webcam + homemade guide scope....

[stan26]

Hi folks, I'm in the process of setting up all the bits and pieces to guide with my EQ3-2 mount. I anticipated a short while back that I would eventualy go down the guiding route so I had already converted my old vixen 60L refractor in a short focal guide scope ready for the job. I done this by removing one of the front objective lenses and working out th focal point and cutting the tube to length (approx 250mm) I have now ended up with an f4 ratio scope which I can focus my quickcam pro 4000 through quite easily, However after a trial run this morning using th moon and brighter stars I soon realised that the scope is giving the webcam a very narrow FOV and much more magnification than I expected, i.e the full disc of the moon won't fit in the FOV, However if I put a diagnol and 25mm eyepiece and look through it I get a reasonably wide FOV. Why is this....? lenses on webcam have been removed....?

Is this mag and narrow fov going to cause me many issues when guiding......? I accept the obvious problem being lack of stars to choose from in the fov.

This is my first experience with a webcam, I noticed that the image in PHD was very noisy and the brighter starts seemed to flicker, do I need to get rid of the "flickering" before I can guide...? The box locks onto th star and follows it ok, but it seems to be a bit jumpy with the flickering star image.....?

Sorry if these are daft questions, steep learning curve and all that...

[Psychobilly]

The Samller FOV is due to the size of the chip in the webcam... typically its roughly the same as the FOV you would get with a 6mm EP if your usign one of the older webcams...

[stan26]

Thanks for the reply psychobilly, So the logitech quickcam pro 4000 is classed as an "older" cam I guess..?? and its because of this I get the narrow FOV.

I actually thought it might be because I removed a front element from the vixen scope, but maybe not. Is there anything I can do to get a greater FOV...?

Cheers

Stan

[Psychobilly]

Yes I would say so... Some of the newer cams have 16:9 format Widescreen sensors...