OT: Gain questions

FrigidNDEditing wrote on 11/24/2004, 8:02 AM
Ok, so I've used a DSR200A and I was not impressed with how poorly it performed under low light conditions. I know that everyone under the sun seems to love the lowlight ability of sony, but I was wandering if things have changed much since the days of the DSR200A in terms of how they do gain etc...

My main issue with the 200A was that gain = quite a bit of grain. Is this just how it is? or is this because it only has 1/4" chips? or a lense that wasn't too large to begin with and can't be replaced?

is grain that I talk aobut the signal to noise ration that you guys talk about? I still use a lot of still photography terms.

Thanks.

Comments

Spot|DSE wrote on 11/24/2004, 8:17 AM
Low light+gain+DV=grain. That's just the way it is. Toss in 1/4 chips, it's not gonna help. Bigger chips mean more light gathering, but overall low light and gain mean grain. You can sometimes punchup under exposures in the NLE, Vegas is as good as any at this, but if the detail isn't there, it isn't there. The higher the compression format, the worse this is, but even in the better/uncompressed formats, you still run into the problem of gain creating noise.
And yes, it's basically the same thing as signal to noise. Light is what provides the signal.
FrigidNDEditing wrote on 11/24/2004, 8:32 AM
thanks again. I new the little chips wouldn't help, but I wanted to make sure. does the number of receptors on the chip make a difference in how much light it needs, like film? i.e. 100 speed film takes more light because it has twice as many silver salts to expose.

Or do more receptors on a chip the same size still only require the same amount of light for the exposure. -- This may not matter at all for all I know but it would seem to me that if HDV is still using a 1/3" chip, then it would have more receptors on the chip and require more light.

like I said, it may not be relivant.
Spot|DSE wrote on 11/24/2004, 9:06 AM
I'm not totally certain of myself here, because I've only studied the Super HAD chips that Sony has on the HDV cams. I've never cared until now, but I've wanted to know everything there is to know about HDV....so I don't sleep much lately.
Anyway, based on Sony's statements, it's not the number of microlenses (receptors as you call them) but how sensitive they are and how they convert the light and color.
You can read more about it at Sony's site, http://www.sony.net/Products/SC-HP/sys/ccd/sensor/super_had.html

The SuperHad technology is Sony's but they've adopted it from other technology. In researching it, I found that this was a reasonably accurate explanation without too much hype.