Backfocus tests

3125 posts
19 years
Sydney Australia

Posted 18/02/2008 - 01:37 Link

I was suspecting some backfocus with my K10 and decided to run a few tests.
It appears ok in this respect but maybe its front focusing a little.
Am i reading it correctly. Thanks

90mm tamron macro

Shutter @ 1/125
Aperture f2.5
iso 200

I also performed a few tests on my DA* 16-50 @50mm

Shutter @ 1/60
Aperture f2.8
iso 100

I also took this shot with the 90mm macro. I set the battery up 50mm in front of the box with the print on it. and shot it from 1metre away.

browngo1 browngo1

70 posts
19 years
Irvine,
Ayrshire

Posted 18/02/2008 - 13:42 Link

Is there somewhere I can download a focus test chart?

I think I've seen it somewhere on the forum in the past, but I can't find it!

Gordon
---------
K10D

Daniel Bridge Daniel Bridge

3458 posts
20 years
Billericay,
Essex

Posted 18/02/2008 - 13:50 Link

There's a clue in the photos above...

Dan

K-3, a macro lens and a DA*300mm...

terje-l terje-l

1384 posts
18 years
Horten,
Norway

Posted 18/02/2008 - 17:30 Link

I would say it is slightly front-focussing. On your 90 mm, the rear figure 6 is out of focus while the frong figure 6 is still sharp. However, judging from the battery shot, it does not seem to give you any major problem.

Best regards
Terry

K20D, Optio I10, DA 18-55 1:3.5-5.6 AL II, A 1:1.7/50, D FA 1:2.8/100 Macro, Sigma 70-300 1:4-5.6 APO DG Macro, Pentax AF 360FGZ

Clarky Clarky

3125 posts
19 years
Sydney Australia

Posted 18/02/2008 - 20:29 Link

Quote:
Is there somewhere I can download a focus test chart?

I think I've seen it somewhere on the forum in the past, but I can't find it!

Here is the test chart Gordon, you can thank ChrisA for it.

Sorry Gordon forgot to add the link

http://focustestchart.com/chart.html