SharpCap

[Neila1975]

Hi guys,

Does any one have a recommendation of a camera & guide scope that can be used for both polar alignment & guidance with SharpCap?  I've been looking at the this camera https://www.harrisontelescopes.co.uk/acatalog/altair-gpcam2-130-mono.html#SID=1714 but unsure which guide scope.

Any suggestions on both very much appreciated.

Many thanks

[City9Town0]

I note that this is out of stock; I use this for my HEQ5pro and ed80dspro. 600mm focal length.

https://www.altairastro.com/starwave-50mm-guide-scope--gpcam-mono-guide-camera-combo-91-p.asp

Works fine for me.

[Neila1975]

Thank you

[malc-c]

I have an old  QHY5 connected to the stock Skywatcher 9 x 50 finder - worked well when using Sharpcap's polar alignment option, and with PHD2 for guiding the main scope (200P / HEQ5)

[Neila1975]

1 hour ago, malc-c said:

I have an old  QHY5 connected to the stock Skywatcher 9 x 50 finder - worked well when using Sharpcap's polar alignment option, and with PHD2 for guiding the main scope (200P / HEQ5)

 

Thanks Malcolm.

This is all prettry new to me....I'm initially using a DSLR & a selection of HQ Nikkor glass. I figured a way to have both a guide scope & DSLR mounted on my HEQ5 but am not sure about the process of using the guide scope & camera for first PA & then guiding.  Is it a simple process? I'll be using a windows 10 laptop.

[Neila1975]

Im actually looking at this one...https://www.rothervalleyoptics.co.uk/skywatcher-9-x-50-straight-finder-with-zwo-120mm-mini-package.html

163mm focal length - would this be OK for both PA & guiding?

[malc-c]

Yup, that's more or less what I use.  I used to use an ST80 piggybacked onto the 200P, but wanted to reduce the weight. so converted the stock finder.  My QHY5 is around 10 years old, so has been superseded with more modern technology.  Even with the shorter focal length the results when using a DSLR as the main imaging camera have been acceptable with nice round stars.

It's a simple process - Point the main scope at a bright start and centre it in the field of view, engage tracking.  Adjust the finder so that the same star is centred in the guidescope camera.  Now the guider is aligned with the main scope you're set to PA.  The instructions on the sharpcap website and the hints through the application are easy to understand, but basically you set the scope in the home position and then start the process.  Once it's gathered data, rotate the scope 90 degrees in RA and do the same... it then plate solves the images and then when instructed tells you when to move the alt / az bolts and by how much, and gives an indication of how much the error is.  I think it took me less than ten minutes to complete the PA of my HEQ5

[KP82]

52 minutes ago, Neila1975 said:

Im actually looking at this one...https://www.rothervalleyoptics.co.uk/skywatcher-9-x-50-straight-finder-with-zwo-120mm-mini-package.html

163mm focal length - would this be OK for both PA & guiding?

Yes. This is probably the cheapest 50mm guiding setup available.

The focal length of the SW 9x50 finderscope is 180mm I believe. To be able to reach focus with the 120MM, I remember you need to unscrew the protective cover from the camera and then attach the C adapter to the camera directly.

[Neila1975]

11 minutes ago, KP82 said:

Yes. This is probably the cheapest 50mm guiding setup available.

The focal length of the SW 9x50 finderscope is 180mm I believe. To be able to reach focus with the 120MM, I remember you need to unscrew the protective cover from the camera and then attach the C adapter to the camera directly.

Thanks - do i need to purchase a c adapter?

[KP82]

1 minute ago, Neila1975 said:

Thanks - do i need to purchase a c adapter?

The combo in your link comes with one already.

[Neila1975]

Yes it does!  Thank you!

I guess it will be OK to guide & polar align with this set up.  

Ive also looked at this one, but its quite a bit more dosh.  Is it worth the extra?

https://www.harrisontelescopes.co.uk/acatalog/altair-mg60-gpcam.html#SID=1729

[KP82]

33 minutes ago, Neila1975 said:

Yes it does!  Thank you!

I guess it will be OK to guide & polar align with this set up.  

Ive also looked at this one, but its quite a bit more dosh.  Is it worth the extra?

https://www.harrisontelescopes.co.uk/acatalog/altair-mg60-gpcam.html#SID=1729

The CMOS sensor inside the GPCAMv2 is exactly the same as 120MM. So no benefit here.

The Altair 60mm provides a slightly higher resolution and is equipped with a more sophisticated guidescope ring. But for your camera lenses and most short refractors, there won't be any discernable difference in performance compared to SW 9x50 + 120MM.

[malc-c]

 If you have the money then the Altair is the better option.  It's a dedicated guide scope, designed for that purpose.  Focusing will be easier, it has a longer focal length which is better compared to the SW finder, and it has 10mm more aperture.  But its a £100+ more so you would expect it to be.  If you want the version that replaces the sock finderscope then this is the option you might need https://www.harrisontelescopes.co.uk/acatalog/altair-60mm-guide-scope-gpcam2-package.html The one you linked to has a dovetail that fits onto the main rings of a mount, which without knowing the mount and OTA you are using I couldn't confirm if it would fit.

The SW finder is just that, a finder scope.  It's as basic as it comes, it doesn't need to have superb optics as it's simply used to get a target into the field of view of the main scope.  These dedicated guidescopes are decent telescopes in their own right, with achromatic objective lenses, so will give you far better images than the stock finder.  But the conversion of the stock finder works, and unless you are in an area of sky with faint stars, never fails.  The 40mm or so additional focal length these dedicated guidescopes offer will help with the guiding, but again, the conversion of the stock finder still gives a decent guiding graph in PHD2

Another alternative is the SW EVOGuide scope https://www.rothervalleyoptics.co.uk/skywatcher-evoguide-50ed-50mm-guidescope.html - but then you would need to add the camera, any adapters and the cost of Sharpcap, which Harrisons throw in with the deal.

The choice is yours my friend, we can't make up your mind for you....  If in doubt speak  with Adam at Rothervalley Optics,  or give the guys at Firstlight Optics or Harrisons  a call and ask them for their opinions.  If you like the look of the scope but want a cheaper camera then see if they will do a deal on a custom package for 

 

[malc-c]

OK if this helps, here are examples of polar alignment and guiding using the stock SW finder with the QHY5 camera

 

And guiding 

 

As you can see the RMS guide errors for both axis is below 0.6 acr seconds with the gear stated in my signature.  The QHY5 has a MT9M001 1/2" BW sensor with 5.2 x 5.2 um pixels.  The sensor in the new cameras listed above is 1/3" and has smaller 3.75um pixels.  What or how that impacts the quality of the image or guiding performance I don't know, and I'm sure someone will chime in and advice.  My guess is that with the smaller pixel gives more precision in detecting star movement, given that both cameras have a resolution around  same size (1280 x 1024 for the QHY and 1280 x 960 for the 120MM)

[Neila1975]

1 hour ago, malc-c said:

 If you have the money then the Altair is the better option.  It's a dedicated guide scope, designed for that purpose.  Focusing will be easier, it has a longer focal length which is better compared to the SW finder, and it has 10mm more aperture.  But its a £100+ more so you would expect it to be.  If you want the version that replaces the sock finderscope then this is the option you might need https://www.harrisontelescopes.co.uk/acatalog/altair-60mm-guide-scope-gpcam2-package.html The one you linked to has a dovetail that fits onto the main rings of a mount, which without knowing the mount and OTA you are using I couldn't confirm if it would fit.

The SW finder is just that, a finder scope.  It's as basic as it comes, it doesn't need to have superb optics as it's simply used to get a target into the field of view of the main scope.  These dedicated guidescopes are decent telescopes in their own right, with achromatic objective lenses, so will give you far better images than the stock finder.  But the conversion of the stock finder works, and unless you are in an area of sky with faint stars, never fails.  The 40mm or so additional focal length these dedicated guidescopes offer will help with the guiding, but again, the conversion of the stock finder still gives a decent guiding graph in PHD2

Another alternative is the SW EVOGuide scope https://www.rothervalleyoptics.co.uk/skywatcher-evoguide-50ed-50mm-guidescope.html - but then you would need to add the camera, any adapters and the cost of Sharpcap, which Harrisons throw in with the deal.

The choice is yours my friend, we can't make up your mind for you....  If in doubt speak  with Adam at Rothervalley Optics,  or give the guys at Firstlight Optics or Harrisons  a call and ask them for their opinions.  If you like the look of the scope but want a cheaper camera then see if they will do a deal on a custom package for 

 

Thanks Malc.  The option for the dovetail- arca base works for my set-up - Scope on one side, DSLR & lens on the other & i can use existing arca clamps that I have in my photography inventory!  Went with the Altair, just ordered!

[malc-c]

No worries, it will be interesting to see how you get on, and how it performs

[Neila1975]

On 03/02/2021 at 18:44, malc-c said:

No worries, it will be interesting to see how you get on, and how it performs

Hi Malc, once polar aligned I guess you close Sharcap & open Phd2?  Seems a silly question but I just want to be clear.  Many thanks

[malc-c]

Yeah, if you have no need for Sharpcap to be open then just close it down.

[malc-c]

You can run the two.. there is no impact other than a little more load on the PC.

I remote into my observatory and use a webcam with Sharpcap to see what position the scope is in whilst its tracking or slewing etc

[rnobleeddy]

On 03/02/2021 at 13:32, Neila1975 said:

Im actually looking at this one...https://www.rothervalleyoptics.co.uk/skywatcher-9-x-50-straight-finder-with-zwo-120mm-mini-package.html

163mm focal length - would this be OK for both PA & guiding?

+1 for this setup. It's cheap and cheerful but works very well, and I'd be amazed if this was ever the thing that limited guiding performance with the popular affordable mounts.

Edited February 7, 2021 by rnobleeddy