Photoshop camera raw export parameters... what matters?

[grommit]

I typically load my photos into Adobe Camera Raw via Lightroom or Photoshop, and save them directly from ACR with the save images function in the lower left of ACR's menu.

I have a choice of exported color space, I've noticed that prophoto, which has a greater gamut than adobe or SRGB, often looks washed-out in Photoscan. Does this effect the creation of alignment between images?

Should dark images have their data tweaked to make the histogram even? Essentially the same data is in the image either way, but would Agisoft benefit by using what would appear to the human eye to be a better exposure.

Should denoise, sharpen or clarity functions be used to enhance local contrast or does this have a negative effect on Agisoft's algorithms?

Does the rgb color even matter to agisoft? In other words does the algorithm ignore RGB or favour the green channel because of its typically higher density?

On another topic, would adding markers to an other wise successful scene improve it in any way? I'm getting great reconstructions but would like to slightly improve them and wonder if this might have any effect.

[bigben]

You'll get a few different answers for this...

Camera exposure as high as possible without blowing highlights on subject (ignore the sky)

ACR settings are typically (for objects, scenes not orthomosaics):

Basics
Blacks: 0
Recovery: 0 to 10 (if I pushed exposure a little too far)
Fill Light: 30 to 50 (overcast-sunny)
Contrast: -20 to -40 (overcast-sunny)
Settings will vary depending on the subject matter/lighting conditions... ie. use common sense.

Lens correction with profile if available
Distortion: 0
Vignetting: 100
Remove chromatic aberration

ProPhoto RGB

No sharpening. Occasionally do some noise reduction but only IF I was desperate enough to use max ISO... Set visually then reduce settings to 2/3.

[jerry7171]

Thanks for the tip BigBen. I had been wondering about the same thing for a long, long time. I've been stumbling blindly along when I'd import my Pentax DNG files and try to tweak them hoping to give Photoscan the best information to work from. Sometimes my projects would work well and other times, not so much. I knew it came down to the quality of the photos I was snapping and the resulting exports to Photoscan.

Now I can take some of my not-so-great projects from the past and give them another try with your suggested settings.