Re: Couple questions about the EXOS2-GT PMC8 #EXOS2 #ExploreStars

Dave Cherry


Thanks Wes, yes sure....


PMC 8 Exos 2 Mount of course 😊 :

Skywatcher 200PDS F5 Newt, no field flattener (yet).


ASI 294MC PRO camera running at -20 degrees

Fitted with a Astronomic Duo Band 1.25 inch filter.


A total integration time of 194 mins using 2 min subs

Using sharpcap to capture


(1 sharpcap master dark comprised of 10 x 2min subs), No flats,  No Bias


Then Re-Stacked in Sharpcap using the folder camera (after throwing out any bad frames (4 bad)) . then exported the stack as a single 32bit fits file to Pix insight to get this final image (no photoshop) .


Guiding was taken care of by an Altair 294 colour non cooled guide cam and a cheap 300mm F/l, 50mm Ap’ Guide scope.

Using PH2 and pulse guiding via the RS232 interface to the PMC-8 interface through poth hub. (Ascom 6.4)

Throughout the shoot,  guide graph really didn’t fluctuate much above or below  the +/-1 Limits, I was very happy about this😊

I found lowering the hysteresis value helped a lot. Use  2 sec exposures and (even 1.5 if you can get way with it ) on the guide cam, Better to do smaller pulses but more of them when using a heavy scope like the 200PDS. ( total weight with other gear about 10.2kG (22 and half pounds)


Hope that’s everything you needed.

Bubble Target started at about 32 degrees ended up at about 54 above the horizon)






Sent from Mail for Windows 10


From: Wes Mcdonald
Sent: 23 May 2020 13:09
Subject: Re: [ESPMC-Eight] Couple questions about the EXOS2-GT PMC8 #EXOS2 #ExploreStars




Your bubble nebula pic is great.


Please share the details:


Guide parameters

Guide camera and scope details

Exposure details...lights, darks, bias, etc



Wes, Southport NC
PMC-8, ES ED 127, 10" LX200GPS, Astro-Tech 8" Newt, ETX-90
Polemaster, Orion ST-80 and SAG
Electrical Engineer, Retired


Scopes: Sky Watcher 200PDS, Skywatcher 72ED
Mount: Explore Scientific PMC8 EXO2
Cameras: ASI 294MCPRO Coooled, Altair guide cam + 50mm scope
Software: Sharpcap Pro ,PH2, Stelarium Startools

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