web cam immaging, first steps

[wiseman]

Ok, so I can now find globular clusters and track them, I have the phillips vn900 webcam, I downloaded the drivers, I downloaded v lounge, I plugged it all in,, centred on the cluster and stuffed the webcam in the focusser, out in the back garden/field, luverly night, milky way visible etc etc

1. How do I know if its foccused, when I click monitor in vlounge, its just, well, black I cant beleive I keep the focusserpositioned as it was for the eyepice I used to find the cluster?

2. how long do I video it for? 2 mins, 20 mins, 2 hrs?

I do realise I have to use registax afterwards, there will no doubt be a subsequent cry for help when I get to that stage.

Cheers

Wise

[The Sailor]

Hi Wise, yes you need to refocus for the cam, before you can do that you need to see something on the screen so you will need to work on the brightness and contrast.

Best way is to start with a bright star, get that focused in the eyepiece, change to the cam and refocus, I am assuming you will have played with the camera controls to get something on the screen.

Regarding length, that will depend on the size of the cam resolution and how much your HDD will take.

If I am wrong someone will soon put you right before long .

Jim

[JamesF]

VN900? I thought that was a motorbike Did you mean SPC900? i'll assume you do since I can't find anything else that might match.

Anyhow, you're correct that you can't generally keep the focuser positioned in the same place for the camera as an eyepiece. If you find focus with the eyepiece and then put the camera in, turn up the gain and brightness to maximum on the capture program (I use SharpCap, so I'm not sure what options Vlounge offers) and that might be good enough to give you a fuzzy image from the camera on-screen that you can work on focusing. Remember to return the gain and brightness to their normal settings afterwards. You need the image to be centred well. The camera sensor is very small and it's easy to miss it completely unless you've got your target right in the middle of the field of view.

Capture time depends on the target. Unless you have a camera that can do long exposures however you will be unlikely to be able to image much in the way of DSOs. Generally the longer the better as long as you're not over-exposing the stars in the image, but if you're using a flextube goto that might be the restriction there. After a while the rotation of the stars will become obvious.

James

[JamesF]

In the event that you do have an LX-modded camera, I posted a couple of LX-modded SPC900 images of M13 here:

http://stargazerslounge.com/topic/156974-my-first-ever-dso-images/

Details of exposure times etc. are with the images.

James

[TheThing]

Never underestimate the power of a parfocal ring!

TheThing

[The Sailor]

Never underestimate the power of a parfocal ring!TheThing

I did think of mentioning but maybe walk before running .

Jim

[wiseman]

sorry, yes it is the SPC900, funnily enough I do have a VN1500 motorbike, so maybe I was getting mixed up ( must rememebr not to use that to look at the stars with)!.

Ok, so next steps, focus on a bright star ( vega/Artcurus, etc, or moon if its on show)

fiddle with gain and contast until you can see something.

Then focus

Then see what you can capture.

OK, will do thanks

Never underestimate the power of a parfocal ring!

Oh dear, there has just been a large increase in the number of things I know nothing about!