Help needed with 18-55 on D5100

Started Aug 26, 2013 | Discussions thread
Mako2011
Mako2011 MOD
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Re: " Focus Box"
In reply to msstella, Aug 26, 2013

msstella wrote:

Mako2011 wrote:

msstella wrote:

Mako2011 wrote:

msstella wrote:

thanks Mako. I appreciate your help. In all pictures I focused on the area by the maroon bush by the building and thought I had focus lock. I will try again.

According to ViewNX2 and other EXIF viewers, focus was never locked in any of the pics. Check the AF/M switch on both lens and camera body. Cycle them to AF. Makes sure the lens is mounted properly, clicks in place, and the lens release button is not stuck...redo testing again. Good luck.

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My opinions are my own and not those of DPR or its administration. They carry no 'special' value (except to me and Lacie of course)

Mako, where do you see that focus was never locked in the viewers. I don't see that information when I look at the EXIF. Where do I look?

Simplest way..use viewNX2 and click on the "focus Point" box at the top right area so it turns yellow. If focus was locked and the green light was lit in the viewfinder at the time of capture...you will see a red box on the image showing what AF sensor was active. If no red box...no green light or lock.

Thanks. Yes, I have the red box.

That makes since. The re-size is causing that part of the EXIF to be dropped and why I can't confirm. Your red box confirms focus.

I retested and did get the green dot indicating focus was locked. I did as you suggested above and retested again at f8. The center is okay but the rest of the image is a mess still, especially on the left. I am getting rather frustrated.

Do you now get a red box in viewNX2 with the new pic? Have you tried with another lens? Do you get a red box with that lens? Me thinks there may be a lens contact issue. Defocus the lens so it is completely blurry (by turning the focus ring)...when you try to auto focus..does it move?

When looking at the RAW files in viewNX2, they all have the red box showing for the middle sensor, the one I thought I was using. This includes the RAW files of the jpegs I uploaded here. After defocusing the lens and trying to autofocus it does move.

Here is the latest test. f8 ISO 200, VR off, shutter 100. Jpeg but the RAW file showed the red box indicating focus was locked. Still the same issue.

It may be that the lens is out of calibration then. Set up a target like a flat newspaper on a wall. Something easy to focus on and flat to the sensor. The problem with using scenes like the one above is that the viewfinder focus system may not focus on what you think it is. 3D scenes can be a problem when testing focus. You need a large flat target like a brick wall. Use aperture priority and shoot wide open (smallest f number). Change ISO so that your faster than 1/200s shutter speed. Take a few shots (in good light if you can) then take a few using LiveView. Liveview will give perfect focus and if the Viewfinder shots are a bit blurry in comparison, then it's a lens calibration issue. That assumes all your other lens are OK.

Don't get frustrated, it takes a little time to sort it out.

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My opinions are my own and not those of DPR or its administration. They carry no 'special' value (except to me and Lacie of course)

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