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View Full Version : first time to a lab?


ceriltheblade
21st of February 2010 (Sun), 06:38
Hi there.
I have been playing with my new 7d and lens a lot and really am loving it. I tend to do things one at a time to focus on the learning...and hence I got to microadjustment of the focus.

I have tried a couple different methods that I read here and other places on the net. What I find is that my tamron 28-75 at 75mm f2.8 is all over the place. I got such warm recommendations for this lens that I am not sure if the problem is with me (and or my expectations) or with my technique or with the lens.

I used most extensively the number ladder at 45 degrees which showed that at 0 adjustment I can have both focus nailed down, backfocusing and slightly front focusing within 10 pictures taken. Each was done at ISO 100, and in good ambient daylight (pic times were under 1/60th of a second),mounted on a sturdy enough tripod and I did this with the 2 second timer because I have yet to buy a trigger. I almost want an adjustment of +0.5.....except for the variation between pictures

I don't live in the US or in Europe and so I unfortunately don't know how many of the various threads speaking about their experience is relevant to me.

Is this a good reason to have the lens examined in a lab (i.e. is my expectation to have it fixed appropriate)?
If so, would you examine it with or without the camera body?

Thanks for any and all input...and if any of you know a good lab in Tel Aviv, I would be happy to hear about it!!!

HappySnapper90
21st of February 2010 (Sun), 21:23
I have tried a couple different methods that I read here and other places on the net. What I find is that my tamron 28-75 at 75mm f2.8 is all over the place. I got such warm recommendations for this lens that I am not sure if the problem is with me (and or my expectations) or with my technique or with the lens.


I have the Tamron 28-75 f2.8 as well. I consider is a great good light lens, but poor indoor/low light lens.

You should have noticed it doesn't have fast silent focusing motor like Sigma's HSM or Canon's USM. If you are trying to use micro AF adjustments, you might try doing it outdoors in good light or in a very well lit indoor room.

I use the 28-75 sparingly indoors if I need to. But most times I'll use my Canon 50 f1.4 and 100 f2 because they let in much more light than the Tamron and have better focusing.