[ChrisRabior]

Ok, I picked up a 28-75mm f/2.8 Tamron lens. I love it. It's capable of some shots that I never could have taken with my other assortment of lenses. Just one issue with it.

What I'm noticing with it is that it performs differently based on the body I put it on. It seems I get fewer 'WOW' shots with it on my XT than I do with it on my dad's 20D. It's the same trend for the overall percentage of keeper shots. I find myself deleting more that were taken with the XT than I do with the 20D.

Logically, I figured it was the body. Well, there are no problems with any of my other lenses when swapping between the two bodies. I get the same performance with the other lenses. So, have any of you ever found that certain lenses perform better when used with particular bodies? If not, is it possible that because this particular lens had previously been used exclusively with a 20D that it's formed some sort of memory to that type of camera?

[Markulous]

Can't think of any reason unless it's the cameras' settings. Maybe the 20D is set up closer to where the lens performs better?

[stepheno]

Are these with jpgs?

[ChrisRabior]

Markulous: That was the weird thing. Exact same settings, varied to cover a good range of functions. Shot sets on each at ISO 100 thru 1600, various shutter speeds, various apertures, and with a mix of priority modes. Still had the general trend of the 20D outperforming the XT with each set.

Stepheno: Yeah, they're all with JPEG, highest image quality settings. I haven't done too many RAW shots with the lens yet. I'm really not a fan of RAW unless I need to be absolutely sure that the image is a good one. I try to limiit post processing to an absolute minimum.

[JMitchell]

I think I know, possibly. I have heard, around, that according to the detail resolving ability, and megapixel count, arguably the same thing in some cases, a lens that may produce great images on a (eg) Nikon D50, would look terrible on a D2X. This may be the problem, although it appears to be the other way round here, wierd :S

[ChrisRabior]

Thanks for the input JMitchell. I've heard of that too, but it had to do with the different sensors between those models. The 20D and XT actually use the same DIGIC image processor, so I don't think that's the case with this one.

[VikingPhotography]

Well both the 20D and XT have roughly the same pixel density - so although JMitchel is correct in his assesment (re. pixel density a la D50 vs. D2X etc.) it's not a factor here.

If you're using autofocus then that might come into play... there's more AF sensors on the 20D and they are supposedly more accurate than the ones on the XT.

Other than that I'd be at a loss to say what the issues may be: perhaps it would help if you posted some example images??

[ChrisRabior]

I deleted all of the stuff that wasn't a keeper. Next time out I'll try to save a few and put them up.

[Liam O'Neill]

Can you be a bit more specific about what actual differences you were getting? Was it focus, contrast, colours? There are loads of reasons why a shot wouldn't be a "keeper".

On a side issue....you deleted them! One of the joys of photography is when you go back to some old shots you rejected months/years earlier and find that hidden gem you just can't believe you didn't spot at the time. Memory is cheap, keep everything.

[ChrisRabior]

The shots look out of focus, almost like a motion blur. At first I thought it was backfocusing, but the whole shot is off. Others come out as crisp as my 50mm f/1.8 lens. I haven't really had a big chance to get out and shoot lately, so the pictures will have to wait a bit.

I'm going to the Pistons game on Tuesday. First row of seats behind the folding chairs. I'll be taking the camera, so hopefully I can get some good shots and not have any examples of the issue =)