Does this prove anything?

I just did a test that I see posted here all the time. I believe this test reveals if a lens is having any back or front focus problems and if that is the case then I guess I have tested my new EF 50mm f/1.8 II and it seems to be doing what it should and the focus is dead on.
Does this test actually prove that? or anything else for that matter?

All 4 pics were shot at f/1.8, 1/80s. The camera was 2 feet in front of the first battery and each successive battery is 1 foot further away and 2 " to the right of the previous.

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what are you trying to prove? I dont get it. where is FP on each shot?

Your batteries are spaced too far apart.

I thought I recalled seeing this as a means of testing a lens using AF to see if it was front or backfocusing. I should have indicated that in each shot the battery in focus is the battery that was the focus point and each time I had the camera AF it did it with accuracy and did not pull anything in front of in back of the focus point into focus.

cdi-ink.com wrote in post #2184064
Your batteries are spaced too far apart.

How close should they be?

The battery test is valid if the batteries are spaced far apart enough across as to avoid the "large" AF sensor catching on another battery, but close enough depth-wise to know whether it's front or back focusing.

cdi-ink.com wrote in post #2184078
The battery test is valid if the batteries are spaced far apart enough across as to avoid the "large" AF sensor catching on another battery, but close enough depth-wise to know whether it's front or back focusing.

So if the batteries were 1 inch or 2 inches apart would that work?

TMR Design wrote in post #2184091
So if the batteries were 1 inch or 2 inches apart would that work?

Depends how accurate you want to test. That would test for 1-2 inches of back/front focus.

cdi-ink.com wrote in post #2184094
Depends how accurate you want to test. That would test for 1-2 inches of back/front focus.

Oh ok, I get it now.

To answer the title question.
It proves that you don't use Duracell batteries.


Looks like your lens/camera combination works right to me.

If you want a quick test without dl the test sheet shoot at 45 degrees on a newspaper pick a certain sentance and check your results. With your test it could be off, just not 2 inches off and you wouldnt know.

newfly5 wrote in post #2184143
If you want a quick test without dl the test sheet shoot at 45 degrees on a newspaper pick a certain sentance and check your results. With your test it could be off, just not 2 inches off and you wouldnt know.

Interesting. I'll give that a try for kicks. I don't actually suspect there is anything wrong with my lens. I am just geeky enough that this sort of thing is fun.