Using AF Charts from Yvon Bourque K10 D

I have tried all of my lenses with the AF charts and it shows some interesting results.

Kit lens 18-50 best AF point at + 150
DA 50-200 best AF point at + 150
DA* 300 best AF point at + 100
Tamron 28-300 XR Di best AF point at + 500

All of the testing was done following Yvon`s instructions and repeated several times. On a tripod, spot focus, max aperture, 2 second delay to avoid shake.

All of the Pentax lenses are there or therabouts the same setting on the K10 D. I doubt if I could detect much visible difference if I inputted a figure of + 100 microns and left it at that. But as for the Tamron that is just way off the mark. This is rather anoying because my daughter has the same lens and I always thought it is her vision that gives her out of focus shots on her K200 D. I am wondering if the Tamron lens itself is in need of "focus alignment" and if so how would it be carried out?

Makes me think that perhaps it`s best to stick with Pentax lenses for Pentax camera bodies and leave the spurious makes well alone. It would be interesting to hear from others that have tried the AF point checks.

Cedric

you should be able to send the lens and camera of to tamron and they can adjust the lens to the body, but it will cost you,but on the k20 this will not be a problem,

Thanks Scott, have not been brave enough to test the K20 D with the charts yet. I have just sent an email to intro 2020 the importers for Tamron. Be interesting to see what they come up with.

Cedric

no probs keep us up to date, the k20 is great for having the adjustment for 25 lenses,

Took the initiative and checked the AF on the K20 D, the Pentax DA 15-50 and the DA 50-200 were so close to perfect I could not really improve the AF point. As for the DA* 300, perfect. Sad to say that as with the K10 the Tamron 18-300 performed dismally with not enough adjustment on the K20 to accomodate the necessary adjustment. I did crank up the adjustment on the K10 to suit the Tamron and the result was fair.

Cedric

Emailed the importers Intro 2020 and had a reply today. If I return the lens they will check the AF system and adjust best possible. My instant thought was that from manufacture it should have been set to best possible. Unless of course it is already set to best possible in which case it`s not very good. Anyone had experience of Intro 2020 or anyone else for correcting AF in lenses?

Cedric