Scope Recommendations for EXOS2


I just got an EXOS2 PMC-Eight for Christmas, and license from my wife to spend another $500 to beef up my OTA.  I'm coming from a 130SLT.  I want larger aperture for optical viewing, but I also want something I can use for astrophotography as well.  I've read countless threads on the topic in general, but now I'm hoping for some mount-specific advice.

I think I could stretch my budget and go for the Explore Scientific Carbon Fiber 8" Newtonian: .  But is this too much weight once I add a webcam or digital SLR?  Seems like a 6" OTA would be safer, but that doesn't seem like enough of a jump from the 5"  already have.  Anyone have any experience using this OTA or any other 8" Newtonian for astrophotography with the EXOS2? 

Or any other alternatives to recommend?  I'm on the fence about the lower focal ratio, and have also been considering this OTA:  It's listed at 18lbs, which is the same as the Explore Scientific Carbon Fiber, but I can't find any other information about it, and I'm not sure I can trust the listing.  


Jennifer Shelly


i have the Exos-2 and an Explore Scientific Carbon Fiber 8” Newtonian with a Nikon DSLR and guide scope and it works just fine.  I have attached some pics of my setup for your reference. Also I have attched some examples of my images I obtained with the setup, so you can see the magnification.  If you are looking for a wider field then you should consider a 6” Newtonian.


Jennifer Shelly

Now that I think about for the moon pic I used a 2.5x Barlow. 
Whatever you decide balancing your scope is paramount. 
If you are not balanced the mount will not behave well.

Tim Robertson

I am using the ES 152mm Mak-Cass First light scope. So far GREAT configuration.

James Buck

Have my Exos 2 PMC8 matched up with a Bresser 8 inch Newtonian with a First Light 4 inch refractor.

Just under the recommended weight limit of the mount.

James Buck is piperjimb@...



Gosh!  That's quite a load!  I see a camera on the 4-inch, and what looks like a guidescope near the newt's focuser.  Mixed use visual/astrophoto?
How's the photo side working for you with all that weight?

- Bob

James Buck

Have an Orion StarShoot autoguider on the 4 inch refractor and a Bresser MikrOkular imaging camera on the Newtonian.  After making sure the mount is level and properly polar aligned I do a three star alignment and all is set.  I’ve had great success with shorter exposures but have not had a real chance at exposures for more than 15 minutes lately.  Lots of clouds and other issues.  But with the mount properly balanced with the load, there is no binding or jittery movements.   I have set up the system with its own power supply and can stay out for 14 or 15 hours at a time! And still have enough power for another night without recharging the batteries.  One laptop for guiding and slewing using CDC or ExploreStars.  The other laptop for imaging using SharpCap and CamLab light from Bresser.  I also use CyberLink software for some editing. 
I’ve not been doing astrophotography very long but have had limited success in using the software and editing.  I’m still learning the limits of the camera hardware.  But with what I’ve gotten so far is nice round stars and good detail of the moon and Jupiter and Saturn. 


Holy moly! That is walking the line! 

What a behmouth of a rig. I thought I was pushing it by having an 8” on mine. You definitely just gave me a whole lot of confidence in the mount! 

Thank you.

What’s your usual exposure time with that?


Thanks everyone for the feedback!  Clearly an ES 8" Newt should be fine, so looks like that'll be my next purchase.  Though James' picture had me wondering for a second if I should dare to go even bigger.  (Only for a second.  Or maybe a few minutes).  :)


James Buck

I would not go any bigger than this setup.  The 100mm objective x 600mm refractor is a smaller scope I had exchanged from a 100mm objective x 1000mm refractor.  The latter was heavier and proved to push the mount to its limits.  Lot of vibration after a slew.  But with the 600mm it cut down on the weight by a couple of pounds and proved to be more compatible with the Exos2 mount.  The mount is rated for 27 pounds if I recall correctly, and this setup is about just over 23 lbs.  Had to get another weight from E.S. to have proper balance.  Once it is all set up, it runs perfectly!
The real reason I went to the 102mm x 600mm FL refractor is I also have a Twilight 1 AZ mount that I also use.  It is easy to transport, set up, and take away when done.  I use it when I just want to go out and look at something without a big fuss over polar alignment, then two or three star alignment after that. 
For the mounting rings on the 8 inch Newtonian, I got a set of rings from Explore Scientific, drilled four holes and tapped them to accept a 3/8”x20 bolt for alignment purposes.  This way I can just un-cradle the refractor pop it onto the AZ mount and run outside.  Then I just have minor adjustments when I remount it on the Newtonian.