Try increasing gamma if dark sections aren't distinguished

Try increasing gamma if dark sections aren't distinguished

Saturday, October 28, 2023

Annular eclipse at the Albuquerque Balloon Fiesta 10/14/23 part III: super-annular eclipse montage and animations

 You may recall that there was a supermoon in late september.  the corollary to this is a "micro-moon" crossing the face of the sun during the solar eclipse at the subsequent new moon, resulting in an annular eclipse rather than a total eclipse 😢

or, to look on the "bright side" a super-annular eclipse with the widest band possible.

in creating a montage of the partial phases, i viewed the annular phase and decided on a clock-like arrangement with small images of partial phases forming a ring around the annular eclipse.  after meticulously arranging the partial phases, i looked at what i had done...not exactly what i was going for, but i'll take it.

flower power!
annular solar eclipse and preceding partial phases 10/14/23
balloon fiesta park, albuquerque, NM
(click for full size)

more conventional montage:

annular solar eclipse and preceding partial phases 10/14/23
balloon fiesta park, albuquerque, NM

partial phases:



annularity animation:


the disturbance mid capture above is likely due turbulence from the burners firing off in the field at annularity :(
Annularity 10/14/23
Balloon Fiesta Field
Albuquerque, NM


if  you look at the final images of annularity, you'll note that the moon does not contact the sun evenly.  mountain peaks contact the sun first:

3rd contact
10/14/23


by offsetting each image (captured at 4 frames per second) by 1 pixel, one can generate a magnified image of the lunar surface:

magnified moon mountains
lower left
Cf. APOD

bigger partial phases
click for full size

field view/filtered view composite:
click for full size

sky view of above:
click for full size


Imaging details:
10/14/23
Albuquerque, NM
nikon D850
AF-S NIKKOR 300mm f/4E PF ED VR
Baader solar film, Fotga IR/UV cut filter
iso 100 1/1250-1/2000 sec exposure
Vello Shutterboss Version II Timer Remote Switch
skywatcher star adventurer tracking mount

Samsung galaxy S22 ultra
for field shot and filtered cellphone image

the final 2 composites are a combination of the cell phone view of the field and nikon filtered images of the sun, scaled down to the sky view size and positioned roughly in the appropriate location in the sky

Thursday, October 19, 2023

Annular eclipse at the Albuquerque Balloon Fiesta 10/14/23 part II: Ring of Fire

a few clouds and a lazy contrail on the horizon made for an interesting sunrise, but didn't impact the rest of the eclipse (click on image for full size):

sunrise balloon fiesta park
abluquerque, NM
8/14/23 06:37:27


first contact:
first contact (upper right)
09:13:22
partial phase:
09:30:12
bye sunspots:
10:14:12

The announcer called out annularity and all the grounded burners in the field fired up.  note the annular reflections below the sun:
annularity, balloon fiesta park
abluquerque, NM
8/14/23 10:36:11
RING OF FIRE: there was a lot of talk about a "ring of fire" eclipse, but no images really show it.  here's my attempt, I digitally overexposed this image to simulate an unfiltered image of the sun (which would melt my camera sensor) to portray an actual "ring of fire"
ring of fire

here's a more conventional portrayal.  bullseye with the camera--my location was dead center eclipse path:
annular solar eclipse
balloon fiesta park
abluquerque, NM
10/14/23 ~10:36:32
cellphone:
filtered

broken ring:
image rotated horns up
10:39:09

Next up: animation and montage

Imaging details:
10/14/23
Albuquerque, NM

nikon D850
AF-S NIKKOR 300mm f/4E PF ED VR
Baader solar film, Fotga IR/UV cut filter
iso 100 1/1250-1/2000 sec exposure
Vello Shutterboss Version II Timer Remote Switch
skywatcher star adventurer tracking mount

Samsung galaxy S22 ultra
for field shot and filtered cellphone image
eclipse image shot with solar filter at 30x

processed in photoshop

    Arriving early for the pre-dawn activities allowed me to dial in my polar alignment for my tracking mount, only adjusted my alignment once.
    While i tested my exposures repeatedly at home, to be sure my images were not clipped, as the sun rose higher in the thin albuequerque air the face of the sun became slightly clipped, losing the subtle surface granulation. fortunately, i caught it relatively early and decreased the exposures from 1/1250 s to 1/2000.  if you look closely at the partial phase above, you'll note a lack of subtle granulation across the bright face of the disk (09:30:12), which can be seen in the subsequent image (10:14:12)
    The nikon D850 has a built in intervalometer which is great for meteor showers and overnight sequences, but awkward to adjust on the fly.  there is software to connect a smart phone via bluetooth or wifi, but it disconnects every time you switch apps and takes >30sec to reconnect.  less than ideal for the eclipse experience unless you use a dedicated tablet.  
    I chose to used the vello shutterboss version II timer remote switch, a wired solution that can trigger the shutter manually without shaking the camera and be used as an intervalometer that can be rapidly adjusted.  i chose 4 minute intervals for the partial phases and 1 second intervals for annularity.  for the 3rd contact i held the manual trigger down with the camera set for continuous low speed shots, having determined 4 fps is the fastest my camera will write full frame raw files (8288x5520 ~53 meg) to the chip.  it can do bursts much faster but only for a few seconds.  
    I found these an excellent focus aid -o-o-


    In terms of processing, the auto color balance with the IR filter and baader film was all over the place.  By trial and error, I came up with something close to white by setting the temperature to 7100 and tint to -40 for raw conversion.  this still gave a slightly non-uniform color white in the center and slightly red red at the edges which was acceptable, though I desaturated the white images above.  not sure why the color was not uniform.  either the camera sensor is non-linear or the solar color is non-uniform.  here's the "natural color"
10:14:12

    for images with a substantial amount of the central solar disk showing, i applied a high pass filter at 1.5 radius soft light, then again at 2.5 radius hard light 50% blend (excluding the solar and lunar edges). this brought out the sunspots and surface granulation.  color images colorized at 25 hue, 100% saturation, -20 lightness

Sunday, October 15, 2023

Annular eclipse at the Albuquerque Balloon Fiesta 10/14/23 part I

In planning the eclipse viewing site, I looked for 2 things: proximity to a major airport and a good probability of clear skies (see references below).  I considered Albuquerque (so fun to spell) and learned the last weekend of the Balloon Fiesta, the  largest hot air balloon event in the world, coincided with eclipse day.  Boasting the most photographed event in the world, the fiesta hosts over 600 balloon teams. The overwhelming synchronicity made this the city of choice.  

Note: some browsers require you to click on videos twice to play, click on images for full resolution, lower right icon will give video in full resolution.  

The event started with a drone lightshow:


propane burners fueled the lighter-than-air crafts and lit up the fiesta:


next came dawn patrol: a small group of balloons launch pre-dawn in order to test the winds at various altitudes for the rest of the pilots.  




dawn patrol meets orion

Next, rows and rows of balloons lined up for the mass ascension:
closest row


next row getting ready


closest balloon setting up




The "mass ascension" started shortly after sunrise.  

Was not expecting much from the star spangled banner.  The flyby pilots timed it perfectly, complemented by all the ground burners going off at once. Had I realized, I would have captured the whole thing.  

up up and away:



Balloon Fiesta, Albuquerque, NM 10/14/23

What do you  get when you cross a balloon fiesta and solar eclipse?
A Balloonar Eclipse! 😂




impending balloonar occultation of venus

special balloons:






the eyes on the ground belong to yoda
who's apparently lost his flying skills

eclipse epiphenomena:


semicircular shadows between fingers
patented ring/annular eclipse pose
semicircular shadows between leaves


Finally all the balloons have launched from the field as spectators watch the moon's shadow cross the sun.  Take a close look at the diffraction pattern around the sun in this image:
Zia symbol heralds annular solar eclipse in New Mexico
the land of enchantment
New Mexico State Flag

Here's a cell phone shot of the partial eclipse:
Partial solar eclipse
10/14/23 9:35 AM Local
Albuquerque, NM

Next up annularity and long focal length DSLR images

Imaging details:
10/14/23
Albuquerque, NM
Samsung galaxy S22 ultra
partial eclipse image shot with solar filter at 100x, then reduced to 10x
Arriving early for the pre-dawn activities allowed me to dial in my polar alignment for my tracking mount, only adjusted my alignment once.


References:
Xavier M. Jubier's website integrates with google maps superimposing the eclipse path and details for any point selected along the path.  

https://eclipsophile.com/ gives historical weather for cities along the path


Sunday, October 1, 2023

pitfalls and perils of solar imaging: testing for upcoming solar eclipses

testing my solar imaging:
sun 
9/23/23
baader film filter
single exposure 1/1,000 sec ISO 100, 300 mm f/4

Close up of the sun this summer, while trying to image venus during inferior conjunction with the sun:
sunspot 8/13/2023 20:05 UTC

I failed to image venus during inferior conjunction with the sun.  The conditions were frustrating: very bright, hot, poor seeing, and windy.  I was able to see it visually, but had difficulty focusing the camera, so slewed to the sun with a solar filter to focus on an obvious target.  while focusing, i noted a bright spot on the ground...the lens cap had blown off the finder scope objective leading to this unplanned modification of the eyepiece lens cap.  At that point I abandoned the attempt.  
Finder scope:
hole burned in finder scope lens cap





boring test stuff:
i cannot focus manually :(
best manual:


typical auto:
autofocus with light clouds
1/1000s

IR/UV block filter off center 4x exposure:
1/250 sec

125x exposure:
1/8 sec

125x exposure no IR/UV block filter:
1/8 sec

1000x exposure no filter, f/4:
1 sec

1000x exposure no filter f/5.6
1 sec


imaging details:
full disk testing 9/30/23
nikon D850
AF-S NIKKOR 300mm f/4E PF ED VR
Baader solar film, Fotga IR/UV cut filter
iso 100

sunspot
camera ZWO ASI 290MM with 850 nm IR pass filter, baader solar film
celestron 11" Edge HD
mediocre seeing
8/13/23

East Bluff, CA