I like this adjustment and tend to get carried away with it. I adjust a lot of the images I place on my corporate photography blog. But sometimes clients see the results of my 'messing around' and prefer the image and want to use them for print and publication. My concern is that after using the shadow/highlight adjustment and then looking at the levels which seem to have changed.
Of course Highlight/Shadow has an effect on the quality of your images. It can make them better, more or less the same or make them worse, all depending on how you use filter. If your clients are noticing AND complaining about your images, then I'd probably take the hint and back off. The people who are paying are telling you it's too much.
When you say you can "see" the effect in Levels, I have to assume you mean that you can see a change in the Histogram display in the Levels dialog. The Histogram is just a map of the distribution of pixels within the image (or selection) and, yes, if you make a move that alters the tonality, then you will see a difference in the Histogram. The real question to ask is "Does the image look better or worse after I altered it?"
Instead of "messing" around with you images, consider learning how correct your images according to a plan - like setting highlight, shadow and midpoint pixel values as your first move before deciding what else might be needed.
Thanks for that - I was not sure about the technical side of this and will put your suggestions into my work flow. Yes you are right the filter does make the images look better and I had only put my adjusted ones on my blog. I was not passing these onto my clients as was not sure if the adjustments would effect the quality of the images at repro stage.
Last week I did a shot for a client - sent them the results all on cd and they were pleased. With one of the corporate portraits
I decided to play around with and adjusted Highlight/Shadow and then posted it on my blog. The client saw it and wanted me to do a high res copy, I did the same process to the high res and sent it over.
If I compare the original and the adjusted image in photoshop will I be able to tell if I have reduced the technical quality in anyway?
If you edit an 8-bit-per-channel image,this will likely lead to a comb-like histogram with a slight loss of tonality values; then, technically, you can tell the photo has been tampered with (the same applies to any editing of the levels and/or curves etc. at 8 bit depth data). Whether or not this will actually show on your monitor or in the printed result is hard to predict. Technically better results can be expected if you edit an original at 16 bit depth per channel and reduce it to 8 bit only before you save the edited copy. Photoshop then applies some dithering that will yield a smoother histogram for those who care.
A couple of things that can trip you up with Shadow/Highlight. One is to set the Black and White clipping points to Zero. That will keep the filter from blowing out highlights and plugging shadows and at the same time will prevent odd tonal behaviour - like when the entire image gets lighter or darker from a very small adjustment - when the result is many times more than expected and often in the wrong direction. The second is to understand that the Color Correction slider is really a Saturation adjustment and that at the default setting of +20, it adds a heaping helping of Saturation. Set it to zero for no added effect.
Using the filter in moderation really shouldn't be an issue even on 8 bit jpegs - something that I do all the time with stock images given to me to spice up for my clients. This is a great tool but by no means the only or even the best tool for fixing your images.
I always apply S/H to a duplicate layer and usually do the shadows first, apply a layer mask to the layer, then brush the correction in where needed, flatten and then do it all over again for the highlights. All too often, trying to do both in one pass results in an overprocessed look, and if that's what you're after, fine, but not me.
After you're finished tweaking your image, try looking at each RGB channel individually, examining for signs of posterization or other artifacts, but don't worry too much if you find something in one channel or another, as the other channels will usually cover up any damage. If you do find posterizing, which is most common thing you might find, consider making an inverted Luminosity mask and adding noise followed by a low degree of gaussian blur - maybe 5-10 % noise and .3-.5 pixel blur. The inverted mask will keep the noise and blur in the shadows and make a very natural looking "fix" to damaged files.
With the advent of ACR and it's non destructive editing, I generally dispense with the masking layer on a dupe, and use the history brush to make local corrections. If S/H is indicated, it's the first step upon exiting ACR into PS.
Over processed look is in the mind of the beholder. Generating B&W images at all is overprocessed, unless you are color blind.
I find the surprise that certain images exhibit with S/H interesting and useful on occasion. Well done, S/H always provides a dramatic alternative to the simple image, which one can employ or not, as desired.
It also helps to set a way different default for S/H as the defaults that come with PS are odious in the extreme for most images. Pick an image that has no blown highlights or heavily clipped shadows, apply the filter, move the sliders until you get what you want, then save it as a new default.
I don't set shadows and highlights in separate operations. Flattening the file after shadows are tweaked precludes the tradeoffs I find showing up when you do the highlights. That's why I have my defaults set differently than the Adobe defaults.
A photograph is meant to be seen and appreciated as any other well done, masterful object, whether sculpture, a weaving a painting and so on. The photograph's basic attraction, what makes a photograph a photograph, needs to be honored at the outset, but don't be afraid to "depart from reality", because you are creating a separate reality (no drugs needed! ).A photograph can sing, a piano can sing, but both need the master touch to do so.
I hoped that by CS5, S/H would have become an adjustment layer, not only for it's non-destructive qualities, but so we can revisit the settings later in processing.