Has anyone used FoCal to determine the micro-adjustment value for their D800 / 105 Micro F2.8 combo? I've run the test at least 4 times (with VR off and view finder closed) and software is stumped. I looked at the data points plotted on the graphs, and I can't blame it for being stumped. The 3 data points for each microadjustment level are all over the board with no discernible pattern. Some of the data points made no sense, at one point for one level the camera generated a test shot which had the highest quality value and a second test shoot with the worst quality value, a graph that had at least 75+ data points plotted. Has anyone had success in calibrating their 105mm with their D800?

I am thinking that the problem lies in the lens and not the D800. Here are the results I got from 3 runs where I tested out each of D800's focus points. The first set of results with my 50mm D nearly gave me a heart attack. I was so much happier with the second run where I used more light to boost the EV. In software's manual I read that the results are also affected by the quality of the lens, and, thus, I switched to the 105mm. It seems to me that quality glass made a difference in the third test run.

So back to the calibration issue...If I am reading these charts correctly, my D800's does not have any major focusing issues...except for a problematic focus point(s) in the upper left side that appeared in all thee runs. I can easily live with that. If it isn't the camera, is it correct to assume there may be something off with the AF on the 105mm? Or is the lens a hard one to calibrate? I ran a AF consistency test and the lens came back as 93% consistent. I am not sure how to interrupt this number. Good? Bad?

BTW, the calibration made a HUGE difference with the 50mmD. I noticed the improvement in the viewfinder instantly. A big THANK YOU to everyone who introduced the software to me and the forum.


50mm f/1.8D with f/1.8,1/60s, & EV: 7.5 -- First Round


50mm f/1.8D with f/1.8, 1/100s, & EV: 8.3 -- Second Round


105 mm f/2.8 with f/3.0, 1/25s, & EV: 7.7

sbp
www.flickr.com/photos/sbpatel75

I tend to clumsily march to the beat of my own off-rhythm drum.

D800 + Way too much $$S spent on Nikon lenses =

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suspect you are right about the 105, my copy calibrates with no problem

Visit my Nikonians gallery.

You might try upping the ISO to increase your shutter speed a bit and see how that works. My 105mm neeeds an AF Fine Tune of -5 on my D800.

Chris

When words become unclear, I shall focus with photographs. When images become inadequate, I shall be content with silence.
- Ansel Adams

Visit my Nikonians gallery.

A HUGE factor in your FoCal results is the illumination of your target. If you're using a longer focal length, mirror slap or any camera movement will blur your images. You can increase your ISO or you can better illuminate your target to improve shutter speeds. I went into the expert setting on FoCal and increased test ISO to 400 and then bought a big halogen work light from Home Depot to illuminate my target ($30). Now I can get quicker shutter speeds and calibrate my 70-200mm zoom. Prior to those changes, shutter speeds were in the 1/20s range and blur was stumping FoCal.

-Alex Rosen
www.flickr.com/photos/klrbee25/

Visit my Nikonians gallery.

Alex & Chris,

I went with your suggestion and it was a success! FoCal was able to generate solid data and recommend a AFMA of -16. Thank you both for the advice. With my love of flowers, the 105mm is by far my favorite lens and I was bummed that I could not get calibration recommendations. This was the one lens I most wanted to be calibrated. The before and after AFMA test shots were quite remarkable!

sbp
www.flickr.com/photos/sbpatel75

I tend to clumsily march to the beat of my own off-rhythm drum.

D800 + Way too much $$S spent on Nikon lenses =