Did a quick test not a good one.
Took out webcam lens and the output picture is just all white.
Tried with scope and it was all white also, then with the scope cover on it showed like a light blue? Just want to make sure I'm on the right track. ..
Haha silly me. Thanks again Raymo, always helpful. I've taken the lens out, only thing to do is test tonight. Cheers
It's probably easier to test by pointing at a fixed distant target in daylight, such as a building or tree on the horizon, to learn how to focus, adjust exposure, test the effect of extension tubes and Barlows and so on. Then you'll have a much easier job of getting some sort of images of a nice bright nighttime target like the Moon, before tackling more challenging night targets.
I had the same problem to solve it the webcam had to be pulled out of the ep holder a bit , not enough out focus
Fixed it with a 35 mm film canister to hold the webcam out a bit
did abit more reading on my webcam with a telescope and looks like I need to remove the IR filter?
edit: ok maybe not.. smashed out the top glass out layer of the webcam now its output is black... haha from a complete white screen to a black screen.. lucky it was just a spare webcam
What's the Focal length of you 8" dob? If it's an F4 it should be a slam dunk but if it's an F5 or higher you could have focal length issues. When I wanted to add a camera to my 12" F5 I had to move the mirror forward 50mm or cut 50mm off the bottom of the tube, which I won't do.
The focal length in itself doesn't decide whether a scope will reach prime focus Doug.
A scope of any focal length can be manufactured to come to PF.
I have 8 and 10" Skywatcher Newts @ f/5 and f/4.7, a Celestron 5" f/8,
and a 6" f/6. All come to PF.
I could be wrong, but I believe that all SW Newts reach PF. GSO Newts
don't seem to, from the posts I've seen on IIS.
raymo
I have a bintel 8" which hs a f6 FL.
Managed to capture Saturn, but as far as DSO, it's zoomed in too much and I can't get a wide fov, if that's what you guys are on about haha
We are talking about the fact that some Newtonians will not allow
a DSLR to get close enough to the scope's tube to be able to focus
on sky objects. Sometimes a low profile focuser will fix it, or if the
adjustment needed is too great for that, the primary mirror can be moved up the tube. Also, the primary mirror collimation screws can sometimes be screwed in further as well. Or any combination of these fixes can be used.
Things are different with webcams, being much smaller than DSLRs, their sensors are nearer to the focuser and hence
can usually focus o.k.
raymo
Last edited by raymo; 11-09-2014 at 12:11 PM.
Reason: more text
I have a bintel 8" which hs a f6 FL.
Managed to capture Saturn, but as far as DSO, it's zoomed in too much and I can't get a wide fov, if that's what you guys are on about haha
You obviously have focus. I assume you are using stacked video to get the Saturn image. This will not work with DSO objects. They require many long exposures, 30 seconds or more each to capture enough photons for stacking.
Your web cam will work though on the moon which is probably a good starting point, bright and plenty of detail so you can focus and get some thing to learn on. Planets need high magnification, longer focal lengths as they are bright but small.
Using FireCapture ( free) you can view the moon on your PC, test focus and capture video to stack and create good images.
mental was able to display Omega Centauri and NGC5128 on his little webcam attached to a C8 - observing rather close to Kings Cross - at f/6 yours may be able to show a few of the bright DSO's.
GSO Newts don't seem to, from the posts I've seen on IIS.
raymo
I made my GSO (Bintel BT-302-b) Newt come into PF by raising the Primary Mirror 50mm. But then you need a 50mm extention to get focus with ep's. What I want now is a pier, EQ 8 mount & tracking for stacking, But the $$$$...
I can't find his blog now but he had some DSO's taken which turned out very nice!
He's probably done a long exposure mod to the webcam. Requires a bit of delicate soldering. The ZWO AS120 series cameras are supposedly capable of DSO exposures. I'm setting mine up now to try it out with Peltier cooling. If you get serious with the photo side of things it's not a bad next step option as it's not too expensive and works really well on planets and lunar pix.
