Really &*^%% off with imaging (at the moment)

[HDJ]

Recently I've spent hundreds of pounds on bits and bobs to help get more out of my scope, which include. filters, barlows and imaging add-ons.

So far absolutely NONE of them have worked at all.

Maybe it's just my scope, maybe it's my focuser, maybe I'm a klutz and I've been buying all the wrong gear!

one thing is for sure tonight I thought, enough is enough, perfectly clear skies, and I get no where.

My 4.5" 10 yr old tasco newt, can and does out perform my 12" dob.

Whatever I pop onto my small scope works first time every time, and when viewing saturn for example, I can get better and larger images on the 4.5" than the 12", pop the SPC900 in there and it works perfectly, not in the 12" though.

Is it me or is the scope to blame?

Totally frustrated after tonight and I looked at almost £1000 of collected gear and thought about Ebay.

I bought a Philips, SPC900NC cam, bought the adapter for it.. bought K3ccd program, etc.. you name I bought it.. plugged cam in tonight and could I focus it, no where near.

Same with Barlows, Filter Wheels, etc.. anything that plugs into my focuser if it isnt a straight forward lens, doesn't work.

I've read about people chopping tubes down to resolve focusing issues, if that's the case here then no chance. Ebay here I come.

before I get rid of the gear though, it'd be good to hear any suggestions and/or advise.

Maybe I should have just bought a small Nexstar with a goto mount, stuck my cam on it and bingo!

So if anyone wants to swap a 12" dob with accessories for a decent goto, then I'm interested

[Kai]

Hi Phil

A question......

When you are trying to focus your dob is the problem running out of travel inwards or outwards ??

also

What are you trying to image ....Planets or Deep Space ??

[HDJ]

Thanks for the reply.

I run out of focus on the Inward travel.

I can get the camera to focus and also the barlow to focus if I remove the 1.25" adaptor and then manually hold the items into the 2" focuser tube, albeit lower down than actual top of the focuser itself. So any adaptor such as a 1.25" is way to high or far out to allow anything to gain focus.

Maybe the mirror need to be moved up the tube a little, but then should this really be needed? do scope manufacturers not make them to work with the most basic add-ons?

As for imaging, so far I have aimed at Saturn.

Last night I had to hold the SPC900 with my fingers down into the focuser to get a somewhat recognisable image, but as you can guess, the scope kept moving due to me handling it and the camera was far from square to the secondary mirror, so at this point I simply gave up.

I will however persevere with this,, but it is very frustrating when you buy items and they simply don't work for you.

[Kai]

Before you go and start moving mirrors.

Is your focusser on a spacer or is it flat against the tube ?

If so can you remove the spacer ? if not then have a look around for a lower profile focusser as it might solve your problem.

I guess most scopes are sold for visual use so when you go and image you have to adapt the scope.

[HDJ]

No spacer unfortunately.

as for low profile focusers, I already looked for those as I figured this would be the case.

Only ones I found cost more than the scope.

Maybe I'll wait it out and put up a trade offer somewhere to swap my ficuser for a low profile one, as maybe somewhere someone has a low profile but really needs a normal one.

It's a single speed Crayford, as new condition.. in case anyone reads this and thinks. hey just what I need

So what about the idea of fitting longer coll screws and allowing the mirror to be adjusted closer to the secondary? Would this not lenghten the focal point up the focuser more?

I mean maybe 20mm of extra screw length might be enough?

I'm open to suggestions.

[legion48]

Have you tried a low profile webcam adaptor? I didn't have enough in travel to get focus with the standard Toucam adaptor with my 130 SLT but I bought a low profile adaptor - about £15-20 - and it's fine with that.

[HDJ]

How do you mean by Low profile.

I use the SPC900NC and the adaptor only makes the cam about 1.5mm higher than the focuser.

To get it near focus the camera would need to go inside the 2" focuser shaft. meaning I would need to modify the camera body to allow it to fit inside.

Which thinking about it for imaging might work, if I file the edges carefully enough on the camera case I should be able to make it a snug fit inside the 2" focuser.

Thus allowing the camera to sit at a point where I can achive focus.

Then simply shroud around the back of it to prevent any light getting into the top of the focuser.

hmmmm, I think I have my project for this evening sorted out

[HDJ]

Right,

I've got the webcam to fit into the 2" focuser tube now. It allows the webcam t-adaptor to sit approx 10mm down into the tube, as opposed to how it was last night which was approx 30mm higher.

So, now I wait until nightfall and hope for clear skies and then keep my fingers crossed.

I still need to make a ring of sorts to go between the cam and the 2" compression ring so it can be held securely, but right now it fits snug enough to allow for testing, as I might need to make it go lower yet.

Does anyone know if there is a 1.25" adapter that actually sits down into a focuder tube?

So instead of sittng on the top it allows the 1.25" add-ons to go lower into the focuser.

[legion48]

How do you mean by Low profile.

This - from web page:

Low-profile webcam lens thread to 1.25” nosepiece

Designed to meet the latest challenges in webcam imaging

Like our standard AC378 (see below) this ultra low-profile adaptor allows most popular webcams, like the Philips ToUcam Pro I and II, to be attached to standard 1.25" eyepiece holders. The big difference is the overall length of the adaptor and the absence of a rear lip at the base of the nosepiece. We’ve made the adaptor as short as possible to make sure that it will work with the increasing number of imaging situations that require a low-profile nosepiece on the webcam, to cope with minimum in-focus motion and other limitations of the telescope focuser.

Here's the link - BTW, it's £13.99.

http://www.astro-engineering.com/Adaptors/adaptorsforteles.html

[HDJ]

Thanks for that link Legion..

That's the one I already have.

What I need now is a ring that fits the 1.25" webcam t adaptor and then fits inside the 2" focuser.

Basically to make the webcam safe, so it cannot fall out.

I have an alloy ring here that's close to the right size, so I bit of filing on that might yield the perfect result.

I'll post a couple of images later of what I've done so far. right now FOOD is calling me..!

[HDJ]

No photos yet.

However I moved the scope outside so is going through it's cooling phase.

I'll see if I can get this working and hope to post my first webcam images later (fingers crossed).

Super Clear skies here tonight... woo-hoo!

[legion48]

Good luck mate.