MONO vs OSC...competitors?

hi guys,

8 weeks passed by without one single chance for decent astrophotography except 1st of november when I imaged the
comet:
http://www.stargazer-observatory.com/holmes2.html

these days we have clear skies with superb transparency,...but seeing is really at its worse! minus 10 on pickering's scale...
so I had some time to write up my thoughts covering the interesting topic
monochromatic vs OSC - quite frankly, I tend to feel, that these different types of CCD do not necessarily need to be competitors....but please find time to check this out:
MONO vs OSC:
http://www.stargazer-observatory.com/mono_vs_osc.html

I'd appreciate any comments and thoughts you might have.

I know we have discussed this a couple of times,...it's just my attempt, to beat the DSI-less time for me here,...

Dietmar,
An interesting discussion that has been pressing on my mind lately. I remember when purchasing my first CCD camera (and still only one) Terry Platt actually suggested I get the monochrome (MX716) due to my mag. 4-4.5 skies. Even Alan Chen had to agree agree at the time . So my assumption has been that in poorer skies is where the mono makes the difference. But your images speak loudly indeed. I also assumed that making a synthetic luminance from an OSC was basically equivalent to one-third of signal as a mono shot for the same duration--my assumption even now when I make a synthetic out of my RGB. But in my rush to shoot both luminance and RGB in one evening I always feel I'm shorting myself of decent RGB signal and that my color suffers for it. So I've been thinking that maybe a one-shot would be the way to go for me.
But you mention that you feel the OSC needs lengthy time to really be the equivalent of RGB and you're now getting 6 hours or so. Unfortunately for me, with having to set up, align, etc. I really don't get that much time on an image. So, given the inability to get more than a couple of hours in, do you still give the edge of OSC?
BTW, on using both cameras, Bud Guinn's latest images using both really do show the benefit.
Regards, and thanks for sharing these observations,
Larry

Dietmar, that's a very interesting write-up... and very good information has been made available to all of us, thank you. 8)

Hi Dietmar,
I found that the Mono was much better than the OSC at least with the Meade Cameras.
I have not really seen any OSC that rival the Mono in capturing an image. It seems the Mono is the choice of most serious photographers that I know.

Great write up and super comparisons Dietmar.

My feelings are OSC and Mono both have place and need not really be competitors.The biggest drawback I see with a OSC is if you want to shoot narrowband you really lose resolution because of the fact you need to bin.

I think this is probably why a larger percentage of imagers choose a mono cam,more versatility.I know this is the reason I switched to a mono after starting out with a OSC.If I could afford to keep around both I would

I personally do not find processing the mono camera images any more difficult than than the OSC.Keeping in mind I was very inexperienced when I owned the OSC.

I am currently on my 4th 8O CCD camera,I chose this time to go with a NABG SBIG ST10xme.After a couple years of experience I decided for my local conditions I wanted a sensitive,high well, camera to get as much signal as possible.
I think I chose wisely this time,though it would be nice to have a little bigger chip

So,I would agree it is important to match your equipment to your local conditions to get the most out of either type of camera.

SBIG cameras are for sure more noisy than the SX cameras and good calibration is essential to get a good final result.For a beginning imager this can seem mysterious(it did to me)and it took me a bit to learn good calibration routines but I think anyone who has been imaging for awhile will tell you it really is not that painful to take a set of darks on a cloudy night and the bias frames only take a few minutes.

With a high quality master dark made up of say 20-30 dark frames at the longest exposure time you typically shoot,at the temperature you usually shoot along with a high quality master bias you can scale the darks for whatever exposure you may take.
This way there is no need for many different exposure length master dark frames.
This is how I have been calibrating for several months now along with my flats and it works great.
Anything left after the dark subtraction gets taken care of on the data reject and the combine.
I will probably use my masters for 3-5 months,it will just depend on how much the chip changes.I of course take new darks for summer use when I run the camera at -20.
I really don't feel this amount of "extra" imaging time will harm the camera at all.

Do I wish I didn't need to take any darks? You bet!Who wouldn't
With my particular camera it is necessary,it just isn't that difficult.

I agree with most of your findings and sure would not argue with the excellent results you and others obtain with your SX cameras,OSC are without question very capable.

I think the moral is just like telescopes,there is no perfect camera for every situation or object one wants to shoot.With the many choices available today everyone is sure to find something that suits them whether it be a OSC or a mono.

Thanks for posting your thoughts and comparisons,

Merry Christmas and Happy new Year!

Jason