Quote (Futurama @ Mon, Jun 1 2009, 12:23am)

100% crop means you have to enlarge the original image so it shows 100% in Photoshop or which ever software you use for cropping and crop it. He wanted one of the center so you just get rid of everything except the center part and do the same with the edge one.

Anyway here is the center 100% crop of one of the pictures I took and I think I posted in one of my topics awhile ago. I am sure you got a crappy lens because I find it sharper than my EF 17-85 IS USM lens and I have heard that it's just as sharp as the Canon version but cheaper that's why I bought it instead.

http://i537.photobucket.com/albums/ff339/SpammersHeaven/IMG_1930crop.jpg


EDIT: btw the Sigma 10-20 won't work well on FF bodies. It will physically fit but you would get images with black corners. I believe only the Sigma 12-24 is usable on FF bodies but it's also quite a bit more expensive.

Quote (chantal7 @ Mon, Jun 1 2009, 01:41pm)

Yeah - we talked yesterday on Ventrillio xD it was interesting. But I got a picture now so I can crop it.

Apparently Sigma has "duds" out there - so depending on what copy you got, it could be one that's not as sharp as the others out there. So I would imagine he wants to know how sharp mine is compared to his, to see if he did get a dud. And I am also curious as well because this lens has mass years of warranty on it, and I might just get it fixed. In many reviews the Canon seems to be the better way to go, if you have the $$. But risk getting a bad copy when it comes to the Sigma.

Anyway, Here's my photo... hopefully I cropped it correctly.

Taken 1/200 shutter
F 8.0
ISO 100

Original:
http://i28.photobucket.com/albums/c206/chantal7/IMG_2074.jpg

Center Crop
http://i28.photobucket.com/albums/c206/chantal7/IMG_2074centercrop.jpg

Corner
http://i28.photobucket.com/albums/c206/chantal7/IMG_2074cornercrop.jpg

Quote (Futurama @ Mon, Jun 1 2009, 02:46pm)

hmm what quality did you use when you took that photo? It looks a bit smaller than the pictures I get with my camera and I know your camera has the same resolution as mine and I think you should take another picture of an open landscape without too much background stuff to really show if it's sharp or not. Well I guess the "you get what you pay for" logic applies here too lol but I think your lens is still quite sharp if you look at the lower part of the image. I believe for a lens that only cost 600 something it's still pretty good and as you said the 10 years warranty is a huge bonus as well. I am not sure if you could just fix the bad image quality on a "dud" other than asking for another copy. Btw what is Ventrillo? lol

Quote (lithfkn @ Mon, Jun 1 2009, 05:18pm)

Hey Chantal, thanks for that xD

http://i21.photobucket.com/albums/b252/mustangnicko/IMG_20741.jpg

The red section is your focal point and that seems sharp enough at f8 (generally the sharpest a lens gets at one point). It actually seems sharper than the Sigma copy I had hehe

The blue section is the corners I was talking about. That tree gives off the impression that it was a windy day but judging by the other trees around it looks still and 1/100 should be suffice in freezing the image. It looks quite distorted and unsharp. I guess that could just be the downfall of Ultra wide angle (UWA) lenses used on 1.6x sensors.

I would be very interested in seeing the results from someone here using a 10-22 Canon or a Tokina 11-16 2.8.

http://i21.photobucket.com/albums/b252/mustangnicko/WHOLE_1.jpg

http://i21.photobucket.com/albums/b252/mustangnicko/CORNER_1.jpg

You can see the corner sharpness/distortion aint too flash aswell in my shot. Maybe Sigma should have built it at 12mm instead of 10mm lol

Quote (chantal7 @ Mon, Jun 1 2009, 04:26pm)

3888x2592 (Symbol looks like it has stairs, and it's L quality)  but don't forget photobucket only allows me to upload 1mb at the most. It's originally 1.91 MB.

Yeah well I don't know if mine is a dud or not. It still is pretty good, and it shouldn't matter what I take a picture of to test out the quality, no? We shall see when Lith sees it..

Ventrillio is a program to speak on, it has a chat feature in which I used to talk to Lith on xD.

Quote (lithfkn @ Mon, Jun 1 2009, 05:18pm)

I would be very interested in seeing the results from someone here using a 10-22 Canon or a Tokina 11-16 2.8.

http://i21.photobucket.com/albums/b252/mustangnicko/WHOLE_1.jpg

http://i21.photobucket.com/albums/b252/mustangnicko/CORNER_1.jpg

You can see the corner sharpness/distortion aint too flash aswell in my shot. Maybe Sigma should have built it at 12mm instead of 10mm lol

Quote (chantal7 @ Mon, Jun 1 2009, 08:21pm)

No problem, glad to help. And glad you could help me out as well! I would imagine a full frame camera would be A LOT better with this kind of lens. After all, it is a pretty wide lens. It was a pretty windy day today actually, the other trees are much more stable than that one, and the huge building I was in probably blocks part of the wind of the other trees.

I don't even know if anyone here has a 10-22 Canon or tokina. Would be cool to see their results too!

Quote (Futurama @ Mon, Jun 1 2009, 08:33pm)

Oh! Sorry I guess I forgot about the stupid size limit when you upload on to Photobucket. Yep, all my pictures are of the same size but I use the highest quality (the rounded symbol, no stairs lol). hmm is the stairs symbol the highest you can have on yours?
Well yours looks fine to me course mines pretty similar to yours maybe because we bought them at the same store. I think a picture of an open landscape taken with narrow aperture would have little or no background blur which would make it easier to determine if the corners are sharp or not but I could be wrong though lol. Anyway I finally decided to check my lens as well and here are the results:

Center:
http://i537.photobucket.com/albums/ff339/SpammersHeaven/IMG_1942c100CropCenter.jpg

Corner:
http://i537.photobucket.com/albums/ff339/SpammersHeaven/IMG_1942c100crop.jpg

The picture (resized):
http://i537.photobucket.com/albums/ff339/SpammersHeaven/Spring2009/IMG_1942c.jpg



Dpreview review on that lens with samples:
http://www.dpreview.com/lensreviews/sigma_10-20_4-5p6_n15/page4.asp



Well on a full frame the vignetting or whatever it's called would be even worse at the corners AND you don't really need such a wide lens for a full frame anyway because a 16mm lens gives the same field of view on a full frame as on those crop bodies if that makes sense lol.

Quote (chantal7 @ Mon, Jun 1 2009, 11:07pm)

Did you use F 8.0?

Quote

Exposure time:  0.002
F number:  5.6
Exposure program:  4
ISO speed rating:  100

Quote (Futurama @ Tue, Jun 2 2009, 03:27pm)

Ooops!!!! I just noticed that I used F/5.6 for a cityscape shot!!! -.-
lmao! I keep forgetting to change to higher F numbers while shooting landscape and cityscape photos because recently I have been shooting mostly close-ups. This is so freaking annoying lol.

Quote (lithfkn @ Mon, Jun 1 2009, 11:46pm)

f8 wont pull this sharp:

http://i537.photobucket.com/albums/ff339/SpammersHeaven/IMG_1942c100crop.jpg