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-   -   How much difference is 2 lux? (https://www.dvinfo.net/forum/open-dv-discussion/22650-how-much-difference-2-lux.html)

Monte Merritt March 9th, 2004 10:47 AM

How much difference is 2 lux?
 
How much difference is 1 lux from 3 lux? I am considering two cameras that have a minimum illumination difference of 2 lux. I know 1 lux is the equivalent of a candle, but that doesn't really help me.
Does anyone know of a website where the difference is actually shown, possibly in a screen capture?

Thanks
Monte

(the cameras are the PD170 and the DVC80)

Ken Tanaka March 9th, 2004 11:35 AM

Hello Monte,
The "lux" ratings for cameras are really not very useful in absolute terms, due mainly to the non-standard ways in which the end-product is assessed.

I know of no comparative shots. Your best bet is to hear from someone who has used both cameras.

Guy Bruner March 9th, 2004 01:09 PM

Ken,
Please correct me if I misunderstand the concept. Presuming that both camcorders are accurately rated for light sensitivity...say at F/1.6 and +18 dB gain. The camcorder at 1 lux would be 1.75 F/stops faster than the 3 lux camcorder, right? Or, looking at it from a shutter aspect, the 1 lux camcorder could capture the same image as the 3 lux camcorder but at ~1 to 2 faster shutter speeds.

Monte Merritt March 9th, 2004 03:15 PM

Ken, I don't need absolute terms, just some idea...

Guy Bruner March 9th, 2004 04:18 PM

Monte,
If pictures of the relative brightness difference is all you are looking for, then go to my website. In the DV953 album, page 7, there are frame grabs at different lux levels. They are not at 1 and 3 but, I believe they will illustrate the relative difference between these two cameras. For example, the frame grab under halogen at 15 lux has the camera at F/1.6 and +18 db. That gives an IRE level of 44%. This would be close to what the 3 lux camera would show at 3 lux, F/1.6 and +18 db. The frame grab at 40 lux is similar to what the 1 lux camera would show at 3 lux.

BTW, I believe 1 footcandle=10 lux.

Frank Granovski March 9th, 2004 04:27 PM

Quote:

How much difference is 2 lux?
This should give you an idea: http://www.dvfreak.com/lux.htm

Jeff Donald March 9th, 2004 04:28 PM

There is no absolute method of determining a lux rating as it applies to DV video cameras. What level (percentage) of color is recorded is entirely up to the manufacture. In other words, one manufacture may rate their camera at 10 lux with 50% color, while another rates their camera at 1 lux with only 10% color.

Ken Tanaka March 9th, 2004 05:15 PM

Guy,
As Frank notes, the lux and f-stop numbers really do not tell a completely useful story with respect to video cameras. "Presuming that both camcorders are accurately rated for light sensitivity..." is not a valid presumption. Each manufacturer has their little, slightly deceptive, spec tricks. That "+18dB gain" figure, for example. Shooting video at that gain level will produce extremely grainy, noisy images. But the images are there and the camera captured them!

Sony has long been considered the "low light king". So if shooting in poor lighting is an important prospective requirement for your camera you may be more satisfied with the PD170.


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