Recovering highlights with shadow/highlights

rutt

It seems that a lot of us know how to use image->adjustments->shadow/highlights to recover shadow detail, but it is equally useful for recovering highlight detail. I've noticed quite a few messages over the last month or so about making two raw conversions and then recovering highlights by using a layer mask and painting out the blown details to allow the darker image to show through.

There is a global (no PS brushes or selections) alternative to this that can result in very natural looking results and which requires no skill or time with the wacom tablet. Essentially:

1. Adjust exposures and shadow in ACR so that neither end of the histogram is clipped.
2. Convert the raw into 16 bit mode
3. Apply shadow/highlight with low shadow amount and large highlight amount
4. Restore contrast with curves

Here is an example. I started out with this image:



I wanted to restore some of the blown detail in the clouds. I followed my recipe above and ended up with this:



Here is the shadow/highlight dialog I used to restore the shadow/highlight details:



And here are the LAB curves I used afterward to fine tune the contrast and improve saturation:

bfjr

thanks Rutt
Use all your tips and have been working all my images in LAB.
Question how do I emulate hightlight/shadow in PS7 or do I have to upgrade?

rutt

bfjr wrote:

thanks Rutt
Use all your tips and have been working all my images in LAB.
Question how do I emulate hightlight/shadow in PS7 or do I have to upgrade?

Shadow/highlight is a CS thing. To get the same effect in earler versions, you have to do some plate blending and very odd things with curves. It's much harder. There is some stuff about it on this thread: http://www.dgrin.com/showthread.php?t=5922&highlight=dynamic+range

I'll bet CS upgrades will be really cheap on ebay now that CS II is out. Probably worth it for ACR and shadow/highlight alone.

Andy

excellent result, rutt!

ian408

If I had to pick one thing I love about your contributions, it'd have to be
these little pearls of wisdom. Well written, informative and very timely.

Thanks rutt!

Ian

rutt

andy wrote:

excellent result, rutt!

I think this will work almost anytime that you can recover the details in ACR. Sometimes they really are blown. Sometimes if you lower exposure enough to get back some details they will be magenta only. When this happens you can't just use this trick without doing something to "colorize" that magenta. But in this case you couldn't just use a layer mask with two differnt conversion either.

The reason that lowering exposure to recover blown highlights sometimes results in magenta only highlights is technical and has to do with the way digtal camera sensors are made. There are twice as many green pixels as red or blue ones. 60% of the luminosity of the image is in the green channel. Magenta is the absense of green, essentially negative values in the green channel. After there is no more information in the red or blue channels, this is all there is.

wxwax

Rutt, a question about step #1. I figured folks did the two exposures/layer mask thing when it wasn't possible to create a single image in which neither end of the historgram was clipped.

rutt

wxwax wrote:

Rutt, a question about step #1. I figured folks did the two exposures/layer mask thing when it wasn't possible to create a single image in which neither end of the historgram was clipped.

I haven't seen such an image. Decrease shadow to 0 and the shadows that can be unclipped will be. Decrease exposure and the highlights that can be unclipped will be. The problem is that the areas of interest are all so compressed in the resulting image as to be invisible. I mean that the highlights and shadows, though not clipped are each compressed into relatively small areas at the end of the curve. The shadow/highlight adjustment overlaps different sections of the curve, essentially exposing detail that exits in the representation but which isnt visible.

Andy

improving the bass
rutt's been after me to try something, so i did. i followed these instructions:

1. In ACR, make sure neither shadows nor highlights are clipped by using the shadow and exposure sliders, respectively. Do just enough to get the whole histogram in.

2. In shadow/highlight, use shadow amout = 0, and play with the highlight settings. You should be able to recover the detail in the highlight if there is any (and we know there will be because you were able to make two conversions and combine.)

3. Use curves (preferably LAB, L) to restore contrast. Start by just moving the endponts in until you have true shadow and are just starting to lose detail in the highlights. Then screw around. (andy: that's a technical term )

this is rutt's method, and rutt's sharpening



here's my original edit from two months ago. this edit involved developing two exposures from the raw file, and blending them in post



it's an interesting approach. i'm going to print these shots off 13x19 in the morning to see if there are noticeable differences in the final output. i do like having the extra control over the exposure, and i believe that after working this thru a couple times that i may be an improvement over my existing workflow for many of my images.

thanks for your contribution to dgrin, rutt, and for working with me on this tonight!

rutt

Andy, I think the sharpening from your original is a little more aggresive and looks a little better. Look at the white on black letters behind the base. To print at large size, you'll need to sharpen again with differnet parameters than when we sharpened the resized image. Be a little braver with Radius and Amount. Remember the trick doesn't work if the results aren't visible.

The ACR+shadow/highlight technique for highlight recovery does seem to work really well.