Should I recalibrate my Tamron 17-50 2.8?

Yeah I noticed they were off centre so I took that last one which also exhibited the soft upper right also (to me anyway )

Looks like I've deleted my test shots at multiple f stops but it is a fair bit softer at f/2.8
this is f2.8 and f6.3 respectively, not exactly real world but it's late and it's what I had on my desk

HTTP response: 403 | MIME changed to 'text/html' | Byte size: ZERO | PHOTOBUCKET ERROR IMAGE

HTTP response: 403 | MIME changed to 'text/html' | Byte size: ZERO | PHOTOBUCKET ERROR IMAGE

I'm happy to report, my Tamron 17-50 is now focusing correctly.

gcogger wrote in post #6821375
The Sigma's problems are mostly that front focus issue at short distances. The early copies I tried did it at all focal lengths wide open (although it was more obvious at the long end), but many people have said more recently that it only does it at 150mm.

Let us know how it is when you get the camera back

Mine only front focuses at 150mm if asked to focus on something within 2.2 metres. If you move back, or zoom out to 135mm the problem goes away.

Regarding its low light focusing, well how can I put it nicely on a 400d/XTi its horrible, on a 40d its fantastic. Buy low light I mean ISO3200 - f/2.8 and needing 1/40 to get a proper exposure. In that light on a 400d/XTi the FTM gets used. On the 40d it seems to work fine with AF.

Hmm - those look pretty blown out/overexposed. When you get some time, try shooting some normal shots at f/2.8 and post one up. If you're blowing out the scene at f/2.8, I can see how it would get soft from too much light (like hitting someone with a full power flash and ISO1600 )

kingdean wrote in post #6824755
Yeah I noticed they were off centre so I took that last one which also exhibited the soft upper right also (to me anyway )

Looks like I've deleted my test shots at multiple f stops but it is a fair bit softer at f/2.8
this is f2.8 and f6.3 respectively, not exactly real world but it's late and it's what I had on my desk

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HTTP response: 403 | MIME changed to 'text/html' | Byte size: ZERO

Maybe that is what they are typically like in terms of apature vs sharpness but I certainly notice it when I'm taking shots and tend to avoid shooting below f/4 with it

0(ʹͦˋ¿ˊͦˋ)0 wrote in post #6818567
The problem seems to be on my other two lenses too, it is not a constant problem, sometimes I'm getting sharp pictures.
I checked older pictures (using DPP to see the focus point) and some of them were showing the same problem, not that bad like with the Tammy but I guess it was there.

I'm sending the body. They ask me if after using the Sigma 50-150 2.8 the problem became worse, and looking trough my pictures it seems like after using the sigma everything got worse. They told that some third party lenses like sigma can cause these problems sooner or later.

I guess I have to start buying canon lenses only

Huh??? How??

yogestee wrote in post #6835283
Huh??? How??

Don't know Jurgen, He never said anything. He just asked me which were the lenses I used with the body. And then he asked me if I noticed that the problem got worse after I started using the Sigma, next he said; -some third party lenses like Sigma 50-150 can cause these problems sooner or later-

My Sigma 50mm can't be used on my 40D or 20D, front focuses by about 2 inches wide open, which is the only reason I bought the lens. From what I've read, this is a fairly common issues with certain lens sizes from Sigma. The 50D works flawlessly and focuses spot on after some micro af adjusting.

GCGuy wrote in post #6835643
My Sigma 50mm can't be used on my 40D or 20D, front focuses by about 2 inches wide open, which is the only reason I bought the lens. From what I've read, this is a fairly common issues with certain lens sizes from Sigma. The 50D works flawlessly and focuses spot on after some micro af adjusting.

So return it or send it in for calibration, same as you would with any canon lens that front focused.

0(ʹͦˋ¿ˊͦˋ)0 wrote in post #6811774
I took more controlled tests. Here the pics:

wide open @ 50mm:


100% crop



wide open @ 17mm:



100% crop:



@ 17mm:


100% crop:

They look good bud.