Monday, June 15, 2009

Just Say No to Chromo Abs

I received soooo many emails about my HDR talk at B&H yesterday that I had to post this Photoshop tip before my usual Saturday Photoshop Mini-Session.

The emailers wanted more info about removing chromatic aberrations from HDR images – and images in general.

Well, here we go!

The top image is my original shot.

I created the middle image using Photomatix (5 exposures) and then by applying the Omaha Beach effect in onOne Software's PhotoTools. More on Photomatix and onOne at pluginexperience.com.

When I zoomed in on my final image (as always), I noticed a chromatic aberration around the trunk of the tree - stroked in red in the middle image.

To reduce that effect, which does creep into HDR images, and into some high-contrast photos taken with less expensive lenses, I turned to Photoshop. I went to Filter > Distort > Lens Correction. I played around with the Chromatic Aberraton sliders until the bright red line was removed, as you can see in the bottom illustrations.

Click on the image to enlarge.

Hey, I am trying to talk my buddy Scott Bourne into doing a Photofocus podcast on HDR imaging. Like the idea? Let is know here!

Remember, I have a new tip every day (when I am not traveling). Subscribe to my blog and get the info pronto. Gotta go for some Mo Joe.

5 comments:

Lars said...

Hi Rick.
Very good idea, about doing a HDR show....
And by the way, just bought 2 of your books, "exploring the light" and "Digital Wedding Photography Secrets". Very good books....
Lars Feodor Frederiksen
www.feodorfoto.dk

Lars Feodor Frederiksen said...

That would be a brilliant idea. Just love the show...
And by the way, just bouhgt 2 of your books: "Digital Wedding Photography Secrets" and "Exploring the Light." Great books....

Loopsta said...

Rick,this is common for low budget shooters(read as broke but enthusiastic). Most of the EF-S lenses are not the greatest for CA. So it almost becomes a necessary part of the workflow to Do correction for chromatic aberration in ACR. Obviously the + EV's are the main cluprit in high contrast edges, correcting it at the RAW stage mitigates the amplification when you tone map it, so quite often i will pre process the RAW files and save them out as 16 bit Tiff files before merging them.

Rick Sammon said...

Hi Loopsta - I agree with you. Thanks for the added tip!

Mike said...

A show on HDR would be very welcome.