My Timelapse Project
Last updated: Lake Placid, 3 Aug 2020 Contact:

  The rig consists of the following components:
  1. Exposure controller - a Timelapse+ View (TL+)
  2. Camera - a Sony a7RIV (a7R4) with 2 x 1TB SD cards
  3. Pan-tilt motion controller and servos - a Cognisys 3X controller (3X) with their servos and a handful of Arca-Swiss rails and clamps
  4. Stable tripod - a Gitzo G1325
  5. Power Monitor - of my own concoction
  6. Batteries - a Renogy 72000 and an Anker 20100
To-do: Replace with better photo (ie. an animated GIF)

TL+
Varies the camera's aperature, exposure time and ISO to create a correct exposure.  Here is an example:
See his whole series here. It includes a review of this particular exposure controller.
 
After setting the exposure, the TL+ "presses" the shutter to take the image, then signals the motion controller (in my case) to move to the next position (aka Shoot-Move-Shoot).
 
Q: Why not use the camera's automatic exposure?  Why the need for this exposure controller?
A: Various videos (e.g. this one and this one) show and describe the shortcomings of using the camera's auto exposure (typically flicker, difficult to remove in post).
Note, it is possible to manually vary the settings (e.g. as discussed here) to get a good result, comparable to using the Timelapse+ View, but for the time and effort, I'll opt for the automatic approach.
Finally, using the TL+ to control the pan-tilt (Shoot-Move-Shoot) seems like it is going to work out better than any alternatives, especially when there are large changes in shutter time as would occur in day-to-night.
 
TL+ Settings (copied from here, author: Elijah Parker): 
  On the View 
    Exposure        Just setup the camera for the current scene before hand and skip this step
    Timelapse Mode  Auto Ramping
    Interval Mode   Auto Variable
    Day Interval    8 seconds
    Night Interval  40 Seconds
    Destination	    Camera - This setting only appears if there is an SD card in the VIEW. 
                             For older Sony cameras connected via USB, you’ll need to set 
                             this to ‘SD Card’ and make sure an SD card is in the VIEW. 
                             For other cameras, performance is best when saving directly 
                             to the camera. Sony can save to the camera when connected 
                             via WiFi instead of USB (see camera-specific notes for more).

    I recommend starting an hour before sunset, setting the camera at the lowest ISO, 
    a moderately wide aperture (e.g., f/2.8) and then setting the shutter speed to whatever 
    is needed for a good exposure (maybe 1/3200). Make sure it’s not overexposed!

    Then, let it run at least 3 hours after sunset to get a good length and transition.  
    Or, if you have external power for the camera, go all night until sunrise!

    To stop the time-lapse, press the menu (lower right) button while in the time-lapse 
    status screen and then select “Stop Time-lapse”.
Lake Placid, 1 Aug 2020
Problem:
The TL+ doesn't seem to output a pulse on AUX2 to the 3X to cause the pan-tilt to advance to the next position.  I am able to advance the 3X pan-tilt by simply shorting the Tip to Shield on the 2.5mm TRS plug (after removing the plug from AUX2) using a short piece of wire.  But get no response when I plug the 2.5mm TRS plug into AUX2 and start the TL+ timelapse process.  I see 0 Ohms on a VOM multimeter on the RCA plug that plugs into the 3X and no variation in the resistance (that I might expect from a pulse) as the TL+ runs.  Finally, when I invert the pulse on the TL+ AUX2 (per the documentation), I continue to measure 0 Ohms - so something is shorted, physically or logically.
To-do Status
Put together a graphical Ohm Meter from an
  • Arduino - builtin ADC,
  • M0 Feather - builtin ADC, 3.5" display, or
  • Raspberry Pi - 3.5" display.
and try to measure the AUX2 signal with that.  The M0 Feather would be my 1st choice.
And/or get an oscilloscope.
 
 
 
 
  		I have ordered and received an ADC if I want to use the Pi.
 
 
 
Siglent SDS1104X-E received.  A very cool device.  Also got a cheap Signal Generator.  I haven't used a scope in 30 years.
Disassemble the TL+ to see if the problem is a bad connection in the 2.5mm jack of the AUX2 port.
Order a 2nd TL+ to try.  If this problem turns out to not be the fault of the TL+, I will simply use the 2nd TL+ as a backup.  If it turns out that this TL+ is bad, I will ask the manufacturer to replace it.
Do I need an opto-isolator?
If the new TL+ shows a pulse on AUX2, then I'll insert an opto-isolator between it and the 3X to insure protection.  It turns out that I have the parts to make one from a previous project, a shutter release which also uses an open/close pulse between tip and shield. 		Ordered
 
 
 
 
See if I can get documentation for the bluetooth API to the TL+.  If I can, then communicate between it and the Power Monitor (Feather or Pi 4) such that after the TL+ "presses" the shutter, the Power Monitor sends the pulse to the 3X to advance the pan-tilt.
My ultimate fall-back plan is to make up a light sensor mounted over the a7R4 display (where the histogram is shown) so that whenever a "shutter press" occurs (causing the a7R4 display to refresh), the Power Monitor sends the pulse to the 3X to advance the pan-tilt. I have ordered and received several light sensors: VEML7700, ALS-PT19 and a Photo Transistor.
References:
Wikipedia: Voltage Divider
 When R2=0 (closed),
    Vout = 0 / (R1+0) x Vin = 0
 
 When R2=∞ (open),
    Vout = ∞ / (R1+∞) x Vin = Vin
Wikipedia: Opto-isolator
HOW TO MAKE AN ARDUINO OHM METER - Arduino and a Voltage Divider
Adafruit 4-Channel ADC Breakouts - A-to-D Converters (needed w/ Raspberry Pi)
Basic Resistor Sensor Reading on Raspberry Pi - Pi and a capacitor
PiScope (Raspberry Pi Based Oscilloscope) - Loadable Kernel Module (LKM)

References
 
a7R4
I'm storing the images as whopping 61MP Raw images.  I bought 2 1-TB SanDisk micro-SD cards rated at 90 MB/s write speeds.  They appear to keep up with the TL+ write speeds (as expected).  I'll be using 5 second shortest intervals.  2 TB is enough room for 16,200 61MB raw Uncompressed images or 22½ hours of recorded time (realtime) using a 5 second interval.  Those 22½ hours would be reduced to 11¼ minutes of playback time.
 
I normally save RAW images as Uncompressed.  Elijah Parker's video shows him using Compressed (the a7R4 initial value).  I'll initially use that to avoid performance problems.
 
a7R4 Settings (summarized from here, author: Elijah Parker):
On the a7R4 Menu...
  Menu 1 ... 1/15 
    File Format ... Raw & JPEG      (Will be saving the RAW files to a7R4's SD card. The Jpegs are used by the 
                                     TL+ to evaluate the exposure and show a thumbnail review of the captured frames.)    
    RAW File Type ... Compressed    (Not explicited mentioned in his video. But I could see this was the setting.)
    JPEG Quality ... STD   
    JPEG Image Size ... 15M   (Smallest possible)
  Menu 1 ... 2/15 Quality/Image Size2
    Long Exposure NR ... Off 
  Menu 2 ... 5/11 Shutter/SteadyShot 
    Silent Shooting ... On 
  Menu Globe ... 1/3 Network1 
    PC Remote Function 
      1 PC Remote ... On 
      1 PC Connection Method ... USB 
      2 Still Img Save Dest ... PC+Camera (This setting causes the RAW to be saved to the a7R4's SD card and the Jpegs to the TL+.)
      2 RAW+J Save Img ... JPEG Only      (This setting causes only the Jpegs to be sent to the TL+, not both the Raw and Jpeg.)
      3 PC Image Size ... 2M 
Set Manual Mode on the dial 
    
The TL+ sets the a7R4 into Manual Focus Mode and Single Bracket.
Plug in the USB Cable, TL+ to a7R4 to see Live View.

 
3X
This is for Pan-Tilt control.  After the TL+ sets the a7R4's exposure and activates the shutter, it will send a pulse to the 3X causing the 3X to move to the next pan-tilt position.  This mode is referred to a Shoot-Move-Shoot.  The 3X path is programmed using the 3X's GUI.  A slider could be added to enable pan-tilt-slide effects.
 
References
 
Power Monitor
I'd like to monitor the battery usage using a microcomputer (either a Raspberry Pi or Adafruit Feather) and a 3.5" display.  The monitor is mounted inside a 3D-printed housing fitted where the legs of the tripod join, easily removed to let me fold the tripod for transport.
 
To monitor (timeseries and numerically on the 3.5" display)
From What Notes
Batteries Renogy 5V USB Output to TL+ Voltage and Amperage
Renogy 12V Supply to a7R4 and 3X Voltage
The 12V supplied by the Renogy is stepped down to 7.2V for the a7R4. That 7.2V supply to a7R4 is displayed on the step-down voltage transformer panel in Voltage and Amperage.
Anker 5V USB Output to the Pi 4 or Feather Voltage
Pi 4 or Feather CPU Usage % Busy
Storage Free Memory

System Options
System Component Power Usage Notes
Adafruit Feather M0 Feather Board TBD
480x320 3.5" Display TBD
Combined ~160 mA My measurement. With a simple program running in a 1 second loop.
Raspberry Pi Pi 4 Board 600 mA (min) raspberrypi.org spec.
480x320 3.5" Display ~100 mA Adafruit rough estimate.
Combined ~525 mA My measurement. Varies between 510 and 550 mA. WiFi was enabled.

Benchmarks
Benchmark Performance Power Usage
Feather Pi 4 Feather Pi 4
Idle System TBD TBD TBD TBD
Drystone TBD TBD TBD TBD
Whetstone TBD TBD TBD TBD
Linpack TBD TBD TBD TBD
MyTSbenchmark TBD TBD TBD TBD

References
 
Batteries
Power requirements
Component Power Usage
At 1 sec intervals At 5 sec intervals At 20 sec intervals 1 hr at 5 sec intervals,
then 10 hrs at 20 sec intervals,
then 1 hr at 5 sec intervals
Timelapse+ View TBD TBD TBD
Cognisys 3X Pan-Tilt TBD TBD TBD
Sony a7RIV TBD TBD TBD
Power Monitor TBD

Lake Placid, 3 Aug 2020
Battery capabilities and ripple/noise measurements
Source Output Port Will feed Ripple / Noise
Renogy 72000
72,000 mAh 		5V/2.1A, USB-A Unused
5V/2.4A, USB-A TL+ TBD
12V/4A or 16V/4A or 19V/3.5A or 21V/3.2A, 2.1mm Unused
The doc. that came with this battery recommends not using this port and the 15A port at the same time.
12V/15A, Cigarette Lighter a7R4 (*)
(after reducing 12V to 7.2V)		 TBD
3X (**) TBD
Anker 20100
20,100 mAh		 2 x 5V/2.4A,
USB-A		 Power Monitor (***)
I estimate 33 hrs of Pi 4, 125 hrs of Feather		 TBD

For comparison
Source Output Ripple / noise
Sony NPAMQZ1K a7R4 battery
(to compare with *)		 TBD
Gonine NP-FZ100 a7R4 battery
(to compare with *)		 TBD
Tether Tools
AC Power Source + CRNPFZ100 		a7R4 battery
(to compare with *)		 TBD
3X AC Power Supply 12V/6A, 2.1mm
(to compare with **)		 TBD
Typical USB AC Wall wart 5V, USB-A
(to compare with ***)		 TBD
Apple USB AC Wall wart 5V, USB-A
(to compare with ***)		 TBD

For learning
Source Output Ripple / noise
Adafruit Adjustable breadboard Power Supply 3.3V/5V/Adjustable V, 2.1mm TBD
5V and 12V AC Power Supply (kit) 5V, 12V TBD

References
 
Location, etc.


Click on image to go to the site, darksitefinder.com

Dark Locations
Where

10 U.S. DARK SKY PARKS YOU NEED? TO VISIT

Top 8 Stargazing Destinations In the World

Notes
GRAND CANYON NATIONAL PARK ARIZONA X
CHERRY SPRINGS STATE PARK PENNSYLVANIA X X Bortle Class 2
DEAD HORSE POINT STATE PARK UTAH X
STEINAKER STATE PARK UTAH X
CANYONLANDS NATIONAL PARK UTAH X
ANZA-BORREGO DESERT STATE PARK CALIFORNIA X
HEADLANDS MICHIGAN X
CRATERS OF THE MOON NATIONAL MONUMENT IDAHO X
KISSIMMEE PRAIRIE PRESERVE FLORIDA X
COSMIC CAMPGROUND NEW MEXICO X
Monument Valley Utah X Bortle Class 2
Cerro Paranal, Atacama Desert Chile X
Death Valley California X
Alberta, Rocky Mountains Canada X
Mauna Kea Hawaii X
Lake Tekapo New Zealand X
Exmoor United Kingdom X

References
Creating Natural NightScapes with Royce Bair & Friends including:
Darksky Locations:
Understanding the Bortle Scale
Wikipedia: Dark-sky preserve
Kissimmee Prairie Preserve State Park: Dark Sky Designation
Kissimmee Prairie Preserve State Park's IDA Dark Sky Park Application
"Data collected during the summer (wet season) will be less favorable than observations made during the winter (dry season). The readings have been consistently silver quality. The cooler months are the best viewing months for night sky activities. Most of our visitors travel to KPPSP during the chiller months, only a few durable guests venture into the prairie during the challenging summer (heat, humidity, dew, mosquitos, etc)."
Silver gives it a Bortle Class of 3-5.
Tools, workshops, tutorials: