HELP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[Alienfox]

I have 3 webcams, 1 cheap and nasty £3.50 from ebay (working), Logitech Pro 900 (not working)? Philips SPC900N (not working)?

All 3 show in Device manager, all the correct drivers are installed, the Logitech and the Philips both detect my hand waving in front of them, both have had the lenses removed, I cannot get either to focus using a 1.25" & 2" nose pieces, I have tried them on 2 scopes a SW 120T and a SW150P?

I have tried using both SharpCap & wxAstroCapture to view, bothe cameras give a very dark screen even though I am pointing at a bright sky?

I am obviously doing some thing wrong, can any help please. 

Thanks, Den

[ronin]

Not sure if the nosepiece is attached to an eyepiece or not.

If not then it sounds like the image plane of the objective is not getting to the sensor. Quite possible as the nosepiece may be keeping the sensor too far back, you may need to take something out of the optical path to get the sensor closer in.

If there is an eyepiece then I do not think it will give an image. A scope operates as collimated light in and collimated light out when there is an eyepiece. In effect the eyepiece does not form an image it is your eye ball that does this bit.

I guess that it is the first instance. You "just" need to manoeuvre the sensor to the image plane of the main scope.

Might involve a big hammer.

[Alienfox]

Hi Ronin, I managed to get the 120T sorted, I needed to attach the 45 angle and I can now focus on both camera's, I have used the Logitech before on the 150p without any problems, wierd?

I have attached a 2" webcam nose piece which brings it really close to the secondry mirror?  Cant work out whats changed?

[beamer3.6m]

Stupid question but have you removed the scope end cap?

Does the camera produce a bright image when pointed at the sky before it is connected to a scope.

I assume that they have had the lenses removed and the nosepiece you mention are the replacements for the lens so that the scope is working in prime focus - i.e. the camera is effectively an eyepiece so no other actual eyepieces are used.

If so you should see something through the scope, even if it does not focus fully.

[Alienfox]

Hi Beamer, Yes, scope end cap is off, it's not a stupid question, Yes it does produce a bright image?

Yes, lenses removed, nosepieces connected directly to scope, no eyepieces or barlows.

That's the thing thats baffling me, I can't see a damned thing? works great when I look through the scope with eyepieces, collimation is spot on?

Went out to setup at 8pm last night, finally put all the gear away about 10:30 this morning, need to go lie down now,

Just remembered, I attached my DSLR to the 150p great shots of the moon in perfect focus, that just adds to the mystery.

[beamer3.6m]

I assume you have racked the focus in and out to see if this improves it and then increased gain and exposure times on the camera.

[JamesF]

Start by working on the problem during the day.  Focus (or attempt to) on something distant.  Then you can see what you're doing and you're not up against a rapidly disappearing dark sky

Get the DSLR focused on the 150P.  The focal plane will be in the same position when you use the SPC900.  That is, 44mm behind the lens mounting ring on the DSLR.  That's where the DSLR camera sensor is at that point.  The SPC900 sensor will need to be in the same position.  If you hold the SPC900 up next to the DSLR with the (SPC900) sensor roughly where you estimate the DSLR sensor to be then you'll see where the camera has to be to achieve focus.  That might give you more ideas about what you need to do to get the SPC900 in that position.

James

[happy-kat]

On my 130p I have to move the webcam as close as possible to the mirror, on my heritage this means dropping the trusses down about 2 inches.

Now with my ST80 the opposite is required. I have to use a 2.5 inch extension in the focuser unit and then the webcam in the extension for the webcam to reach focus.

Moral is don't assume both scopes need the same treatment.

[Alienfox]

Hi James, I have done what you said reguarding the position of the DSLR & the SPC900N, and I did get focus in the same position, the Logitech needed another 2 cm out to achieve focus, both no problem so it begs the question why could I not see the moon with either of those cameras and yet the DSLR was easy?

I used the Logitech on my 130p  (Last winter) using the Logitech and wxAstroCapture and SharpCap to capture the moon no problem, I have i think upgraded both bits of software since, so maybe it's that.

[JamesF]

Nothing specific occurs to me as to why you'd not be able to see the Moon with the webcams, unless the additional focal length means that you're not getting the image on the camera sensor at all.

Again, I'd go back to working in the day.  Put the webcams in, and use SharpCap to get a focused image of a distant target.  If you can't get an image at all with the webcams and the camera sensor looks like it ought to be somewhere pretty close to where the DSLR sensor is when you can get an image with that then I'd start wondering about the software.  If the image in SharpCap responds to dark and like though (say when you put the cap on the OTA and remove it) then I'd say the software is probably ok.

James

[Alienfox]

Hi Happy-Kat & James

I understand that the cameras will need different positions for the 2 scopes I am using, thats now sorted, I am now awaiting a clear night to see if I can see the moon at least with either cameras?  The more I think about it the more I think it's a software error, will just need to wait and see.

Den

[JamesF]

If you fire up SharpCap with the camera out of the OTA and just put your hand over the end to see if it responds to dark and light and you do get a darker and lighter image on the screen then I doubt it's software.  If the image stays flat then it may well be hardware or software.

I think though that it's most likely to be that the focuser has insufficient travel (either inwards or outwards) to get some of the camera sensors to the focal plane or that you've just missed the target altogether (I think this is less likely with a target such as the Moon).

It's probably fair to say that just because the OTA reaches focus with one camera that doesn't mean it will reach focus at all with another.  If the focuser needs additional outwards travel for one camera then that's not too hard to sort.  If you're short of inwards travel that's rather more tricky to fix.

James

[Alienfox]

OK, so tonight is looking good for a camera test, will let you all know what happens.

[Alienfox]

So last night was my first real test since checking that the webcams worked in daylight (yes they do), so set everything up stuck on the webcams nothing, not even registering the bright orange street light 20 fett away?  I had no moon to try and focus on like last time but I think there is something not right somewhere? Used the latest SharpCap with the gain turned right up?

So until I get a moon to try again, I don't think I stand any chance of trying to see a planet or anything else for matter, so it was back to my trusty DSLR where I now have another question????? Sorry guys, but I set my scope towards M2, Synscan almost coreect (think I need to read the Alignment settings) anyway, through the eyepiece it looked pretty good focus spot on (re-collimated the scope on Friday) so, I then attached my DSLR, my question is how do you focus on something so faint through the eyepiece on the camera (Nikon D200 no live view).

Thanks in advance.

Den

Image from last night single frame.

[JamesF]

I suspect your problem with the webcams is either that the target doesn't even appear on the camera sensor because the sensor is so small -- a typical crop-sensor DSLR has a sensor about 22mm x 15mm, whereas the webcam sensor may only be 4mm x 3mm or perhaps even less, or the image is too far out of focus to actually show up at all.  An eyepiece with crosshairs may help with the first problem, allowing you to get the image perfectly centred.

As for focusing the DSLR I think I'd get a bahtinov mask and then take subs of a bright star to check  the focus.  If there's one in the field of view of the image that's helpful, otherwise you'll have to focus and then slew to the target.

James

[happy-kat]

If you have no live view I guess it is the take a picture, check focus, adjust, take a picture adjust focus... Unless you can tether the camera to a laptop and check focus that way dynamically.

[PeterCPC]

+1 for using a Bahtinov mask to get focus.

Peter

[Alienfox]

OK guys thanks for your advice, hopefully another clear night to try and you ideas.

Den