Finderscope or ST80 for guiding?

[steppenwolf]

I bought your book a few months back so much of this your fault!!!!

Ooooops, sorry .....

[gnomus]

Ooooops, sorry .....

I suggest you steer well clear of my wife ........ (and bank manager)......

[Astroboffin]

I will try your suggestion if the sky ever clears. Thank you for your assistance. I bought your book a few months back so much of this your fault!!!!

If it helps I use a calibration step of 750 with my ST80 (400mm fl) and that works perfectly, so with a fl half that (200mm fl) then 1500 or double would be about spot on I would say.

AB

[Russe]

For the initial question - I use a finderguider with a QHY5 on my 130 PDS which works just fine. I've imaged upto 1200s. Recently though, the finderscope shoe had come lose and caused all sorts of weird guiding. Weight wise the finderscope is better. But it depends on your mount.

[gnomus]

Thanks all. The consensus seems to be that I should stick with the finderscope.

[allotmenteer]

Hi - this seems to be a very fortunate thread to have happened on as I am a few stages behind you in the AP game and had similar questions.

I have a CPC 800 and have bee trying to work out whether I can use the 9x50 finderscope with the ASI 120 camera (which I am thinking of buying if it all joins together!)

You have obviously been successful with this - can you tell me what adaptors etc you needed to fit the camera and scope together.

I had thought about buying the colour version of the camera you have - do you have any advice on whether the mono or colour offers the best solution - I have seen some comparative photos of Jupiter and clearer with mono but don't know about all the  extra work of using filters.

As you seem to have done - I've read the 'Every photon counts' book (great help) and have my shopping list which I'm working through and hoping to spend my money wisely (and once!)

Would be great to benefit from your experience with your Celestron.

Cheers

Mark

[gnomus]

Practical big... 12". Proper big 20".... Lottery win.... 30". Even 40" is portable.... There's one on Germany that lives in a garage! Storage space, doorways, general fitness and wallet depth are the key factors. Aperture fever is a bad disease, even I am not fully cured.

Peer

Hi - this seems to be a very fortunate thread to have happened on as I am a few stages behind you in the AP game and had similar questions. I have a CPC 800 and have bee trying to work out whether I can use the 9x50 finderscope with the ASI 120 camera (which I am thinking of buying if it all joins together!) You have obviously been successful with this - can you tell me what adaptors etc you needed to fit the camera and scope together. I had thought about buying the colour version of the camera you have - do you have any advice on whether the mono or colour offers the best solution - I have seen some comparative photos of Jupiter and clearer with mono but don't know about all the  extra work of using filters. As you seem to have done - I've read the 'Every photon counts' book (great help) and have my shopping list which I'm working through and hoping to spend my money wisely (and once!) Would be great to benefit from your experience with your Celestron. Cheers Mark

Hi Mark. The adapter is a simple ring. I think they come from Modern Astronomy, though I got mine from Rother Valley Optics. The ring screws onto the ZWO. The eyepiece of the finderscope screws out. The ZWO on the ring then screws into the finderscope - where the eyepiece came out from. I found that I needed to adjust the focus. Unfortunately, the thread on my Celestron finderscope was a bit ragged. I couldn't screw the adapter all the way home and so I couldn't get focus without taking off the locking ring on the Celestron finderscope. (They use horrible black grease which is difficult to get off your hands.). The Skywatcher Finder looks identical to the Celestron and I had no issues with that.I hesitate, as a beginner, to dip my toe into the whole colour vs mono debate. However, when I read a bit about Bayer matrices, interpolation, and how 'colour' works on a CCD chip, I was drawn towards mono plus filter wheel. I shoot the moon in plain mono.

[Tinker1947]

Like this, Lodestar screws onto Adapter ring, Adapter ring replaces the eye piece on the Finder Scope, i think its been said in other threads that long focal length scope are much better with OAG system though this is another can of worms...

[allotmenteer]

Thanks - from reading around OAG looks the better bet but maybe have to wait until phase 2 or 3 or get lucky on ABS!

Are the filters that come in the standard Celestron set of EPs and filters of adequate quality to use with this type of camera?

[Geordie mc]

I use the st80 on skywatchers guidescope mount that allows very easy adjustment - much better than guidescope rings in my opinion. I made a rig up with some aluminium sttips and a dovetail bar to attach it as rigidly as possible to my main scope. Works well but adds a lot of weight. I'm now looking into the finder guider option instead. Hope to have the bits this week so will post soon on any differences in guiding ease/accuracy.