Daft CCD question

[hayju01]

I see a number of CCD camera's offered as mono or colour versions like the Atik Titan on FLO here it seems there is no price difference.

So why would you buy the mono and not just go for the colour?

[StevieDvd]

The mono are better quality images but you need to use filters and several captures to get the colours. From what I've read, not done myself, the more ardent imagers go for mono.

A real imager will be along soon to correct any errors.

[hayju01]

Thanks. I figured it was something like that but if you don't aslk you'll never know:-)

at £400 I'll have to save up both cash and brownie points ;-)

[brianb]

There's also the point that if you are imaging with monochromatic filters (hydrogen alpha, for example) the resolution of a one-shot colour camera is seriously compromised as only a quarter of the pixel sensor sites will be active.

The only advantage of the one-shot colour camera is when you're not trying anything special, just standard RGB imaging, then you get away without having to buy a filter wheel & colour seperation filter set. The monochrome camera has many advantages though ease of use for beginners is not one of them.

[steppenwolf]

This is a discussion that will no doubt roll to eternity! There is a good argument for using a one shot colour (OSC) CCD camera in the UK where we have such fickle weather - at least with a OSC camera you get some kind of colour image in a short period of time. However, the key to the best quality images is held in the luminance channel as this is where the detail comes from and this channel is integrated into the data collected using a OSC camera but collected separately when using a mono camera and filters. A mono camera allows you to concentrate on collecting luminance data and then painting an overcoat of colour on top of that data. This results in higher fidelity images.

[ollypenrice]

Yes, this is almost as controversial as reflectors and refractors...

I use both, the mono being more flexible because it can do efficient H alpha narrowband (a specific deep red) where a colour camera only has one red-sensitive pixel in four. My pet example is this, One shot colour on the left and one shot colour with Ha shot in the mono camera on the right. Startling difference!

Much is written about the lower quality of OSC images over mono. I find, using both regularly, that it is more complicated than the discussions would have you believe. Some objects work brilliantly in the OSC, some less well. Anyone doubting the power of OSC cameras should look at the work of Greg Parker/Noel Carboni and Dietmar Hager. Another OSC plus is that you can use them sensibly with camera lenses. Changing filters with CCD to lens adapters is a titanic palaver and not something to be doing in the dark!

But one thing is certain, if I had only one it would be mono on the basis of the images posted above.

Olly

[hayju01]

Thanks guys.

It seems that whatever area of Astronomy you look at you will always need two pieces of kit!!! :-)

[iwatkins]

It seems that whatever area of Astronomy you look at you will always need two pieces of kit!!! :-)

Ain't that the truth

[brianb]

It seems that whatever area of Astronomy you look at you will always need two pieces of kit!!! :-)

Ain't that the truth

Well, a small fraction of it ... two is nowhere near enough ... when you can fill Hilbert's Hotel (*) with your kit, you're starting to get somewhere ...

(*) Hilbert's Hotel has a (countably) infinite number of rooms