Planning for Observing and Shooting the Eclipse. Bill Preston Fremont Photographic Society

Transcription

1 Planning for Observing and Shooting the Eclipse Bill Preston Fremont Photographic Society 12/13/17

2 Total Solar Eclipse Briefing Why see a total solar eclipse? Where to see an eclipse (geography, weather, logistics) Megamovie Project How I photographed the eclipse: camera, lens, solar filter, accessories, and how I used automation to free me to watch the eclipse instead of only taking photos Resources Links, handout, copy of this briefing 2

3 Why see a total solar eclipse? 3

4 Four types of Solar Eclipses Total Eclipse (100%) - the moon completely covers the sun. Partial Eclipse (<100%) - the moon passes in front of the sun, off center and only a portion of the sun s disk is obscured. A 100% eclipse is 10,000 times darker than a 99% eclipse. Annular Eclipse - the moon passes dead center in front of the sun but, because the moon s orbit is elliptical and so is sometimes closer to Earth, it appears too small to fully cover the disk of the sun Hybrid Eclipse - a combination of total and annular eclipses. The eclipse begins as one type and ends as another. Annular Eclipse 4

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6 Portland San Francisco Smith s Ferry, ID Salt Lake City Denver Kansas City St. Louis Nashville Atlanta Charleston 6

7 Path of Totality Smith s Ferry, ID 7

8 Where - Choosing a location to see totality Geography: plains (to allowing viewing of the moving eclipse shadow) vs mountains Weather: Likely to be clear? Smoke? Haze? Crowds/Traffic Camping spots/private property 8

9 Where - Smith s Ferry, Idaho Campsite A24 9

10 Where - Future Eclipses 10

11 Where - Future Eclipses Total Solar Eclipses over North America eclipse.gsfc.nasa.gov/ SEmap/SEmapNA/ TSENorAm2001.gif 11

12 Eclipse Watch Groups/Resources 12

13 Megamovie Project

14 Megamovie Resources 14

15 Megamovie Community WebBlog Daily update messages addressing issues with: Camera operation Lens/accessories Software Uploading images to Google servers Tactics for testing gear before heading to eclipse site Video conferences One of the biggest benefits of joining the Megamovie project was gaining access to a large number of experienced eclipse watchers who provided one-to-one help when requested. I got significant help learning how to use the Magic Lantern program from a member of the team. 15

16 Phases of solar eclipse Baily s Beads f/11, 1/750, ISO100, 330mm, ND100,000 f/16, 1/90, ISO100, 400mm, ND100,000 f/8, 1/2000, ISO100, 400mm, no filter C1: First Contact 10:11:14AM MT C2: Second Contact 11:26:36AM First contact (C1) - The instant the Moon's disk first touches the edge of the Sun. Second contact (C2) - The instant when the total or annular phase of an eclipse begins. Diamond Ring effect - The horns of the crescent sun converge to form a diamond. Baily s Beads - The horns of the solar crescent close completely and the diamond breaks up to be replaced by an array of brilliant beads of sunlight caused by the sun shining through valleys and depressions on the moon s leading limb. 16

17 Phases of solar eclipse Totality - The moon blocks the sun between C2 and C3 (2min 12 secs at Smith s Ferry) Third contact (C3) - The instant when the total or annular phase of an eclipse ends. Baily s Beads followed by the Diamond Ring appear again. Fourth contact (C4) - The instant when the partial phase of an eclipse ends. Corona Max Totality 11:27:42AM Diamond Ring C3: Third Contact 11:28:48AM C4: Fourth Contact 12:50:11PM 17

18 How to photograph the eclipse What do you want to shoot? The partial phases The transitions between the partial phases and totality Totality All of the above Light conditions among these phases vary dramatically, some requiring solar filters and others requiring long low-light exposures. Technical tradeoffs are necessary to take proper exposures of the phases and the corona 18

19 Camera Settings/Tradeoffs Shutter speed - fast then slow Shooting a moving target (sun): using either a fixed tripod mount or a tracking mount Slow shutter speed to shoot the corona Aperture Lens sweet spot/area of sharpest image ISO Noise vs speed Focal length of zoom lens Capturing large disk image or corona Time 132 seconds from C2 to C3 Bracketing images across a wide range of lighting conditions 19

20 Tripods Mounts/Heads Equatorial (Sky Tracker) Mounts 20

21 Shooting a moving target without a tracking mount The minimum shutter speed I used was 1/125 21

22 Camera Settings/Tradeoffs Shutter speed Shooting a moving target (sun): using either a fixed tripod mount or a tracking mount Low light slow shutter speed for corona Aperture Lens sweet spot/area of sharpest image ISO Noise vs speed Focal Length of Zoom Lens Capturing large disk image or corona Time 132 seconds from C2 to C3 Bracketing images across a wide range of lighting conditions 22

23 Choice of Aperture: Canon mm lens image field tests Canon/Canon-EF mm-F45-56L- IS-USM-mounted-on-Canon-EOS-6D--- Measurements

24 Camera Settings/Tradeoffs Shutter speed Shooting a moving target (sun): using either a fixed tripod mount or a tracking mount Low light slow shutter speed for corona Aperture Lens sweet spot/area of sharpest image ISO Noise vs speed Focal Length of Zoom Lens Capturing large disk image or corona Time 132 seconds from C2 to C3 Bracketing images across a wide range of lighting conditions 24

25 ISO vs Speed Modern DSLRs are designed to minimize noise from higher ISOs. So choosing an ISO for shooting the eclipse is largely dependent on your camera s capabilities. Higher ISOs give you more flexibility in addressing other eclipse photography constraints. Fred Espenak s Exposure guide for shooting totality (from just before C2 to just after C3) 25

26 Camera Settings/Tradeoffs Shutter speed Shooting a moving target (sun): using either a fixed tripod mount or a tracking mount Low light slow shutter speed for corona Aperture Lens sweet spot/area of sharpest image ISO Noise vs speed Focal Length of Zoom Lens Capture large image of the sun or the full corona Time 132 seconds from C2 to C3 Bracketing images across a wide range of lighting conditions 26

27 Megamovie Project guidance for capturing the corona during totality: The minimum Field Of View requested was 3 to 4 disks of the Sun while the maximum requested was 9 disks of the Sun. 27

28 Full frame moon image _MG_7746 The larger desired FOV was intended to allow room for capturing as much of the solar corona as possible, because capturing the corona was a major data collection goal of the project. 28

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30 Camera Settings/Tradeoffs Shutter speed Shooting a moving target (sun): using either a fixed tripod mount or a tracking mount Low light slow shutter speed for corona Aperture Lens sweet spot/area of sharpest image ISO Noise vs speed Focal Length of Zoom Lens Capturing large disk image or corona Time 132 seconds of totality (from C2 to C3) Bracketing numerous images across a wide range of lighting conditions 30

31 Shooting Plan Making test images and comparing results with expected exposures from eclipse exposure tables Shooting midday sun at eclipse equivalent solar altitudes, temperatures, etc. Shooting moon at eclipse equivalent lunar altitudes, operating equipment in dark environment Preparing checklists of equipment and camera settings Practice, practice, practice 31

32 Shooting Plan C1 to C2: Partial phase lens solar filter and camera cover solar glasses Approaching C2 remove solar filter recenter and refocus camera At C2 - Diamond Ring then Baily s Beads Shooting the corona during totality Approaching C3 Baily s Beads then Diamond Ring replace solar filter and solar glasses C3 to C4: Partial phase - same as C1 to C2 32

33 Gear Checklist Because of the time constraints of the eclipse, I needed a well-rehearsed plan for taking images. Equipment set up: Tripod Solar filter Remote shutter release Timer Camera body shade cover Chair Hat Sunscreen 33

34 Camera Settings Camera settings based on which phases you intend to shoot and bracket (partial, Baily s Beads, Diamond Ring, Totality): Manual operation Autofocus OFF Live View ENABLE (for precise focus) Image stabilization OFF (Depends on what you are shooting. With a long lens, IS may be useful.) Auto power OFF (to preclude shutdown) GPS ON (for Google data collection) Mirror Lockup - to minimize vibration 34

35 Be sure to SEE the Eclipse Astronomer Isabel Martin Lewis warned of the dangers of too many things to do during an eclipse: A noted astronomer who had been on a number of eclipse expeditions once remarked that he had never SEEN a total solar eclipse. Spending too much time looking through a viewfinder can preclude experiencing an awesome event with all of your senses. Automation can free you to observe the eclipse instead of spending the entire time taking images. 35

36 Automation - Magic Lantern Software Magic Lantern is a free software enhancement that offers increased functionality with Canon DSLR cameras. It is NOT a Canon product so there are caveats about possible damage to your camera. ML is not a "hack" or a modified firmware, it is an independent program that runs alongside Canon's own software from your memory card. Each time you start your camera the program is loaded from your memory card, not from the camera operating system. ML firmware enhancements are also available for Nikon (nikonhacker.com ), Panasonic (personalview.com ), Pentax (pentax-hack.info ), Sony (nexhack.com /.info ), GoPro (CHDK forum), etc. 36

37 Canon 6D LCD display 37

38 Canon 6D LCD display after the Magic Lantern menu is loaded - buttons selectable with SET button. 38

39 Magic Lantern menu - Scripts buttons in right-most column. 39

40 Plan for use of ML scripts during eclipse 40

41 Partial.lua ML Script code excerpt menu.new -- Makes a new menu item in the Scripts menu in ML titled Partial { -- Script for C1 to C2 partial eclipse. Shoot sequence every 10 mins until 5 mins before C2 (same process in reverse for C3 to C4). Takes 16 images, alternating f/stops. name = "Partial", select = function() task.create(run_bracket) end, depends_on = DEPENDS_ON.M_MODE, -- Must be in Manual modefi } run_bracket = function() msleep(2000) -- Sleep for 2s to let any vibration settle out camera.iso.value = Sets the ISO camera.aperture.value = 16 --Sets the aperture to f/16 camera.shutter.value = 1/60 --Sets the shutter speed camera.shoot() msleep(1000) camera.aperture.value = 11 camera.shutter.value = 1/160 camera.shoot() msleep(1000) camera.aperture.value = 16 camera.shutter.value = 1/100 camera.shoot() 41

42 ML script editing ML script editing TextEdit Third party edit software, mostly free 42

43 Gear: Solar Filter ND-100,000 Solid Neutral Density 5.0 Solar Eclipse Filter (16.5 Stops) Standard ND filters typically only cover the visible spectrum whereas solar filters will also cover Infra-red(IR) and Ultraviolet(UV) radiation, important for eye and sensor protection. 43

44 Gear: LCD shade/magnifier Shades LCD screen from glare 2.5x magnification makes LiveView use easier 44

45 Gear: Shutter Release/Remotes For rapid fire exposures (during Diamond Ring or Bailey s Beads), for long duration exposures (corona), and to minimize vibration. DSLR/Prosumer Cameras - built in settings or manual Bulb exposures Wired shutter release (includes self-timer, interval timer, long exposure timer, continuous shooting) Wireless remote (ex: apps on smartphones, or laptop computer) 45

46 Gear: Solar Glasses Confirm reputable manufacturer of solar glasses Should be ISO compliant, which includes IR and UV protection. Should be labeled on the glasses. 46

47 Gear: Solar Glasses Cautions: Standard or polaroid sunglasses are NOT solar filters Don t use exposed film, X-ray sheets, eyepiece solar filters. Telescopes/Binoculars focus and intensify visible and UV rays to the eye, with a risk of eye damage during partial eclipse phases. Avoid staring at sun for lengthy periods LiveView is the safest means of targeting and focusing the camera and observing the eclipse. Research homemade filters with great care. Links:

48 Other gear to consider Pin Hole art 48

49 Questions? 49