I never had this problem with my Rebel XT and T3i but for the first time experienced this 'phenomena' with my new D5100. I just found out what it's called! Darn! Bought the camera used in mint condition. At least it's in warranty luckily. Many sell this model used when they purchase it for video and it doesn't have the manual settings they would like..
When we were looking over the pictures of a wedding we attended, my wife took many pics with the AF-S 35mm 1.8g at f1.8 (dark hall). We noticed that when reviewing pics, all the focus was behind the subjects.
I then made some time now to play around with the camera and sure enough, you focus on the eye ball, the ear ends up being in focus every time.
We tried every focus mode, different distances, etc, etc. Basically at f3.2 (optimal sharpness f range for this lens), the ear will be in focus when you focus on the eye. It does this maybe 80% of the time.
I had the shutter at 1/250 and flash. It definitely wasn't shake or a settings issue. It just reliably focuses on the ear, rather than the eye which from what I'm reading is 'classic back focusing'.
Maybe you guys should try it yourselves if you have the AF-S 35mm f1.8g. Might be fun.
#4. "RE: D5100 back focusing! " In response to Reply # 3
I did take some pics and took some focus measurements using a chart and sure enough it's back focusing. It also does this 100% of the time during further inspection on my computer. This explains the 'nikon softness' people talk about.
I went to Best Buy and got ANOTHER lens at another location with a serial number that was in a lot different than mine and sure enough it does the exact same thing which means it's a Nikon AF issue potentially.
Again, grab your 35mm lens, focus on an eyeball, and then see if the eyeball, or ear lobe is in focus.
#8. "RE: D5100 back focusing! " In response to Reply # 7
>You can see my post here for documented proof this is an issue: >http://forums.dpreview.com/forums/readflat.asp?forum=1034&thread=39917592 Are you sure this is "documented proof"? Sure you have some issues with AF sometimes not being where you want it, but that is not necessarily front or back focus in the sense you mean. You are likely to be using an outer AF point - which is not as efficient with some targets as the central cross type sensor. I do not own a D5100 but the information in this Nikon link is in your camera instruction book https://nikoneurope-en.custhelp.com/app/answers/detail/a_id/4585 The link explains fine texture targets and low contrast light (the eyebrows and lighting of your face shots are similar) can make AF unreliable and manual focus can sometimes be more accurate. The link also mentions details at different distances in the AF area (as in your 45 degree target) can also cause poor focus. This target is known to sometimes wrongly indicate back focus starting from infinity, and front focus starting from minimum focus. All camera, including Canon, use AF systems which are not infallible and sometimes focus at an unexpected distance. Sorry - whether your camera is faulty or good cannot be determined from your "documented proof" - your "proof" is based only on subjects where AF may not be accurate.
Photography is a bit like archery. A technically better camera, lens or arrow may not hit the target as often as it could if the photographer or archer does not practice enough.
#10. "RE: D5100 back focusing! " In response to Reply # 7
It's interesting that - amongst all the "noise" common at sites like DPR - your post attracted some responses that questioned whether you actually want to solve the problem or just rant about it.
You'll find that ranting doesn't go down too well at Nikonians. If you DO want to solve this problem, please post some examples here - with full shooting data. Without that we can't do anything to help you.
#11. "RE: D5100 back focusing! " In response to Reply # 10
I'm serious about fixing the problem:
I'm not trying to act as an employee for Nikon. I'm not on their pay roll and not here to defend them. I'm here to be honest and impartial.
I'm trying to get the thing to take pictures properly like any other camera. The last thing left to do is try another camera which I might do tommorow and report back results.
I also am going to adjust back focus manually using a hex screw and see how it turns out as I'm essentially on my own as I can not rely on the online community who are not interested in camera's taking pictures, but rather defending a brand name.
#12. "RE: D5100 back focusing! " In response to Reply # 11 Fri 25-Nov-11 08:59 AM by briantilley
>The last thing left to do is try another camera which I might do >tomorrow and report back results.
If you do that, please report back with images and shooting data, not just your conclusions. Then we might be able to help.
>I also am going to adjust back focus manually using a hex screw >and see how it turns out.
I would not recommend that approach, even if it is possible outside a service centre. Until you know where the problem actually lies, it could easily make things worse - especially if you don't know what you are doing. That's not a personal criticism - I don't know what I'm doing when it comes to tinkering with a camera's critical innards, and I've been using SLR's for 40 years...
>I can not rely on the online community who are not interested >in cameras taking pictures...
I think Brian's post below shows that, at least at Nikonians, we ARE interested in taking good pictures
...but rather defending a brand name.
I don't think anyone here is blind to possible faults - we recognise that you might have a problem of some kind: with your camera, lens, technique or testing setup. But... we justifiably feel the need to put the record straight when someone takes an individual problem and turns it into generalised and unsupported statements about "Nikon softness".
#13. "RE: D5100 back focusing! " In response to Reply # 11
Mount Laurel, US
>I'm serious about fixing the problem: > > > >I'm not trying to act as an employee for Nikon. I'm not on >their pay roll and not here to defend them. I'm here to be >honest and impartial. > >I'm trying to get the thing to take pictures properly like any >other camera. The last thing left to do is try another camera >which I might do tommorow and report back results. > >I also am going to adjust back focus manually using a hex >screw and see how it turns out as I'm essentially on my own as >I can not rely on the online community who are not interested >in camera's taking pictures, but rather defending a brand >name.
I do not buy only Nikon photography products and I am in no way endorsing one product or the other. What I see is a fundamental problem with your understanding of the technology and how to trouble shoot it correctly. It may well be a hardware problem.... your conclusion is yet baseless because of your techniques or lack there of for solving it.
I also see you have convinced yourself you already understand the problem and do not want to muddy up your conclusion with false explanations from what you consider Fanboys of the Brand that would argue user error instead.
I understand your frustration but you are jumping to conclusions and have yet to give these guys what they asked for to try and help you sort out the issue with proven techniques and decades of experience using the technology.
In the end you need to do what it is that you think will make you happy. If the solution in your mind is to head over to the dealer and pick yourself out a trusted Canon body then I think you are well on your way to solving this back focus problem once and for all.
#14. "RE: D5100 back focusing! " In response to Reply # 5
For the record, the cat's nose is what is in focus - but even in the worst case, that's not a demonstration of back focus. If anything, it would be front focus, as there is absolutely nothing between cat and camera - so it couldn't possibly have focused on something in front, then erroneously "back" focused onto the nose.
I didn't check for the AF point indicator, but having done this more than once myself, IF this is an error, it's almost certainly a user error, not a fault in the camera or lens.
_____ Brian... a bicoastal Nikonian and Team Member
My gallery is online. Comments and critique welcomed any time!
#15. "RE: D5100 back focusing! " In response to Reply # 11
I am a relative newbie here, much like yourself. I read through this thread as well as the one at DPreview and I was take back by your sensitivity, and the willingness to accuse.
Troubleshooting problems is a pain in the butt, regardless of brand. I too like others would lean toward suggesting you stick with Canon products, as clearly you either have a problem with the Nikon brand, or you are predisposed to Canon - and there is nothing wrong with that for sure.
In the future though, you might want to avoid the over-reaction and name calling as it takes away from the topic - I saw no evidence of anyone wanting to make this personal except for you.