Lens question

Hi everyone. Have not been on the lens forum in awhile. I was wondering if some of you might be able to help me out. Earlier this year, I bought a Canon EFS 55-250 mm Image stablization and a Tamron AF 17-50mm 1:2.8. Last night I was working on trying to get my studio light right and was using both lens. Now the Canon lens when I took the picture, I could zoom in on the face after I took the picture and it was clear as a bell, example on the eyes.

When I took a picture with the tamron and then looked at it zoomed in the face was blurry. From just looking at the regular picture it looked fine. Only when I magnifided it did it look blurry in the face.

Can someone help me understand if this is suppose to happen with that lens or is this not normal. Any help would be appreciated.

Teeny

I use a Canon 40D

Post some samples.

Yup, without samples little can be said.

ok, give me a few minutes.

Teeny

try and refocus, maybe the second one was not focused right. or the camera moved when you pushed the button

Ok here you go.
These two are with the tamron 17-50

Teeny

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These are with the canon

Teeny

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Are you shooting them both at F4? Have you test the tamron for front or back focusing?

Are you using them on a tripod? This could just be a case of the IS from the canon kicking in. Shutter speed of 6-8 is kind of slow.

I'd normally think the tamron would be the sharper of the two.

The tamron was shot at 2.8 and the canon< i am not sure, maybe 4.5.

How do you test for front and back focusing?

Teeny

Put the camera with the tamron and take a test shot of something at 2.8. Take a stop down and take the same shot, do it a couple times and pixel peep. You should see a difference in sharpness. You should get to know your lenses and how they'll perform in certain situations.

Compare some of hte same shots with the canon and tamron at the same aperture.

You can google "focus testing" and read some more about it. I just use the chart found here:
http://focustestchart.​com/

Thanks Kelvrick, I will check it out.

Teeny

All the shots were at f/4.

Are these self portraits? If so, how did you focus?

Hi, all these were shot at 4.0 except one of them. It was one of the tamron pics shot at 2.8.

No this is not a self portrait. This is my husband after just getting off work, hence dirty work shirt He was trying to help me out learning my lighting.

By the way, I shot in Manuel mode.

Teeny

teeny wrote in post #6713447
...all these were shot at 4.0 except one of them. It was one of the tamron pics shot at 2.8.

The EXIF shows all 4 of the pictures being shot at f/4.