Celestron 70mm Travelscope as a Guider

[Adaaam75]

Hi guys,

So I'm looking at entry level guiding and wondered if i could save a few quid and use my Celestron 70mm refractor (400mm focal length) scope as the guidescope? This would allow me to purchase a guide cam to use otherwise it will be a non starter. I'd be guiding my DSLR for info with the view to step up to a decent monochrome camera in the future.

I understand weight capacity of mounts and the issues with imaging DSO's with a DSLR so I have that covered.

If I cannot use my Celestron travel scope as a guidescope could I use my Skywatcher 9x50 finderscope? Please don't laugh at me if I'm hitting a round peg in a square hole!

 

IF the Skywatcher finderscope and Celestron travelscope are not adequate for guidescopes, my plan B would be to use my mount and a CCD to start imaging planets\DSO's. I do have filters so monochrome would be preferable. Advice around this please.

 

Humbly,

Adaaaam75

[Pompey Monkey]

It would help a lot if we knew what imaging scope and mount you would be using.

Even better if you put these details in your signature so that they appear in every post that you make. This will work retrospectively too!

[michael8554]

Looks like the Celestron is similar to the 400mm ST80, which is a popular guidescope.

But as Paul suggests, depends on which scope and mount you have, and the guidescope/mainscope image scale ratio.

Michael

[Adaaam75]

Apologies there, I'll spend a little more time later trying to work out how to create a signature (unless you'd be so kind to assist.....), I have a Celestron 9.25 on a fixed pier mounted AVX.

?

[spillage]

Top of the page click the arrow next to your user name and click account settings. Then click on signature on the left hand side. hth.

[Pompey Monkey]

1 hour ago, Adaaam75 said:

Apologies there, I'll spend a little more time later trying to work out how to create a signature (unless you'd be so kind to assist.....), I have a Celestron 9.25 on a fixed pier mounted AVX.

?

I think you might be heading for some disappointment when it comes to imaging DSOs:

This is a 20 lb OTA on a mount rated at 30 lb. Even without the weight of the camera(s) and guide scope (not to mention a possible filter wheel) and you'll be pushing closer towards the manufacturers specced maximum weight. It is a general rule of thumb that 1/2 - 2/3 of the stated payload is about the maximum weight that a mount can handle and perform reliably enough for long exposure imaging. On top of that, F10 is very slow and the 2350 mm focal length will require a seriously accurate mount/guiding combo to work well. Or are you intending to go the Hyperstar route?

Planets, on the other hand, are imaged with many short exposures (video) and any inaccuracies in guiding will be compensated for by the staking and alignment software. As a DSO imager, I'm sure that someone with more experience at planetary imaging will come along with more info soon

 

HTH

[Adaaam75]

5 hours ago, Pompey Monkey said:

. It is a general rule of thumb that 1/2 - 2/3 of the stated payload is about the maximum weight that a mount can handle and perform reliably enough for long exposure imaging. On top of that, F10 is very slow and the 2350 mm focal length will require a seriously accurate mount/guiding combo to work well.

In all honesty I was just looking to see what is actually acheivable and whether starting a guiding setup would be worth the purchase with a DSLR. I am aware of the 2/3 rule. Do you think my mount accurately tracking will be my limits for my DSLR? I have seen some very satisfying DSO's imaged with a DSLR at short exposures (few minutes) with just the mount tracking but thought I could take the first step towards a Espirit 80ED world of deep sky by purchasing a guide setup and using my Celestron 70mm or 9 x 50 finderscope.

I guess my question is, is there any point guiding a DSLR?

A second question to solar system imagers is, what equipment could i purchase to add to my 9.25 AVX set up to get good-excellent results (I'm aware Mastercard cannot buy clear skies, dark skies or good seeing)!!!!

[Pompey Monkey]

18 minutes ago, Adaaam75 said:

I guess my question is, is there any point guiding a DSLR?

Absolutely!

TBH, I thought that you wanted to do DSOs with the SC... My bad.

[dph1nm]

On 25/06/2017 at 20:27, Adaaam75 said:

So I'm looking at entry level guiding and wondered if i could save a few quid and use my Celestron 70mm refractor (400mm focal length) scope as the guidescope?

I have tried this, although not successfully yet, using a synguider. The one thing I would say is that the focuser is very wobbly on this scope, and you have to lock it down very tightly!

NIgelM