HDR vs. Shadows/Highlights tool

Hi everyone,

I'm starting to learn about the concept of HDR and just like with the shadows/highlights tool in Photoshop, it is used to bring out the details in the shadows and highlights. From my research, it seems that HDR is a better method but I haven't found any explanations why it is so. I'd appreciate it if anyone could let me know the advantages of using the HDR technique over using the shadows/highlights tool. Thanks!

If there is no detail in the file, the shadow/highlight tool will not help you much. HDR allows you to combine details from multiple files/exposures to extend the dynamic range of an image.

Some people are too conditioned to the look of film images (i.e. very restrictive dynamic range,) and may find HDR "unnatural". In fact HDR may be more "natural" than any single exposure can be, considering the human eye is capable of discerning about 20 stops of light - far more than any film or current sensor technology.

Guy

Thanks for the reply Guy. If I'm understanding you correctly, HDR involves the use of multiple exposures which will result in a greater chance of more detail. However, using the shadow/highlights tool is usually associated with just single images. I hope I'm interpreting this correctly.

The way I look at it Byron, the S/H tool is kind of a sledgehammer, useful only for quick "demolition" and not for subtlety and refined work.

I use S/H frequently for editorial photos where the results are going to be printed on newspaper stock, and in fact there was no opportunity for multiple shots while shooting or time-wise in post processing to do the better job that's possible with HDR. I wouldn't consider it for a landscape shot to be published in a high-end magazine or as an art print.

It's a useful tool for a specific job, but not a universal tool for all jobs.

This is true, Byron. However, I find that HDR applied to a single exposure has certain advantages over the S/H tool. First off, if you create two or more exposures in RAW conversion, you can use the "headroom" to salvage any lost highlights. You can also apply noise reduction to shadow salvaging exposure but leave the highlight salvaging exposure untouched. I strongly suggest trying "2 Image - Shadow/Highlight" tool in the the trial version of Photomatix. This is a not quite an all-out HDR and its associated tone-mapping problems, but I think you will immediately like the way the image looks without much fuss.

Scott

Thanks for the replies so far everyone. So it seems like using the HDR method allows for more control and therefore, detail.

I use the HDR blending technique mentioned by Scott quite often. It definitely beats the S/H tool in many situations.

Byron - The main way HDR gets you more detail is that the multiple exposures are used to properly expose parts of the scene that would otherwise go totally white or black. Pretend you have an image that has a dark shady foreground, a moderately lit mid ground, and a very bright sky. If you expose so that the FG has detail, the sky will be pure white. If you expose correctly for the sky, the FG will be pure black. If you expose for the middle, you'll probably have portions of the sky as pure white and portions of the FG as pure black. Pure white or black would mean a total loss of detail in those areas (even though it's likely your eye could still see detail there - how often has the sky looked completely white to you? )

In this case, 3 or more exposure, exposed properly in steps for the various parts of the image, can be combined to create something that retains detail everywhere and can actually look very natural. A lot of people over do it, though, and even out the exposure everywhere, giving some odd looking scenes.

If you don't have any clipped values (pure black or pure white) in your scene, you don't really need HDR, but as noted in places above, there could still be advantages.

Here's a terrific article on HDR that's a little out of date, but still should tell you a lot.

Hi everyone. Thanks for your combined input. I really appreciated your helpl. That one article on HDR really helped out too (Thanks David!).

Not to start a controversy here, but here is an example of a nine exposure HDR that was my first attempt - clearly it was not a scene that required it, since the scene did not exceed the tonal range of the camera, but I include it here because of the platinum-print type of gray scale expansion that is evident in the final image -

http://www.flickr.com/photos/9961692@N04/1142079976/

Hey Gene - Not sure why that post would start a controversy. It's got a neat look to it to me - just on the fringes of being surreal. I think it's an example of what some people don't like about HDR - individual pieces of the scene look "normal" but the overall tonality seems "off" to what you'd expect.

Gene, thanks for putting up that image. That's very nice image indeed and it has a painting-like quality to it for sure.

HDR software is essentially an extension of what people have been doing for several years with blended exposures. Taking two or more in camera shots at different exposure setting and blending them using layers, masks, etc.

What a lot of people don't like about HDR is the surreal look that some users try to create. Take it too far and you end up with a result that looks more like a comic book illustration than a photograph. This is achieved in the tonemapping stage of the HDR process and at this stage you can essentially make it as realistic or surrealistic as you want.