guider using a philips spc880nc flashed to spc900 ???

[MarkS]

I agree with Carole.  If you use a webcam as a guide cam then you will definitely need guide rings so you adjust the direction of the guidescope to find a bright enough guide star.  Something like the QHY5 is far more usable  as a guidecam and (I am told) the Lodestar is the ultimate.  A webcam modded for long exposures also works much better than a standard webcam giving a pecking order like this;

Webcam - bad but just about usable
LX modded webcam - pretty good
LX modded and monochrome CCD webcam - good
QHY5 - better
Lodestar - best

I've been recently using a standard webcam again, to do some periodic error tests (PERecorder only works with webcams).  It brought back all those (pre QHY5) memories of the pain of trying to find a guidestar!

[Carole]

Lodestar is the most expensive of these options, but I had a bad experience with one in France where Olly told me the cables did not provide a good connection and intimated that this was a general problem with Lodestars.  Because of this we had to abandon it in the end and use a QHY5 which is what many people swear by and it's a fair bit cheaper than the Lodestar.  Robert uses the latter and can provide more info on this.

You can still use the Phillips webcam for planetary imaging if you decide to get a different guide camera. 

BTW I used to use a modified webcam and it did work, but after some guiding problems where I was not sure what the problem was - Mark recommended I buy a QHY5 and I have to say this revolutionised my guiding. 

Carole

[Les R]

Hmmm.... So the Philips 990 isn't any good to use then? That was the reason I posted the thread, so I didn't buy something not fit for purpose. I already have a 5MP imaging cam (NexImage5).

On the skywatcher rings, there are two camera type screw threads. Is that where rings would be attached.

[mickw]

It is fit for purpose although not great and needs to be used with something with more aperture than a finder scope.

[MarkS]

The Philips 990 will definitely work and will give good results but it is not always easy to find guide stars.  Most of us started out with a webcam as our first guide camera because it's cheap way to start guiding. However, depending on the distribution of stars in the vicinity of your imaging, sometimes you'll find a suitable star straight way and at other times you can  spend 10 minutes of frustration trying to locate one - that's why you need plenty of adjustment on the guidescope.  On the other hand, with a QHY5 you will almost always find one straight away but that comes with a much higher initial cost.

As with most things in astro-imaging there is no single correct way to do things and everyone tends to take a slightly different approach depending on many different factors - expense often being a major consideration.

[The Thing]

On the skywatcher rings, there are two camera type screw threads. Is that where rings would be attached.

Les, there are two types of rings. Tube rings go round the imaging scope and fit tight around the tube. Pairs of guidescope rings have three screw adjusters around each ring so you can adjust where it points to pick up guide stars or align it with the imaging scope to use as a finder as well as a guidescope. (you probably know this).

The camera tripod bush type threads are for mounting cameras (suprise suprise) but you could also use them to piggyback a guide scope. If you use a piggyback arrangement, especially if you end up using a bigger guidescope, the effective weight  on the end of the scope goes up and you need far more counterweight. Side by side mounting mitigates this. Also the big thing you have to watch out for is flexure between the scopes which can vary at different angles as stresses and load vectors change during an imaging session. This will give you funny shaped stars on your images. Everything has to be very rigid to counter this.

However the most important thing is to assemble what you have got into an arrangement that will work to a point and try it out! Get out there and take some pictures. There is no substitute for practical trial and error and the new moon is approaching (again). That's how we all got going 

HTH and good luck

Duncan

[Les R]

Ok, cheers again guys.

I will give it a go using the cam and WO66 with a side by side mount. (I bought one a while ago) there doesn't seem much point shelling out on another adapter to get the 9x50 to work if it's likely I will run into problems. That said, I'd need rings to do this anyway?

Carole, isn't yours connected using the connectors on the two camera mounts on your 80ED?

All being well, I am picking up the WO66 on the 19 October..... As long as it doesn't look like it has been run over!