Guide Scope and Camera suggestions

[gmessyhome]

Hi all , can any of you good folks suggest and good autoglide setup please. IE scope and camera. Its to mount on Cel evo 8. Have a double vixen holder ready to mount.

Looking at William Optics 50mm Guiding Scope and a QHY 5L-II Colour Imaging/Guiding Camera. Open to any other suggestions please, thanks in advance

[Astrosharkey]

Many would suggest the use of an OAG system with an evo, but I went like this for my rig as I already had it for my 80mm, its the evo guide 50mm scope and altair GPCAM2 290M which I also occasionally use on the moon and planets as well.

[Skipper Billy]

At over 2000mm focal length I think most will suggest an AOG.

Not saying it cant be done with a guide scope but better with an OAG.

There is a very useful calculator here that will help you choose a suitable scope and camera combo that will match your imaging scope - aim for about 1:4 - I know many people go way over this figure or well under it but about 1:4 is the sweet spot. 

http://astronomy.tools/calculators/guidescope_suitability

The QHY camera you mention is a colour camera - mono is far more sensitive and personally I had nothing but grief with QHY drivers!!!!

The 50mm guide scope is probably way to short FL for the scope but have a play with the calculator.

 

[Skipper Billy]

It occurred to me after I had pressed 'Submit Reply' that you might be confused about what I meant by 1:4

I have put my own rigs details in and snapshotted the screen - the number in the yellow circle is the one that wants to be about 1:4 which in my case its is - if I bin my guide camera it drops to 1:1.7 but is still works OK. The acceptable range is about 1:2 to 1:8

Hope that makes sense!

I am guessing that when you put in your own rig and the guide rig you are thinking about it will be in excess of 1:20 +++

[gmessyhome]

Thanks Brown Dwarf , super usefull

 

[Shimrod]

20 hours ago, gmessyhome said:

Hi all , can any of you good folks suggest and good autoglide setup please. IE scope and camera. Its to mount on Cel evo 8. Have a double vixen holder ready to mount.

Looking at William Optics 50mm Guiding Scope and a QHY 5L-II Colour Imaging/Guiding Camera. Open to any other suggestions please, thanks in advance

What problem are you hoping to solve by guiding?

In your thread on cameras you said you wanted to image deep space objects which implies long exposures. Guiding your Evolution on an alt-az mount is not going to solve the problem of the earth's rotation and you will still be restricted to very short exposures which are unlikely to need guiding.

[smashing]

19 hours ago, Skipper Billy said:

It occurred to me after I had pressed 'Submit Reply' that you might be confused about what I meant by 1:4

I have put my own rigs details in and snapshotted the screen - the number in the yellow circle is the one that wants to be about 1:4 which in my case its is - if I bin my guide camera it drops to 1:1.7 but is still works OK. The acceptable range is about 1:2 to 1:8

Hope that makes sense!

I am guessing that when you put in your own rig and the guide rig you are thinking about it will be in excess of 1:20 +++

Stupid question time, why don't you want the ratio to be as close to 1:1 or even 1:less than 1? 

I always thought the 1:4 was the upper limit of what you should be aiming for.

[Skipper Billy]

1:4 seems to be the sweet spot - you can guide at 1:1 (I have guided at 1:0.72 and it worked) equally you can guide at 1:8 but its harder work to get it right.

The nearer you get to 1:1 the more flexure and weight becomes a problem - hence 1:4 seems to be the sweet spot.

This is at 1:3.45 in average seeing

 

[gmessyhome]

On 29/11/2020 at 10:27, Shimrod said:

What problem are you hoping to solve by guiding?

In your thread on cameras you said you wanted to image deep space objects which implies long exposures. Guiding your Evolution on an alt-az mount is not going to solve the problem of the earth's rotation and you will still be restricted to very short exposures which are unlikely to need guiding.

After reading the replys about alt-az and the headaches it gives for long exposures, im going to get a eq mount. Hence the question on guilding for longer exposures. Im asking the question now so i can get an idea on the target requirements.  Brown Dwarf has reply with something that  makes sense, . Im after information on what other users are using for setups so i can guage what would be suitable for me. Im still looking to inspiration on a main camera to use on the main telescope, however i think im got an idea on what ill end up going for, but ideas are always welcome.

Edited November 30, 2020 by gmessyhome