chris321
I like the ginger one
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- Chris
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So I've thought my 24-70 was a little soft wide open, but recently I needed to use it wide open at 24mm (usually reserved for landscapes, so a smaller aperture and AF less of an issue) and noticed something was going slightly awry with the focussing. So I thought I'd take a shot out of my window and see how it was looking. I used just the centre focus point, and didn't recompose. So the sharpest bit should be right bang in the middle of the shot. The two red squares are where the following 100% crops are from. I'm not a pixel peeper, but it's fairly obvious something's not quite right 
. I fact by my estimation it's back focussing by a truly impressive 15/20m!
Not a thrilling test subject I know. Now look at the centre, this bit that should be in focus:
compared to the side (which isn't great, but it's hard to work out exactly where the focus is, distance window reports 1.5m away when focussing on something on the horizon)
Am I right in saying there's a pretty big problem there?
The odd thing is there's no problem at all at 70mm. It's slightly out, but about 5 on the microadjust sorts it out fine.
So obviously it's going back to sigma, they did a great job tweaking my 70-200 as it was a tiny bit out and I wanted it perfect before selling it, but I wasn't sure how much it would be.
To check the focus and tweak that, it's a flat rate of £35, regardless of lens, but if there's something more serious then it starts to go up pretty quickly. I can afford the £35 to sort out the focus, but if it'll be an £85 job (which it will be if any parts need replacing etc) then it'll have to wait till I've got the cash. So could any technically-minded people have a thing about whether it could be a 'tweak-able' AF issue, or a more serious repair? I know only Sigma can really say for sure, but if I send it to them, and turn down the quote, it'll still cost £20 anyway which I'd rather save and put towards the actual repair!
Sorry this has been such a long one, any help is very much appreciated!
Chris
. I fact by my estimation it's back focussing by a truly impressive 15/20m!
Not a thrilling test subject I know. Now look at the centre, this bit that should be in focus:
compared to the side (which isn't great, but it's hard to work out exactly where the focus is, distance window reports 1.5m away when focussing on something on the horizon)
Am I right in saying there's a pretty big problem there?
The odd thing is there's no problem at all at 70mm. It's slightly out, but about 5 on the microadjust sorts it out fine.
So obviously it's going back to sigma, they did a great job tweaking my 70-200 as it was a tiny bit out and I wanted it perfect before selling it, but I wasn't sure how much it would be.
To check the focus and tweak that, it's a flat rate of £35, regardless of lens, but if there's something more serious then it starts to go up pretty quickly. I can afford the £35 to sort out the focus, but if it'll be an £85 job (which it will be if any parts need replacing etc) then it'll have to wait till I've got the cash. So could any technically-minded people have a thing about whether it could be a 'tweak-able' AF issue, or a more serious repair? I know only Sigma can really say for sure, but if I send it to them, and turn down the quote, it'll still cost £20 anyway which I'd rather save and put towards the actual repair!
Sorry this has been such a long one, any help is very much appreciated!
Chris
Last edited:
), so it's the £80 flat fee for fixing both the zoom and the focus mechanism (apparently it's not in a good way!), then calibrated etc. Still, cheaper than buying the Canon version I guess 
. New zoom mechanism, new af mechanism, and all seems good! I'll do some proper tests after the weekend, but it's another big thumbs up for the Sigma Servicing department! 
