Try increasing gamma if dark sections aren't distinguished

Try increasing gamma if dark sections aren't distinguished

Tuesday, January 6, 2026

sun 12/7/2025

the series of sun spots (active regions AR 4296, 4294, 4298) were indeed active, blasting ions at the earth in early December.  i happened to catch them during a day with good seeing (i can't usually discern the "granules" in the white regions so well):  

AR 4296, 4294, 4298
12/7/2025
21:51.6 UTC
Granules are convection cells in the sun's photosphere.  "The rising part of each granule is located in the center, where the plasma is hotter. The outer edges of the granules are darker due to cooler descending plasma" (wikipedia). 

I also captured a series of full disk images in Ha:

Sun Ha Surface
2025-12-07 20:58.3 UTC


Sun Faint Ha prominences
Digital occultation of disk
2025-12-07 2058.9 UTC

Sun 2025-12-07 
Ha composite

Ha composite
difference

Solar surface
Ha vs off band

Sun Ha vs white light


Image details:
close up
Celestron 11" Edge HD
Baader solar film
green filter
unguided solar tracking on celestron CGX

full disk
Lunt 60 PT B1200 single stacked

zwo ASI 174MM
2025-12-07
all 20 second captures full frame
East Bluff, CA
better than usual seeing

close up:
Frames captured=2064
FPS (avg.)=103
Shutter=0.082ms
Gain=325 (81%)

full disk surface Ha:
Frames captured=2610
FPS (avg.)=130
Shutter=0.073ms
Gain=280 (70%)

full disk prominences:
Frames captured=2606
FPS (avg.)=130
Shutter=1.958ms
Gain=280 (70%)

full disk off band:
Frames captured=2609
FPS (avg.)=130
Shutter=0.032ms
Gain=302 (75%)

captured in firecapture
stacked in autostakkert
sharpened in BiggSky or registax
combined/finished in photoshop.  

Processing notes:
for the close up
a zwo green filter gave slightly better contrast compared to luminance (UV/IR block).

i also captured 30 minutes of the full disk in Ha for an animation...there was minimal activity over the course of the animation :(

BiggSky wasn't as good as registax for full disk or proms, but looked better than registax to me for the close up green light image (though slightly over-sharpened). 
raw big sky:

registax:






Saturday, December 27, 2025

falcon over the back bay take II

still working on composition.  my first attempt managed to catch the backlit falcon in the middle of the frame over the back bay, but wasn't well positioned relative to the foreground.  

my second was a night launch, so no backlight rocket plume, only the bright fist stage:

Falcon-9
Newport Back Bay
10/7/2025

Positioning was better over the back bay, but i've not got the reflection right.  looks like i'm going to have to wade out on the slippery rocks and mud.  

full field:


Imaging details:
Newport Back Bay
for this iteration i moved further north to where the bike path goes under Jamboree
10/7/25 
approximately 20:53 - 20:58 Local
nikon D850
Sigma 15mm F/2.8 EX DG fisheye
video capture 30 frames/sec
composite of a video processed in photoshop
simulating one long exposure
the video was output to individual frames which were combined in groups of 500 in lighten mode
if anyone has a better way to stack the video in lighten mode, please let me know

Sunday, November 30, 2025

saturn's disappearing rings 11/23/24

Saturn's rings disappear
9/13/25 7:08.3 UTC
11/1/24 6:08.4 UTC
11/23/25 4:01.3 UTC

Saturn's rings are tilted 27 degrees to the axis of the solar system.  During the course of a saturnian year (29.5 earth years) saturn will have two "equinoxes" with the rings perfectly edge on relative to the sun (once every 13-15 years).  As the rings are extremely thin they will seem to disappear at this point.  On May 6, 2025 when saturn was only visible during daylight, the rings were edge on (my capture attempt failed).  the rings were again edge on on November 23, 2025*.  The animation above shows the rings fading as they tilt to edge-on over the past 2 months.

*why were the rings on edge twice?
my guess is that there are actually 2 different "on edge" conditions.
1. perfectly on edge relative to the sun.  on this day the rings will cast no shadow.
2. perfectly on edge relative to the earth.  
this is rarely at the same time as #1.
In this case my assumption is that the rings were on edge in May.  
Then the earth zipped past saturn (saturn in retrograde for you astrology buffs) with saturn "catching up again" in november. 
This explains the prominent ring shadow across the face of saturn as the rings are slightly less than perpendicular to the sun.  

I will say that visually, the rings were faint but still visible.  guessing this is due to the high dynamic range of the mark II eyeballs.  
they were clearly present on longer exposure images.  

Imaging details:
Seeing has been terrible for the most part this season
exemplified on all of these nights

ZWO ASI664MC
baader IR/UV blocking filter
the sunobserver eADC 
celestron 11" Edge HD, no barlow
East Bluff, CA

9/13/25 7:08.3 UTC
7x90 sec
FPS (avg.)=158
Shutter=6.255ms
Gain=431 (71%)

11/01/25 6:08.4 UTC
7x90 sec
FPS (avg.)=145
Shutter=6.829ms
Gain=431 (71%)


11/23/25 4:01.3 UTC
7x90 sec
FPS (avg.)=173
Shutter=5.714ms
Gain=431 (71%)

captured with firecapture
stacked in autostakkert (upsampled 1.5x)
combined in winjupos 
processed in registax and/or biggsky
photoshop

processing was not consistent across nights
so had to work in photoshop 
to match brightness etc for the animation




Monday, October 27, 2025

ghoulish prominence

Some nice prominences from a sunny weekend:

Prominence 
10/12/25
22:08 UTC

anyone see a ghoul dancing on the sun?
or maybe kokopelli (wikipedia)


animation from the day before (worse seeing):

Solar Prominence 
30 minute animation
10/11/2025 
19:37 to 19:57 UTC

Imaging details:

Here's the lunt on a tracking mount:





Lunt 60 PT B1200 single stacked
zwo ASI 290MM
20 second captures
best 75%
animation
10/11/25
unguided solar tracking on celestron CGX
single frame
10/12/25
manual guiding with alt-azm mount
East Bluff, CA

as you can see, the "seeing" wasn't great during the animation with frames seeming to go in and out of focus.  
took a stupid amount of time to process the 59 frame continuous animation.  
should have put a delay between frames.  
the seeing and prominence shape was better the second day, but didn't have the time for an animation

animation
Frames captured=2328
FPS (avg.)=116
Shutter=0.357ms
Gain=351 (58%)

single frame
composite of two captures:

Frames captured=2328
FPS (avg.)=116
Shutter=1.925ms
Gain=351 (58%)

Frames captured=2325
FPS (avg.)=116
Shutter=1.215ms
Gain=351 (58%)

captured in firecapture
stacked in autostakkert
combined/finished in photoshop. 
maybe a little oversharpened on the single frame ;)

Thursday, October 2, 2025

falcon over the back bay

trying this wide field composite of the entire falcon path over the back bay

by a stroke of luck, i managed to center the rocket's arc in the wide field frame.  next time i'll position more to the right to catch the arc centered over the water.  


close up shows the 1st stage trail with intermittent bursts below the rocket and a smaller trail of the fairings:




Imaging details:
Newport Back Bay
7/18/25 
approximately 19:55 - 19:59 Local
nikon D850
Sigma 15mm F/2.8 EX DG fisheye
video capture 30 frames/sec
this is and "artistic" composite of a video requiring a lot of work on photoshop
simulating one long exposure
the video was output to individual frames which were combined in groups of 500 in lighten mode
next came separate processing for the sky and foreground:
sky combined in lighten mode after airplane streaks removed
foreground combined in darken mode to remove car trails.
then final lightening of the sky and rocket trail with curves.  
if anyone has a better way to stack the video in lighten mode, please let me know



Sunday, September 28, 2025

Titan transiting Saturn 9/20/25

Saturn's iconic rings are edge-on this year--almost invisible--but this gives an opportunity to appreciate rare shadow transits as the moons (in the plane of the rings) move directly across the face of the planet.  

titan and shadow crossing saturn
9/20/25 06:44 UTC
edge-on rings also allow better appreciation of the subtle bands on the face of the planet (color enhanced).  

Here's and animation of the transit (starting in progress) over 3 hours:
titan and shadow crossing saturn
3 hour animation
9/20/25 05:53 - 08:54 UTC

If you look closely at the animation you can see a few other faint moons dancing around the planet:
titan and shadow crossing saturn
9/20/25 06:44 UTC




Imaging details:
ZWO ASI664MC
baader IR/UV blocking filter
the sunobserver eADC 
celestron 11" Edge HD, no barlow
East Bluff, CA

9/20/25 05:53 - 08:54 UTC
34 x 90 second captures for the animation
20 x 90 second for the still frame
Shutter=~4.02ms
Histogram=~43%
gain 431
~244 fps

captured with firecapture
stacked in autostakkert (upsampled 1.5x)
combined in winjupos 
processed in registax and photoshop
animations are individual captures at 1x

processing notes
caught the transit in process.  
the seeing was not great, though improved
rings were flapping like a bird's wings.
so i'm quite happy with the final processing
at first i thought the "double black dot" was due to seeing errors, 
then realized the lower was titan and the higher, darker it's shadow
the single frame is highly processed with separate processing of the core planet, 
fringe and rings.  
i tried biggsky on Saturn it really didn't like the 1.5 upsampled version
here it is compared to registax on 1x sampling.  
seemed better than registax on the disk, but didn't handle the lower signal rings well.  
probably could have pushed the sharpening in registax, but abandoned this and went with 1.5x upsample.  

registax:
BiggSky:

final registax 1.5x upsampled,
reduced to 1x:



Sunday, September 7, 2025

sunny day 6/28/25, bigg sky

perhaps the best combination of surface filaments, sunspots and prominences i've seen this year

Sun 2025-06-28 19:12 UTC, 19:20 UTC
Ha composite (difference)
overexposed version for outer filaments
combined with negative of the central detail

Sun 2025-06-28 19:12 UTC, 19:20 UTC
Ha composite to include faint outer prominences


Sun 2025-06-28 19:12 UTC
Ha color version

Sun 2025-06-28 
Ha vs continuum (off band)
conventional sunspots vs plasma filaments and prominences

Image details:
I tried BiggSky blind deconvolution on the images
I have to say it was amazing on the full disk
one click and it was as good or better than tons of fiddling with wavelets in registax
unfortunately blind deconvolution failed miserably on the higher exposure capture for the outer prominences--it can't handle clipping well.  
the file management is still a bit clunky, but it's still in development.  
looking forward to trying it out on planetary images.  

Lunt 60 PT B1200 double stacked
manual guiding with alt-azm mount
zwo ASI 174MM
20 second captures
best 75%
2025-06-28
East Bluff, CA

full disk single stacked bright
19:12.9 UTC
Frames captured=2609
FPS (avg.)=130
Shutter=0.236ms
Gain=370 (92%)

full disk single stacked off band
19:16.3 UTC
Frames captured=2611
FPS (avg.)=130
Shutter=0.032ms
Gain=286 (71%)

full disk double stacked
19:20.9 UTC
Frames captured=2132
FPS (avg.)=107
Shutter=0.173ms
Gain=378 (94%)

captured in firecapture
stacked in autostakkert
sharpened in BiggSky or registax
combined/finished in photoshop.