SPC900 - again and again

[blusky]

So, I have failed to find the answer to the question how to capture a wider FOV using the camera. Using Barlows and extenders I can easily increase the magnification to the point where I start losing contrast, but there is no way I can fit the whole Moon or M42 onto the CCD chip of the camera.

Is my thinking correct that a larger CCD/CMOS chip would allow for that (hence all that new Canon EOS/T-ring affair?)

Is there any way to capture M42 using SPC900?

Thanks...

[Cornelius Varley]

You need to think differently abot getting the whole of the moon onto a webcam chip. At 640x400 the image will become pixelated and lack detail. By creating a mosaic of a number of overlapping images you can get an image which has detail. If you want to get the whole of the moon onto a chip 3.58 x 2.69mm in size you need to calculate the focal length required. The formula is 109 x height of chip (mm) This will give a image of the moon 2.69mm in diameter at a focal lenght of 293.21mm, not really practical with SW 200. A DSLR would give a moon diameter of with your dob.

Peter

[astromerlin]

You'll need a focal length of about 200mm, I use a Skywatcher finder with an Spc900 attached for my wide field and I can get all of M42 in the FOV.

A larger chip with a similar pixel size will give a wider FOV with your current setup

[blusky]

Thanks, good idea, but what shall I do with the cross-hairs of the viewfinder?

[malc-c]

I think you'll find that the cross hairs are probably part of the eyepiece, which is removed when you fit the adapter to attache the web cam

[Neil McRae]

Take various overlapping shots of the moon as Cornelius said and then use Microsoft Ice (free download) to stitch them together for a "whole" moon. Make sure all the exposures are the same or it will look patchy.

Neil