Lens that accentuate chrimatic aberration for colorful effect.

petrochemist wrote:

SmoothOperator wrote:

SmoothOperator wrote:

I was wondering if there are any lens that distortion colors on purpose to add color. I've seen the prism lens and filters, but I am thinking of something more like a fisheye lens than a lens ball. Specifically, not making multiple images or facets, but excentuating a normal image with CA.

I imagine soething could be achieved digitally by tweaking a CA correction the wrong way.

I was thinking about this more. Most CA looks especially bad because it's just a blue and red edge. Maybe to accentuate the CA a lens could make a better spread separating more colors more uniformly, sort of rainbow edges.

CA can't give you full rainbow edges. the most you can get is a portion of the spectrum the reds on one side & blues on the other.

The more you spread the colours the less you'll see of the central normal image.

You could try a plain ruled diffraction grating. That will give you a series of images in different colours with each colour displaced according to it's position in the spectrum. More finely ruled gratings will spread the colours more. Note diffraction filters as sold for photography are slightly different, typically having several gratings, and probaly with bigger spaces between the lines.

A diffraction grating is neat.

I've been thinking about the a reason for a lens which doesn't correct for CA(or even accentuates it to exist).

One scenario is colorful scenes in low light.

The theory would be if you are shooting things that have mixed pan colors( whites, tans, browns, some purples), you'll end up with muddy looking scenes.  If you are shooting things where the colors are relatively pure, say tones of red or green, then CA won't even show up.