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Ten minute subs with an EXOS2 PMC8! #EXOS2

 

All,

I decided to try a dual-band filter to see if I could get better results on nebulas from my light-polluted back yard.  I wanted to pick one that would provide improvement without being super-specialized.  Definitely helps.  The shot below is a 200% blowup/crop of the Western Veil (NGC 6960) that I took last night (well...this morning...:-) with an Optolong CLS-CCD filter. 
 
I knew that with this filter, I should try to take longer exposures - but how long?
I'd done some tests before and knew that if I did my part, the mount was capable of doing much longer exposures than I had been using, so...
 
Note the file and camera info in the upper left hand corner.  600 seconds - 10 Minutes!  
Note the stars... they're round - at 200%.  
 
I have 14 of these to process, and we'll see how that goes - but pretty happy with the data capture from last night.  I also did a 300s test shot while deciding what length to run with.  The stars in that one are a bit tighter, the nebulosity's fainter but still visible, and the teal-colored sky is less pronounced. I may try a session like that as well at some point, but for last night, well... 10 minutes was such a nice round number :-)
 
- Bob


 
 
--
Mounts: ES PMC-8 EXOS2
Scopes: SV 102EDT, ZWO 60/280 Guide
Cameras:  Nikon D5300, Altair GPCAM2-IMX224C
Software: ASCOM, CdC, AstroTortilla, BYN Pro, Sharpcap, PHD2
Computer:  Thinkpad x230, Win7Pro/64

Jerry Hubbell - Explore Scientific VP Engineering
 

That's pretty awesome Bob!  Thanks for sharing.
--
Jerry Hubbell
Vice President of Engineering

Explore Scientific, LLC.
jrh at explorescientific.com

www.explorescientificusa.com
1010 S. 48th Street
Springdale, AR 72762
1-866-252-3811

Author: Scientific Astrophotography: How Amateurs Can Generate and Use Professional Imaging Data
             Remote Observatories for Amateur Astronomers: Using High-Powered Telescopes From Home


Mark Slade Remote Observatory (MSRO) IAU MPC W54 Equipment
Wilderness, VA
Mounts
: ES PMC-Eight G11 + Telescope Drive Master (TDM)
Scopes: ES 165 FPL-53 ED APO CF, ES 102 FCD100 ED APO CF
Cameras:  QHY174M-GPS + FW, QHY163C
Misc: 3-inch 0.7x Focal Reducer Field Flattener, Filters: Luminance,
Red, V-band Photometric, Diffuser, 200 lpmm Spectral Grating

Software: MaxIm DL 6, Cartes du Ciel, Astrometrica, AstroImageJ, AutoStakkert!

Cybermonk
 

I'm finally getting time to learn and play with my new-ish  mount. I have been reading some discouraging posts about length of exposures, Its good to know that once I get it right, there is something to look forward to. :)

eric.harant@...
 

Congratulation Bob,
Your focal length is 714mm, is't it ?
With camera do you use for guiding ?

I begin to get descent shot at 5minutes with a 300mm F/5.6 canon lens.
Guiding with a 60/240 scope and a ZWO 120MM.

Best regards
Eric


On Sun, Aug 25, 2019 at 08:32 PM, Robert Hoskin wrote:
SV 102EDT

 
--
Eric
Nargis (45) France.

57 years old, Computer science engineer.
Some skills in sofware development (Windows / Unix)
Canon EOS 10D, 40D, 600D 1300D, EOS-R. + several lenses.
ToupTek IMX 294 cooled camera.
ZWO ASI120MM
BRESSER Messier AR-102xs/460, Bresser Messier AR-152S/760
Orion 80ED.
MAK INTES 713.
Meade LX200 GPS 10"
Old Losmandy G11.
SvBony 60mm x 240mm guide scope.

 

Cybermonk,
 
Absolutely - but as to discouraging posts, it's all about expectations. :-)
 
The mount, with out-of-the-box adjustments, will likely track fine for visual users.  Putting a camera on one changes the game, and requires the operator to be more involved in the mount's tracking performance.
 
When I first got my mount, I was pretty disappointed that just by plunking it down and turning it on, I didn't get good tracking.  And, like many, I expected that good UN-guided performance was a prerequisite for good guided performance later. Both wrong, as I found out. 
 
I ended up going over the tripod, mount head, and power train, looking for things that contribute to mechanical tracking errors.  Basically, a collection of seemingly small things, but when I found  and corrected them, it made a big difference.  Those out of the way, the PMC8 is fast enough that it can then guide out remaining mechanical errors to the point where, when operated with care, the mount can perform far better than you'd expect for its price point.  
 
It was enough work chasing down those small things, that I figured I'd better document them and save others the trouble - my notes are over in Mounts/Files, if anyone needs them.     
 
- Bob
 
--
Mounts: ES PMC-8 EXOS2
Scopes: SV 102EDT, ZWO 60/280 Guide
Cameras:  Nikon D5300, Altair GPCAM2-IMX224C
Software: ASCOM, CdC, AstroTortilla, BYN Pro, Sharpcap, PHD2
Computer:  Thinkpad x230, Win7Pro/64

 

Eric,
 
You can do a lot with 5 minutes at 300mm - that's great!
 
Thanks!   No, it's faster than that.  Mine's a 102/621mm.
 
I started out with a 50/200mm guide scope, and on Jerry's advice went to a 60/280mm.  That helped considerably.
 
My guide camera, well...  
When I picked it, I had no idea and just wanted 'something to guide with', so I went for versatility and ended up with an Altair GPCAM2 IMX224 Color, with 3.75um pixels.  Just the thing for shooting Jupiter with, but not what I'd pick for a guide camera, if I had to do it all over again. One of these I'll probably switch it out for something IMX290-based and mono, w/2.9um pixels - and that should give me another bump. 
 
 
- Bob
 
--
Mounts: ES PMC-8 EXOS2
Scopes: SV 102EDT, ZWO 60/280 Guide
Cameras:  Nikon D5300, Altair GPCAM2-IMX224C
Software: ASCOM, CdC, AstroTortilla, BYN Pro, Sharpcap, PHD2
Computer:  Thinkpad x230, Win7Pro/64

 

And...

Here's a first-cut try at processing the stack from that session.    

12 X 600s used, plus flats and dark flats, stacked in DSS and processed in StarTools.  Lots of room to do better (both capture and processing), but much better than I was getting before the filter.

No idea whether 600s is the sweet spot for my gear and targets like this, or whether there's a more optimal setting, but it was a kick to see that the mount just handled it and wasn't a limitation. 

- Bob







--
Mounts: ES PMC-8 EXOS2
Scopes: SV 102EDT, ZWO 60/280 Guide
Cameras:  Nikon D5300, Altair GPCAM2-IMX224C
Software: ASCOM, CdC, AstroTortilla, BYN Pro, Sharpcap, PHD2
Computer:  Thinkpad x230, Win7Pro/64

technogeek001@...
 

That is great! I’m sold!

 

On which part?  :-)

--
Mounts: ES PMC-8 EXOS2
Scopes: SV 102EDT, ZWO 60/280 Guide
Cameras:  Nikon D5300, Altair GPCAM2-IMX224C
Software: ASCOM, CdC, AstroTortilla, BYN Pro, Sharpcap, PHD2
Computer:  Thinkpad x230, Win7Pro/64

technogeek001@...
 

I have the EXOS2 PMC8 mount but have not stepped up to guiding yet. 
I’m impressed with your results.
Being a relative beginner, I’ve been happy with what I’ve been able to do unguided after a good polar alignment

 

Good!   

Just wondered - there was more than one thing going on in the post :-)

--
Mounts: ES PMC-8 EXOS2
Scopes: SV 102EDT, ZWO 60/280 Guide
Cameras:  Nikon D5300, Altair GPCAM2-IMX224C
Software: ASCOM, CdC, AstroTortilla, BYN Pro, Sharpcap, PHD2
Computer:  Thinkpad x230, Win7Pro/64

Jim McKee
 

Beautiful shot Bob. 10 minutes is terrific! 
--
Scope:        Orion EON 115mm APO
Mounts
:      ES EXOS2-GT w/ PMC-8
Cameras:   Canon 6D Astro Mod, Canon 7D2, 1D Mk 2, EOS 60D Asto Modified
Lens:
          Canon EF 100-400mm f/4.5-5.6L IS II
Misc:          TELRAD, ZWO ASI120MM Guide Camera, Astromania 60mm Guidescope, Senso Sesto Focus Motor
Software:   EXPLORESTARS IOS & WIN, Stellarium. Backyard EOS, StarTools, APT, DSS
Computer:  Dell Latitude E5450, Windows 10

Darryl Ellis
 

Outstanding.

I've recently gotten five minutes subs and I too am very impressed and satisfied with my mount performance.

I'm sure it could do twice that amount or more time permitting.

Darryl
--

DHEllis59, Dover, DE
Astro Tech RC 6 w Pegasus Focus Cube,
Orion Starshoot II Pro Imager,
QHY 5 II Guide Camera and 30mm Guidescope,
Explorer Scientific EXOS GT 2 With PMC Eight Controller,
Orion XT8 with Nexus II DSC via Sky Safari Pro,
Celestron Luminous 31mm, Meade MWA 10mm, and 5mm EPs
Celestron Skymaster 15x70 binoculars,
20/20 or better vision in both eyes due to recent cataract surgery!!!
"The LORD by wisdom founded the earth, By understanding He established the heavens" - Proverbs 3:19