Not achieving focus with webcam

[louie_the_fly (Stew)]

Several nights ago I set up my webcam for the first time and shot some footage of the moon. 31 seconds. It was a bit breezy outside so the footage was a bit shaky. I put it thru Registax 5 and got an image which I was kind of pleased with, although it could have been better, and it was my first use of Registax. The next clear night I thought I'd have a go at Jupiter. I couldn't achieve focus on Jupiter but the moon focused OK.

Here's the setup. Celestar 8 (8" f10 SCT fork mount on a wedge tripod) with a 10:1 crayford focuser, and a modified Microsoft Lifecam VX-1000 mounted in a custom made 1.25" adapter (into the crayford). The adapter is only about the length of a 10mm plossl. I also put the adapter into my 2x barlow and still no focus. Does mycamera need to be further out than this? I'd like to image a few other bright objects, to get some experience, but I thought I'd start nearer to Earth and work my way out before I shell out for more equipment.

Help...

[Merlin66 (Ken)]

Stewart,
Sounds like you're doing everything right....
Stick with the moon to refine your focus...mark the focuser/ adaptor so you can repeatedly return to your focus position. Try all the different variations you want to use...reducers/ barlows etc etc and get their focal dialled in also.
Once you can do that, then you confidently move on to things like the planets knowing that you'll be pretty close.

[louie_the_fly (Stew)]

Originally Posted by Merlin66

Try all the different variations you want to use...reducers/ barlows etc etc and get their focal dialled in also.

Merlin66, can I use the barlow as an extension tube (with the lens body removed) or is there no need/benefit in doing that? Being in engineering for the last 30 odd years I've learned to always write stuff down. But guess what, I didn't when I got moon focus. I'll have to start a new book.

When I modified the webcam I removed the lens. Right thing to do right?

Stewart

[Merlin66 (Ken)]

Stewart,
I'm assuming you would only need an "empty" barlow to provide a suitable spacer....
After, getting the "prime" focus sorted out....then do the same with the reducers etc.
Onwards and Upwards

[EricB (Eric)]

Stew, I wonder if the poor seeing conditions we have had in Adelaide lately could also be a factor (assuming that you live in or around Adelaide).

The best focus I can get at the moment looks like what's on the attached photo (sorry it's in monochrome). Is is similar to what you get?

Eric

[louie_the_fly (Stew)]

Eric, I didn't even get that on Jupiter, although I was able to get focus on the moon. I would have been happy with an image like that at this point in time. I'm in the hills - on the eastern side in the Onkaparinga Valley. Generally pretty dark here, but its been a bit cloudy recently, but I don't think that was the problem. I put an EP in and had a good view of Jupiter & it's moons. Then webcam & nothing for the full focus range.

[EricB (Eric)]

Strange. I can pretty much move from the Moon to Jupiter during the same session without touching the focus much. What's your set up?

[BlackWidow (Mardy)]

Are you sure you were out of focus? With Jupiter you often get a white blob that is over exposed rather than being out of focus. If this is what you got, it's due to the gain being set too high in your software camera control. The moon does not do this with the same settings as it is large and takes up more of the image frame. Jupiter is small so most of the frame is black and Jupiter will over expose.

That's all assuming this was your problem. Would have been good if you posted an image of what you are getting.


Hope this helps.
Mardy

[2stroke (Jay)]

Turn your shutter all the way down and the gain all the way up first. Then once you see a donut focus it till its the smallest image you can achieve. Once that's done drop your gain and shutter till you see it Then record away If you dont have the shutter down and the gain up to start with life will be hell unless its bright enough to see off focus.

[louie_the_fly (Stew)]

Thanks for all those tips. You can tell I'm new to this imaging stuff. Gain? Shutter? I'll have a fiddle with the webcam software and see what I can work out. I'll take some images and post my results when i get a chance to get out again. What a great forum...

Great night tonight - clear as. Then the cloud came in.

[2stroke (Jay)]

Give this a go stew http://www.sharpcap.co.uk/ , i have found it the best software to date that's free for webcam imaging. Has all the gain/shutter/lighting controls on offer and have used it with c210 Logitech and the 900nc Have fiddle in the lounge room and tinker with the cam just hooked up to the pc and looking at a wall Cloudy nights don't have to be a loss lol.

[louie_the_fly (Stew)]

So a few nights ago I managed to finally achieve focus with my webcam. I removed the lens assembly from my barlow and fitted the webcam to it. It took a while but I managed to get the attached image (which I just processed tonight with Registax 5. 515 frames @ 12 frames / sec. Still couldn't get any of the moons in focus tho. Think I'll give this webcam the flick and save up for a CCD camera.

Thanks for all your tips everyone. IIS is a great place to learn.

Stewart