Photography & Graphics Tips
- What is the best way to adjust a photo? S-Curves!
- Converting Color Images to Black & White with Photoshop: two approaches
- FREE download and instructions for making a flash diffusion hood
Why is it necessary to apply unsharp mask to every photo?
Slightly controversial, but appears to be completely true that in order to eliminate anti-aliasing and moire patterns all (as far as I know) digital cameras ever so slightly blur the image. This kills the stair-stepping, but also looses some of the detail. A tiny bit of Photoshop's Unsharp Masking will bring this back. Typically a radius of 0.2 - 0.5, an amount of 180%-220%, and a threshold of 3-6 is what you want. Here are two good discussions of this:
Ask A Scientist: Optical Low Pass Filter
Understanding Sharpening
Note: if you run noise reduction on an image, such as NoiseNinja, do so before applying Unsharp Mask. For one it may no longer be necessary, depending upon the profile you use, or, two, the noise filter may soften details too much -- requiring a bit of sharpening afterwards.
What's the purpose of a UV filter?
On a digital camera -- nothing, except that you've spent a lot of money on that lens and it would be a shame to scratch it. A decent UV filter is $20-$30, which is much cheaper than replacing a lens. As far as absorbing light these don't affect the exposure enough to count. Bottom line: get one for all of your lenses and don't take them off.
