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Finding things with a webcam help...


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Hi all,

Got myself a Philips SPC880 - flashed it to SPC900. Installed all fine on a Windows 7 laptop.

Downloaded SharpCap - connected to the webcam fine.

Removed the lens piece from the webcam, screwed on the nosepiece adapter and screwed on an IR filter onto the end.

Now the problems begin.

What's the best way to actually start tracking down Saturn, centreing it in the view and focusing properly.

All I could get last night was black (until the clouds arrived).

I tried centreing using a Meade 5000 4.7 UWA eyepiece, but still nothing but black. Where am I going wrong..?

Cheers in advance, Richard

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Its a good idea to get it centred using a high power eyepiece first, as you've done :-) Then I'd set the cam to a longish exposure and turn the gain up all the way. That way you'll have a bright blob which will be easy to find (the glare from it should show up even when its not in the field of view). Once you've got it on the chip you can turn down the expsore time and gain until you can just see the details - remembering that you'll almost certainly need to refocus from the eyepiece focus position. It is actually helpful if the scope is quite a bit out of focus when you are searching, as that makes your target much bigger!!

Have you got a driven mount? If not, this will all be much more challenging! So you might want to carefully watch which way the planet drifts through your eyepiece and set it so that its just outside the centre of the view in the eyepiece to allow space for it to drift to the centre of view by the time you've switched to the webcam.

HTH

Helen

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First thing I'd suggest is that you get the finder and main tube accurately aligned. You can do this iteratively - start with a low power ep - say the 25mm - and canter up. Then do it again with the 10mm and re-center. Than maybe pop in the barlow or use your Meade 4.7mm and re-center. At each stage you'll notice the error in the previous ep.

Do this all in daylight and get as accurate as possible - even at 10mm you should be aligned well enough to find objects. Saturn is past it's best right now so perhaps use Jupiter instead. Also Saturn is low for several years so not going to be a brilliant subject unless it's a really excellent night.

The webcam produces an image approx equivalent to a 6mm eyepiece and planets are further away than you think - so accuracy is required at those distances.

Do you have an RA motor or is it manual tracking? Is it an EQ or Alt/Az mount you're using?

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i used to use a lxd55 10 snt and once set up the go to worked okish. I always found my 9mm was roughly at a parfocal length with my web cam so i used to find the object using eyepiece 32mm then 15mm then 9mm centering each time then swap the 9mm for the web cam it only took a slight tweak on the focus as it was only ever so slightly out.

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Try and get your eyepiece and webcam parfocal - that is, when you swap between them you don't have to refocus.

You can do this with a parfocal ring that clamps with an allen screw ono the eyepiece or webcam barrel, preventing you inserting further than the correect focus distance.

Or cheap alternative to get pretty close - an elastic band wound tightly.

Start with webcam gain full up so you can hopefully spot the planet as it passes over the chip while you make very small changes in dec and RA

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After my first disastrous attempt when I could see nothing, I got my scope out on Saturday afternoon and focussed it on some treetops and then put in webcam and realised that what the cam picked up was not what I saw through the EP. It all came down to alignment - so I centred object in a 25mm EP - then used a 15mm EP re centred and then again with a 9mm - re centred and then I found that my laptop was seeing the same as the cam.

I also practised focussing and realised again that I didn't have to re adjust the focus "too" much - I think the night before I'd turned the focussing so far that I was miles out. When trying again, any more than 2 or 3 twists on the focus knob meant that I wasn't lined up properly.

Also you may try focussing on a star cluster which obviously has loads more stars in close proximity to each other so you may "stumble" across one?

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im pretty new to all this but i would make sure that everything is lined up like the others said.it took me a while to get saturn for the first time through a webcam and much longer when i added the barlow.

as long as its all working ok it just takes patience, and that is just the beginning.i want to see some pics too when your done!

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I agree with all of the above but I will add this.

Try it out in the daylight first ****** NOT AT OR ANYWHERE NEAR THE SUN ******.

This way it is a lot easier to get your alignment set up correctly as you can see what you are looking at.

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Cheers everyone for the tips - the daylight setting up hads proved fruitful. Now processing a sunset image (yes I remembered a filter and didn't burn my eyes or equipment out).

Will post a few after some processing.

Cheers again everyone :)

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with my dob i usally start low power centre then as fast as i can stick the 6mm in re centre and get the web cam in the telrad is aligned brill usaly centre there and start to nudge that is a art in its self

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Cheers everyone :eek:

Attached is my now finished process of Jupiter and four of it's moons.

Manually tracked by hand :)

wow how many frames was that? i can never nudge the 12 inch enough to get a decent stack , what frames per sec was this great banding as well and very wide as you got all the moons great shot for the 130p rock on,trouble is now you will become obssesed with it its so adictive great pic this is my best effort to

date

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