How to check Sigma lenses?

Carlo

Carlo

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Carl
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Still relatively new to digital photography, and since (re)taking up the hobby i've bought a couple of Sigma lenses.
I made these choices (to buy sigma over other makes) due to price, performance, and reliability. and the fact they come with lens hoods and soft cases...you listening Canon????
However, i have read a lot about quality control issues, especially with the models i have (F1.4 30mm, and f4-5.6 10-20mm).
Is there an idiots guide how to check my lenses? some of the terms i'm still not familiar with e.g 'back focusing', soft one sided, or soft edges (does this mean out of focus in relation to the rest of frame?)
Hopefully some article/guide that can explain exactly what to look for.
I have even read some people send their lenses straight back to Sigma to have them calibrated 'just in case' they may have focusing issues!
I doubt i could go down that road as my camera funds are now in the red!

ps. my 30mm f1.4 does tend to struggle for focus on close ups when in low light in AF mode, which makes me sceptical as i'm sure this lens should be able to cope easily with this type of shot! (it's basically what i bought it for!!)
 
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Take a photo of a wall straight on and all the image should be in focus.
Then switch to live view and take another focus and this will use edge detection to set the focus and the image should be the same as the first image. If its noticeably sharper then the autofocus may be a little off in the lens. Just make sure the wall has plenty of contrast so the auto focus can work properly.
 
neil_g said:
unless youre seeing issues with your lenses i wouldnt waste your time personally
Click to expand...

+1

The Sigma 30mm f/1.4 is a cracking lens. Struggling to focus with a lens this fast in low light is not a lens problem.
 
I wouldn't bother doing too much checking TBH.
Just go and use the lenses and take lots of piccies with them.
If you are happy with the results, then all is well.
I wasted a load of time doing all sorts of pixel peeping "not real life shots" type of testing, and if I'm honest, it was a complete waste of time.
I got to the stage where I was taking shots with a pro Nikon lens, known to be a good lens, but I was convinced it wasn't sharp. It was. I became almost paranoid about it.
Take any camera, any lens, blow it up big enough and it will start to look soft.
Use it in the real world and it will be fine.
Enjoy your gear, and don't become a pixel peeper.
 
The problem with testing lenses if you don't know exactly what you're doing, or what you're looking for, or whether what you find is good or not, you will find something to worry about.

This question comes up a lot on here, often accompanied by pictures that are either user error or showing non-existant issues. Nine times out of ten, there's nothing wrong at all.
 
If it ain't broke don't fix it, and stop pixel peeping you'll go blind. Seriously 99% of lenses are fine and 99% of poor IQ is user error.
 
I got a new Sigma 150-500 delivered today and spent a while outside this afternoon trying it out. Took the shots below hand held and they have been well cropped and im happy enough with it if i can improve my technique a bit and bet used to the lens. This is as much testing and pixel peeping as i am going to do! Just enjoy whatever lens you have!

7107529427_8f0d8b0262.jpg
[/url] DSC_7433 by philip blair2011, on Flickr[/IMG]

7107528731_d9ba245134.jpg
[/url] DSC_7293 by philip blair2011, on Flickr[/IMG]
 
If you continually have issues getting focus spot on in normal light conditions, then consider checking. Otherwise, just go take some photos!
 
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