Chromatic aberration
 

Does anyone know how to get rid of it? Im using an iscorama 54 anamorphic adapter on an EX-1 and noticing a degree of colour fringing sometimes that just doesn't happen on the EX-1s amazing lens. Just wondered if anyone knew of a program to get rid of this?

Iscorama 54 huh? So you're shooting 2.66:1 movies. Great! The punch of that is probably worth having some fringing on board.

Agree Tom!

Mark,

It depends on the type of aberration. You might be able to run the footage through after effects and scale the RGB channels differently if it's a simple type of fringing. Other things you can do is to key the fringe colours and desaturate them, sometimes this can work, it really depends on the type of footage.

I'd love to see a frame. What's the resolution like through that adaptor?

cheers
paul

Hi Paul

This is without the anamorph

http://www.freewebs.com/markwilliams/without.png

And this is with

http://www.freewebs.com/markwilliams/Anamorph.png

Oh dear - I see what you mean. Almost better to mask down the original frame rather than have to accept wooshy edges like that.

I was about to say something similar. i thought the lens would give you a much wider fov. In this case you'd get better results cropping the original down as Tom says.

Is the adaptor meant for 4:3 cameras perhaps?

Having said that you could squeeze the channels horizontally (try expanding the red a little bit widthwise, 100.25%), i think it would clear it up a bit. Or run it through a photographic (RAW converter) style defringer.

cheers
paul

VirtualDub has a free CA correction filter. Do a search.

Bill I was just thinking about you! I was using your picture profile when I took it. This is with Picture profiles off

http://www.freewebs.com/markwilliams...20pp%20off.png

Err, having looked at the pictures; don´t really know which way to take this. Better without?

Mika I would say no difference with PP on or off. I just thought people might like to see nd judge for themselvves. Bill I've found the plugin and downloaded virtual dub. Imported the picture and added the filter. However I cant see the effect in the preview screen? When I do get a preview screen its zoomed in so much cant see a lot?

I would guess though whatever I do Im not going to get rid of this! Im surprised virtual dub has a tool like this and after effects doesn't.

I wonder if I moved the iscorama forward a bit? I'll try that tommorow.

I guess you could get away with it quite simply by forgetting about the anamorphic adaptor, having framing guidelines in your monitor/viewfinder and cropping afterwards. I don´t know if it´s possible to define a box cursor to the ex, hardly so.

The PP settings won't be the cause of CA.(doncha just love acronyms?)
But, my question to you is what aperture settings did you use on the shot with and without CA. CA, in hi quality optics, is made worse by long zooms and apertures too far from the sweet spot. If you were shooting down around f/8 or less, this would be my guess. Also, how does the adapter mount to the cam lens? If it's tilted, even slightly, relative to the lens axis, you could induce CA.