Help with scratches on Sigma 10-20mm!

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SuperCNJ

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Just after some advice on the above. I bought a used Sigma 10-20 (Nikon Fit) recently and when it arrived I noticed some (quite a few actually) small scratches on the outer glass element. However, having looked at the photos it doesn't seem to effect the photos so I'm not sure if I should bother kicking up a fuss about it or returning it as I did get it for a good price.

Also, I would like some opinions from those with the Sigma 10-20 (Nikon Fit) as to whether you think it is as sharp as it should be. I've never had a sigma 10-20 before and it just doesn't seem quite as sharp as I hoped. :'(

Here are some test shots I took today, they've been reduced to 1024 x 768 but I have kept the EXIF data.

Thanks in advance! :thumbs:

20mm
[URL=http://imageshack.us][IMG]http://img225.imageshack.us/img225/5976/dsc1202reducedxe0.jpg[/IMG][/URL]

20mm (Cropped to 1024 x 768)
[URL=http://imageshack.us][IMG]http://img61.imageshack.us/img61/6393/dsc1202cropzn4.jpg[/IMG][/URL]

10mm
[URL=http://imageshack.us][IMG]http://img91.imageshack.us/img91/5517/dsc1203reducedkf4.jpg[/IMG][/URL]

10mm (Cropped to 1024 x 768)
[URL=http://imageshack.us][IMG]http://img224.imageshack.us/img224/3429/dsc1203cropob7.jpg[/IMG][/URL]

 
Can only answer the question about marks on front element...IQ won't be affected providing there are no marks on the rear element, in which case it will. However, marks on the front element may create flare..

I have the same lens but Canon fit and IMHO that's as sharp as you're gonna get.

Not Sigma's sharpest lens, not by a long shot!
 
I've never found photos of brick walls to be inspiring, or an indication of real-life performance;)

Go take some photos of landscapes etc with the lens, then I'll offer you an opinion! Small marks on the outer element shouldn't affect the IQ at all. As for sharpness, it depends on what format you shoot in, and what sharpening you do in PP on the image. I love my 10-20mm!
 
Thats about right I'd say, for corner crops.
 
markta said:
Can only answer the question about marks on front element...IQ won't be affected providing there are no marks on the rear element, in which case it will. However, marks on the front element may create flare..

I have the same lens but Canon fit and IMHO that's as sharp as you're gonna get.

Not Sigma's sharpest lens, not by a long shot!
Click to expand...

Thanks, I couldn't see any scratches on the rear element, only the front element. If this is as sharp as it gets with the sigma 10-20 then I'll probably just keep it.
 
reddeathdrinker said:
I've never found photos of brick walls to be inspiring, or an indication of real-life performance;)

Go take some photos of landscapes etc with the lens, then I'll offer you an opinion! Small marks on the outer element shouldn't affect the IQ at all. As for sharpness, it depends on what format you shoot in, and what sharpening you do in PP on the image. I love my 10-20mm!
Click to expand...

Agreed, not very inspiring lol but they were solely to test the sharpness etc of the lens. I wanted something with texture and lines so I can see the distortion at the 10mm end.

I'll take a few more later but at the moment, it just doesn't seem very sharp. :thumbsdown:
 
I'll admit I am one of those flippin' pixel peepers... I have never found a wide angle shot to be terribly sharp at 100% crop.

But then again, that sort of shot it doesn't bother me too much.
 
To support my argument... have a look here:

http://www.bobatkins.com/photography/reviews/tokina_12-24_f4_review_3.html

Bob Atkins is well known to Canon users, his site is a goldmine of info. Ignoring the Canon aspect, have a look at that article just for background. He is talking about the Tokina 12-24 vs the Canon EFS 10-22, but ignore that - just look at how he's not saying "blurgh both of these are really, really soft at 100% crop".

If that was something like a Nikon or Canon 70-200 he would be saying that....
 
Cheers guys. So would I be correct in saying that theres no problem with the sharpness from my 10-20 lens? I.e. I would get pretty much the same result from any other sigma 10-20?
 
I use my siggy 10-20 as a landscape lens and is therefore very rarely wide open (or anywhere near to wide open).

I get great results from my siggy at the f8 and above apertures I use. Mine is a canon fit and on my 40D the images are sharp in RAW straight out of the camera. But as I said I mainly use mine for landscapes, mainly at f8 and above (i.e. smaller hole) and as often as not it is on a tripod.

I would not worry about the scratches on the front element, concentrate on technique and I guarantee that your sharpness will improve.

Neil ...
 
Hi Super
I just got that lens a couple of weeks ago and used it when I was down at the south coast last week. I used it with my D300. Don't have any brick shots for you to compare with
( and I aint' goin' out to shoot my brickwork - although my bricks do look remarkably like yours) but some of the shots I took with it on hol are in the landscape section of the POTY comp - If yo've a mind take a look

http://poty2008.dcmag.co.uk/userGallery.aspx?UserId=3124bce6-766a-4d00-8feb-1619a86ce1d2
 
The 14-24 is better than any other wide angle lens made - ever.

Its astonishingly good. Its stupidly sharp wide open, right into the corners even on full frame.

On a DX, its just jaw dropping.

Big b****r. And pricey. And it doesn't take creative filters.

But optically its in a different league to anything else. shame about the filter thing.
 
To stop the scratches causing flare, you can run a very fine permanent marker along the scratch, and when it's dry, polish off the surface.

You'd be surprised at just how big a fault on the front element can be. Try this.... thae a piece of blue tack (other sticky putty products are available0, about the size of a pea, and stick it lightly on the lens surface. Now take a picture. You won't be able to see it!!!
 
I've stopped your oversize pictures from showing. i'd normally make them into links but that is difficult with your clickable images. people can copy and paste the addresses into their browsers if they want to see them.

If you change the links to 800 pixel versions then feel free to edit them back.
 
dougdarter said:
You'd be surprised at just how big a fault on the front element can be. Try this.... thae a piece of blue tack (other sticky putty products are available0, about the size of a pea, and stick it lightly on the lens surface. Now take a picture. You won't be able to see it!!!
Click to expand...

Yes indeed... a while back when taking lunar eclipse shots I thought it would be funny to make my own while waiting for the moon to start going... i tried a 2p piece in front of the lens... couldn't see it at all!!

(Yes, I realised the science afterwards when thinking about it, but just to illustrate the point....)

Also, my mates 70-200 has scratches on the front element like you wouldn't imagine... makes no odds to the shots....
 
Agreed, it always makes me laugh when folks want to "protect" a lens with UV filters, so thereby permantly degrading their optics to prevent a scratch that *might* happen.

Even if it did get a scratch, that scracth would have much less impact that the UV filters they use for protection to prevent them... :lol:
 
puddleduck said:
Agreed, it always makes me laugh when folks want to "protect" a lens with UV filters, so thereby permanently degrading their optics to prevent a scratch that *might* happen.

Even if it did get a scratch, that scratch would have much less impact that the UV filters they use for protection to prevent them... :lol:
Click to expand...

It depends on what you do puddleduck, I shoot alot of photojournalism work which involves pretty heavy treatment of gear. I can't afford to be worrying about chucking my £1000 lenses about and scratching the front element, and i would say a scratch on a lens of that quality would be much worse than the very slight degredation in optics in the pictures.

Now obviously if your a studio photographer your never gonna really need UV filters (unless you are really clumsy!) and i take mine off if im shooting portrait work.
 
russbates said:
It depends on what you do puddleduck, I shoot alot of photojournalism work which involves pretty heavy treatment of gear. I can't afford to be worrying about chucking my £1000 lenses about and scratching the front element, and i would say a scratch on a lens of that quality would be much worse than the very slight degredation in optics in the pictures.

Now obviously if your a studio photographer your never gonna really need UV filters (unless you are really clumsy!) and i take mine off if im shooting portrait work.
Click to expand...

Sounds sensible to me. I am one of those who put UV filters on my lenses as I am always out and about with my camera. Also, scratches on the front element whether or not it affects the photos is going to affect resale value one way or another.

Anyway, going back to my original questions, I am now clear that the scratches are not going to affect my shots. However, I just want to be 100% sure that the sharpness is what would be expected from this lens. I will print out the sharpness test chart and post some results up later.
 
Yes, but have a look at what I showed you at Bobatkins.com.... I wouldnt expect a 100% crop from one of these to be pin sharp...
 
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