I don't know if this is what you're talking about or not, but there's a technique called HDRI(High Dynamic Range Imaging).
I have some experience with 3D renderings and this is what the technique is for, but the end result is amazing as far as quality goes for any image.
You take a series of snapshots at multiple stops of exposure.
You want them to be about 4 stops of exposure apart.
You then combine all the images using Photoshop CS2's built in module and you end up with a 32 bit float image.
These images contain ALOT of data, and being 32bit float they are able to display a much higher dynamic range of luminance values in the image.
RAW conversions are 16 bit images, which is still considered low dynamic range.
By using HDR imaging, you end up with image data that describes the real world levels of light present in the scene.
This technique was developed by Industrial Light and Magic for the specific purpose of combining computer generated objects and characters with live footage. Since the image contains real world light values, they input that data into a 3D rendering application so that the lighting of the computer effects exactly matches the lighting of the live film footage.
It's pure genius!
ILM's format is known as OpenEXR, and photoshop cs2 can open and manipulate them. There's also a format called Radiance which photoshop can understand. The general one is .hdr.
You can find them all over the web.
If you've never seen one you should take a look at them.
The contrast and resolution of these images is mind blowing.
They can actually represent the entire dynamic range that the human eye is capable of. The problem is finding a display that can accomodate that.
I've never actually taken one on my own. I've worked with them alot in 3D applications though.
There's a free application for windows only called HDRshop.
Here's the explanation::
How do I shoot an HDR image?
Most digital cameras are only able to capture a limited dynamic range (the exposure setting determines which part of the total dynamic range will be captured). This is why HDR images are commonly created from photos of the same scene taken under different exposure levels.
Here are some recommendations for taking different exposures for the HDR image:
1. Mount your camera on a tripod
2. Set your camera to manual exposure mode. Select an appropriate aperture for your scene (e.g. f/8 or less if you need more depth of field) and the lowest ISO setting.
3. Measure the light in the brightest part of your scene (spot metering or in Av mode to point only the highlights) and note the exposure time. Do the same for the darkest shadows of your scene.
4. Determine the number and value of exposures necessary. For this, take as a basis the exposure time measured for the highlights. Multiply this number by 4 to find the next exposure with a stop spacing of 2 EV. Multiply by 4 successively for the next exposures till you pass the exposure measured for the shadows. (Note: For most daylight outdoor scenes excluding the sun, 3 exposures spaced by two EVs are often sufficient to properly cover the dynamic range).
5. You can make use of Auto-Exposure Bracketing if your camera supports it and if it allows a sufficient exposure increment and number of auto-bracketed frames to cover the dynamic range determined in step 4. Otherwise, you will have to vary the exposure times manually.
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