David's Astronomy Pages
Notes - Session 598.2 (2016-12-30)

2017 Equipment Plans
Bullet New Equipment Plan for 2017
Bullet Planetary Camera Selection  (ZWO ASI178MC)
Bullet Guide/Imaging Scope Selection (TS Optics 80mm f/6 FPL53 Triplet APO)
Bullet Image Capture / Processing Software
 

New Equipment Plan for 2017

Proposed Additional Hardware for 2017

Equipment Proposed Brand/Model    Supplier    WebPage   Other
              
Planetary / High Resolution OSC Imaging            
- CMOS Camera ZWO ASI178 MC First Light Optics   Webpage    
 - Atmospheric Dispersion Corrector ZWO 1.25" ADC First Light Optics   Webpage    
- Adapters EOS Lens to T2 ZWO Adjustable EOS Lens to T2 Adapter First Light Optics   Webpage    
- Camera Mount (to fit on Losmandy dovetail) ADM Camera Mount with clamp (to dovetail) First Light Optics   Webpage
              
Guide & Imaging Scope   Teleskop Service   Webpage    
- 80mm refractor with medium FOV TS Photoline 80mm f/6 FPL53 Triplet APO Teleskop Service   Webpage    
- Losmandy Type Dovetail for 12" LX200 ADM Losmandy-type Dovetail  for Meade 12 First Light Optics   Webpage    
- Guide Star Finder (instead of 3 Point Tube Rings) Orion X-Y Guide Star Finder Teleskop Service   Webpage   Manual
- Dew Heater Tape for 112mm diam Astrozap Dew Heater Tapes (5" scope) First Light Optics   Webpage    
- 360 Rotator for guidescope or for LX200 TS T2 quick changer and 360 rotator Teleskop Service   Webpage    
- Various T2 Extenders Various Teleskop Service        

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 Planetary Camera Selection (ZWO ASI178MC)

- Proposed Camera Use
- Selected Camera (ZWO ASI178 MC)
    Pros / Cons
    Risks & Uncertainties
- Other Options Considered
- Specifications
- Image Scale & FOV
- Links


Proposed Camera Use


The prime purpose of a new imaging camera is for high resolution planetary imaging through existing 12" LX200R SCT scope(especially Mars, Jupiter & Saturn).   In addition the new camera will also have a number of potential secondary uses including autoguiding and wider field imaging through a new secondary scope (mounted on top of the LX200R SCT).

1)  Simple, High Resolution Colour Planetary Imaging through 12" LX200

     Key criteria:
     - high FPS (ie short exposures with fast USB2/3 connection) to freeze seeing
       (My existing SBIG ST10 camera, limited to 0.11s min. exposures and 1-2s download time,
        is unable to take good planetary images)
     - high resolution (ie small photosite with a good match to 12" LX200 to stand best chance
        of getting good planetary images if seeing conidition are good)
     - single shot colour camera with good ADC/dynamic range
     - supported by good image capture and processing software with good workflows

2) Colour Imaging of Stars and Deep Sky Objects through 12" LX200, including objects with Dec 70-90 deg.

     Key criteria:
     - small camera (no filter wheel)
     - short imaging train allowing objects to be imaged between 70 & 90 deg Dec which can't be
        imaged with my current ST10 camera & filter wheel
     - low read noise
     - supported by good image capture and processing software with good workflows
     - use of dark frames to remove any amp glow

3) Autoguiding through a 80mm guidescope, to allowing well guided long exposures to be taken using LX200 main scope + ST10

     Key criteria:
     - small light camera (no filter wheel)
     - high resolution (ie small photosite with good match to 80mm f/6 APO, 1.03 arc sec/pixel)
     - large FOV for selecting suitable guide star
     - ROI support and good/high FPS
     - robust & rigid connection between APO guidescope and LX200
     - supported by good autoguiding software.
    
     (I've seen one comment online that a colour camera shouldn't be used due to variation in sensitvity, and thus
    variation in pixel values) between Red, Green and Blue pixels. I don't consider this is a showstopper given the
     camera's small photosites (2.4m), the resulting image scale of 1 arc sec/pixel and the typical seeing (3-5 arc sec FHWM))

4)  Medium Field Deep Sky Colour Imaging through 80mm APO refractor, piggy-backed on LX200 SCT
     with option for autoguiding with ST-10 camera through LX200

     Key criteria:
     - small light camera (no filter wheel)
     - high resolution (ie small photosite with good match to 80mm f/6, 1.03 arc sec/pixel )
     - large FOV for imaging extended deep sky objects,  comets, moon etc
     - robust & rigid connection between APO scope and LX200
     - supported by good image capture and processing software

5)  Wide Field Deep Sky Colour Imaging through through Canon camera len(s) piggy-backed on LX200 SCT.
     with option for autoguiding with ST-10 camera through LX200

     Key criteria:
     - small light camera (no filter wheel)
     - high resolution
     - large FOV for imaging extended deep sky objects,  comets, conjunctions etc
     - robust & rigid connection between Camera Mount and LX200
     - supported by good image capture and processing software

6) Super-finder using eithe

7)  AllSky Colour Imaging using 150-170 deg fisheye lens supplied with ZWO camera

    Key criteria:
     - small light camera (no filter wheel)
     - single shot colour camera with good ADC/dynamic range and high resolution

8) Colour Imaging of Stars and Deep Sky Objects through old  8" LX200 Classic

    Key Criteria:
    - small light USB camera (replacing old parallel port ST-7 camera)

Selected Camera (ZWO ASI178 MC)

Pros
- Single Shot Colour Camera
  > Simple Colour Image Solution
  > No requirement for filter wheel + filters
  > Option to view Live Colour images
  > Option to view Live Deep Sky images,  for target acquisition & centering)
  > Simpler imaging, Simpler reduction & stacking
  > Arguably a better method gives the variable weather conditions in Scotland where the breask in the cloud are typically short
    (at least one gets a colour image or some sort, rather than an incomplete set of frames through individual RGB filters)
  > Option to use ADC to correct for atmospheric dispersion  (potentially as good or even better than colour registration)
  > All colours are in focus (or at least of equal focus) so no need to refocus for each colour filter
     (Jupiter's fast rotation means one has just 2 minutes or so to take an RGB suite with a monochome camera)
- Good Dynamic Range
  >  14 bit ADC (dynamic range) is supported ( some other cameras only support 10 bit or 12 bit)
      (ASI178 apparenty uses 10 bit ADC when 'high-speed' is enabled, otherwise it uses 14 bit ADC)
  >  14 bit is better for lunar imaging where there is detail in both bright areas and shadows
- Reasonable Sized Chip (1/1.8", 7.43 x 4.99mm)
   > Good FOV through 12" LX200  (8.3' x 5.6' at f/10)   
   > larger chip/FOV compared to other planetary cameras
   > quicker to locate planetary target and bring it to centre of view.
   > larger area of Moon can be covered in a single view.
   > Good FOV through 90mm APO  (51' x 34' at f/5.6)
   > more chance of being able to cover extended DSO objects
   > larger chip is helpful when using a atmospher diffraction corrector (ADC), as the position of the target object (eg Mars)
     on the sensor will move when the ADC's prisms are adjusted.
- High Resolution
  > Potential high resolution imaginary (2.4m pixel size)
  > resolution of 0.16 arc secs through 12" LX200 at f/10 (3048mm focal length)
  > meets Nyquist sampling requirements at Prime Focus (f/8.7 for 12" LX200, no need for Barlow lens)
  > Good size Planetary Images   Jupiter 250-300 pixal diam.,   Mars 87-156 pixel diam., Venus 125-150 pixal diam.
  > resolution of 0.99 arc sec through 90mm APO refracter at f/5.6 (500mm focal length)
- Fast Speed
  > supports very short exposures (32s minimum)  (cf  0.11s minimum for current camera, ST10)
  > fast USB 3 connectivity (but backward compatible with USB 2 ports on current laptop)
  > 60fps for full resolution image 30962080 with 10bit ADC  (30 fps with 14 bit ADC)
  > 130fps for mid-sized image 1280x960 with 10bit ADC  (65 fps with 14 bit ADC)
  > 253fps for small-size image 640x480 with 10bit ADC  (126 fps with 14 bit ADC)
  > option to use 10 bit ADC where faster FPS needed.
- Other  
  > Autoguiding capability
  > Low read noise  (2.2e / 1.4e)
  > IR Cufoff built in (no additional filter required)
  > Option for long exposures (1000s maximum), but likely to be limited by dark current, as camera is non-cooled
  > Good software options

Cons
- Large File Size at Full Resolution (6.4 Mega Pixels, 3096*2080)
- Large Image Size at Full Resolution but size can be reduced since 'Region of Interest' (ROI) is supported
- Uncertain Binning Effects    (2x2 binning loses colour information)
- Uncooled (not an issue for planetary imaging, and of little significance for short exposure Deep Sky Imaging)
- Likely to be seeing limited on most nights (high resolution rarely used to best effect)
- Shutter type (rolling shutter) not as good a global shutter offered by certain other cameras (eg.
- Working relative humidity limit (80% max) is likely to be tested by conditions that reach 90-98% RH on dew prone nights

Risks & Uncertainties
- Pixel size (2.4m) may be too small for the seeing at my site (typically 4-5 arc secs FWHM). Objects are oversampled.
- Data handling /storage issues may occur due to the large file size generated per image and the number of frames that can be shot at high frame rate.
- Difficult in managing a master dark library where the number of variables are Colour Space (Type), Binning, Exposure Time, Gain,  Bits, Gamma, Brightness, Temperature, ROI ,Other? (ROI, Save Format, Number for Frames) . Imaging with SBIG ST10 camera has far fewer factors (Binning, Exposure Time, Temperature).  SharpCap only stores master dark frames based on Colour Space (Type), Exposure, Gain
- Relative humidity at site (frequently 80-96% or 100% during dew conditions) is frequently higher than the Working Relative Humidity range given in Camera Specs (20 to 80%) and might cause problems during operation of the camera
- Ambient Temperature at site occassionally falls below the Working Temperature range given in the Camera Specs (-5 to +45 degC)and might cause problems during operation of the camera
- Photosites in ASI178 camera have a low full well capacity (just 15000 e- at 0 gain), this is typical of sensors with small photosites. This would seemingly suggest that exposures have to be shorter than other cameras in order to prevent saturated pixel values, but smaller photosites capture photons/build electons more slower than large photosites due to there smaller area - so the effect probably cancels out ?

Calculations

Minimum focal length required to fully sample a high resolution (planetary) image using ZWO ASI178 camera  (2.4 um)

Scope
    Aperture
(mm)
 
Colour
 
Wavelength
(nm)
Minimum
Focal Ratio
   Minimum Focal Length
(mm)
 
                  
12" LX200   304.8 Red 650 f/9.1   2767  
       Green 510 f/11.6   3527  
      Blue 475 f/12.4   3782  
                  
80mm APO    80 Red 650 f/9.1   726  
       Green 510 f/11.6   926  
      Blue 475 f/12.4   994  

For planetary imaging using the 12" LX200 f/10 scope at prime focus without a barlow provides about the right sampling. 
(i.e. there is little advantage in using a barlow, especially given the seeing conditions

Planetary imaging using 80mm APO would require use of a x2 barlow.
 
(Calculations using 'Wilmslow Astro - Useful Formula': http://www.wilmslowastro.com/software/formulae.htm )
using   Focal Length >=  3 * (Aperture (in mm) * PhotoSite (in um)/1000)) / (Wavelength  *1.22)
 

Other Options Considered

Monochrome Camera:   ASI 178MM (the monochrome version of the ASI 178MC camera) costs 378 (vs 344), and would require extra costs for ZWO's 5 position electronic filter wheel (175, 300g) and an LRGB filter set (72)

Cooled Camera:   ASI178 MC-Cool (the cooled version of the ASI 178MC camera) costs 727 (vs 344), weighs 410g (vs 120g),  is x cm longer, and requires an extra 12V power supply for cooling operations. 

Alternative ZWO colour cameras:  Other colour cameras in the ZWO range where rejected for a number of reasons:
  - ASI034 MC, 112, 8 bit, 5.6 m, USB2  - rejected due to small chip size, low resolution, lower ADC & absence of USB 3
  - ASI120 MC, 199, 12 bit, 3.75 m, 4.8 x 3.6mm, USB 3 - rejected due to small chip size/small FOV & lower ADC 
  - ASI224 MC, 268, 12 bit, 3.75 m, 4.8 x 3.6mm, USB 3 - rejected due to smaller chip size/smaller FOV & lower ADC,
    IR cutoff not built in (+/-)
  - ASI290 MC, 297, 12 bit, 2.9 m, 5.6 x 3.2mm, USB 3 - rejected due to smaller chip size/smaller FOV & lower ADC,  IR cutoff not built in (+/-)
  - ASI185 MC, 298, 12 bit, 3.75 m, 7.3 x 4.6mm, USB 3 - rejected due to lower resolution & lower ADC
  - ASI178 MC, 377, 14 bit, 2.40 m, 7.4 x 5.0mm, USB 3 - selected camera (for info)
  - ASI174 MC, 615, 12 bit, 5.86 m, 11.3 x 7.1mm, USB 3 - rejected due to lower resolution,  lower ADC & cost
  - ASI1600 MC, 717, 12 bit, 3.80 m, 17.7 x 13.4mm, USB 3 - rejected due to lower ADC, cost & potential vignetting (large chip)

Prices at Dec 2016 on First Optics Website ( https://www.firstlightoptics.com/zwo-cameras.html), prices went up on 1st Jan 2017.

Alternative Makes
 - QHY5III 178 C (uses the same sony chip as the ASI178 MC) - around same price (347 vs 344), but offers anti amp-glow control function, supposedly better passive cooling, and slightly wider exposure range, 9 s to 1200s).  Some people have reported problems with QHY drivers /cameras.

Camera Specifications / Technical Data

Specifications of the ZWO ASI178MC camera are listed here for information. 
(for definitive specifications please visit the ZWO website (see ZWO Links))

 
Parameter Name    Parameter Value
Sensor   1/1.8” CMOS IMX178 cm
Resolution   6.4 Mega Pixels 3096*2080
Pixel Size   2.4m
Sensor Size   7.4mm*5mm
Diagonal   8.92mm
Exposure Range   32s-1000s
ROI Support   Yes
ST4 Guider Port   Yes
Focus Distance to Sensor   12.5mm
Shutter Type   Rolling Shutter
Protect window   IR-CUT window
Operating System Compatibility   Mac, Windows, Linux
Interface   USB3.0/USB2.0
Bit rate   14bit output(14bit ADC)
Focuser   135 mm from the 2" connection and 170 mm from the female M63 thread
Adaptor   2" / 1.25" / M42X0.75
Dimension   75 mm
Weight   120g or 4.2 ounces (without lens)
Working Temperature   -5C—45C
Storage Temperature   -20C—60C
Working Relative Humidity   20%—80%
Working Relative Humidity   20%—80%
     
More Specs on ASI178    
Full Well Depth   15,000e (at 0 amplifer gain)
Largest Value with 14bit   Largest Value with 14bit (2^14) = 16384
Unity Gain   -15 (estimated from ASI178 graph)
Gain at 0db   0.9e/ADU (estimated from ASI178 graph),    0.916e/ADU from 15000/16384
Camera Gain   0 (0dB) : 0.9e/ADU
    100 (10dB) : 0.28e/ADU
    200 (20dB) : 0.10e/ADU

 

Image Scale and FOV

Scale and Field Of View of images taken with ZWO ASI178MC camera through different scopes/lenses are listed below.
(Rows are ordered from shortest to longest focal length, i.e. from wideest view to narrowest view)

Scope / Lens    Focal
Length
(mm)
Field
of
View
   Image Scale
1x1 binning
(arc sec/px)
Image Scale
2x2 binning
(arc sec/px)
Image Scale
3x3 binning
(arc sec/px)
Canon Lens 18-55mm   18 23.7' x 13.9'   27.5 55.0 82.5
24mm Canon Lens   24 17.7' x 11.9'   20.6 41.3 61.9
35mm Canon Lens   35 12.2' x 8.2'   14.1 28.3 14.14
55mm Canon Lens   55 7.7' x 5.2'   9.0 18.0 27.0
                
Canon Lens 70-300m f/4-5.6 IS   70 6.08' x 4.09'   7.07 14.14 21.22
Canon Lens 70-300m f/4-5.6 IS   100 4.26' x 2.86'   4.95 9.90 14.85
Canon Lens 70-300m f/4-5.6 IS   135 3.15' x 2.12'   3.67 7.33 11.00
Canon Lens 70-300m f/4-5.6 IS   200 2.13' x 1.43'   2.48 4.95 7.43
Canon Lens 70-300m f/4-5.6 IS   300 1.42' x 0.95'   1.65 3.30 4.95
                
TS Photoline 80mm f/6 x0.63   302.4 1.41' x 0.95'   1.64 3.27 4.91
TS Photoline 80mm f/6 x0.79   379.2 1.12' x 0.75   1.31 2.61 3.92
TS Photoline 80mm f/6   480 0.89' x 0.60'   1.03 2.06 3.09
                
12" LX200 f/10 x0.63 (f/6.3)   1920 13.30" x 8.94"   0.258 0.516 0.773
12" LX200 f/10   3048 8.38" x 5.63"   0.162 0.325 0.487
               
Scale and Field of View
with ST-10XME (for reference)
             
12" LX200 f/10 x0.63 (f/6.3)   1920 37.69" x 25.32"   0.731 1.461 2.192
12" LX200 f/10   3048 16.75" x 11.29"   0.460 0.920 1.381
12" LX200 at f/10.4   3170 16.11" x 10.86"   0.442 0.885 1.327
               

Links

ZWO Website (Chinese) : http://zwoasi.com/
ZWO Website (English) : https://astronomy-imaging-camera.com/

ZWO Supplier UK: https://www.firstlightoptics.com/zwo-cameras.html

ZWO Users Forum: http://zwoug.org/

Sam at ZWO :   sam.wen(at)zwoptical.com

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Guide/Imaging Scope Selection (TS Photoline 80mm f/6 FPL53 Triplet APO)

- Proposed Scope Use
- Selected Scope  - TS Photoline 80mm f/6 FPL53 Triplet APO
    Pros / Cons
    Risks & Uncertainties
- Other Scopes Considered
- Other Guiding Setups Considered
- Proposed Mount
- Telescope Specification
- Image Scale & FOV
- Links


Proposed Scope Use


The scope is intended to have a dual role as

1) a guidescope and
2) an alternative imaging scope with a medium field of view.

Both roles would use ZWO ASI178MC as the principal camera when it's not in use for Planetary/Lunar or other imaging through the 12" LX200R main scope. The scope would have a number of other potential uses as well.

1)  Guidescope for 12" LX200R main scope

     Key criteria:
     - reasonably fast scope (~ f/6)  and moderate focal length (~480-500mm) with an image scale (~ 1arc/sec)
       suitable for successful guiding of main scope operating at focal length of 3048mm
     - sufficient field of view with ZWO ASI178MC camera to find a good (sufficiently bright) guide star
     - reasonably small/light (~ 80mm aperature)
     - can be piggy-backed on 12" LX200R without passing andy weight constraints and with impacting tracking on the main scope
     - connection between guidescope / guidecamera and LX200 main scope /ST10 imaging camera is robust & rigid
       (ie no flex between guide and imaging sensors)    
     - easy and quick to put on/take off scope from the 12" LX200
       (there isn't room between top of 12" LX200 and the observatory roof to allow a permanent attachment of the guidescope)
     - good polar alignment.
     - guiding is supported by good guiding software
     - ideally the setup will allow adjustments to be able to centre the guide camera view on the imaging camera (main scope) view
     - an arrangement that can allow auto-guiding on a comet nucleus being imaged in main scope.

2) An alternate imaging scope with ZWO ASI178MC camera
     (for extended objects (larger than FOV of 12" LX200R + ST-10), fullmoon lunar imaging,
     and objects benefitting from single shot colour imaging)

     Key criteria:
      - good quality optics
      - apochromatic / very good color correction
      - no flex between the camera on alternate imaging scope and the ST-10 camera on 12" LX200R main scope
       (for cases where LX200R + ST10 is being used to autoguide the imaging on the smaller scope.
      - a reasonably flat field (camera sensor is reasonably small and doesn't challenge the extremes of the scope's
        field of view when centered, but  camera may be placed off-axis for either guide star finding or to colliminate
        centre of view with than in the main scope)

     Other variations on an imaging role is using the scope with a DLSR (Canon EOS 400D (=Digital Rebel XTi ))
    or a future Cooled CMOS camera with a larger sensor  to obtain a wider imaging view.  
    A good flat field (astrograph quality) would be very desirable for this.  
    Potential also to use the scope for white light observations of Sun/Sunspots (with suitable Mylar filters).

3) A super-finder (to aid star centering, understand pointing issues and help locate comets or lunar features)

    Key criteria:
     - moderate focal length (480-500mm) to provide a c. 1 deg field of view through camera
     - scope/camera is setup to centre the guide camera view on the imaging camera (main scope) view

4) Visual observing scope (providing an alternative or break from permanent imaging with LX200R main scope).  

   Key criteria:
      - good quality optics
      - can be used with existing variety of eyepieces
      - potential to be taken and used on a standalone tripod system

Selected Scope - TS Photoline 80mm f/6 FPL53 Triplet APO

Pros
- Apochromatic
  > High-quality Photoline Triplet APO with FPL53 element from Ohara (Japan)
  > Reasonable price compared to more expensive ADO alternates
- Suitable Aperature, Focal Ratio and Focal Length for intended uses
   > 80mm aperture, f/6 and 480mm focal length
   > provides 1 arcsec/pixel when used with ZWO ASI178MC camera at 1x1 binning
- Good Focuser
   > Rack-and-pinion focuser, plain bearing mounted.
   > The support is decoupled from the drawtube drive   
   > Oversized drawtube with 60 mm clear aperture capable of full illumination with full-frame sensors
   > 1:10 dual speed system for ultra-precise focusing
   > Option to mount imaging train directly to focuser using M63 connection, rather than 2" connection with knurled screw

Cons
- As supplied the field is not corrected to keep stars nicely round to the edge of the view - a typical consequence of any fast refractor
  (options exist for 2" or 2.1/2" field correction at an additional cost and with/without focal reduction)


Risks & Uncertainties
- the precise connection to be used between TS 80mm f/6 Triplet APO and the 12" LX200R is not yet finalised.  The TS 80mm f/6 is supplied with high-quality CNC rings and GP style dovetail bar.   The dovetail with be replaced with connection to a planned Losmandy style dovetail bar sitting on the 12" LX200R main scope, but it is not clear what is required to achieve a two bolt connection for each ring (Losmandy / ADM dovetail clamps have 0.5" hole spacing whilst the ring tube is likely to have metric hold spacings)
[ Mitigation is to delay choosing final connection until the CNC rings supplied with scope can be assessed ]

- flex between the guidescope / guidecamera and LX200 main scope /ST10 imaging camera is too high and doesn't provide successful autoguiding for long exposures with the main scope camera (or vice versa). Main risk is probably in the flex in the imaging train on the main scope (heavy CCD camera, filter wheel and AO7 unit, 2" connection with focusser)
[ Mitigation is to use rigid tube rings and heavy duty Losmandy dovetail for connection between guidescope and main scope, double bolt connection between rings & clamps and willingness to experiement / optimise the imaging train on the LX200 to reduce flex(e.g remove A07 unit, use of alternate, self centering compression connectors)

- it is difficult to connect / disconect the TS 80mm f/6 Triplet APO from LX200 in cold & dark
[ Mitigation is to use clamps with large knurled knobs ]

- the TS 80mm f/6 Triplet APO is left piggy back on the LX200R main scope when the observatory roof is closed, resulting in equipment damage. Roof closure is manual but potentially subject to human error, e.g a desire to quickly shut roof if it starts to rain ]
[ Mitigation : adherance to procedure and instill a habit of visual check before final roof closure ]

- the guidescope view can not or cannot easily be centred on the view through the main scope (desirable for certain functions & uses).  This risk is increased by using circular tube rings rather than 3 point tube rings (the latter being unsuitable given the need to put on/take off the secondary scope each session, and the need to have a firm connection between the two scopes for autoguiding.
[ Mitigation is to use a X/Y positional adjuster, and for this purpose the Orion X-Y Guide Star Finder is the chosen solution ]

- although the sensor on the ZWO ASI178MC is of reasonable size compared to many alternative planetary cameras and the focal length of the secondary scope (480mm) is reasonably short, there is a risk that a suitable guide star can not always be found (either too dim or compromises framing on the main imaging camera  (the choice of guide stars with a secondary scope setup is still a lot higher than using the ST-10 secondary guide CCD or an off-axis guide scope)
[ Mitigation is to use a X/Y positional adjuster, and for this purpose the Orion X-Y Guide Star Finder is the chosen solution ]
 
Whilst adjustment can be done with Orion X-Y guide Star Finder without effecting focus the adjustment has to be done manually which requires going out to the observatory/scope ]

- Use of Orion X-Y guide Star Finder introduces flex into the guiding setup.  Risk is low based on reading other users reports online

 

Online scratch notes:  "My Nikon pixel sizes are 3.9 micron.  The diffraction spot size of the SV80ST with 0.8 reducer is ~5 microns.  That's a good match.  With your 4.3 micron pixel size, that's even better.  Given seeing and tracking, I really don't see how you could get to an under sample condition. "



Other Scopes Considered

Telescope    Cost
()
  Aperture F-Ratio Focal
Length
Specification    Notes
TS Photoline 80mm f/6 Triplet APO   697   80mm f/6 480mm     - Selected Option
Starwave 80 ED_R                  
William Optics GT81   1049   81mm f/5.9 478mm      
William Optics Star71 II   1274   71mm f/4.9 350mm     focal length shorter than desired, more expensive
Stellarvue SV80ST-25SV   $1195             same design as TS Photoline 80mm f/6
(but sold by Stellarvue in US
($1795 with Feather Touch focuser (+$600)
                   

   - ASI034 MC, 112, 8 bit, 5.6 m, USB2  - rejected due to small chip size, low resolution, lower ADC & absence of USB 3
  - TS Photoline ASI120 MC, 199, 12 bit, 3.75 m, 4.8 x 3.6mm, USB 3 - rejected due to small chip size/small FOV & lower ADC 
  - ASI224 MC, 268, 12 bit, 3.75 m, 4.8 x 3.6mm, USB 3 - rejected due to smaller chip size/smaller FOV & lower ADC,

Other Guiding Setups Considered

To be written..

Other GuideScope Alignment Options Considered

To be written..

Telescope Specifications

Specifications/technical data for the TS Photoline 80mm f/6 telescope (with 2.5" RAP Focuser) are listed here for information. 
 
For definitive specifications please visit the TS PHOTOLINE 80mm f/6 FPL53 Triplet APO page on the Teleskop Service website.

Parameter Name    Parameter Value
Objective design   Apochromatic triplet with FPL53 element
Coating   Fully multi-coated
Aperture   80 mm
Focal length   480 mm
Focal ratio   f/6
Tube material   Aluminum
Tube length with retracted dewshield   375 mm
Tube length with dewshield   420 mm
Tube diameter   89 mm
Dew cap diameter   112 mm
Dew cap design   Retractable
Tube weight   3.14 kg with tube rings
Focuser   2.5" RPA with 1/11 dual speed, reinforced plain bearings
Connections on the eyepiece side   M63x1 female thread, 2" and 1,25"
Focuser   135 mm from the 2" connection and 170 mm from the female M63 thread
Maximal load of focuser   5 kg
Drawtube travel   75 mm
Thread between tube and focuser   M89x1

Other spec on Stellarvue site for

- Tube Rings:  Stellarvue R90SET precision hinged rings.
  Each ring has five 1/4-20 holes top and bottom with one in the center and two spaced 1.5” and 60mm apart.
  Rings on the SV80ST2 have a height of 4 3/4 inch, measured between the two flat sides, one of which is where
  you attach a dovetail.  The maximum width is 5 inches.
  The 1/4-20 mounting screws that Fred refers to applies to all of our clamshells and telescopes that are 5 inch or larger.
  Dual ring mounts for telescopes of less than 5 inch (80 mm - 115 mm) use metric M6 X 1 screws,
  not 1/4-20. We used 6 mm threaded holes on these smaller dual rings since we used to sell the M4 mount that
  came with 6 mm screws. Just FYI

 
- Light Gain:  131x (human eye = 1)
- Theoretical Resolution :  1.5 arc sec (Dawes Limit)
- Weight :  The optical tube assembly weighs about 5.8 lbs. The dual rings weigh about 1.2 pounds total.

Image Scale and FOV

Scale and Field Of View of images taken with ZWO ASI178MC camera through different scopes/lenses are listed below.
(Rows are ordered from shortest to longest focal length, i.e. from wideest view to narrowest view)

Camera    Configuration    Focal
Length
(mm)
Field
of
View
   Image Scale
1x1 binning
(arc sec/px)
Image Scale
2x2 binning
(arc sec/px)
Image Scale
3x3 binning
(arc sec/px)
                    
ZWO ASI178MC   TS Photoline 80mm f/6 x0.63   302.4 1.41' x 0.95'   1.64 3.27 4.91
ZWO ASI178MC   TS Photoline 80mm f/6 x0.79   379.2 1.12' x 0.75   1.31 2.61 3.92
ZWO ASI178MC   TS Photoline 80mm f/6   480 0.89' x 0.60'   1.03 2.06 3.09
                    
Canon E400D   TS Photoline 80mm f/6 x0.63   302.4 13.30" x 8.94"   3.89 7.78 11.66
Canon E400D   TS Photoline 80mm f/6 x0.79   379.2 8.38" x 5.63"   3.10 6.20 9.30
Canon E400D   TS Photoline 80mm f/6   480 2.65' x 1.76'   2.45 4.90 7.35
                   


Airy Disk Diameter

(from Wilmslow Astro Useful  Formula: http://www.wilmslowastro.com/software/formulae.htm )

     Colour Airy Disk Diameter  
Configuration    Colour
Name
Wavelength
(nm)
arc secs    mm    no. of 2.4um
photosites
 
                    
TS Photoline 80mm f/6   Red 650 4.09"   0.0095   4.0  
     Green 510 3.21"   0.0075   3.1  
    Blue 475 2.99"   0.0070   2.9  
                    
TS Photoline 80mm f/4.74   Red 650 4.09"   0.0075   3.1  
    (f/6 x0.79)   Green 510 3.21"   0.0059   2.5  
    Blue 475 2.99"   0.0055   2.3  


Autoguide rates

Using TS Photoline 80mm f/6 (480mm focal length) and AS178MC camera (2.4um)

    Autoguide Rate in pixels/sec  
Declination     at Guide Rate
  x0.50
 
0   7.29  
10   7.18  
30   6.31  
45   5.16  
 60   3.65  
 75   1.89  
       

Critical Focus Zone


Critical focus zone (length of the zone in which the focused image of a star is smaller than the size of its Airy disk) is around 0.1mm wide using TS Photoline 80mm f/6 & ASI178MC camera.  Fine focusing is therefore important for achieving best quality images.
 
(This compares to a critical focus with of 0.25mm using LX200 F/10)


     Colour   Critical Focus Zone  
Configuration    Colour
Name
Wavelength
(nm)
microns    mm  
                
TS Photoline 80mm f/6   Red 650 114   0.11  
     Green 510 90   0.09  
    Blue 475 83   0.08  
                
TS Photoline 80mm f/4.74   Red 650 71   0.07  
    (f/6 x0.79)   Green 510 56   0.06  
    Blue 475 52   0.05  

 

 

Using TS Photoline 80mm f/6 (480mm focal length) and AS178MC camera (2.4um)

    Autoguide Rate in pixels/sec  
Declination     at Guide Rate
  x0.50
 
0   7.29  
10   7.18  
30   6.31  
45   5.16  
 60   3.65  
 75   1.89  
       

Links

Teleskop Service Website (English) : http://www.teleskop-express.de/shop/index.php/language/en
Teleskop Service Telescopes (English) : http://www.teleskop-express.de/shop/index.php/language/en/cat/c4_telescopes_for_astronomy.html

Telescope's web page:  TS PHOTOLINE 80mm f/6 FPL53 Triplet APO page (Teleskop Service website)

Stellarvue Telescope Forum: https://groups.yahoo.com/neo/groups/Stellarvue/info

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Planetary Image Capture / Processing Software

Whilst looking into the software that I could potentially use for capturing and processing images with Zwo camera (including software especially helpful for planetary images) I created the following list - valid as at Jan 2017.  
Of these the only one that I had used before were RegiStax and CCDSoft.

Please note that the list is not necessarily or intended to be a complete list of all available software.

(Notes made whilst using some of these programs in 2017 with ZWO ASI178MC camera & its acquired images can be found here.)

Free Software - Image Acquistion
- SharpCap, Vn 2.9 (http://www.sharpcap.co.uk/) - Image acqusition incl. ZWO
- Firecapture, Vn 2.5, 64 bit  (http://www.firecapture.de/) - Image acqusition incl. ZWO
- AstroLive  (http://astrolive.io/astroliveusb.html) - Free Version for ZWO cameras only

Free Software - Autoguiding
- PHD 2, Vn 2.6.2 (http://openphdguiding.org/) - Autoguiding
- MetaGuide, Vn 5.2.9 (http://www.astrogeeks.com/Bliss/MetaGuide/) - Autoguiding

Free Software - Processing
- SER Player, Vn 1.6.0 (https://sites.google.com/site/astropipp/) - SER viewer and processing
- FITS Image Grader (http://mainsequencesoftware.com/Products/ImageGrader), FITS review/grading
- DeepSkyStacker, Vn 3.3.2  (http://deepskystacker.free.fr/english/index.html), includes 'DeepSkyStacker Live'
- PIIP, Vn 2.5.8, 64 bit (https://sites.google.com/site/astropipp/)  - Pre-processing planetary images and general image conversion
- AutoStakkert, Vn 2.6.8 (http://www.autostakkert.com/) - Planetary processing
- RegiStax, Vn 6.1 (http://www.astronomie.be/registax/) - Alignment/stacking/processing of images
- WinJUPOS, Vn 10.3.1  (http://jupos.privat.t-online.de/) - Planetary/Solar Surface Position Mapping, Measurement & Computation

- GIMP 2, Vn 2.8.18 (https://www.gimp.org/) - Image manipulation
- Regim, Vn 3.4 (http://www.andreasroerig.de/regim/regim_e.htm) - Image Processing

Free Software - PEC
- PECprep, Vn 2.03 (http://eq-mod.sourceforge.net/pecprep/)  - PEC analysis.

Free Software - Planetarium
- Stellarium, Vn 0.15.1.1 (http://www.stellarium.org/en_GB/) - Desktop Planetarium (Jupiter Moons)

Commercial Software
- Astroart, Vn 6.0 (http://www.msb-astroart.com/) -  Full works, 135 EUR + VAT or $169
- PixInsight, Vn 1.8 (https://pixinsight.com) , 45 day free trial then 230 EUR + VAT
- Genika Astro, Vn 2.13, 32/64 bit (http://genicapture.com/) - Image acquisition incl. ZWO, - restricted trial then 70 EUR
- FITSX, Vn 2.4.9 (https://www.coaa.co.uk/fitsx.htm) - Image manipulation (FITS files), 21 day free trial then 25 EUR  + VAT
- Nebulosity 4, Vn (http://www.stark-labs.com/nebulosity.html) - Image captue & processing, highly functional demo then $95
- Sequence Generator Pro, Vn 2.5 (http://mainsequencesoftware.com/Products/SGPro) , Fullworks (45 day free trial then $99 (or automatic conversion to a Lite version), Extra for Framing/Mosaic Module.
- AstroLive  (  - Commercial Version for version additional to ZWO cameras.
- CCDSoft5
- MaximDL

- APT, Astro Photography Tool, Vn 3.20 (http://www.ideiki.com/astro/)   Unlimited Trial, then 18.70 EUR, 1 year support, then 6 EUR per year)

(DARV - Drift Alignment by Robert Vice method)

- IC Capture.AS ?
- FlyCap ?