Sigma for Minolta 28-300

[javyanez]

Hi, everyone,

I have a Sigma for Minolta lens 28-300, model EX, that I used with my Minolta Dynax 7000i. I tried to use it recently with a Sony Alpha 200 and the lens fitted and functioned perfectly in Manual Focus; however, the lens would not function in Auto Focus mode. When I looked the lens closer I noticed that it has 5 pins inside and the Sony Alpha 200 body had 8…

Do you know if there is a form of fixing this problem (like and adaptor or something like that)? Were not Sigma-for-Minolta supposed to be compatible with Sony Alpha cameras? Thanks a lot for any advice!!!

[Javelin]

Sigma lenses generally are fine on Sony cameras. some of the very early ones though can't autofocus. Sigma reverse engineered the electronics for it and some early ones only work on the early film cameras because of a mistake. Sigma used to fix these for free but I understand they haven't got any parts left to do it. but all is not lost, David posted a how to with pictures on what to do to fix these lenses. read this article and you might decide to make it work yourself,

http://www.photoclubalpha.com/2009/03/0 ... ck-rechip/" onclick="window.open(this.href);return false;

[stevecim]

The rechip will not fix the auto-focus. it fixes lenses which get the "no lens fitted" error or don't work at all.

Cheers, stephen

[Javelin]

You might be right. at the end of the article DK says "Do not expect fast focus" which implies it will focus. but it doesn't specifically say anywhere I can find. I can see it not working if the lens had a focus motor built in as the old contact block is pushed inside basicaly bypassing the lens connections but these are screw drive lenses connected to the camera motor and should still focus like on the 7000.

David can you clarify ?

The rechip will not fix the auto-focus. it fixes lenses which get the "no lens fitted" error or don't work at all.

Cheers, stephen

[David Kilpatrick]

Yes, fitting the chip to the 400mm enables AF as well as focus confirm. No problem there. As stated, it is a bit sluggish but fully functional.

David

[stevecim]

Doh. forgot about the screw drive for auto focus, been looking at a lot of review for ssm and sam lenses

Sorry for the incorrect info