sigma 10-20mm field test (image heavy)
Posted 27/09/2010 - 17:49
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Have you got your 17 and 20mm uncropped shots mixed up :
Was the darker 12mm due to white balance:
In any case it does show the quality of the lens, 10mm does seem a tad soft, but quite acceptable. An interesting test. Now, if you send it to me I will comparwe it against my samsung 12-24 :
Davex.
Was the darker 12mm due to white balance:
In any case it does show the quality of the lens, 10mm does seem a tad soft, but quite acceptable. An interesting test. Now, if you send it to me I will comparwe it against my samsung 12-24 :
Davex.
Posted 27/09/2010 - 18:03
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No they are not mixed up . (I hope :roll. After doing this you see images and files and folders swimming about in front of your eyes.
I only got the lens recently so I'm just getting to know it. I'm sure the 12-24 is a bit better. I'll be up in Cheshire in October, we could swap.
There will be a bit more to squeeze out of the lens processing the RAW and tweaking sharpening etc.
I only got the lens recently so I'm just getting to know it. I'm sure the 12-24 is a bit better. I'll be up in Cheshire in October, we could swap.
There will be a bit more to squeeze out of the lens processing the RAW and tweaking sharpening etc.
Lurking is shirking.!
Posted 27/09/2010 - 19:07
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Quote:
No they are not mixed up . (I hope ).
You are correct, apologies, it`s my beer beffudled brain No they are not mixed up . (I hope ).
The 12-24 is a good lens, but cannot compare it to yours, have never used it. If you venture near chester give me a nod and well do a head to head.
Davex.
Posted 27/09/2010 - 20:14
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Hi Doug - good to see that you've got some decent weather to give it a whirl now!
May be worth a bit of exposure compensation.... I found that my K-7 tended to under-expose a little with the Sigma 10-20 (it's worn more than one of them in its time). And it consistently over-exposed with the Tamron 10-24 (of which I've tried two, but not mine)! I have no idea why, but it chooses exposure values that are about 1 EV apart when comparing the two lenses at the same time with the same scene!
Have you tested at other apertures as f5.6 doesn't show the lens at its best?
From memory the lens shines at around f8-f11. Don't venture beyond f16. The biggest difference when you stop down is around the borders, which really do sharpen up quite a lot when you go beyond f5.6. There's quite a difference between 10mm shots taken at f5.6 and those taken at f11. You also reduce vignetting a little, although it's never all that bad.
Will be interesting to see how things go - give it a whirl in portrait format too, as UWA does really interesting things to skies with fluffy white clouds in!
May be worth a bit of exposure compensation.... I found that my K-7 tended to under-expose a little with the Sigma 10-20 (it's worn more than one of them in its time). And it consistently over-exposed with the Tamron 10-24 (of which I've tried two, but not mine)! I have no idea why, but it chooses exposure values that are about 1 EV apart when comparing the two lenses at the same time with the same scene!
Have you tested at other apertures as f5.6 doesn't show the lens at its best?
From memory the lens shines at around f8-f11. Don't venture beyond f16. The biggest difference when you stop down is around the borders, which really do sharpen up quite a lot when you go beyond f5.6. There's quite a difference between 10mm shots taken at f5.6 and those taken at f11. You also reduce vignetting a little, although it's never all that bad.
Will be interesting to see how things go - give it a whirl in portrait format too, as UWA does really interesting things to skies with fluffy white clouds in!
Posted 27/09/2010 - 20:28
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Jon,
Thanks for the advice. I'll get out and try it out a bit more. I was going to bracket but time was pressing. Somebody had queried what I thought of the lens and to be honest I hadn't had a chance.
I did try a few more but not testing the full capabilities yet. The clouds had naffed off.
[IMG]http://i740.photobucket.com/albums/xx49/df8/IMGP4057.jpg[/IMG]
[IMG]http://i740.photobucket.com/albums/xx49/df8/IMGP4064.jpg[/IMG]
The cat's broken!!!
[IMG]http://i740.photobucket.com/albums/xx49/df8/IMGP4002-1.jpg[/IMG]
Thanks for the advice. I'll get out and try it out a bit more. I was going to bracket but time was pressing. Somebody had queried what I thought of the lens and to be honest I hadn't had a chance.
I did try a few more but not testing the full capabilities yet. The clouds had naffed off.
[IMG]http://i740.photobucket.com/albums/xx49/df8/IMGP4057.jpg[/IMG]
[IMG]http://i740.photobucket.com/albums/xx49/df8/IMGP4064.jpg[/IMG]
The cat's broken!!!
[IMG]http://i740.photobucket.com/albums/xx49/df8/IMGP4002-1.jpg[/IMG]
Lurking is shirking.!
Posted 28/09/2010 - 13:30
Link
Aww look at the iddle puddy tat! Don't you just wanna squeeze those paws!
Re the 10-20, these shots show that it can be plenty sharp enough, especially if you take care with your focussing, as the lens has lots of 'field curvature' which creates blurrier edges in some shots than others.
It is quite a difficult lens to focus with in my experience - I can point it at different objects and the camera does not attempt to refocus, so I have to throw the focus completely out, by pointing it at my hand or something, before trying again. I'm getting better results using live view and manual focusing.
Re the 10-20, these shots show that it can be plenty sharp enough, especially if you take care with your focussing, as the lens has lots of 'field curvature' which creates blurrier edges in some shots than others.
It is quite a difficult lens to focus with in my experience - I can point it at different objects and the camera does not attempt to refocus, so I have to throw the focus completely out, by pointing it at my hand or something, before trying again. I'm getting better results using live view and manual focusing.
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2917 posts
17 years
another place
Bright day, set to f5.6 ISO 100, Slik 88 tripod, K-7 set to 2s timer.
Jpegs out of the camera, no processing
10mm
[IMG]http://i740.photobucket.com/albums/xx49/df8/s1020/s1020at10.jpg[/IMG]
12mm
[IMG]http://i740.photobucket.com/albums/xx49/df8/s1020/s1020at12.jpg[/IMG]
14mm
[IMG]http://i740.photobucket.com/albums/xx49/df8/s1020/s1020at14.jpg[/IMG]
17mm
[IMG]http://i740.photobucket.com/albums/xx49/df8/s1020/s1020at17.jpg[/IMG]
20mm
[IMG]http://i740.photobucket.com/albums/xx49/df8/s1020/s1020at20.jpg[/IMG]
100% crops from a central selection of the images.
[IMG]http://i740.photobucket.com/albums/xx49/df8/s1020/s1020_100pcnt_crop.jpg[/IMG]
No idea why the camera decided on darker for 12mm.