CCD imaging - starting out

[RichardK (Richard)]

Does anyone have any suggestions of a good CCD (webcam) for starting out? I will be using an 8" DOB and be starting out with the moon and planets. (I have read about limitations with a DOB - but this is where I will start). I also have a lap top that I can use to hook up to the scope.

I have read some articles about using an off the shelf webcam (i.e. ToUcam Pro 840k - Mike Sallaway on this site) but see there are now reasonably priced cameras i.e Starshoot Solar System IV - $149.

Any suggestions would be greatly appreciated.

Thanks

Richard

Feluga

[[1ponders] (Paul)]

Hi Richard.

If you are going for solar system objects, (don't forget asteroid and widefield with a suitable lens for meteors) then think about exposure length and small pixel size. Around 6.4 microns is a good all round pixel size and the ability to go for at least a minutes exposure avail. Longer would be better. Add to that next a good frame rate with minimum compression.

Colour is a personal choice, I like mono, you then have the ability to add various filters later on, not just rgb but Ha and others. Or you could go one shot colour. If you are doing luna and solar mainly I'd suggest go for the mono. But starting out on the planets then one shot colour would likely be the go.

There are plenty of cameras around that fill those criteria in a very reasonable price range. I have tried the DBK31 and must say I am a bit disappointed in its sensitivity (and willingness to work with other softward). I have only really used it as a guide camera and found it lacking. I can't say how it would go as planetary camera. I do know though I had issues with getting the settings right so that Registax would open it. Mono I love my DMK21. Its a fantastic little camera for me and a good step up from a OSC.

[RichardK (Richard)]

Paul

thanks for your reply. I assume that the 'cheaper' cameras are fairly limited and the DMK21 while a little more expensive would be much more satisfying in the long run.

Also, if you use filters to get colour, does this mean you have to put one colour in, take some images change to the next etc (I assume Red,BG).
Does this then make it more challenging to to get a crisp image compared to a OSC (One shot colour?)?

Thanks for your suggestions so far.

Richard

[[1ponders] (Paul)]

Not really Richard. There are some very good OSC out there starting at the ToUcam 840 (still have mine and the 900) either modded or standard. However a dedicated CCD camera is what you are after then the DMK do take some beating as an imaging camera. And you will get improved resolution, not less. Which is why imagers move to RGB. Plus you have more control over the quality of the image output.

I've used my DMK for long exposure (5 min) subs on Eta Carina and it does a very reasonable job. It will be noisy, they are not deep sky cameras, but darks do wonders and it can be processed in registax. I have tried RGB with it on planets using a manual filter wheel but it wasn't my cup of tea so i moved the wheel and filters on. But I kept the camera. Iceman (Mike) did fantastic RGB of Jupiter and Saturn, but that certainly isn't with a Dob. RGB, must have tracking.

So if you are going for a dob and don't want to primarily image in colour (moon, sun, meteors, asteroids) then DMK or similar would be the go. If you want colour with the planets then the Starshoot Solar System IV might be the go.

Oh and the DMK make great guidecameras with phd. I know i sound like a salesman for DMK but I'm not . Mines just a great little camera. Outperforms by quite a way what my poor ol' ToUcams used to struggle to do.

[multiweb (Marc)]

OSC and a small sensor would be my recommendation to start with. That should get you to a good start with minimal amount of field problems.

[RichardK (Richard)]

Marc

what is a sensor?

Richard

[multiweb (Marc)]

Originally Posted by RichardK

Marc

what is a sensor?

Richard

The CCD itself. If it's within 20mm diagonal you'll be ok with most scopes. Anything bigger you might run into issues such as field curvature, coma, etc... depending on the optics used. You'll need correctors and it all starts to add up.