Webcams, Mono and RAW

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Webcams, Mono and RAW

Postby Dion » Mon Dec 05, 2011 12:38 am

So what's the deal with webcams, mono chips and raw mode?

Put very simply, a colour webcam only uses a third of it's potential as it has to split everything up into reds greens and blues, a mono chip doesn't, so mono chips tend to be more sensitive but also give better picture quality as they technically have less to do. However, you can give the electronics even less work by taking the images from the chips in a less processed state, normally RAW mode, in effect this is the image taken almost directly from the chip without the camera being allowed to process it, a PC can process it a lot better, so again you'll get a better overall image quality.

If you look at the above with regards a webcam, things become easier to define, you can image with a standard SPC900 and results are adequate, you can change the chip for a mono chip and you gain at least 3 times the sensitivity but also get an increase in image quality. BUT, at this point, the webcam 'thinks' it still has a colour chip in it and will treat any imaging accordingly before sending it to the PC, so next, we can flash a webcam to make it process in mono raw mode.

The thing is, a webcam isn't made to be used in RAW format, and even though it can be flashed to RAW and even told that RAW is it's factory default, it will still 'forget' So, if you have a mono chipped webcam that has been flashed to RAW, when you first plug it in, it will actually behave like the second scenario above, ie, treat it like colour even though it's mono, not giving the benefit of the RAW mod.

SO

Firstly, if you have a mono modded webcam flashed to RAW, EVERY time you use it you NEED to just run wcctrl, point it to the camera and in the second tab, click the orange button that says "Factory Defaults". This will then force the camera into RAW mode, and you need to do this EVERY time you use that camera.

Something that will become apparent when processing images in registax with a RAW modded camera, is that if you did the wcctrl factory set above, when the images are loaded into registax, it will give a popup saying "images appear to be in mono" If you did NOT do the wcctrl thing, it wont! (remember, the webcam 'thinks' it still has a colour chip in it and will treat any imaging accordingly

So what are the results?

well, in the below images, first in full size :-

1) Colour still, grabbed with a bog standard SPC900

2) Mono chip fitted but the camera still thinks it's a colour camera and treats the imaging as such.

3) Mono chip fitted and imaging in RAW mode. It's very apparent that 3 is cleaner, sharper and less noisy.

Image


Now the same 3 images with a cropped section and zoomed 4 times :-

Image

Discuss here :-

viewtopic.php?f=42&t=6099

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Dion
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Re: Webcams, Mono and RAW

Postby Dion » Mon Dec 05, 2011 2:07 am

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Dion
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Joined: Thu Sep 16, 2010 3:03 am
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