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SPC880/900 no image :(

Celeste

By Celeste
in Imaging - Discussion

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Celeste

Celeste

Posted
Posted

Last night was a stunningly clear night so my son and I decided to try out the webcam....we didn't have high expectations but we weren't expecting nothing either....which is what we got :) We couldn't see anything at all.....not one single thing (and yes the caps were all off :evil6:) The only visible thing on screen was if we pushed gain or gamma up full then the screen showed alot of grainy noise. Are these cams only usable on planets? We tried the Orion nebula, M45 and Jupiter (but that was just going below the rooftop at my mums so may have missed it in the view) but couldn't see even one spot of light. I have seen youtube vids of this cam and they all seem to show 'something' so what have I done wrong? I tried settings in sharpcap, focusing etc but still nothing. Hopefully tonight will be clear and we can go out and try again, any advice for us?

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brantuk

brantuk

Posted
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Webcams are best for planets/moon, but for dso (nebs/galxies/clusters) you need something capable of long exposure e.g. dslr or ccd cameras.

That said - a webcam can be modified for LE but you need to know what you're doing electronically. It can be done professionally but costs a lot (over £100). Have a word with Glider - he's a dab hand at electronics and cameras :)

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Glider

Glider

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An LX modified webcam is perfectly OK for having a go at some DSO. M42 (neb), M13 (glob) and M31 (galaxy) will give you hours of fun.

If you get the DSO bug then you know you won't be wasting you money upgrading to a DSLR or other CCD camera.

Having said all of that, I'm surprised you didn't see anything even with your unmodified camera.

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paraman

paraman

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Last night was a stunningly clear night so my son and I decided to try out the webcam....we didn't have high expectations but we weren't expecting nothing either....which is what we got :) We couldn't see anything at all.....not one single thing (and yes the caps were all off :evil6:) The only visible thing on screen was if we pushed gain or gamma up full then the screen showed alot of grainy noise. Are these cams only usable on planets? We tried the Orion nebula, M45 and Jupiter (but that was just going below the rooftop at my mums so may have missed it in the view) but couldn't see even one spot of light. I have seen youtube vids of this cam and they all seem to show 'something' so what have I done wrong? I tried settings in sharpcap, focusing etc but still nothing. Hopefully tonight will be clear and we can go out and try again, any advice for us?

You may find the planet etc was there all the time but so far out of focus that its almost invisible. The camera and eyepiece focus at completely different points as I found out one freezing night:)

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Glider

Glider

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Yes, the focus can easily be so far out that you don't see the target at all. Also, the webcam is probably working something like a 5mm eyepiece (EP) so a small misalignment could easily put the target completely out of the field of view (FOV) even if it is in focus. The Moon is much larger in the FOV so far more tolerant.

I start by centering on a 25mm EP. Then go to a 10mm EP and tweak the centering. Then I barlow 2X the 10mm EP and tweak again to get something approaching the camera FOV with a good alignment, then pop the camera in the holder.

Bear in mind, as you focus in and out your centering may also wander a little if you focuser does not run true.

Take small steps.

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vulcan

vulcan

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I had exactly the same problem. It is all to do with focal planes ie, the point at which the image is in focus. You need to point the telecope at a big object (ie The Moon) and manually slide the webcam in and out on its tube to get a rough idea where it should be. This will genearlly be futher out of the socket than your eyepiece would sit. Mine is almost fully out (but still lockable). When you get in the 'ball park' then you can use the usual focus knob to fine tune. When you move on to another smaller object, you should be able to focus with your focus knob. Mark the webcam adaptor position for next time.

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  • 2 weeks later...
JamesF

JamesF

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I found exactly this when attempting to take pictures with an SPC880 (reflashed with the 900 firmware) the other night. When you swap the ep out for the camera the focus point can be way off and I found it's very easy to go past the point of focus without realising it.

I found I couldn't get an image if I put the camera in place of the star diagonal. It just had to go in afterwards. I don't know if that would change if I used a Barlow. I might have to experiment with that in daylight.

The other problem I had was that my finder scope wasn't sufficiently well aligned because I'd been mucking about with things earlier in the day. I could still find them when I had the ep in, but not with the camera.

In the end though I did manage to get a few pictures of some of the stars in M42 and the Pleiades. They're not good pictures because I hadn't really done enough reading and was making a lot of it up as I was going along, but it definitely was possible so keep trying.

James

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JamesF

JamesF

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If you focus with a diagonal then try to image without it - it has to be replaced with a 50mm spacer - a 50mm "extension".

Oooh, that's a handy thing to know. Is it a "standard" that the diagonal is 50mm of the focal length?

James

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Steve C

Steve C

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There is definitely a trick to lining up the webcam & getting proper focus as I eventually found out.

I've found this method works for me:

1. get an initial alignment with the object you wish to capture using a low mag ep, something like a 25mm should suffice.

2. step up by swapping to higher mag ep's, ensuring the object stays centred with each step up (it doesnt matter if the object gets out of focus, in fact it helps if its out as its easier to align using the big blob effect an object makes when it gets out of focus)

3. when you're happy all is still aligned with a high mag ep, swap out the ep for the webcam which should already be powered up & connected to laptop/ netbook whatever but without a barlow if using one. Do this quickly but gently, trying not to knock the scope too much or you'll be starting over again.

4. get the object focused first then centred by making the necessary adjustments whilst watching it on the laptop screen very closely.

5. Once happy its on the screen & centred, remove webcam & fit barlow, replace & do step 4 again.

6. Have a good one!

I'm not saying the above is how it should be done, just that it works for me

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