Sigma 24-70mm

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NJG

NJG

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Nick
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Hello

Im after some help. I have the Sigma 24-70mm F2.8 lens. Im having issues with not very sharpe focus. Alot of my pictures taken with this lens seem to be having the effect. What im wanting to know is if there is anything I can do to check this or is there a like a sigma service centre where it can go and be calibrated as such?
 
Can we see some unedited examples?

Is the lens new? I had a similar issue with an 18-50 f2.8 Sigma last week.
 
Hi

What was your problem? I will try and upload one to here
 
Im trying to sort

I can not get it to upload picture. Ive gone through the faq's and done what it says but still no luck.
 


click it to go to flickr and see the fullsize one. you can't tell from this...
 
4503504456


http://www.flickr.com/photos/nickgodfrey/4503504456/
 
Ok thats fair enough. Im still relativly new to all this, Trying to improve each time that I take a shot. This is such a good Forum for learning. Although I think i may well take a course in photography to try and get some good hands on learning.
 
No worries fella, i think you're always learning with photography and if you claim not to be - you're probably not as good as you think you are!

As a rule of thumb - 1 over the focal length should really be your upper limit for shutter speed to stop camera shake happening.

so - you have a focal length of 60mm, the slowest you should have the shutter speed is 1/60 of a second. 40mm - 1/40 of a second.

you were shooting @ 60mm with a shutter speed of 1/30 of a second - and whilst not impossible, it is likely to introduce camera shake.

you might well have a sharpness issue though - those sigmas have been known to have a dodgy one every now and then, but to eliminate the possibility of camera shake, take a shot at around F/8 (where it should be sharpest) - and at a focal length/shutter speed combo that will eliminate the possibility of camera shake - and then have a look. if it's still soft, then you have your answer.

hope that helps.
 
Ok thank you.

WOuld I do best taking picture on a tripod, and an object with a very good sharp shape aswell?
 
NJG said:
Ok thank you.

WOuld I do best taking picture on a tripod, and an object with a very good sharp shape aswell?
Click to expand...

i'd take a range of photos at different focal lengths on a tripod (and out of the wind) and see where you're at then - if it's only a tiny bit soft you can sharpen it in post proccessing but to be fair you'll know if it's noticeably soft and then you'll have every right to try and get it fixed.

take a few pics and put them on here and we'll have a gander.
 
Ok, Thank you

I also need to work out how to load up on to here also as that would be much easier. I guess Ive got lots to look at.
 
Also when downsizing the images (which appears to be the case even with the flickr image) they will become softer. Do you have an image straight from the camera?

My Sigma 24-70 is probably the softest lens (discounting the long end of the 75-300 IS) I own. It's not bad, but not exceptionally good either and can be a bit hit and miss focus wise so that may be the problem you're having too. :)
 
If you don't get on with it then just flog it. I had one and it went back a day later. Tamron 28-75 or Tokina 28-70 are much better lenses for similar price. Regardless of lens, you should try to improve the technique as well.
 
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