Eric, how do you save a 32 bit file as DNG in Photoshop. It's not an option in the Save As dialogue.
Thank you Eric. I also enjoyed you as guest star in the video!
What should be adjusted in LR before merge to HDR?
WB? Camera and lens calibration? Neutral curve?
The HDR software wants linear files as inputs. What it will do is reverse out the gamma curve built into the colour profile the image is tagged with. If you do any other adjustments with tone curves this could impact the ability of the HDR software to create linear image files for merging. It's better to leave things like tone curve, hue/saturation, etc. untouched prior to HDR merging. Another reason for this is that these adjustments can become quite enhanced via the HDR merging process which can leave you with less desirable results.
Prior to merging you want to make sure your white balance is 'correct'. When I say correct I'm talking as neutral as possible. Any WB colour cast can get exaggerated in the HDR process and be difficult to correct later on.
Lens aberrations can also be taken care of before merging. Better done at the RAW stage than later on. LR or ACR can use a lens profile for distortions and any CA is easier dealt with on the RAW file than later on. If I'm doing things like perspective distortion on architectural images, I do that after merging/tonemapping.
The last adjustment that can be done before merging is cloning/healing. This one isn't as important and can be left till after if you want.
All three of these can be applied to one file in the bracketed set and synced to the others.
I've got one question left : Does it make any difference when converting my source-files for HDR to DNG 6.6 or 7.1 ?
Robert, you can convert to TIFF as well and the HDR plugin for CS4 will read those files too. If you're going to use DNG, it really shouldn't matter if it's 6.6 or 7.1.
In all honesty though, I wouldn't bother using Lightroom for processing 32 bit files. 32 bit TIFF files are HUGE. Adobe really needs to step up and provide support for .exr and .hdr files as well. What you can do with 32 bit files in LR is quite good. I did some comparisons earlier this year and posted a couple on my Facebook Page
. Both were tonemapped in LR, one was merged in Photomatix, the other in HDR Pro. Highlights and shadows were handled quite well. This scene had, if I recall, about a 16 stop range.