Webcam advice

[earth titan]

Well the DSLR for DSOs is progressing well, but with Jupiter coming up I'm keen to have a go at that as well.

Just worried about magnification though. Tried taking a video of Jupiter with the DSLR hooked up to the 80D to drop into registrax, but only got a small spec. I've tried using eyepiece projection But the quality is very poor...

Am I likely to get better magnification with a webcam? If so, why?

[Bizibilder]

If you use something like an SPC900 (Morgan computers sell them for a sensible price) you can "guesstimate" the webcam as being roughly equivalent to a 6mm eyepiece. To get a planetary disc you will almost certainly need a barlow with the refractor but you should be able to get some good images from the lightbridge - both with and without the barlow.

[chemtom24]

a webcam like the spc900 will allow you to take an avi clip of the planet containing hundreds of frames - unlike a single shot dslr. this avi clip can be processed in registax, which basically collects all the good frames and stacks them one on top of the other, resulting in a much more detailed image that you could ever get with a single shot.

dont know the FL of the meade but you should be able to get a very decent size image with that scope. get nicely polar aligned and collect a 5 min avi fiel and you'll be very suprised at the result after using registax.

with webcam recordings, i dont think ( not 100% on this) that it matters if you push the mag way past the 200x which is the b est you can usually get for viewing, because again its a video which will be stacked. so ramp up the mag, get nice large image appearing on the screen, get focused, and record. proess with registax and youll have a lovely image

[Steve 1962]

Bizibuilder and ChemTom24 are both right (if you can't get am spc900, the 880 is available from Morgans preflashed to make it a 900).

Webcams (and other planetary cameras such as the QHY5, ISDMK21 etc) generally have much smaller sensors than a DSLR and so are capable of relatively high frame rate videos which take up a "sensible" amount of disc space.

Stacking of large numbers of video frames (which are quality selected) in programs like Registax or Avistack also have the advantage of reducing blur caused by atmospheric distortion. These programs also have wavelet routines included which provide an astonishing (to me anyway) degree of sharpening.

With the use of barlows and extension tubes you could get your 12" scope working up into the f30 to f40 range (so for your Lightbridge which I think is f5 (1500mm focal length) you could easily add a 5x barlow / powermate and some extension tubes to image the planets at (at least) a 10m focal length which would give you around x1600 magnification).

Whether you could locate/track an object at x1600 with a Dob would be an interesting exercise!

Putting a webcam and a barlow into your refractor would give you some great lunar shots too.

Hope this helps.

Steve

[Nova]

You may find this FOV calculator handy to give you an idea of how large the moon and planets will appear through your scope when coupled to an SPC900

http://www.12dstring.me.uk/fov.htm