Try increasing gamma if dark sections aren't distinguished

Try increasing gamma if dark sections aren't distinguished

Sunday, July 23, 2023

Venus and Mercury

took another crack and venus and mercury.  unfortunately seeing was not great...

Venus 4/16/23 02:43 UTC
IR pass 850nm

Mercury 4/16/23 02:33 UTC
IR pass 850nm

i decided image venus during the day (venus is bright enough to see in broad daylight, it's just really hard to find) for 2 reasons: 

-all other things being equal, the seeing should be better with the planet at higher altitude 

-i was hoping to capture motion of venusian clouds by imaging over a long period of time.  

sadly it was a total bust. imaging runs over 20 minutes captured no cloud detail whatsoever (until earthly clouds obscured my view).  perhaps a hint of something towards the upper half as venus got lower in the sky:

Venus 4/17/23 00:36 UTC
UV

Venus 4/17/23 00:05 UTC
IR pass 850 nm

at a recent meeting of the OC astronomers, Chris Go (who admittedly doesn't image venus) suggested that sunlight saturates the daylight sky with UV ruining the detection of clouds.  or perhaps it was just a clear day on venus ;)

I have captured cloud detail in the past with this set up at twilight:

venus UV clouds


Image details:
camera ZWO ASI 290MM 
filters: ZWO IR pass 850, Baader U-filter bw 320-380nm
celestron 11" Edge HD
East Bluff, CA

4/16/23
mediocre seeing
02:43 UTC
2x barlow
IR pass 850 filter:

venus
FPS (avg.)=215
Shutter=0.746ms
Gain=351 (58%)
Frames captured=69635

mercury
02:33 UTC
2x barlow
FPS (avg.)=116
Shutter=3.281ms
Gain=436 (72%)
Frames captured=12765

4/17/23
Venus 
no barlow as UV is faint
mediocre seeing

UV filter:
00:36 UTC
FPS (avg.)=217
Shutter=2.055ms
Gain=351 (58%)
Frames captured=39233 

IR filter:
00:05 UTC
FPS (avg.)=42 ?!
Shutter=0.191ms
Gain=351 (58%)
Frames captured=12865

Saturday, July 22, 2023

another falcon

dragged the kids out to the front yard to see a falcon launch with potential for a sunlit plume against the night sky. having been dragged out the night before for a launch that was delayed an hour and then aborted at T-5 seconds, their patience was wearing thin.   

after seeing a thin rocket trail rise above the trees followed by a faint orange plume, my son went back inside...  


only to miss the sunlit plume light up as the rocket passed out of the earth's shadow:
rocket and the owl tree


Falcon-9 7/19/23
note detached fairings and 1st stage trailing in the plume. 


Falcon-9 7/19/23
note detached fairings and 1st stage trailing in the plume

local color


Image details:
wide view
Samsung galaxy 22S ultra

close ups
nikon D850
F-S DX NIKKOR 55-300mm f/4.5-5.6G ED VR
ISO 1600

7/19/23 Newport Beach, CA

Monday, July 3, 2023

night owls

 decided to try my astrophotography skills on a noisy pair in a tree across the street:

Great Horned Owl

Note the big black eyes indicating a night shot, in contrast to the golden irises seen in daylight images.  The owls were not visible to the eye so it took a bit of work to aim and focus.  

Here's the noisy couple in the "owl tree" across the street where they hoot away to the chagrin of my neighbor who is less enamored with them due to their noise and their abundant droppings.    


Great Horned Owls

Oh, and here's M97 the owl nebula for comparison:


image details:
birds:
tall view
Samsung galaxy 22S ultra
f1.8 1/4 s 23mm ISO 2500
1/7/23 eastbluff, CA
close up
nikon D850
F-S DX NIKKOR 55-300mm f/4.5-5.6G ED VR
f/5 @130 mm 1/2 sec ISO 1600
11/10/22 eastbluff, CA

Owl nebula:
Celestron Nexstar8GPS @f/6.3(1300mm), SX AO-.2 sec exposures, CS 10 nm HA/baader oiii 8.5 nm, H9.
4/12-16/08 los alamitos, CA
HFD 3-4 arcsec
bortle white skies
21x20 min Oiii, 20x20 min Ha
maybe time for a reshoot with NII


a rocket for the 4th (falcon 9 6/22-23/23)

 there was a late night falcon 9 launch on 6/22

it being a weekday in the midst of a loooong run of of clouds, i chose to give at quick try from my front yard rather than an optimal viewing site.  so with the spaceX stream running on my phone i went out and looked northwest towards vandenberg.  i'd seen the orange glow of a night falcon launch in the past, so i thought i might catch it.

12:19AM "Lift off"...nothing

T+1:16 "Max Q"...nothing

T+2:35-2:38 Main Engine Cut Off, "stage separation"...nothing

I begin packing up just as a cone of light grazed the owl tree:

Falcon 9


i was able to catch a few closer shots as it faded. difficult catching a moving target in the dark:




Image details:
in viewing the spacex stream, it looks like they were clouded out locally which might be why i couldn't see the rocket on initial lift off.

Eastbluff, CA
6/23/23 ~12:25 AM

wide view
Samsung galaxy 22S ultra
f1.8 1/4 s 23mm ISO 4000
10/27/22 Newport Beach, CA

nikon D850
F-S DX NIKKOR 55-300mm f/4.5-5.6G ED VR
f/4.5 @55 mm 1/80 sec ISO 102,400!
used absurdly high iso to capture the faint moving object
this resulted in very noisy images which had to be denoised after dark subtraction





Tuesday, December 27, 2022

More mars: northern polar hood, bonus jupiter

 After imaging the mars occultation (which occurred at low altitude), I waited a few hours for mars to reach maximum elevation and increased the magnification.

A layer of clouds, referred to as the northern polar hood, covers the north pole in these images.  Surface structure is more evident in the IR images which cut through cloud cover. 

Mars 12/8/22  07:26.1 UTC

probably snowing on the north pole.  


also got some bonus time on jupiter:



Jupiter 2022-12-08 04:36.3 UTC

Jupiter 2022-12-08 04:29.9-04:42.6 UTC


Image details:
average seeing
Mars 12/8/22  07:26.1 UTC
Jupiter 12/8/2204:29.9-04:42.6
eastbluff, CA
celestron 11" Edge HD
ZWO ASI 290MC (one shot color camera)
2x powermate
baader IR/UV block filter
ZWO IR pass 850 nm for IR images

Jupiter 
Image reduced by 50% due to poor seeing
10x90 sec
FPS (avg.)=42
Shutter=2.581ms
Gain=351 (58%)
Histogramm=41%


Mars
RGB 6x120 sec
FPS (avg.)=145
Shutter=1.000ms
Gain=351 (58%)
Histogramm=46%

IR 2x120 sec
FPS (avg.)=147
Shutter=5.000ms
Gain=351 (58%)
Histogramm=33%

Monday, December 19, 2022

mars eclipse (occultation) 12/7/22 aka 12/8/22 ~02:27 UTC

 On December 7th, both mars and the moon were in opposition--directly opposite the earth.  for the moon that means a full moon.  for mars it means the planet is roughly closest to the earth in it's orbit, so visually much larger and brighter than other times during the year.  since the planets in our solar system generally orbit in the same plane...the moon "eclipsed" (occulted) mars this year at opposition--an excellent photo opportunity.  

Mars emerging from lunar occultation
12/8/22 ~03:34 UTC
stacked composite

A different perspective:

Mars has risen
occultation egress
stacked composite
Same image, full scale crop:
occultation egress
stacked composite
full scale crop




Occultation start, 4x speed:


I used sky safari, to preview the location of mars at egress then, eyeballing the craters, navigated my narrow high power field to where I thought mars would appear.  Miraculously it appeared dead center in the field.  
Occultation end 4x speed:
Kudo's to the sky safari app

Imaging commentary:
The occultation occurred with the moon rising low in the east (6:30 PM local), so I had to move from my usual imaging location.  Unable to set up the night before, I had to bolt from work like Fred Flintstone at the whistle and set up from scratch.  polar aligned sighting thru the saddle at polaris, then 1 object align on mars.  did not have time to tune the ADC. Whatever settings I had last time were probably better than nothing.  

Used a lower gain and max histogram to improve the dynamic range.  
Processing was a bear.  Stacking software (autostakkert) could not handle my occasional field adjustments, so I wound up having to edit the video into smaller clips with PIPP, virtual dub, and photoshop, then process separately.  

The first two images are composites combining a stacked mars image, a stacked moon image, and a single frame.  

Image details:
12/8/22  ~02:27-03:34 UTC
eastbluff, CA
celestron 11" Edge HD
ZWO ASI 290MC (one shot color camera)
ZWO ADC
baader IR/UV block filter
12 fps, 1.844 ms, 152 gain, 100% histogram
isolated mars after egress
56 fps .924 ms, 251 gain (only 41%, should have been higher)

This was my second time using the celestron CGX which has some nice ergonomic features for rapid set up




Wednesday, November 30, 2022

Mars is here, 11/26/22. filter tricks--IR filter with RGB camera

 Mars is here.

The seeing wasn't great this session, so i imaged without a barlow.  I wanted to test out an infrared filter with a color camera which worked perfectly (see details below).

Mars 11/26/22 8:51 UTC
RGB left, IR 850 pass center, IR-RGB composite right

as i was breaking down the gear, i noticed that the stars were no longer twinkling ;) 
broke out the barlow and got less sleep than planned:
Mars 11/26/22 9:26 UTC
single 120 sec capture

Why an infrared (IR) filter works with a color camera:
the color filters in many color cameras pass infrared light.
(which is why you should use an IR blocking filter)
The ZWO 290 MC passes the IR from an 850 nm IR pass filter equally through all color filters.
as a result, you can get a uniform full resolution monochrome IR image when using an IR filter with a color camera.  
just be sure to set the color balance for all filters to neutral (see below).  

Image details:
11/26/22  08:34-09:26 UTC
celestron 11" Edge HD

first set
ZWO ASI 290MC (one shot color camera)
baader IR/UV block filter for RGB images
400 fps, .191 ms, 351 gain, 40% histogram, 120 sec x 4
ZWO IR pass 850 nm for IR images
set green and blue gain to .5 in fire capture for IR
400 fps, .855 ms, 351 gain, 35% histogram, 120 sec x 3

second image
ZWO ASI 290MC (one shot color camera)
baader IR/UV block filter
televue 2x barlow
152 fps, 2.132 ms, gain 291?, histogram 49%, 120 sec
single 120 sec capture

firecapture, autostakkert 5% stacked, winjupos, maxim, photoshop
elevation ~80 degrees
Eastbluff
Southern California

for IR-RGB blend IR was used as red channel and 30% luminance, color rebalanced on white pole structure.  

ref:
IR filter with ZWO camera
https://astronomy-imaging-camera.com/product/1-25-ir-850nm-pass-filter
"just don’t forget to keep the WB_R and WB_B to 50 (no White Balance applied)."
fire capture screen shots:
click for full size

click for full size