spc900 problems (i think)

[sytra]

OK, clear sky, webcam working... set up everything, blinking webcam won't pick anything up, cant focus or anything.

Camera tested of the scope and works fine, put it in focus tube and nothing, so aimed at a light about 200m away, picks it up perfect from then on it worked and i got a couple of short pics of Jupiter. i tried the 2x barlow and then the camera would not work again.

Any ideas why, if, i test it on a light it would suddenly start working properly?????? but if i just put it in the scope it wont get anything, i even tried a house the other night but it wouldn't focus on that.

I am using sharpcap, one thing i did notice was when it was focused after the light incident the sharpcap screen was a bluey colour but any other time it is jet black.

thanks for your help

[mallorcasaint]

Check your exposure and gain settings. Also you may find that your focal point is different with the barlow.

[Atlas]

When you add a barlow, you lower the brightness of your target, so you'll have to adjust your light setting to make it more sensitive.

[Probablynot]

Hi - I'm a newbie myself, but I did note that my own webcam has about the same responses as a 6mm eyepiece. You have to be very careful to centre the sky-object of your desire in your finderscope before switching to a 25mm ep, then centre it again before going lower. If you don't, then you're in serious danger of not seeing what you hope to see.

(Hope I'm not inviting a grandparent to suck eggs! Sorry if so!)

[DOBBY]

Have you read this thread ? http://stargazerslounge.com/primers-tutorials/40665-primer-planetary-imaging-toucam.html

[sytra]

Thanks for the advice everyone, hopefully it will be clear over the weekend so i can get out and about to give it another go.

[brucen]

It's one of those things that takes an age to do the first few times but, after a while, you wonder why. Not sure if it will help but I cannot get focus on planets with my 130P (which has the 2" focuser with the 1.25" adaptor) just using the webcam as there is not enough inward travel, I have to use a Barlow. I can focus without the Barlow only if unscrew the top part of the adaptor with the holding screws and just wedge the camera in the hole - I have made an adaptor from an old Barlow to make it a better fit though. I also turn up the gain and brightness whilst looking for the object and adjust once I have it in view. With the Barlow and the equivalent of a 6mm eyepiece it is not that simple to get anything in view but will get much easier after a while.

[todd8137]

the web cam would give you x108 mag if you use a barlow,then you have x208 i think you are pushing it to its limits i think ?

[brucen]

the web cam would give you x108 mag if you use a barlow,then you have x208 i think you are pushing it to its limits i think ?

You don't get 'magnification' using a webcam as there is no lens involved, it just affects the field of view. You should aim for a focal length of at least 2000 so, if yours is 650, a 3x Barlow is about right. I mainly use the 2x though as it's easier to find things! This may help: http://www.project-nightflight.net/webcam_imaging.pdf

[themos]

You don't get 'magnification' using a webcam as there is no lens involved

The magnification is not produced by the lens, it is produced by the geometric arrangement. A pinhole camera can produce any magnification you like and yet uses no lens. What the lens does is it allows you to open up the hole of a pinhole camera (so as to get more light) and still have a sharp image. The down side is that this magic only works at a certain distance from the hole, hence lenses have a definite "focal length" and the geometric arrangement becomes fixed, producing only one value of magnification.

[sytra]

Thanks again, the problem was the camera for some reason wont show anything through the scope, yet it works fine out of the eye piece, as soon as i aimed the scope at a security light in the distance the camera picked it up and worked fine afterwards, then i tried to involve the 2x barlow and the camera refused to pick anything up again it wouldn't even pick up on the security light.

As i said before i was using sharpcap and as soon as the camera worked the screen went a bluey sort of colour and showed a reasonably good image of jupiter although very small, thats why i treid the barlow but after that the camera refused to work again.

My scope is the f900 version