webcam problems

[cristian abarca]

Hi guys

I,m having problems with my webcam. I have a 150mm Reflector with a barlow attached to the bottom of the focuser, which gives it a focal length of 1400mm. The tube is only 750mm long. My webcam is a Philips Toucam pro 2 840k. The adaptor I made threads all the way to the bottom of the camera and attached toit is a Baader filter. I managed to get some pretty reasonable pictures of the moon but when I tried Jupiter all I got was a very blurry image. It looked like a white fuzzy ball with no detail at all. I could see two bands with a 25mm lens in my telscope,but no detail with the webcam on the screen. The 3 moons looked like out of focus dots, through my telescope they look like small stars. Can someone tell me what I did wrong.

Regards Cristian

[[1ponders] (Paul)]

Sounds to me like your not getting enough back focus. How long is the adapter you made?

[acropolite (Phil)]

Could have been focus, and maybe overexposure as well.

[[1ponders] (Paul)]

TRue Phil. Christian can you give a few more details. Like exposure, gain, FPS, exposure etc. Along with as about your adapter length, plus do you still have the problem without the barlow?

[gbeal]

I,m with the above two experts.
Focus (3 moons out of focus dots), and exposure (blurry washed out ball.
Try reducing the exposure as well as shifting in and or out of focus.

[cristian abarca]

Hi guys

I am a real beginner at this webcam thing. all I did was point pick the frame rate and press the button. Here is the information you required Shutter speed was on automatic 1/25 sec. Frame rate 60. Colour/space compression 1420. Output size 320 x 240. Brightness was about a third, same with gamma and saturation. Gain was near high. White balance was on automatic. My adaptor is 35mm long. When I took the video of Jupiter the adaptor was light grey, I have since painted it matt black. It is made out of 38mm PVC pipe. Attached to it ia a amall 12mm aluminium tube pressed onto an aluminium plate. This I epoxied to the PVC pipe. The aluminium tube is fine threaded like the lens that came with the camera. A friend did this on a lathe. This image was taken without a Barlow infront of the camera, only the one at the bottom of the focuser. I did try with the barlow and the fuzzy image just looked bigger. I also made an adaptor for lens projection but I haven't as yet tried on Jupiter the clouds got me. I did the moon and it looked ok.

Regards Cristian

[[1ponders] (Paul)]

Ok Cristan, try this: Frame rate no faster than 5-10 for jupiter, (can do 15 for saturn) as little compression as possible, Output is ok but you could go higher to 640 x 480. Start your brightness about half and gain about 1/3 to 1/2. Gamma on zero, saturation between about 65 -90 (depends on how intense you like your colour basically). Leave white balance on auto to start with. Exposure set to about 1/25 of a second.

Once you have these settings when you focus you should be able to see jupiter clearly enough to get a more accurate focus. Focus as close as you can get then start dropping the gain until jupiter is no longer washed out. Try refocusing again to see if you can get it clearer. Unless the seeing is great you will still get fuzzyiness with the occassional good view.

Try it without your barlow first. The barlow that is already in the focuser is a trick manufacturers use to increase the focal length of the scope. I gather that it is a fairly stumpy little refractor. Unfortunately the barlows they use for this purpose are generally not very good quality. How does jupiter focus using just an eyepiece and no additional barlow. Now when you add your own barlow how much does the image degrade. If its hard to tell try using a clear crater on the moon. If there is a large difference then you may not be able to use your own barlow as its pushing the capability of the scope too much.

Oh quick question (should have asked this first with the other questions) have you collimated you reflector yet? This can also make quite a difference.

Once you've changed all your settings and checked the quality of the scope. Try a shot without your barlow and see how it turns out. Then try it with your barlow in. If your unable to get a focus now then you more than likely have a back focus issue. If that's the case let us know here and we can walk you through the next step.

Good luck

[cristian abarca]

Thank's Paul

That's a fair bit of information you gave me . Can't wait to try it out. Hanging out for clear skies here in Melbourne. Sunday night seems like the best night but who knows down here. Will keep you posted on how I go.

Regards Cristian