuracy is very noticeable. The below are what I get with my camera, it appears that the left and right outer points are pretty symmetrical (with the left just slightly less accurate). I don't have a lens align tool so I've fine tuned the focus with a printed chart taken at 45 degrees. I had to tune my 24-70mm by -5 (which seems to be consistent at all zoom ranges) and my 14-24mm by -10 (at 14mm, I needed about -6 and at 24mm I needed -12).
Another issue is from what I gather You are using a 28-75 tamron 2.8?
THe sony side cameout with theie own labeled version Sony 28-75. At 24mp The sony 28-75 (same Tamron lens)was not as accurate for focus as the Zeiss 24-70mm. It was always close but had a varience. You had to make a micro change of 5-7 before the lens would move.
So not saying it is your lens but is is part of the equation, and on the Sony it was not as accurate a focuser as primes or pro lenses. At 36mp every micro adjust is critical
