Tone Mapping?

[Donald Miller]

I am posting the two images here as an example of what is available by tone mapping an image. While these images are digital, the process is also capable of being used with scanned images for either digital printing or enlarged negatives.

The first image is a normal exposure and shows clipping in both the highlights and shadows. The second image is the compilation of three exposures (one two stops under normal, one two stops over normal, and the selfsame normal exposure). A HDR image was created from these three exposures and then tone mapped to allow display of the HDR image on a monitor or output to a printer.

While this is not applicable to every exposure, it seems to go a long way to solving those situations of excessive SBR without some of the undesirable aspects of reduced or compensating negative development.

[chilihead]

Wow!!!

[Ken Lee]

I'm not sure what is meant by Tone Mapping, but one can find a variety of HDR methods on the web. Photoshop CS3 has built-in tools to enable it. As you say, it's a great solution for many problems. Not all, but many.

Is this something a bit different ?

[D. Bryant]

I am posting the two images here as an example of what is available by tone mapping an image. While these images are digital, the process is also capable of being used with scanned images for either digital printing or enlarged negatives.

The first image is a normal exposure and shows clipping in both the highlights and shadows. The second image is the compilation of three exposures (one two stops under normal, one two stops over normal, and the selfsame normal exposure). A HDR image was created from these three exposures and then tone mapped to allow display of the HDR image on a monitor or output to a printer.

While this is not applicable to every exposure, it seems to go a long way to solving those situations of excessive SBR without some of the undesirable aspects of reduced or compensating negative development.

You may wish to read the HDRI Handbook written by Christian Bloch,

http://www.hdrlabs.com/book/

This is a very comprehensive book intended to give the reader an introduction in the fundementals of HDRI along with a chapter on Tone Mapping.

I think that it is important to emphasize that HDRI and Tone Mapping are not equivalents as I think many people immediately associate HDRI with some of the cartoon like work as seen on Flikr and other web sites.

Photoshop CS3 Extended provides a fair amount of capapbility to edit 32 bit HDR images which the standard version of CS3 does not.

After reading this book it is pretty clear to me that 32 bit image capture is the next big step for digital imaging for still photographers. IOW, HDRI isn't a fad.

Don Bryant

[Ken Lee]

Thanks. I tried the tools available in standard CS3, and was... underwhelmed.

[Donald Miller]

I tried the tools that CS2 (on my laptop) incorporates (CS3 is on my desktop back home in Arizona) and I was not terribly impressed with the results I got with PS...probably in large part because I haven't spent much time with those tools.

I used a third party software for these two images.

Tone mapping, from what I understand, is used to enable the HDRI being brought back to a useable form since a HDRI will have a density range beyond what a monitor can display or a printer can print. (The sole exception to that is the High Density television that is being produced by a subsidiary of Dolby...cost $49,000.00)

Tone mapping can be done on a single image psuedo HDRI but then that is not true HDRI...so I assume that is what Don Bryant is drawing the distinction on.

32 bit is the next big step as Don mentioned.

Don, Thanks for the information on the book.

[jetcode]

to be honest - IMO while clipping may take a bad rap the original image has greater contrast to my eye, the second image may have more content but it doesn't mean it is more pleasing aesthetically, at least to my eye

tone mapping is a translation process - using curves is tone mapping

I took the liberty to adjust the HDR image according to my tastes (please take no offense). I used curves to correct the image contrast, and desaturated the yellow a bit. I noticed the espresso machine yellow cast is more saturated from the HDR process.

The real benefit is saving the blown out window. Thanks for sharing this process. I have seen it before and saw a couple of HDR images that were done in camera pre PS days with a 3 stop neutral density filter. The effect was much like an overdone HDR.

[Kirk Gittings]

to be honest - IMO while clipping may take a bad rap the original image has greater contrast to my eye, the second image may have more content but it doesn't mean it is more pleasing aesthetically, at least to my eye

tone mapping is a simple translation process - using curves is tone mapping

I agree completely. And I think simply clipping he first image differently in the raw processing would give you the second image virtually identically and if the second image were simply clipped tighter it would be virtually identical.

IMO, A better test would be to hold the values in the first with better and the full detail in the window. After playing with Tone Mapping for some months, I think the later test would at best display some weirdness and artifacts.

As I have said on other threads. I think this technology has allot of promise, but is not there yet. That is if you want to produce believable images with rich tonalities and extended dynamic range.

[Michael Gordon]

I'm with jetcode.

While the clipped highlights in the original are mildy distracting, it's a more tonally 'robust' image to my eyes. IMO, the 'corrected' version has been killed by HDR...

I don't get the whole post-processing-by-the-numbers thing. What happened to visual aesthetics?

[jetcode]

check out the image in my original post after I added the contrast and desaturated the yellow a bit. It still doesn't have the feel of the original though without reference I'm not sure anyone would notice.

This following edit of the image desaturated the yellow even more and the levels were adjusted. It seems that I am chasing the original. I like the image.