View Full Version : Grain


Stephen Finton
June 9th, 2005, 11:08 PM
I've been tooling around with the HC1000 and have decided that its grain issue at 18dB is negligible. The 1.07MP CCDs is the reason. You see. I realize that though larger numbers of pixels mean dimmer video but at higher gain levels, it's not as noticeable as a camera that has fewer pixels.

Stephen Finton
June 10th, 2005, 07:47 AM
The stigma of higher pixel count CCDs (and CMOS) is an illusion. Especially since you can't get HD without them. Standard definition may suffer due to lower light that more pixels produce but since the GAIN on the TRV950, PDX10 and HC1000 is added at the CCD block and not electronically to the 720x480 or 720x576 signal, the GRAIN is not as pronounced as it would be with a lower pixel count CCD.

Tom Hardwick
June 10th, 2005, 08:42 AM
If you want to be shown why you shouldn't use high levels of gain-up Stephen (especially +18db, and I don't care what your pixel count is) try this simple test. Set up your camera on a triopd in good light and film a colourful scene. Now go into manual and set a very high shutter speed (or use ND filters) such that your camera has to use high levels of gain to achieve correct exposure.

Now go indoors and rock and roll the tape over this join, watching the footage on a TV. The A / B test will make you use gain up only when there's simply no alternative. Slow shutter speeds (where appropriate) are less damaging to the image quality.

tom.

Stephen Finton
June 10th, 2005, 09:28 AM
Tom,

I wasn't saying it was pristine, I was saying that gain on a higher pixel count CCD beats gain on a lower pixel count CCD. There is still grain, just smaller. And when you fit 1152x864 into an NTSC signal (for example), you get 1.7 times more pixels per NTSC pixel. Almost a 2:1 ratio where the pixels compliment each other. If one is exhibiting noise at one moent in time, its neighbor may be darker and the two will average out to a shade somewhere in between, which means less discernable grain than a CCD that has a lower pixel count.

I'd rather have lower light handling capabilities than use gain but I'm just saying that higher count pixel CCDs do not suffer the same as lower count CCDs when gain is applied.