[AH11]

Today I just received this lens that I purchased used from Adorama. I began testing it right away and I am seeing chromatic aberration that seems unreasonable (purple at the front and green at the back) . However, at 200mm f2.8, this may be common. Here is a picture of the Tamron cap that I took (unedited and not cropped) in a cloudy day inside my room by the window at 200mm f2.8. Can someone please tell me if this much CA is usual for this class of lens.

[Philoslothical]

Seriously? Maybe my eyes are tired, otherwise yours are working overtime.

[AH11]

Thanks for the reply. Here is the cropped picture showing only "Tamron" letters. The CA seems high for me but again may be normal for this lens. I used a pentax K-x at ISO of 800 (maybe 1600) to take this photo.

[Philoslothical]

I can't see your second pic, but I do see what you're getting at from the first. Idiot me was looking at the edges of the cap more than the letters, and thinking "this is better than most". I definitely see a tint to the lettering now.

Sorry, it's 5am, tired eyes. Whether its worse than it should be for that lens, I don't know. You should get faster replies once the sun is up in NA.

[AH11]

I don't understand why the cropped picture is not showing in the message. I uploaded it into my album.

[Philoslothical]

I think you used a URL tag instead of an IMG tag? Or, maybe it partially stripped out a malformed tag when you submitted it.

[AH11]

OK. I am doing something wrong it seems. I am using a URL tag but that is how it does it! Anyways it is not working so here is the link:
Never mind. I got it. Here it is, cropped:

[Lowell Goudge]

I can't tell if this is normal or not with the lens, but it is definitely longitudinal CA .

I have the sigma APO 70-200 F2.8 EX (non DG non macro) which does not exhibit this level of CA, but considering being at the limit of close focus, it could be reasonable to expect some issues, remember this is not a true macro lens

[creampuff]

This is NORMAL.

[AH11]

Well. I have been noticing that there is a small piece of broken glass inside the lens situated below the top lens. There is cover around the top lens. I just opened it and I am seeing lots of small pieces of broken glass. It seems that one of the lenses was broken and it was replaced. I am wondering if it was placed and positioned correctly or maybe it is another replica of the lens that doesn't have the same coating?! I think I am returning this used lens (it was described as excellent condition!). Here are two photos of the broken glass pieces which I don't believe would be there during manufacturing of the lens.

[Philoslothical]

Yep, swap it out. That isn't normal at all. The CA might be, but glass chunks in the lens? No way.

[JohnBee]

I say send it back!
I wouldn't be satisfied with that.
Outside in the sunlight with chrome perhaps, but I wouldn't expect this on a lens cap writing.

[AH11]

thanks for the responses. I am sending it back.

[rawr]

The perils of buying used.
At least you bought from a reputable retailer.

[JinDesu]

Mine's new, and it will do what you see.



Where there is huge contrast and you are wide open at 200mm, and you are overexposed (because the lens cap is black), it will do that.

edit - The image in the real world I used was actually in the wrong focal length.

However, using this lens, I haven't been too hindered by the performance wide open at F2.8. In general, I have been pretty pleased with images shot at those settings. The occasional times when my focus was just a little bit off, the image would have terrible softness and bloom that you can see in the OOF areas of this picture.