DSLR Color Flicker Problem

[Pete Burger]

Hi, Casey!

The way DSLR cameras reduce picture size from those huge image-sensors to comparatively small HD size is by skipping information, which raises or even creates artifacts like moiré. Letting the camera sharpen those pictures internally, boosts these problems by raising local contrast (darkening dark edges and brightening bright edges).

So dialing the sharpening down, will help to reduce picture artifacts.

Reintrudcing sharpness is just as easy as applying a sharpness filter in post. Some guys (myself included) rather use the “unsharp mask” filter than “sharpness”, since it gives you more possibilities to fine-tune, but that’s just a matter of personal taste.

Sharpness filters in an NLE do the same thing as the ones inside your camera, but you can adjust the intensity to your needs and likings or even use masks to apply the sharpness to parts of the image.

Hope this helps!

[Casey Petersen]

I’ve never used the unsharp mask before…must be the name! Looks very interesting, and I think it would look better than the plain sharpen filter.

What kind of “typical” settings do you use with it….the base settings you use that work on most clips without having to customize it?

Thanks!
Casey

[Richard Harrington]

Must shoot 100% manual

Richard M. Harrington, PMP

Author: From Still to Motion, Video Made on a Mac, Photoshop for Video, Understanding Adobe Photoshop, Final Cut Studio On the Spot and Motion Graphics with Adobe Creative Suite 5 Studio Techniques

[Pete Burger]

Well, it depends largely on the picture… I don’t think there’s a perfect setting that works with most footage.

I don’t work with FCP, so I don’t know the FCP default settings, but starting with the defaults and playing around with threshold and radius might give you good results.

My approach is as follows:

Unsharp mask has three sliders: strenght, radius and threshold.

When using that filter, first step for me is to set the strenght very high (default in Premiere is 50%, so I set it to about 150% or even higher), just to see more clearly, which parts of the picture are affected by the settings.

Threshold defines, “when” the filter attacks, in terms of “how dark or bright must a pixel be to be affected”. Lower values create more extreme results.

Radius defines how “far” the darkening or brightening goes. Higher values create more extreme results.

After tweaking threshold and radius, I reduce the strenght back to what looks good to me (something between 20%-50% in many cases).

So, you can create very subtle effects or even very extreme effects with halos and stuff…

Hope this helps!