Guide Scope for RC8

[Newforestgimp]

Hi,

I’m about to take delivery of a TS-Optics RC8 and I’m looking for advice on a suitable guidescope.

currently using WO 50mm x 200mm Uniguide with ASI120MM , hoping to move it across but if it’s not a good match what should I look for instead ?

regards

Andy

[Astroscot2]

Andy  why not look at using an OAG?

[newbie alert]

Deffo OAG..

[Newforestgimp]

47 minutes ago, Astroscot2 said:

Andy  why not look at using an OAG?

It has crossed my mind but not sure what’s involved in setup and the relative pros n cons ?

[fwm891]

I use a TS 60mm as Guidescope on my TS RC 8. OAG’s are great but can be very restrictive on fov. I have my 60mm guider mounted under the main ota and forward, that really helps with balance as the RC 8 is back heavy to start with. TS do an 80mm guide scope which would be better still. I use an ASI120mm as  guide camera on the 60mm.

[Newforestgimp]

36 minutes ago, fwm891 said:

I use a TS 60mm as Guidescope on my TS RC 8. OAG’s are great but can be very restrictive on fov. I have my 60mm guider mounted under the main ota and forward, that really helps with balance as the RC 8 is back heavy to start with. TS do an 80mm guide scope which would be better still. I use an ASI120mm as  guide camera on the 60mm.

Think I’ll give the 50mm a go first, good tip about underslung and out front mounting, I will look to do this.

Do you use the reducer or straight through ? Filter wheel/drawer ?

keen to understand what spacers I might need if I were to filter drawer &/or OAG

[michael8554]

OAG

Michael

[fwm891]

4 hours ago, Newforestgimp said:

Think I’ll give the 50mm a go first, good tip about underslung and out front mounting, I will look to do this.

Do you use the reducer or straight through ? Filter wheel/drawer ?

keen to understand what spacers I might need if I were to filter drawer &/or OAG

I use my RC8 with and without a reducer (0.67x). I use an ASI533MC Pro as my imaging camera. Filter wise when there’s little or no moon I use. Baader UV/IR cut filter for galaxy’s star clusters or globulars, for nebulae I use an IDAS NBZ.

I have  homemade filter draw which allows me to keep the correct face of the filter to the sky. I no longer shoot mono, so no filter wheel. I use the 2” and a 1” extension tubes my filter draw (19mm) and the standard focuser. I also have a motor focus unit as it’s difficult getting that last fine adjustment manually.

I hope that helps.

[Clarkey]

I have moved to OAG now with my RC8 but before this i used my st80 which worked ok. I do find OAG a bit if a faff, but it helps keep the weight down as I have to set up each time I image.

[Craig a]

After using a guidescope with a mirrored telescope I’m my case a Newtonian, I switched to OAG and came to the conclusion that all mirrored telescopes should use OAG’s to eliminate differential flexure, my images changed immediately when going over to OAG 

[Newforestgimp]

21 minutes ago, fwm891 said:

I use my RC8 with and without a reducer (0.67x). I use an ASI533MC Pro as my imaging camera. Filter wise when there’s little or no moon I use. Baader UV/IR cut filter for galaxy’s star clusters or globulars, for nebulae I use an IDAS NBZ.

I have  homemade filter draw which allows me to keep the correct face of the filter to the sky. I no longer shoot mono, so no filter wheel. I use the 2” and a 1” extension tubes my filter draw (19mm) and the standard focuser. I also have a motor focus unit as it’s difficult getting that last fine adjustment manually.

I hope that helps.

It does thank you, I will initially be using a DSLR, I had read that the 2” and a 1” extension tube will give correct focus. If I introduce a filter drawer into the mix do I then have to remove the 1” extender and replace with a 6mm extension if using your 19mm filter drawer as an example ?

[fwm891]

4 minutes ago, Newforestgimp said:

It does thank you, I will initially be using a DSLR, I had read that the 2” and a 1” extension tube will give correct focus. If I introduce a filter drawer into the mix do I then have to remove the 1” extender and replace with a 6mm extension if using your 19mm filter drawer as an example ?

If using a dslr then yes. A dslr has circa 45mm of extra body depth so you need to allow for that. My asi533 only has 6.5mm so I need the extra extension tube to make up the difference.

Best thing is to simply mount the camera body and point it at the moon and focus it. What you want to avoid is having the focuser racked right out to get focus. If you find that add a 1” extension ring to bring the focus to about half travel or less. 

[Newforestgimp]

Thank you 👍

Im coming round to OAG I think after doing some more reading this evening, so think I might be investigating which OAG & filter drawer to get. Thinking the ZWO OAG and the Altair filter drawer.

[fwm891]

With an OAG the important thing is the size of the pick-off prism face. Some of the slimmer models have long/narrow prisms, best avoid those. Filter draws, check you can mount your filters so the correct side faces the ‘sky’. Baader filters are edge marked to show which side should face the sky.

[Craig a]

9 hours ago, Newforestgimp said:

Thank you 👍

Im coming round to OAG I think after doing some more reading this evening, so think I might be investigating which OAG & filter drawer to get. Thinking the ZWO OAG and the Altair filter drawer.

The zwo OAG is a good choice, set it up during daytime on a distant object if you can see one then do final tweaks under the stars 

[CCD-Freak]

I used an old University Optic "Kit Scope" which is 80mm F6.25 with 500mm FL with my RC-8 and now with my AT10RC and it woks very well.  It gives me a wider field with lots of stars to choose from.  I don't use rings for mounting to limit possible differential flexure.  These scopes are rare now but if one could find or make something similar they would be happy.  The attached NGC4565 was guided with the UO 80mm and an ASI-290MM using Astro-Art and PHD guiding.

 

 

[Newforestgimp]

2 hours ago, CCD-Freak said:

I used an old University Optic "Kit Scope" which is 80mm F6.25 with 500mm FL with my RC-8 and now with my AT10RC and it woks very well.  It gives me a wider field with lots of stars to choose from.  I don't use rings for mounting to limit possible differential flexure.  These scopes are rare now but if one could find or make something similar they would be happy.  The attached NGC4565 was guided with the UO 80mm and an ASI-290MM using Astro-Art and PHD guiding.

 

 

Wow, love the shots and love how that guide scope looks. Do you have an idea of overall weight of the entire rig ?

[CCD-Freak]

The UO 80mm scope is actualy very light weight. 

The overall weight of the whole 10"RC with Moonlite focuser, cameras and guide scope is somewhere north of 50 pounds.  The AP900 manages it very well.