After looking at "Capture Sharpen" in RawTherapee and seeing how it can clean up an image, and after taking a look at images that come from a system that has a strong anti-aliasing (AA) filter (for which "Capture Sharpen" was made for) and a system with a weak AA filter (for which "Capture Sharpen" might not have been designed for, but might have an influence on), I thought I'd have a look at a known "horrible" lens and see how it compares with a known "good" optic.
Setup -
- Using a Sony NEX7, one each image from
- Sony 18-55mm f/3.5-5.6 SEL OSS
- Shot at 26mm
- Shot at f/10
- Sigma 30mm f/2.8 EX DN E
- Shot at f/10
- Process in RawTherapee
- Lens Corrections
- chromatic aberrations
- field distortions
- "Auto Levels"
- Set "Curves" black to the bottom end of the image's histogram
- "Capture Sharpen"
- Pull 100percent resolution 500x500pixel sections from the image and display them along with a down-rez'd copy of the original image
Comparison -
[If you click on the following images and then select full-resolution versions of these images you will be able to see differences between the photos]
Starting with a Sony "el-cheap-o" 18-55mm kit lens image...
Following up with a Sigma 30mm f/2.8 EX DN E image...
Comments -
Can you tell any difference between them? Seriously. Look carefully. Any difference at all? Now think about this.
OK. Sure. The kit lens has some "interesting" behaviors when shot wide open, but... Sure. The Sigma is brilliant from wide open. But what's wrong with shooting a lens at its best aperture? In the case of this Sony kit optic that would be f/8, f/9, f/10, or f/11.
Keep in mind that I'm using the lens correction functions in the image processing application. Who doesn't these days? Things like chromatic aberrations and field distortions can be corrected. Add "Capture Sharpen" to the processing sequence and I'm able to re-confirm for myself something that I've been saying for a long time, now.
Have a lens? Good. Use it! No excuses. None.
Crazy, isn't it?
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