Phillips SPC900NC Webcam Problems

[Lonnie]

Having problems viewing Jupiter and other planets with the SPC900NC although viewing the Moon is OK. I have a 200mm newtonion, F6 and use a 2x Barlow to view the Moon, using SharpCap Application.

The procedure I have used is to set up and focus on the moon with an appropriate eyepiece, swap with the webcam and adjust focus, then exposure and gain in SharpCap, using the histogram option. I, then, swap back to an eyepeice and focus on Jupiter and try to reproduce above, without success. I have tried adjusting the Gamma and white balance but could not pick up anything apart from a few hot spots.

Can you advise on what I'm doing wrong?

Thanks!

[Wildwood]

Hi, when using Sharpcap on a 250mm newt with an SPC900 and 2x Barlow I set exposure to -7/8 and gain to around 33. Anything higher and I find that I see nothing but a white disc. HTH

[Lonnie]

Thanks for the info, I'll try the settings tonite.

Incidently, can you see any star fields (not DSO's), say around cygnus, using the non-LX version of the webcam or is it planetary only?

Thanks!

[themos]

I can easily pick up the Jovian moons in my ToUcam Pro.

[Lonnie]

Thanks Themos - you've helped to raise my level of expection, which was quite low! Weather permitting, I'll be up early tomorrow morning to catch Jupiter in the West.

[Jamie]

I am thinking that maybe your frame rate is a little too slow.....

[themos]

Ok, here's what should work: First find something bright with a low power eyepiece. Align any finders you have. Move to Jupiter (with the help of the finder) and center it and track at sidereal rate. Then put the barlow in and a low power eyepiece and recenter Jupiter. Then the barlow with a high power eyepiece and recenter. Now, when you pop in the webcam on top of the barlow you should have a defocused Jupiter in view. Use the automatic gain setting at this point as the defocused doughnut may be too faint. Change focus until Jupiter shows up. Do a rough focus and switch to manual gain, at maximum with longest exposure (use 5fps for this). Slew east or west, looking for one of the moons. They can help you nail focus but at a high f-ratio the focus is quite "soft", not 40 microns in width but more like 500 microns or more. Then slew back to Jupiter, set to 10fps and longest exposure. Adjust the gain so that the histogram is well to the right but does not show clipping on the right edge.

[Lonnie]

Finally tracked Jupiter down, very will-of-the-wisp, though, down to trying to nudge-nudge the dobsonian scope into alignment. As you can see with the attachments, the snap shots were OK but very fleeting - next move - motorised equatorial mount.

Anyway, Webcam working perfectly, thanks for your help.

For reference, the settings were:

Frame Rate - 5 fps

Resolution - 640 x 480

Exposure - -6

Gain - 21

Again, thanks!

[michaelmorris]

I'm glad to see you got it sorted. I remember that it took me two evenings just to get Mars on the chip of my first webcam.

[todd8137]

i would suggest a bit of software called castrator google it as with dobs it drifts jupiter) through the fov very quick i would also bump the fps to 15/25 but do not turn the gain ect to compensate for the dark image it will just add noise

run the avi through castrator and then through registax you will get more frames stacked this way and you can fiddle with you image after to lighten

[Lonnie]

Todd8137, Thanks for the suggestion! I'll give it a whirl, although the idea of castration in any form brings a tear to the eye

[bottletopburly]

Here's my pennies worth I use a 200p on eq5 dual axis motors ,find Jupiter with 25mm ep reduce to 10 mm centre in eyepiece now reduce to 6mm ep recentre now swap for webcam turn up brightness keep eye on laptop hopefully bang on now just focus and reset settings in sharp cap to suit.

[Carl Reade]

Yep have to agree with Bottle, highest mag eyepeice centred then pop webcam in or frustration can rapidly follow. Good shots by the way!