Chromatic Aberation & CAC

S

scynda

Member
So we started do event coverage with our 300s and I checked to make sure the CAC was on before the shoot, it was. Then we get our footage back like this!
CAC.png


Any idea what's going on here? The CAC settings were on default but it was the stock lens so it should be calibrated. I have a channel offset filter in FCP helping out but im not too happy about this image. Our 500 has never given us this issue.

FYI, we shot at AVC-Intra, 1080, 30p, if it matters...
 
grrr, good call. I wasn't involved in that first shoot but on the next shoot I was and thats the one i checked for CAC on. However, on that shoot, I think we nailed the exposure must better, nothing was over 100 and we still got some, specifically on the lower left.

exposure.png


Is this still an over exposure issue? Also, what exactly is causing that flare? Is this something like the result of clipping or something? Just trying to get this in my head so I know why its happening and how best to avoid it, etc. Thanks Barry!!
 
No, there's some cA there, you can see it on the cord, how it goes purple on one side and green on the other. flare is usually purple and shows up on all four directions.

CAC is good, but probably not perfect.
 
What was your F-stop on those two grabs? No extender, correct? I think the stock lens is going to show CA error close to wide open and/or zoomed in close to max. It is a pretty inexpensive lens and CAC can only do so much.
 
self-made CAC

self-made CAC

Self-made CAC corrections

Is it possible to use other lenses and make the CAC for the lens you want to use? Cause I own a lot of B4 lenses that I want to use on the 300er.
 
We shot at around 4.0 and we're at 95-99 zoom for most of the show. No extender and stock lens.

I've improved the image a bit in FCP with the channel offset filter but it only does so much. Kind of a bummer when had such good guests and content. I'll have to look into tweaking the CAC setting and maybe bumping it up when we do event coverage like this from now on...
 
Pack said:
Self-made CAC corrections

Is it possible to use other lenses and make the CAC for the lens you want to use? Cause I own a lot of B4 lenses that I want to use on the 300er.
Click to expand...

I don't think you can use a 2/3" CAC enabled lens with a 300, unless Panasonic has a downloadable CAC file for that lens model with 300 combination.
 
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