On HRDI and TG 2

[piggy]

What is the best way to do it?

Straight export from TG2 ?

Do 3 renders from TG2 with different exposure (very high, mid, very low) and then merge the 3 outputs ?

Use Tram 2 ?

Which way gets the best result ?

Any suggestion ?

[Oshyan]

It really depends on what software you are using to process (likely "tone map") your image for an end result. Ideally the program will handle EXR output well. Unfortunately Photomatix (one of the most popular dedicated "HDR" programs) does not seem to handle TG2 EXRs ideally, so the "multiple exposure" method is somewhat favored for that software. That being said you can in fact create "multiple exposures" from a single TG2 EXR file simply by adjusting exposure level and saving out multiple LDR (low dynamic range or "standard" 24 bit) files as e.g. TIFF. There is no need to render the scene multiple times to get different exposures and doing so is rather wasteful.

- Oshyan

[piggy]

you can in fact create "multiple exposures" from a single TG2 EXR file simply by adjusting exposure level and saving out multiple LDR (low dynamic range or "standard" 24 bit) files as e.g. TIFF.

- Oshyan

Thanks !

On the exposure, has anyone found the optimum exposure setting for HDRI - for all hi, mid and lo ?

[domdib]

Unfortunately Photomatix (one of the most popular dedicated "HDR" programs) does not seem to handle TG2 EXRs ideally, so the "multiple exposure" method is somewhat favored for that software.

- Oshyan

Oshyan, could you expand a little on this - in what way does it not handle EXRs "ideally"? I ask because opening them directly in Photomatix is a bit less labour-intensive, so I'd like to know what I'm missing out on.

[Oshyan]

I haven't really experimented much with it myself, but reports from others seemed to indicate that the results were more aesthetically pleasing from merging of multiple exposures vs. using a single EXR. I don't know why this is the case, perhaps there is just so much information in the full EXR that the top and bottom of the scale are putting off the balance of the mid-range and the compression isn't as effective. Or perhaps there is some bias due to extremely bright pixels (e.g. sun) skewing the tone mapping algorithms. I'm just speculating. I'd really hope that the EXR would actually give the superior results as it has the most information in it. I think it's worth someone doing some more formal tests, particularly in comparison to other apps (like the recently released Photoshop CS5 with enhanced HDR and tone mapping functionality).

- Oshyan

[domdib]

Thanks!