First post here on Nikonians, and first of all I'd like to thank you for providing such a helpful resource.
I'm now the proud owner of my first DSLR; a Nikon D5100. So far I am blown away by the quality of photos that this camera is capable of, far above and beyond anything I've owned before.
I just got back from a bit of a test photo shoot at the park, with my girlfriend, and it was really the first time that I've been out in full daylight taking pictures (I'm a bit of a night-owl).
After getting home and reviewing some of the pictures, a whole series of them seemed to be out of focus -it almost appeared as though the tree behind my girlfriend was in focus and not her.
(Let me just interject that after 5 minutes in the park, and realizing that I couldn't review my pictures at all in the sunlight, I was really longing for the LCDVF 'loupe' that I had been looking up earlier in the day!)
So, in any event, I will be the first to admit that it could have been user error: I was sweating something awful (Vegas =P) and being attacked by bugs, so I wasn't exactly fully committed to the shoot. I had it in the '3d tracking' AF area mode and was locking focus on her face using the center focus point and then letting the focus points track her face (with shutter release half pressed) as I framed the picture with her face out of the center. Not sure if that was a part of the problem or not? It appeared as though the focus points were correctly following her face.
I've included 4 photos:
Two are from under under the tree where almost every single picture produced the same 'backfocus' effect, appearing as though the tree behind my girlfriend was more in focus than she was. The file named out-of-focus-tree-2.jpg appears to be quite a bit sharper than out-of-focus-tree-1.jpg, but both appear to be out of focus to me.
The other two are from 5 minutes later but are both taken one after the other, at almost the same exact settings. One appears to have my girlfriend in sharp focus, making her pop from the background; in the other she seems to be out of focus, flat and doesn't pop from the background at all.
Can I rule out camera shake and subject motion blur at 1000/s and above shutter speeds? What about 125/s? (The tree shots were at 125/s and the bench shots were 1000/s+)
Note: I didn't realize that I wasn't going to be allowed to attach pictures, then imageshack and tinypic said the photos were too large (with no file over 10mb, I thought that was strange) so I ended up having to use my own host.
Any thoughts and opinions would be greatly appreciated. Apologies for the wall of text! =P
TLDR: Do 3 out of 4 of the attached photos appear to have 'backfocus' problems to you?
#1. "RE: Is this the D5100 'backfocus' problem?" In response to Reply # 0
Welcome to Nikonians!
The good news is that there is no general "D5100 backfocus problem", so the chances are you will be able to get great results once you understand how best to set up the camera for different types of subject.
The 3D tracking AF option is intended for moving subjects, and is liable to give unpredictable focus with static (or almost static) scenes.
#3. "RE: Is this the D5100 'backfocus' problem?" In response to Reply # 1 Thu 01-Aug-13 07:28 PM by zumaneil
Thank you very much for the quick responses.
I was just talking it over with my girlfriend, trying to decide what was the most likely culprit, and one of my thoughts was that perhaps the 3D tracking played a role. In retrospect, it was kind of foolish to be using '3D tracking' for any kind of shooting of a completely stationary subject! =P
I look forward to getting back out there and giving it another go with it more appropriately set to 'Single-point AF'.
ericbowles Atlanta, US Nikonian since 25th Nov 2005
Thu 01-Aug-13 07:37 PM
#4. "RE: Is this the D5100 'backfocus' problem?" In response to Reply # 3 Thu 01-Aug-13 07:40 PM by ericbowles
3D tracking could be a bit of a problem, but most likely it does not make any difference. 3D tracking is for situations when a subject is moving toward the camera - for example, your girlfriend walking, running, or biking toward you. It tracks the subject as it moves toward you.
Single point AF is quite precise - it does not guess what the intended subject is and where you should focus. That being said, the dynamic focus modes are also good if you have a moving subject that is hard to track. Use the smallest number of focus points that allows you to keep the indicator on the subject. If you are struggling to keep the indicator on the subject, 9 point Dynamic is a good option. If you struggle to get the subject in the frame - you can use all the AF points. In all cases, only the focus point you intend to use is highlighted.
ericbowles Atlanta, US Nikonian since 25th Nov 2005
Thu 01-Aug-13 07:10 PM
#2. "RE: Is this the D5100 'backfocus' problem?" In response to Reply # 0
I agree - backfocus to any significant degree is much more of an urban myth than reality. Certainly there is no systemic issue related to the D5100 or releated cameras.
The issue is typically user error based on one of the following: 1) photographer motion 2) slow shutter speed 3) subject movement 4) wrong aperture (too shallow) 5) AF sensor missing target 6) AF sensor on target but focus not achieved 7) Aperture or focal length that normally is soft (any of the extremes)
pjonesCET Martinsville, US Nikonian since 11th Jul 2011
Sat 03-Aug-13 01:30 AM
#5. "RE: Is this the D5100 'backfocus' problem?" In response to Reply # 0
The last two items are actually focusing on the Girl and not the the trees. Your depth of field is set so the main focus is on the girl and the trees are being blurred slightly If you want trees as focused as the person you have to change the DOF.
#6. "RE: Is this the D5100 'backfocus' problem?" In response to Reply # 5
There's no reason to post such huge images, a free editor like Faststone can handle RAW images, or any other format, and can easily allow you to resize to a much more manageable size to upload......I think Nikonians limit is 150K per image....