[Deni]

Hello!

I have a photo taken in raw and was trying to make a hdr image out of it. I tried to process the raw into several jpg files (tried with 3, 5 and 7) and setting the exposure compensation at different levels for every jpg. I thought this will work as I have several jpgs of the same scene with different exposures. But it didn't PS cs2 tells me there isn't enough dynamic range in the files for a hdr job.

Am I mad for trying this, i.e. it's impossible to process a hdr image with files with just different exposure compensations?

I did try to compensate by 1stop, i.e. 1, by 2 ect, but the same story.

Thanks for the input!

Deni

[philmorley]

cs3 you can, but not cs2. try the tone mapping plugin by photomatix HDR photo software & plugin - Tone Mapping, Exposure Blending & HDR Imaging for photography

rgds
phil

[attack11]

you can't make an hdr image from 1 raw. you can only tone map it, and you don't need to save multiple jpgs to do that task.

real hdr requires 5 or more exposures at the same aperture and different shutter speeds to record different ranges of light information; 1 raw doesn't give you high dynamic range

[dingnecros]

I have been trying my hand at hdr and must say that its not that easy . Some photos yeild perfectly to HDR and some dont and as already mentioned tone mapping is really important. just to give an example I feel HDR worked great for This but did not make much of a diff for This

It felt as if the second image just doesnt have enough range to actually justify an HDR photo. Both of these done with CS3

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Last edited by dingnecros; 07-02-2007 at 01:02 PM.

[attack11]

hdr is meant to bring out shadow detail without blowing out the whites; so it doesn't really work for day shots unless there's shadows.

the misrepresentation of tone mapping as hdr on flickr and other gallery sites has got tons of people tone mapping images which is unfortunate imo, 'cause they don't know the difference or how to even make an hdr image.

[chrisman]

attack11 is right - multiple images changing only the shutter speed, then you can try the HDR technique. The essentials are:

1. Camera on a tripod
2. Set the f-stop and do not change it
3. Take several shots (min. 3) of the same scene, each at different shutter speed eg 1/100, 1/250, 1/500, running from under- to over-exposure
4. Use the 'Merge to HDR' tool in Photoshop

The resulting HDR'd image will have a dynamic range far in excess of a single shot and allow you greater latitude for bringing the 'correct' amount of detail out of shadow or blown areas.

[Deni]

Thanks everyone for the input! I understand now how a hdr file can be composed. I tried shooting with the camera on a tripod but I always manage to bump the tripod a bit and the images don't align very well.

I guess I need to try better .

Thanks again!

Deni