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Old 29th August 2007   #1
ortega
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Default Review - Sigma 18-50mm F2.8 EX DC

Sigma 18-50mm F2.8 EX DC

for those who want to know, I did some tests shots and post them here
make your own conclusions about the quality

All images taken using a Nikon D80, ISO 100, Aperture priority



Resized full frame @ f8 and f2.8 (tripod mounted)
note the vignetting on the f2.8 image

now at 50mm uncropped images

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Old 29th August 2007   #2
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Default Re: Review - Sigma 18-50mm F2.8 EX DC

Next some 100% cropped images

100% Crop - Center from the 18mm shot


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Last edited by ortega; 29th August 2007 at 10:54 PM.
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Old 29th August 2007   #3
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Default Re: Review - Sigma 18-50mm F2.8 EX DC

100% Crop top right hand Corner from the 18mm shot


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Last edited by ortega; 29th August 2007 at 10:55 PM.
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Old 29th August 2007   #4
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Default Re: Review - Sigma 18-50mm F2.8 EX DC

Next, CA tests at different aperture settings

All images taken with the same exposure using manual mode






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Last edited by ortega; 29th August 2007 at 10:58 PM.
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Old 29th August 2007   #5
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Default Re: Review - Sigma 18-50mm F2.8 EX DC

Magnification - manual focus set to minimum
for greatest magnification at maxumum focal lenght

image resized to 700px wide

Bokeh

set to get minimum dof and maximum oof of background
image resized to 700px wide
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Last edited by ortega; 2nd September 2007 at 02:21 PM.
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Old 29th August 2007   #6
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Default Re: Review - Sigma 18-50mm F2.8 EX DC

I have also at the same time done the same test for the

Tamron SP AF17-50mm F/2.8 XR Di II LD Aspherical [IF]

and the

Nikon AF-S DX 18-70mm f/3.5-4.5G
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Last edited by ortega; 31st August 2007 at 01:49 AM.
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Old 8th February 2008   #7
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Default Re: Review - Sigma 18-50mm F2.8 EX DC

the pix look a little soft @f2.8. does it improve by f4.0?
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