HDR question

[VegasMike]

I've been playing around with HDR and I set my XSi for automatic exposure bracketing. I took my three shots and went +1 and -1. Ithen took another 3 shots at +2 and -2 to give me multiple exposures. My question is, would it make a big difference to add more exposures? I was thinking about using my nuetral density filters to add more exposures to the mix besides what my XSi will do. Any thoughts?

[inkista]

Uh. Wouldn't use ND filters. Kind of defeats the purpose. I think you may want to go back and review what HDR is actually doing.

The point of HDR is to extend (or if you want to look at it from a tone-mapping view, compress) the dynamic range. But you only need an extended dynamic range if the scene itself has a dynamic range larger than your sensor can capture in a single image. If you haven't covered the entire range with three shots, bracketed at ±2EV, then yes, adding additional shots to further extend the dynamic range will get you more dynamic range to work with, assuming that you're using HDR to actually extend the dynamic range, and not just to super-saturate or get those Photomatix exploding skies.

Here's an example of someone who bracketed by shutter speed to get a dynamic range of eight stops. That would be twice the amount you can cover by bracketing ±2EV (four stops). He used enfuse, rather than going the HDR route, but the principle is the same. Note how he avoided both blown highlights and lost shadow detail by combining that large a range; something that could not be done by any single member image.

[VegasMike]

Thanks for the info. I like most of the HDR work I've seen, I'm not quite sold yet on the work that no longer looks like a photo. Some of it is ok depending on the subject matter but some I've seen look almost over done.

[Daoust]

Thanks for asking this question, Mike. Like you, I have an Xsi, and like you, I did the same thing with the exposure bracketing thing, but I've never been satisfied with the outcomes. I've never been able to make my HDR pics look as good as the ones that people post on DPS . And I can't quite figure out why. But anyway, thanks for the help that this question provided.

[data5amurai]

Your multiple exposures due to bracketing dont really have too much to do with overprocessed images. The tone mapping procedure really is where that comes in. Most people (especially those who are new to the technique) tend to overprocess. However, tone mapping can add relevant beauty to many types of photo's if done correctly. Using a bracketing procedure of +-2 tends to work for me 80% of the time. If I just want to tone map and get a clear shot without physically bracketing (Especially when things are moving like trees, etc..) then I only shoot one RAW shot and use PS RAW editor to manually up the exposure for that shot by 1 and then 2 stops saving each one. Then create the HDR from the 3 combined.