262 The Astrophotography Manual. Templates

Transcription

1 262 The Astrophotography Manual Templates I really didn t foresee the Internet. But then, neither did the computer industry. Not that that tells us very much of course the computer industry didn t even foresee that the century was going to end. Douglas Adams selection of templates is provided here for various A recording, calculating and setting-up purposes. Here they serve as examples and are just a suggestion or thought-starter. In those cases where it makes sense, the original spreadsheet is made available on the support website: Equipment Spreadsheet The purpose of the spreadsheet is to provide all the essential information for a particular equipment configuration, which may be required by the imaging software and for a quick and repeatable setup. The original Excel spreadsheet calculates the values in the green boxes from the values entered in the clear boxes. Spaces are left for values from focusing trials with different filters and temperatures. It can also be conveniently loaded by Apple s Numbers application and displays conveniently on an ipad via icloud. Imaging Startup Process (Maxim DL) This is an example of an instruction sequence for the hardware and software leading up to the imaging run. It assumes Maxim, FocusMax, MaxPoint and EQMOD; your setup will be different, but the concept is sound. The trick is to carefully document your own setup and settings as you go along, so that you can play them back, or at a later stage, when they are totally reliable, use them in a script. Imaging Sequence Process (Maxim DL) The imaging sequence is next, which goes through the alignment, focus and exposure determination. It also includes the shutdown sequence: returning the mount and focuser to their home positions, ready for the next session. Alternative Imaging Process (Sequence Generator Pro) By way of comparison, this gives a startup/sequence list for SGP / PHD2 on a Paramount MX mount (using TheSkyX as the telescope driver). This setup is up and running from power-up in less than 10 minutes, helped by pre-alignment of the mount using repeatable tripod fixings. This setup is fast and easy, the software has proved reliable and the sequencer controls are more powerful than those in Maxim DL (in its out-of-the-box form, that is, without resorting to scripting). Imaging Record Spreadsheet I keep a small logbook to record the settings for each imaging event. This record sheet is a digital alternative. It is not the last word by any means and serves as a starting point for further adds and deletes. Several versions of this sheet may be created with the yellow cells pre-populated (the green cells auto-calculate). To develop this further, one could create a database that logs data on an ongoing basis for quicker lookup. The FileMaker range of applications may be something that fits the bill, since it is currently available for multiple operating systems.

2 Appendices 263 (This spreadsheet documents key imaging parameters, and calculates others for use during acquisition.) Equipment Spreadsheet Scope: WO FLT98 WO FFIV WO Effective Guider Focal lengths (mm) Aperture (mm, f/, area) mm Field flattener spacing (mm) 76.5 QSI Imaging Sensor: QSI 683 Pixel size (W, H microns) Pixels Size (W,H mm) Well capacity (electrons) ADU 0.39 QE: 57% Noise (electrons/pixel) 8 doubles every 5.8 C Guider Sensor: Lodestar Pixel size (W, H microns) Pixels Size (W,H mm) Well capacity ADU 0.76 QE 65% Imaging: FOV (W,H deg) Diagonal 2.53 Resolution (arc sec/pixel) Guider: OAG Finder FOV (W,H deg) Resolution asec/pixel Guider offset (centers) Guide rate 0.5 PHD Cal. Time (milliseconds) 1161 Focus: (MicroTouch) steps time (s) Scale steps/dist Cal Size Microns per step 4 Critical focus (CCD, Zone microns) Focus (Lum) extension (mm) 45 Focus point (steps) (30000 = 40 mm) reference position Red offset (steps) n/a SII offset n/a Green offset (steps) n/a OIII offset n/a Blue offset (steps) n/a LPS offset n/a Ha offset (steps) n/a Temp coefficient (steps/ C) n/a V-Profile slope n/a Eyepieces: Focal length (mm) Angle (deg) FOV (deg)

3 264 The Astrophotography Manual (This example assumes Maxim DL5, MaxPoint, FocusMax and EQMOD with an EQ mount.) Startup Sequence Action Application Menu Setting Setup hardware Maxim DL Configuration Select system Observatory / Setup Connect Telescope PC IVC4 Gateway 192:168:1:1 Mask 255:255:255:1 Virtual Handset (device ) 10 Micron ASCOM Connect Focuser (after FM fires up) Approx. focus Focusmax System choose configuration System Maxim DL (connects camera) Jog Set approx. focus distance Move to Close Jog Scope setup Align Alignment star - slew to Align finder with Alt/Az controls Model Maker Connection Mount / Maxim 3-Point Calibration (Clear Model) Update mount Alt/Az if >5' 3-Point Calibration (Clear Model) 42 Point refine Accept and shut down Camera check Maxim DL Camera Control / Setup Cooler on Cooler set to -10 C Camera Control / Expose Single, simple auto dark Focus 5s 1x1 Bin Start (system check) Focus Focusmax Telescope Tab / Site Uncheck/check use scope Close Telescope Tab First Light Wizard (if no profile) Run wizard (Profile already loaded?) Focus Tab Focus Note focus position Calibrate centering Maxim Camera Control /Setup Cooler - 20 C Expose 10s, Single, Start Observatory / Zoom / Options Overlay Image Observatory / Telescope Calibrate Set Auto Use PinPoint

4 (This example assumes Maxim DL5, MaxPoint, FocusMax and EQMOD with an EQ mount.) Appendices 265 Imaging Sequence Action Application Menu Setting Imaging setup Maxim Observatory / AllSky - Search object Goto object (10s 2bin auto) PinPoint PinPoint solve it Observatory Telescope tab Sync Select Pinpoint Solved Position Observatory Zoom Options Overlay image Observatory / Telescope Select new center point Click desired center of image Auto-guider Maxim Camera Control Setup / Guider Check Bin=2 for OAG Maxim Set Calibration Check calibration is set to Lodestar darks Camera Control Setup / Guider Check option set to full calibration Pick star (away from pole star) Calibrate (10 // 20 s) Track Graph - check settled Determine exposure Camera Control / Expose Bin 2, 60 sec Select Lum exposure for 75% Multiply by 4 for Bin1 Autosequence setting Dither via guider Save sequence to FITS data card Apply Set destination to FITS data card Imaging Minimise Maxpoint, Focusmax etc Exit planetarium Camera Control / Expose Autosave start Focus check Maxim Camera Control / Expose Stop FocusMax Focus Tab Select // Select star to focus Maxim Camera Control / Expose Start Shutdown Return to defaults EQMOD Park scope FocusMax Jog Move to 30,000 (my focus park position) Turn power OFF Maxim Camera Control Setup Disconnect (software) Observatory / Setup Disconnect all (software) Disconnect leads

5 266 The Astrophotography Manual (This example assumes Sequence Generator Pro, PHD2 and TheSkyX with a Paramount mount.) Startup, Imaging and Shutdown Process Action Application Menu Setting Startup Turn power ON Guider setup PHD2 Camera Select Profile and Connect All Initial focus (optional) Goto approximate focus position (likely to be automatic in future version and may not be required) Setup sequence SGP New sequence with profile Select profile (pre-prepared) Sequencer Setup (Target) Load ref. image and solve for target or File - Import Targets (AstroPlanner) Sequencer Setup (Exposures) Type, filter, suffix, exposure, bin, repeat Enable events for session, cycle events? Select Output Directory Enable Autofocus for start of sequence Imaging Timed or immediate start Start Sequence Connects equipment; slews, centers tells auto-guider to calibrate and start guiding, autofocus, exposes sequence, meridian flips; re-centers (if required and enabled). Go back to bed Good Night System Monitor progress with ios App Shutdown Return to defaults SGP Sequencer Setup Abort and / or Run end of sequence Focus Tab Goto to focus reference position Sequencer Setup Disconnect All, Shut down SGP PHD2 Camera Control Setup Disconnect All, Shut down TSX Telescope Tab Disconnect All, Shut down Turn power OFF SGP Settings (stored): Sequencer settings: Timed start, auto-slew and auto-center on start. Focuser settings: AF every 1 C, on filter change, at sequence start, after centering, crop 10%, 9 steps of 25 Telescope settings: Auto meridian flip (15, park on completion, pause for meridian flip) Auto-guide settings: Dither (medium), PHD, settle 0.3 for 1sec, restart >2 pixels, pause during download Camera settings: Start cooling on connect, set to -20 C, warm-up on end of sequence, fast download enabled PHD2 Settings (Stored): RA - Hysteresis, 60% / 10% DEC Low Pass, 5 sec exposure, fast re-center, 0.1 min. move

6 (An Excel version with calculated fields is available at Appendices 267 Imaging Record Spreadsheet Common Name Catalog RA DEC Rises (>40 ) Sets (<40 ) Subject Andromeda M31 0:42:43 +41:16:9 20h 6h Place Long Lat Altitude (m) Date Time Location Chelmsford 51.73N.479E 10 1/10/14 20:00 Weather Temp C hpa Dew Point C Humidity Wind Kph Weather clear after rain % <10 Light Pollution Seeing Transparency Cloud Moon Phase Other Conditions country town % Telescope Aperture FL Reducer Imaging FL Focal Ratio Optics WO FLT Camera Pitch (µm) Well Capacity W (pixel) H (pixel) read noise (e) Camera QSI683WSG Camera / Software Pitch (µm) Well Capacity W (pixel) H (pixel) Guide Rate Guider Lodestar X2 / PHD Focus Software Focuser Zone (µm) Dither Object Alt Object HA Imaging Sequence Gen Pro Feathertouch ENE arcsec / pixel W (arcmin) H (arcmin) arcsec / pixel cal. pix/sec Camera Calc Guider Calc Exposure Focus Notes Filter Suffix Time Bin Count Position Temp C Sequence Night #1 L L1 2m 1 10 ~ Night #1 - cut short by mist L L2 5m 1 15 ~ Night #2 - cut short by mist L L3 10m 1 15 ~ Night #3 R R 5m 2 15 ~ Night #3 G G 5m 2 15 ~ Night #3 B B 5m 2 15 ~ Night #4 Ha H 10m 1 15 ~ Notes Autofocus with ever 1 C change and with every filter change. PHD2 mode set to hysteresis, RA & DEC 70 / 15