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Kronie
29th of September 2008 (Mon), 13:44
I'm kind of new to processing HDR images and had a question.

I understand that the best way to create an HDR is to bracket 3 or more exposures and blend with PM or CS3.

You can also take a 1 RAW file and get the same look.

Whats the advantage of the multiple RAW files if you can get the same look from one? I understand your working from Jpegs in PM instead of RAW files.

I haven't yet done a side by side comparison but does it create a better image with multiple RAW's?

Is there less noise?

whats the benefit?

hawkeye60
29th of September 2008 (Mon), 13:51
Multiple images capture the whole dynamic range. One raw file does not, and therefore it's only a simulated effect.

canonloader
29th of September 2008 (Mon), 14:40
Whats the advantage of the multiple RAW files if you can get the same look from one?
You can't get quite the same look starting from a single RAW file. Like Hawkeye said, there is only 5 stops of dynamic range in a 40D and 7 in a 1D sensor. You have to take multiple images to cover them all.

But when you start with one, it opens in CS3 ACR as 0 exposure. Don't touch the other sliders, but move the Exposure slide to -4, then save a .tif of that, then slide it to -3 and save another tif. Just hit Alt + Save image and it will save another image automatically, using one number higher. Saves a lot of work. When your done, you have 9 images with different "psuedo" exposures. You can then import those to Photomatix and tone map them.

But when done, save that as a tif also, then in CS3, go to File/Open As, drop down the files of type picker and choose RAW. It will open that tif in the ACR interface and you can use the RAW sliders to change the image. Very neat. You can open almost any image as a RAW this way. ;)

When you have it like you want it, then Save Image as a jpg for final cropping, noise removal and sharpening. And since you have CS3, you should buy this little action (http://www.fredmiranda.com/shopping/1DISORpro) for $15. I Paid a hundred for Neat Image and now don't use it since getting this. ;)

Kronie
29th of September 2008 (Mon), 14:55
Multiple images capture the whole dynamic range. One raw file does not, and therefore it's only a simulated effect.

Right but is the quality the same in the end product?

Also, if you cant tell the difference between the correctly exposed RAW file converted to a jpeg or tiff and an underexposed RAW file, fixed, and then converted to jpeg or tiff then really whats the difference?

zacker
29th of September 2008 (Mon), 19:30
in a real HDR.. meaning a realistic looking scene, ther is a difference, its when you go to heavy tone mapping, it gets tuff to tell... there isnt the same amount of tonal range in a one shot raw file than in three or more. in fact alot of folks call a one file image HDR but its not, i like to call it a Pseudo HDR or forced HDR..

Oneslowz28
30th of September 2008 (Tue), 04:18
I use multiple raws (2-3) as a means to get 9+ exposures with out the chance of shake or movement that could come from taking the 3 exposures in jpg and then adjusting settings 2 more times.

Gum6y
30th of September 2008 (Tue), 12:45
I can open any file like a RAW with the ACR interface??!!?!? This is gold, thanks Mitch.

canonloader
30th of September 2008 (Tue), 13:19
I can open any file like a RAW with the ACR interface??!!?!? This is gold
The final selling point for me. I really didn't have the money to spend, but when I heard about that, I went ahead and upgraded from CS2. It's a really, really nice addition. :)

Gum6y
30th of September 2008 (Tue), 14:25
Its gold cause several times opening tifs I wanted the ACR interface and all along I could have had it. PS is one of those programs where you keep learning its just such a beast.

Am heading out this afternoon to take some more HDR pictures, is a beautiful day here in Bogota!

zacker
30th of September 2008 (Tue), 14:53
i use it all the time when working on jpegs.. in fact i have my file handeling in preferences on to open all files in ACR.

Duder
30th of September 2008 (Tue), 14:56
the whole point of High Dynamic Range imaging is to use bracketed exposures to capture more detail than a single image could in a scene with a wide dynamic range.