View Full Version : Dynamic range - stills vs video.
Doug Bennett March 29th, 2006, 07:25 PM Is there a difference in dynamic range between HDV and DV, or between different manufacturers and models?
Do DSLRs have significantly better dynamic range than HDV/DV?
Is there any difference in dynamic range between taking shots in photo mode on the H1 vs screeb grabs from video
Thanks
Robert Sanders March 29th, 2006, 08:18 PM Dynamic range really depends on the bit depth of the rendered image. Whether it be 8-bit or 10-bit.
Doug Bennett April 3rd, 2006, 09:39 PM Robert, bit depth is the number of stairs in the staircase, dynamic range (latitude) is the height of the staircase. A 10 bit image may have less dynamic range than an 8 bit image.
Steven Thomas April 4th, 2006, 10:10 PM Last time I checked, more bits means more dynamic range.
Having said that, dynamic range is a composite of of the entire signal path.
So it could be possible to have a greater dynamic range with 8 bit over 10 bit.
Levan Bakhia April 4th, 2006, 10:44 PM so, what type of measurment is used to mesure the dynamic range? And has anyone done comparison of H1/HVX200/JVC/Cinealta/Viper in this aspect? How well does H1 compare to other ones, and more importantly to bigger cameras like cinealta. I have seen all the comparisons of resolution, but nobody ever mentioned this.
Nick Hiltgen April 6th, 2006, 01:33 AM Levan I'll try to do a dynamic range test tomorrow. If I recall the way to do it is to open up the lens on a chart so that you can see 105% then close down a stop at a time until you're completely black. (monitoring of course on a waveform monitor) Seems like that might be wrong for some reason though.
Barry Green April 6th, 2006, 01:41 AM Seems like that might be rong for some reason though.
One problem with that technique is that the lenses on these cameras aren't necessarily calibrated in T-stops, so changing one stop on the iris ring may or may not actually result in cutting the transmitted light in half.
However, you can probably rely on the shutter speed, so if you want to sequentially double the shutter speed that may be more reliable than changing the iris.
Pekka Uotila April 6th, 2006, 04:24 AM Levan and Nick,
check this first,
http://www.cinematography.net/digital-latitude.htm
Nick Hiltgen April 6th, 2006, 12:47 PM thanks for the heads up, Pekka, I'm afraid I'm not really sure how to make any sense of the results though, I think maybe changing the shutter speed as Barry suggested might be the best option. But I really have never done a dynamic range test (I know, what kinda nerd am I if I haven't even done that!) so if someone wants to walk a step by step through for me, that would be awesome, or I'll just look on the internet for suggestions.
Pekka Uotila April 9th, 2006, 03:46 AM Nick,
I guess I just wanted to save your time. The Canon XL-H1 dynamic range test is there.
As far as I can understand the dynamic range is very much the same as digital latitude. The main tests were done with Viper,Sony F950 and... But there is a test that is done similarly with Canon XL-H1, it is named Canon HDV. It is done by an other person in other conditions but I believe it is very precise.
I think that this testing method is very simple and reasonable. The results just made me very happy as a Canon XL-H1 owner because I cannot have the viper...
Please correct me if I am misunderstanding something.
Anyway. I believe that this weekends Texas happening will bring new light to these issues aswell.
Btw, the information you've given here at DVinfo has been very valuable for me.
Thanks.
Ps. It really seems that the T stops are not very accurate with very large or small apertures. Atleast the cameras own exposure meter gives me such readings.
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