Backfocus tests


Clarky

Link Posted 18/02/2008 - 01:37
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.


Camera:|K-7|
Pentax Lenses:|DA12-24/f4 ED AL|DA35Ltd Macro|FA31Ltd|FA77Ltd|FA50/1.4|F70-210|FA20-35 f4/AL|A*200/f4 Macro ED|A50/1.7|A50 Macro f2.8|1.7xAF adapter|
Voigtlander|125/f2.5SL Macro APO Lanthar|
Sigma Lenses:|EX DG 100-300 f4|2X & 1.4X TC|
Flashes:|AF540FGZx2|RingFlash AF160FC|

browngo1

Link Posted 18/02/2008 - 13:42
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

Link Posted 18/02/2008 - 13:50
There's a clue in the photos above...

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

terje-l

Link Posted 18/02/2008 - 17:30
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

Link Posted 18/02/2008 - 20:29
browngo1 wrote:
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
Camera:|K-7|
Pentax Lenses:|DA12-24/f4 ED AL|DA35Ltd Macro|FA31Ltd|FA77Ltd|FA50/1.4|F70-210|FA20-35 f4/AL|A*200/f4 Macro ED|A50/1.7|A50 Macro f2.8|1.7xAF adapter|
Voigtlander|125/f2.5SL Macro APO Lanthar|
Sigma Lenses:|EX DG 100-300 f4|2X & 1.4X TC|
Flashes:|AF540FGZx2|RingFlash AF160FC|

browngo1

Link Posted 19/02/2008 - 08:40
Doh!

Thanks guys.
Gordon
---------
K10D
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