Guide scope suggestions for Skywatcher Evostar 150ED

[bluesilver]

Hi,  I am brand to to guiding and looking to get a guide scope to start out.

So basically what i have all up so far is:

SkyWatcher AZ-EQ6

Skywatcher Evostar 150ED

Canon EOS 600D camera

Skywatcher SynGuider 2

 

I am sure that the SynGuiders 2 is not the best ideal choice,  but for starting out,  i picked it up for a good price.

 

So i am looking for a guide scope that will work well for this setup.

Using the Astronomy tools calculator https://astronomy.tools/calculators/guidescope_suitability  and information i have found to keep the Imaging  Guiding ratio to around 1:5

it looks like i need a guide scope with a focal length of around 400 mm,  Trouble is that there is not much of them around here where i am to select from.

I have found a APM Guidescope Imagemaster 60mm secondhand here but the focal length of this is 240 mm making the ratio 1:6.96,   

Would this still work?  I can add a 2x  barlow to get a ratio of 1:3.48

The only other option is a Astromania 70 mm,  this has a focal length of 40 mm making the ratio 1:4.48  but only available through Amazon and not sure how all the weight will add up.

Any advice or information would be appreciaed.

Thanks.

 

 

 

[TerryMcK]

I think your calculations are out. 1:5 is 240mm with your scope natively at 1200mm focal length.

Also if you factor in a x0.85 reducer/flattener (that you will need to correct star elongation in the corners) then this comes down to roughly 200mm focal length for a guide scope. In which case there are many guidescopes that meet that criteria.

The SKywatcher 9x50 guidescope and ZWO ASI120MM mini will nail it.

Edited August 13, 2020 by TerryMcK

[Seelive]

I would suggest the 1:5 ratio you quote is a maximum limit rather than an ideal value.  A lower ratio would certainly do no harm and possibly improve guiding (I guide with a ratio of just under 1:2).

[dannybgoode]

Following the tradition of recommending what you have this is what I use.  Really nice package; the scope is very good and the focuser ideal for guiding.  Once dialled in it can be locked down with almost zero chance of bumps etc knocking it out of focus.  The guide rings are very solid mounting point are very solid too.  You could get away with using the SynGuider however you would be better with a standalone guide camera and using pulse guiding to control the mount over USB than via the camera and ST4 via PHD2.

The AR0130 is a nice little camera and works very well.  Could be pushed into use as a planetary/lunar cam as well if desired.

https://www.altairastro.com/altair-60mm-guide-scope--gpcam2-mono-camera-combo-with-polar-alignment-assist-75-p.asp

[bluesilver]

14 hours ago, TerryMcK said:

I think your calculations are out. 1:5 is 240mm with your scope natively at 1200mm focal length.

Also if you factor in a x0.85 reducer/flattener (that you will need to correct star elongation in the corners) then this comes down to roughly 200mm focal length for a guide scope. In which case there are many guidescopes that meet that criteria.

The SKywatcher 9x50 guidescope and ZWO ASI120MM mini will nail it.

I am sure i could be out on my calculations,  but going over them again they appear correct unless i have something wrong.

Imaging camera / Telescope =  Camera 600D  CCD Pixel Size 4.31  Ezostar 150ED Focal length 1200

Guide camera / Telescope =  Guide camera SynGuider 2 CCD Pixel size 6  Telescope APM Guidescope Imagemaster 60mm Focal lenght 240

All comes out as  a ratio of 1:6.96

Unless i have done something wrong.

11 hours ago, dannybgoode said:

Following the tradition of recommending what you have this is what I use.  Really nice package; the scope is very good and the focuser ideal for guiding.  Once dialled in it can be locked down with almost zero chance of bumps etc knocking it out of focus.  The guide rings are very solid mounting point are very solid too.  You could get away with using the SynGuider however you would be better with a standalone guide camera and using pulse guiding to control the mount over USB than via the camera and ST4 via PHD2.

The AR0130 is a nice little camera and works very well.  Could be pushed into use as a planetary/lunar cam as well if desired.

https://www.altairastro.com/altair-60mm-guide-scope--gpcam2-mono-camera-combo-with-polar-alignment-assist-75-p.asp

Got a tad confused here when you mentioned what you have is what i use,   I haven't really got a guide scope yet,  still trying to find out what to go with.

What guide scope was you referring to if you don't mind me asking?

 

[bluesilver]

Also forgot to ask if adding a barlow is a good idea or not?

 

[dannybgoode]

9 hours ago, bluesilver said:

Got a tad confused here when you mentioned what you have is what i use,

Apologies-what I meant was in forums people often just recommend what they themselves use. So that’s what I did  

I popped a link to the guidescope and camera in my first post

[bluesilver]

Thanks for the link,  must of missed that the first time round.

So basically you will need some sort of pc with this setup then i take it?

I was trying to do it without a pc,  but looking more into it,  it appears that most of the better guiding systems all do use a pc or table device.

 

[dannybgoode]

On 14/08/2020 at 23:03, bluesilver said:

Thanks for the link,  must of missed that the first time round.

So basically you will need some sort of pc with this setup then i take it?

I was trying to do it without a pc,  but looking more into it,  it appears that most of the better guiding systems all do use a pc or table device.

 

Your SynGuider will work without a PC but you still need the actual guidescope to mount it in. Guiding via a PC or something like a Raspberry Pi will give better results and would probably be easier to use.