[HDRI] Scaling artifacts in Photoshop CS2 w/ Radiance files?

[Mark Banas (lists)]

On Jun 16, 2006, at 12:57 AM, Chris Cox wrote:

> This is because of the sharpening aspect of bicubic kernels (they  
> really
> don't work for HDR images), and can be made worse in the Radiance file
> format because we weren't clamping negative values correctly.

Hi Chris,

Glad you are on this list as well!

Hot on the heels of my previous post about the Radiance files from  
Photoshop CS2, I've put up a page to explain the amplified artifacts  
I have seen in "Merge to HDR" in CS2 (and why I stopped using it).  
Perhaps you can take a look at this and tell me where I've either  
gone wrong or perhaps why I'm seeing these dramatic effects. The odd  
part is that I don't remember having this problem in the past, but I  
know that I recently upgraded to 9.0.1 and because of this problem I  
have switched to batch HDR-creation with Photomatix instead (despite  
using CS2 in my workflow right *after* creating the HDRs).

Here is a page (with links to the "originals") illustrating the  
problem I am seeing with "ghosts" in PS CS2 Merge to HDR:

http://www.mab3d.com/temp/ot3d/HDartifacts.html

At the same time, this is a general query to see if anyone else has  
seen/ had these problems with Merge to HDR in CS2, and what they have  
discovered.

-Mark

BTW, for those that are interested, the ZIP archive of stitched  
exposures includes JPEGs that have the metadata from the pre-stitch  
images appended to them by EXIFtool - makes HDR creation a bit  
easier. Plus, if you peruse this data in a capable image browser you  
can get a good idea of how I process my RAWs for HDR creation.