Help with TouCam settings

[DJVege]

Hi guys,

I've noticed after playing around with the TouCam 840K, taking vids of Jupiter, that the higher magnification I use, the darker the image is. For example, using just the TouCam, the image is very bright, I take gain to 0, saturation to 100% etc.... and the image is great.

However, stick a 2X barlow, and with the gain at 0, the image is darker...5X barlow, and the image is darker still!

Why is this? And is there a way to brighten the image? I'm guessing I just play with the gain...but as I'm no expert (or amateur) in imaging, I thought I'd ask.

Thanks.

[[1ponders]]

First off check what your exposure settings and frame rates are. The darker it gets the longer your exposure needs to be. The longest you will be able to go for is 1/25 sec. For an average night of seeing (twinkling) set your frame rate to 10 frames per sec. If the night is really good you might get away with 5 frames per sec. If your exposure is maxed at 1/25 and your fps are at 10 then start to slide your gain up. It will start to become grainy, that is normal. If you are capturing the images of jupiter, keep it to under 120sec and then stack them in registax 4. You will find that most of the grain will start to disappear.


btw the image is getting darker because you are taking a set amount of light reflected from jupiter and spreading it over a larger area of ccd chip.

[DJVege]

Ok. Cheers Paul.

I'm guessing I need to be polar aligned and not have jupiter moving from the top left of my screen to the bottom right. :) I'll only be able to registax once I've fixed my drive motor issue. At least now I know what to do. :thumbsup:

[[1ponders]]

Try rotating the ToUcam in the eyepiece holder to get it to run parallel to the RA and Dec. Oh and yes you will need to be roughly polar aligned otherwise your drive motors won't keep jupiter in the field of view.

What is the issue you are having with your drive?

[DJVege]

http://www.iceinspace.com.au/forum/showthread.php?t=23566

The normal speed is too slow, 2X is too fast. Hopefully it's just a battery issue. I'm going to try a 12V DC supply, and also a rechargeable battery pack instead of 8 x 1.5V DC batteries.

[[1ponders]]

:confuse3: is this the motor and controller? https://www.bintelshop.com.au/Images/Stock/6532X.jpg What sort of mount is it on?

[DJVege]

Yeah, that's the one.

I have no idea what mount it is. I bought it off Phil. All I know is that it's an equatorial mount. I'll post an image here of it.

[DJVege]

What do you mean parallel to the RA and Dec?? Say I'm only roughly polar aligned, where on the screen should the object move? Left, Right, up, down? :)

[[1ponders]]

I don't know how others do it, but when I align my camera I make sure that when I press the "up" Dec button the star moves up, exactly parallel to the sides of the screen and down when I press down. This is infact the reverse of what it should be :P but for me it makes more sense that when I press up I want the star to go up (when in fact the scope is going "down" if you follow what I mean")

[DJVege]

Oh ok. Yep, I follow!

Thanks. Once the skies clear and I get my rehcargeable battery pack, I'll give it a go. :thumbsup: