My D7000 focus testing

Started Oct 20, 2012 | Discussions thread
ken5678
Junior MemberPosts: 43
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Re: The only test that counts..
In reply to Ando72, Oct 28, 2012

Ando72 wrote:

ken5678 wrote:

i just did the "photographylife" calibration test as linked above. big thanks for the link.
overall, i'm very happy with the results.
a few really detailed questions if anyone is still paying attention:
i had a bit of difficulty really eyeing the very fine precision of the targets on the computer screen, one of my checks was just to fully zoom into the pixel level, and then take a look at straight lines. they all seemed straight to within +/- one pixel (seemed freakin' great to me). is this a valid method ?
i also did some manual focus shots, to check for how well the viewfinder adj. is set to my eye (figuring consistent out of focus would point this out) and just plain how well i could manually focus. ( i was happy with my ability, about 50% of the time, could match the best autofocus). once again, any reasons this wouldn't be valid ?
do the different focus modes of the camera matter much here ? (i'm still kinda new to the d7000, and still kinda learning all the auto settings, and not in a huge rush since mostly i do still lifes, and use everything in manual modes)
cheers

Hi

This is mainly a comparative test i.e. comparing how the shots taken with Liveview (most accurate) look against those taken with the phase detect (regular autofocus). "Straightness" of the lines is not so much an issue; more the sharpness or edge definition between the two focus methods.

If by different focus modes you mean selecting between AF-A, AF-S, AF-C and the various options for number of focus points, my understanding is that technically it shouldn't affect the underlying accuracy of the autofocus system. However the more you let the camera take control, the more chance that the AF system picks a focus point that you didn't intend.

Often this is interpreted as poor AF performance; and therefore why it pays to understand the different modes and how they function.

Shane

thanks shane,

yes,  by different focus modes i was referring to AF-A, AF-S, AF-C etc.,  and you have answered my question here - since it doesn't affect the underlying accuracy,  now i know the autofocus is working well,  and it will be up to me to use the proper settings and technique.

and i wasn't really looking at how straight the lines are,  but rather that if i have a straight vertical line to start with in the photo,  then if i zoom in all the way down to the pixel level,  then if i see the darkened pixels in a vertical straight line,  then i'm focused well ( a  very tall stack of boxes).   the converse being, that if i have the same straight vertical line to start with,  if it's out of focus,  then the darkened pixels will be wavy (stacking boxes after drinking too many beers).

ken

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