Best post processing in Lightroom

[vchmiele]

Just wondering what the best technique is for post processing images in Lightroom?

I suspect that I might need to "open up" some of my shadows. However, would I want to just adjust the levels or is there a better way to optimize the images for PS?

Any advice would be helpful, thanks!

[chadfx]

I haven't done any exhaustive tests, but generally I have found that bringing up the Shadows and also sometimes bringing down the Highlights when converting RAW images for PS can yield better results in a lot of situations.

It really depends on your source images, of course; and it is important to make sure to examine the results of the adjustments. You can end up just boosting a lot of noise in the shadow tones if you are not careful. A lot of it probably depends on how well the images were photographed and how well your camera captures shadow detail.

At least it is easy to experiment with the settings and see what difference you get from Photoscan. Good luck!

[vchmiele]

Sounds about right... My lighting is pretty good, but I'm using continuous lighting and therefore I don't have as many lumens as strobes.

On screen the adjusted images from Lightroom look way "punchier", hopefully this translates into a better scan.

Also, is it worth doing any kind of noise filtering or would that alter the data too much?

[chadfx]

Hmm, I would expect that if you increase the Shadows adjustment and decrease the Highlights adjustment, the resulting image should appear less contrasty, not more. See below for a quick example, the second image I brought up the Shadows to +100 and the Highlights to -50. It's not the best example as I just grabbed an already converted jpg image...but you can see how the tweaks are revealing a broader range of values. This 'seems' to create better reconstructions from what I have found, but I am not sure if technically this is making a real difference. There was some discernable range of values already in the image, and these tweaks are just sort of expanding them out a bit.

Noise reduction will probably depend on your source material. You would not want to push it too hard and wind up softening details that you are trying to reconstruct; but you would also not want PS to try and interpret a bunch of noise as actual details either. There are some very good 3rd party tools, such as Neat Image, which do a very good job of reducing noise artifacts.

[David Cockey]

I adjust the images so that none of the areas which are needed are either saturated or "black". Setting of the controls depends on the images.

I use the Chromatic Aberration correction and vignetting correction in Lightroom since there are profiles available for my lenses. I make sure to turn off distortion correction.

[Bulbokan]

Hi,

I did quite a lot of test with processing pictures before using them in Photoscan. I am modelling caves, so the problem of light is always present for me.

What you can do depend a bit of the quality of the picture you first took. For example, if it's noisy because your ISO sensitivity is set to high, you might exaggerate that noise in lightroom when post-processing it.

When postprocessing the pictures, I start correcting the exposures. And as David Cockey said, I'm also using the Chromatic Aberration correction and vignetting correction available for my lenses (turning off the distortion correction).

Then, I play with Highlight and Shadows recovering the overexposed and the underexposed areas. I always use the same parameter for the whole set of pictures. Changing highlights/shadows can improve the geometry of the 3D scene when those areas are really under/overexposed (meaning areas of full white or black pixels). If they are just a bit dark or a bit light, it seems that it will have no (or almost no) effect on the geometry of the model. But editing those parameters can still be interesting to get a more uniform light on the texture (less contrasted too), if it is what you want.

But you should not use filters on the pictures like "noise reduction", "sharpness", etc... It changes the pattern of the picture and might decrease the quality of the model. At least that is what I saw from the few test I did. I would not even push the contrast higher, which will exaggerate the noise.

To get the best model AND best textures, I should try to edit two set of pictures. To build the geometry with a first set, then texture the model using a second set of the same pictures, which were specially edited to look good. Anybody tried it already ?