Not my idea of a good time out with my cameras, but an interesting technique nonetheless.michael.panoff said:My understanding is that a digital exposure on a modern day SLR has more dynamic range than film, depending on the sensor size. 32-bit-per-channel HDR is a floating point format, it is nearly inifinite in the dynamic range it can represent. I can take 5 or 6 exposures 2 or 3 stops apart, and combine them via HDR to an image that exceeds the range the human eye can even see. Hence the problem with squashing it to a viewable/printable mode.
The details of how floating points are used to reprsent this giant range currently escapes me.. even with a CS degree, I'm sure I can dig up some papers on the painful details.
If you're interested in the technique, at least how I've been doing it:
1) setup my 20d on a tripod,
2) dial the camera into the exposure I belive to be correct
3) take exposure at -2 stops,
4) another at -4 stops (from original)
5) go back to the original exposure +2 stops
6) then another at +4 stops
Only adjusting the shutter speed, messing with the aperture will affect the DOF, this no good for HDR combining. I have gotten good results by hand-holding when auto-bracketing my camera at +/- 2 stops. Your shutter speed has to be pretty quick and you camera has to be super quick at snapping all the exposures, too avoid any hand motion.
The New York Times' senior film critic, A. O. Scott, actually had a few nice things to say about the big-screen Miami Vice, the cinematography being merely one aspect (and I'm not yet a fan of digital filmmaking, at least from what I've seen). I might see it just for a hoot, as well as out of digital curiosity.As a side note. I don't recommend seeing Miami Vice in general, but from a technical perspective they used digital HD cameras for the explicit purpose of higher dynamic range.. which translates to smaller f-stop, less bokeh, more background details.. while shooting at night.
My understanding is that a digital exposure on a modern day SLR has more dynamic range than film, depending on the sensor size.
SuitePhoto said:Digital still cameras actually have less dynamic range than film - with 16 bit depth. HDR allows you to go to 32 bits by combining the two images.
Finder said:????
Dynamic range is the luminous difference of the scene recorded between the black point and white point. Bit depth is just how many levels that range is divided into. One is not related to the other. Combining two different images is a method of compressing scene contrast to fit in one image file, not for changing the dynamic range of the camera - there is a difference.
The same goes for film. Printing a negative on a piece of paper using dodging, burning, or different contrast indices does not change the density range of the film, nor that of the paper. Those methods simply control the density range of the film to fit the paper.
Wow, that's really interesting. I wonder what kind of sensors those HD cameras use.SuitePhoto said:Digital still cameras actually have less dynamic range than film - with 16 bit depth. HDR allows you to go to 32 bits by combining the two images.
On the other hand, HD Video has a HUGE amount of dynamic range. When I do photoshoots for my company, we usually hire a multimedia company to shoot HD video alongside of the stills that I shoot. It's incredible - the same shots from two different cameras are completely different. HD is usually much more saturated and can handle at least two stops more of contrast.