HDR Question

Just exactly what is HDR (multiple exposures compressed together)? If so, what about camera shake? Can be done only on a tripod? Does the Nikon D90 offer this feature? If not, is there a "work around" to achieve the same result?

Simply put, HDR is combining multiple exposures to increase the dynamic range in an image. In order for it to work, the frames need to be identical so you will need to use a tripod. Just about any camera that you can adjust the exposure on can be used. The camera is only taking the photos. You need to combine those separate exposures together using the computer and software. There are many different programs you can use to create your HDR images.

I think I'll give a generic answer to your questions and let others more skilled at the technique to elaborate:

It's a technique where you take varying exposures of a particular scene and combine them to create a single image. It's usually used in high contrast scenes that have a lot of shadow/highlight detail, and where a single exposure would result in either blown highlights and/or featureless shadows. By taking a series of images at different exposures, you have preserved that information across a series of images, which can ultimately be post-processed into a single image.

Tripods are critical because you don't want the scene itself to be altered in your images, just the exposure. Without a tripod or something similar, you can (as a last resort) use exposure bracketing and continuous drive mode to get a series of shots and hope you or your software can align it properly later on. Also, objects in motion can be problematic, such as swaying leaves, swinging signs, moving people, etc.

Since creating an HDR image is a post-processing technique, no specific camera is required - just one where you can manually control the exposures. So while you might not a need a camera "work around," as you asked, you will probably need software that will be able to combine your images properly. Some graphics editors have built in HDR functionality, but I hear the third-party alternatives usually produce better results (or at least allow more control).

It's easy to get carried away and create surreal, almost absurd, HDR images. Just do a google image search for "HDR" and you'll see what I mean. It's a technique that some love and others hate. However, I've seen some extremely skilled HDR work on this forum by a couple of users, who will hopefully chime in.

Here is a good example of what a simple in-camera HDR can do. Not overdone; simply capturing more of what is there.

http://forums.dpreview.com/forums/re...ssage=36661968

EDIT - Click on the images to show the full width.

Terry

I've gotten pretty good results using the bracketing and a quick burst, however I'm finding that be best results come from using 5-7 exposures that are 1 ev apart rather then the 3 shots with 2 ev difference when using the burst. I, and I think a lot of people here (that toy with hdr anyway) use Photomatix for their hdr work, although there are others. Also, you can always shoot one image in raw, adjust your exposures, and stack them that way too. It's not the most ideal, but can be effective.

Quote:

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Originally Posted by n8

...a lot of people here ... use Photomatix... Also, you can always shoot one image in raw, adjust your exposures, and stack them that way too. It's not the most ideal, but can be effective.

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Photomatix will do the stack for you. Just load the single RAW file. - Terry

Thanks to all that answered. I really appreciate it.
Paul Johnson in OKC