View Full Version : Rating Dynamic Range


Richard Zlamany
October 14th, 2005, 08:23 PM
Which Camcorders have the best dynamic range for light? What is the spec to tell dynamic range?

Richard Zlamany
October 17th, 2005, 11:34 AM
Please, can anyone help me with any info on this subject? Or is this a stupid question in the wrong forum?

Robert Knecht Schmidt
October 17th, 2005, 03:05 PM
Many manufacturers advertise ISO numbers for their digital cameras, the ISO sensitivity ratings being a holdover from film cameras. Bit of comparing apples to oranges, but better oranges than nothing at all.

Dynamic range is more correctly measured in decades of relative intensity. You can use a program like HDR Shop to determine the gamma curves for your particular camera.

The maximum limit of any digital camera system's dynamic range will be determined by the bit depth of the A/D or the storage medium (in bits per channel per pixel). For many cameras the A/D is 12 bits (74 dB) and the storage medium stores data at 16 bits (98 dB). So if you're interested in dynamic range, a good first question to ask is, "What's the sampling resolution of the A/D?"

On the other hand the A/D and storage resolutions are rarely the limiting factors in consumer camera systems. For total system dynamic range you're usually looking at something in the 40 dB to 50 dB zone for camcorders.

I'm sorry if the above doesn't supply the answer you're looking for. You can find a number of good resources by Googling, but not, as far as I can tell, lists of the dynamic ranges of popular camcorders by Sony, Canon, Panasonic, etc. This doesn't prevent you from testing out these cameras yourself. If you were to put together a web site with dynamic range test data it would probably become a prized resource, especially for people in the computer graphics and cinematography fields.

http://www.debevec.org
http://www.hdrc.com/hdrctech.htm

Richard Zlamany
October 17th, 2005, 05:31 PM
Thanks for answering. I'll do more research.

The reason I am asking is I have a pd 170 and sometimes the sky looks white when I set the exposure for my subject. I was looking at my fathers 50 yr old slides and the pictures he shot had his subject and the sky exposed much better than pd170.

I really like that look of a person with a blue sky behind them so I guess I will have to light my subject better if I want to have blue sky backround. I hope one day I will have camcorder that could shoot this shot without the light for the subject. Thanks again. :-)

Glenn Chan
October 17th, 2005, 06:36 PM
Hi Richard,
I started a thread about this some time ago and didn't get that many responses to it. The problem mostly lies in that:
A- Most manufacturers do not publish exposure latitude / dynamic range stats.
B- When they do, it's subject to fudging for advertising purposes.

Some of the newer cameras out there have adjustable gamma settings so you can increase dynamic range. The DVX100 is one such camera that does this (the cinegamma mode).

http://www.dvinfo.net/conf/showthread.php?t=48634

2- Another way to get blue skies may be to use a polarizer filter.

Richard Zlamany
October 17th, 2005, 07:59 PM
Hi Glenn,

Thanks for the thread and the info. That helped a lot. I'll try the filter.

I appreciate how helpful you all are and love this place.

I came through a side door to videography so I am missing some of the fundamentals. This thread has expanded my vocabulary so I may try new searches on this forum and google. Thank you.

ps. The Andromeda DVX100 sounds perfect.

John Jackman
October 17th, 2005, 08:33 PM
The reason I am asking is I have a pd 170 and sometimes the sky looks white when I set the exposure for my subject. I was looking at my fathers 50 yr old slides and the pictures he shot had his subject and the sky exposed much better than pd170.

I'm afraid this is very basic to video cameras, which have come a long way in recent years but still do not have the dynamic range of film. The best high-end cameras are catching up through tricks in DSP, but lower end cams like the pd170 don't have this.

Even with film, graduated filters and polarizing filters are often used to get a decent exposure on the sky. If your dad was much of a photo hobbyist, it is likely that he may have used a polarizing filter -- or at least a UV/haze filter -- on his camera. No filters on your cam would have made the difference even more dramatic.

Richard Zlamany
October 17th, 2005, 10:51 PM
Hi John,

Thanks for replying. Which cameras are consider high end?

Are digital beta, beta, DVcam, or HDV considered high end? Is that the order for high to low end camera formats? Sorry for all the questions but the more I learn the more I wonder.

There are so many options it is confusing. Thanks in advance for any information.