Unable to focus a webcam

[louiegoods]

Any advise would be greatly appreciated. Just modified a Logitech 9000 pro, simple enough and using SharpCap software. I could not get any image after connecting to my Nexstar 8se. I even tried a daytime terrestrial view with a good, clean, clear image but still could not get an image on the webcam. While tweaking any and all controls in SharpCap, I  just get different shades of light and dark shadows but I never see any  hint of a picture. I've tried it with a 2x barlow as well as 32mm Plossl lens. I'm using a windows 7 64 bit OS. 

Any ideas on what else I can try?

Thanks

Bill

[ronin]

I would guess the mod is to remove the lens from the webcam, if so then you shouldn't have an eyepiece in the system. Although you may want a barlow.

Not exactly sure what the modifiction was.

One check is with the camera connected put you hand over the camera, there should be a change of light to dark, that at least would show the camera is still operating.

Further details on the mod would be useful.

Just not sure if the lens is in place or removed.

[Cornelius Varley]

The chances are that you haven't got the telescope focused properly. If you are getting some sort of image from the webcam, even it is just patches of light and shade, then you need to concentrate on getting a focused image.

[Mukv]

Greetings

Quote " I even tried a daytime terrestrial view with a good, clean, clear image " this would seem to indicate the webcam lens is still attached and as such will not reach prime focus. What was involved with the mod you carried out?

Andy

[ronin]

Glad Andy reads better then I do.

Missed the bit about a good daytime image.

As said that would imply the lens is still there in which case attaching it to a scope is no use.

The webcam lens assumes an image at infinity which is not what a webcam gets when put into the focuser of a scope.(generally).

[louiegoods]

Wow, these were quick responses.   

I did remove the webcam lens and auto focus mechanism where the cmos chip is completely exposed and placing my hand over the camera does change the shadows from light to dark so this indicates the camera is still working. I found this mod on youtube http://www.youtube.com/watch?v=C90MgJq7EwI. I believe it shows the USB cable disconnected because a longer one was installed as I understand the USB cable remains on its same connectors.

The daytime image I mentioned was through the scope without the webcam attached and perfectly focused.. I wanted to start with a good wide image before adding the webcam. I've mostly tried with the a barlow and additional lenses attached. I'll now try some more with just the webcam itself and then barlow.

I also tried the K3CCD software but that does not work on win7 64bit. I won't have access to the scope this weekend, it's remote. Any addition thoughts or questions?  

[Mukv]

Greetings

thanks for the tube link that shows what's happening a little clearer. A few things to check are that the chip is VERY central in the barrel of the film can and at 90 degrees to the focuser when fitted together, how far are you inserting the film can into the focuser as this can have a large effect on the focus point, try it fully in and partially in ( if you have already tried this please ignore me )  when focusing do it slowly as the point of focus may be very shallow less than a few millimetres . 

good luck and sorry for misunderstanding your earlier post.

Andy

[ronin]

Really sounds like getting an accurate focus is the problem. Stars are both small and relatively dim, so if out of focus you get almost nothing, not helped by the light nights we have at present.

If the moon isn't around aim at Casseiopia and slowly adjust the focus. Casseiopia has the milky way behind it so hopefully a bright star will come into focus or the band of the milky way might.

Many clubs use a par focal ring the idea being you get the scope focused with a specific eyepiece and drop the webcam with the par focal ring and move the webcam up and down by hand (do not adjust the focuser) until you achieve decent fosus, then lock the ring in place.

Means you can then focus by eye and swap to the webcam and it should be close to focus.

[louiegoods]

Thanks, will try everything mentioned  and report back. Won't have access to the scope for a few days yet.

[louiegoods]

Update... The CMOS chip was not exactly centered. After correcting that I was able to get a very blurry picture during the day. Last night I tried to view the moon but was not able to bring it into focus. I expect some very good conditions late tonight so I'll try once more to solve what I'm sure is a focusing problem.