black and white - possibly stupid question

[nicks90]

Sorry if this is a really dense question - but I am trying to eek out more detail on my widefield constellation shots using my camera and fixed tripod. Obviously subs are very short (8 sec), so getting as much light on the chip as possible in that time is essential.

This had me thinking, if I set the camera to take black and white pictures instead of normal colour, would it pick up more light as it isnt applying a colour filter to each of the pixels - eg red, green, blue?

[Langy]

I think that if you are shooting in RAW mode then any information will be there that is available. Choosing one of the modes (i.e. B&W) the camera will take the original data and process it differently.

At 8 seconds on a tripod I guess you also have quite a short FL lens or you would be picking up star trails.

[steppenwolf]

Unfortunately, taking in black and white won't help this particular problem as the RGB filters are permanently overlaid as a matrix on top of the sensor surface - producing a black and white image from this type of sensor is simply a software process.

[Knight of Clear Skies]

I'm afraid not, no. The sensor on your chip is fitted with a physical Bayer Filter, which blocks much of the incoming light. This is the most important reason why a mono CCD is more sensitive.

[Leveye]

In this situation the only way to really get a bit more detail with only 8 seconds is raising the ISO which will of course add more noise. The best way to go is get a tracking mount and add more time to those subs. Afterwards when you have a stacked tiff try levels and curves to bring things out even more.

[nicks90]

thanks for that fast responce, much appreciated.

oh well, worth a quick ask - you never know!

the camera wont be getting astro modded, its my first decent camera after putting up with point and shoots all my life and I enjoy using it for normal photos. So far all my widefields have been taken with the kit 20-55mm lens, which means I can get 10sec exposures depending on where in the sky I'm shooting without signicant star trails.

But I am considering going for a longer fl zoom lens and picking up a cheap eq1 with ra drive to get some longer subs out of it.

Currently looking at getting an adaptor t-mount thingy to the older cannon thread, so I can purchase some of the cheaper 'obsolete' manual cannon zoom and prime focus lenses. I might even get a Tmount to focusser adaptor and have a go at sticking it in my 12" tracking dob and doing a few second exposures of some dsos too.

yep, I know - this could be the start of a rocky road to ruin.....

[Knight of Clear Skies]

Sound like a good plan. I've experimented a little with my DSLR on a fixed tripod using the kit and 50mm lenses, and my next step is to get a tracking mount of some kind.

[Langy]

You could also consider a barn door tracker, a lot of people have a go at building these.

[lensman57]

Sorry if this is a really dense question - but I am trying to eek out more detail on my widefield constellation shots using my camera and fixed tripod. Obviously subs are very short (8 sec), so getting as much light on the chip as possible in that time is essential.

This had me thinking, if I set the camera to take black and white pictures instead of normal colour, would it pick up more light as it isnt applying a colour filter to each of the pixels - eg red, green, blue?

In short the answer is no. A colour camera can not get rid of the Bayer martrix at a push of a button. What happens when you choose to shoot monochrome is that the on camera chip disposes of the colour data and presents you with sort of a "LUM" version of the capture after having applied some corrections simillar to curves so no the sensitivity is not affected. A monochrome CCD just does not have any Bayer matrix or any other filter on top of the chip so there is no light loss due to filtering.

A.G