On Friday night it was clear in Bromley although, by the sounds of it Headcorn was clouded over...
Anyway I managed to pop out & try my first LRGB image using the SC3 & MN56. Image is of M57 details as follows:
L=80 X 12sec
R,G,B = 15 X 12secs
It was quite a learning curve figuring out how to do an LRGB in Photoshop - also because I don't have a filter wheel I had to take the camera out between exposures to change the filter which also meant I had to figure out how to align & rotate images... Thks Chris for Stella Magic tip.
Anyway here's the image...
(http://homepage.ntlworld.com/john.punnett/graphics/oas/m57_03062006.jpg)
John,
That is the clearest image I have ever seen, you must be very pleased.
What does LRGB mean, is it the colour of the filters? If so, what is L?
Fay
Thks Fay - I was just pleased to have figured out how to do LRGB :-) An LRGB image is a high resolution colour image acquired using a B&W camera (like my SC3)
Basically the L is for luminosity - You just take a black & white image with no filter (you could also use a Ha or SII for the L) - This image needs to be as long as possible because it is what will give the image all its detail.
The RGB are images taken through Red, Green & Blue filters respectively. These images can be a lot shorter than the L (typically 1/3 the time) & just provide the colour information.
Once you have taken the 4 images you can then combine them all in Photoshop to produce a high resolution colour image...
Sounds easy but I can assure you it isn't... especially when like me you haven't got a filter wheel which meant that each time I took an image I had to take the camera out, change the filter, put it back in & refocus etc....
It's a long old process....
Hope that helps, John
Lovely image John, and they do say 'you can never rush a goog thing' and as you see it may have taken a while to process the image but i bet you it was worth the wait.
Keep it up.
Tony G
Thanks Tony... I'm working on sorting out autoguiding which will hopefully mean I can take longer exposures without drift.. What I have learnt with all this deep sky stuff is that if you want to do it properly you need to just concentrate on capturing one image per session.. don't try & grab lots of images in one night...
It's all good fun...
John
Nice one John, that camera is a beauty