JudeIscariot
Senior Member
I have a Sigma 28-105mm lens which suddenly no longer appears to be in focus no matter what I do. I stick it on my D300, and I can never get it into focus. I stick it on my D3000 and manually focus, and the green light lights up, telling me it's focused, and it isn't.
I couldn't find the photo I wanted to use for comparison when I was writing this, so I did a quick test at the stuff closest to my computer:

The first was taken with the Sigma lens at 35mm f/3.2 and the second with a Nikor 35mm at f/3.2.
When I first picked up the Sigma lens (I got it when I bought an F70 for $40 at Goodwill) it was a really great, sharp lens. I didn't often use it on my D3000 because I didn't like manually focusing it (it has a short range L-R when focusing, so it's hard to really nail it), but I had noticed last year that some of my film shots from vacation where a bit blurry... It wasn't until I bought a D300 a few months ago and stuck the Sigma on the front to use as an AF lens when I noticed how far off it seems to be.
I'm not really sure where to go from here. Is it hosed? Is it even worth getting fixed (is it even fixable)?
(I realize now in the scaled-down version, there is a little bit of added distortion - but I think anybody can still see how fuzzy the first one is to begin with.)
I couldn't find the photo I wanted to use for comparison when I was writing this, so I did a quick test at the stuff closest to my computer:


The first was taken with the Sigma lens at 35mm f/3.2 and the second with a Nikor 35mm at f/3.2.
When I first picked up the Sigma lens (I got it when I bought an F70 for $40 at Goodwill) it was a really great, sharp lens. I didn't often use it on my D3000 because I didn't like manually focusing it (it has a short range L-R when focusing, so it's hard to really nail it), but I had noticed last year that some of my film shots from vacation where a bit blurry... It wasn't until I bought a D300 a few months ago and stuck the Sigma on the front to use as an AF lens when I noticed how far off it seems to be.
I'm not really sure where to go from here. Is it hosed? Is it even worth getting fixed (is it even fixable)?
(I realize now in the scaled-down version, there is a little bit of added distortion - but I think anybody can still see how fuzzy the first one is to begin with.)