Sunday, August 13, 2017

Scorpius Constellation Over Kilauea Volcano Caldera, Hawaii

On August 1, 2017, my wife and I were part of a tour group to the Kilauea Volcano caldera on the big island of Hawaii. The constellation Scorpius was hovering over the playfully erupting volcano that night. Quite a sight ! The camera was hand-held for about 6 second exposure.

Here were the camera settings info:

Tuesday, August 8, 2017

Testing Exposures and Lenses for the Solar Eclipse 2017

or... How to Fake a Solar Eclipse!

Hi, everyone!

Yesterday I got this crazy idea of how to practice for DSLR imaging (in addition to the primary imaging with the CATE Experiment).

With my Canon T3i, I wanted to practice with the HDR and intervalometer functions so that imaging would be fairly automatic during the eclipse as well as test my lenses to see what the image size of the Sun/Moon would be.

My crazy idea:
Wait until dark, place a flashlight behind a soccer ball propped up on a concrete block.
Set up the camera in the HDR/Intervalometer/P mode on a tripod so that the flashlight is "eclipsed" by the soccer ball. Then I would toss some dust up in the air between the flashlight and the soccer ball to help simulate a corona.
Then by experimenting with + or - overrides and setting the ISO to 800, I would run the camera and see what would result. By the way, I used a 2012 version of MagicLantern firmware with the camera to be able to control the HDR/Intervalometer functions and settings.

I found that it may well provide the various bracketing exposures during totality with very little attention!

Then since the Moon was full (and the skies thick with smoke from forest fires all around and a thin cloud layer) I tested the settings on it as well. It also provided with with a way to test with my zoom lens set to 250mm as well as used a 5" Celestron f/5.6 telephoto to determine the image size of the Sun/Moon since last night was a full Moon.

Telephoto Zoom set at 250 mm (tripod mounted)

Celestron 5" 750mm f/5.6 telephoto scope (tripod mounted)

So the result is that I am quite comfortable with the possibilities of good exposures!

Wednesday, August 2, 2017

Major Sunspot Group AR 2665 Makes It Around the Sun a Full Revolution !

Scientists call sunspot groups by a letter and number designation. This sunspot group is labeled AR 2665. It has just REAPPEARED after making it all the way around the Sun fairly intact!

August 2, 2017
Sunspots move from left to right.

August 2, 2017
This is a close up of AR 2665

Most sunspot groups fizzle much quicker, their average "life expectancy" is only a few days. Occasionally one will make it all the way around the Sun in about 28 days. AR2665 is one of those few that make it that long recently.

Here are some full Sun images from prior imaging of AR 2665 that will show the rotation, size, and location of this sunspot group:
July 8, 2017

July 10, 2017

July 13, 2017

And the size and shape of AR 2665 also was constantly changing:

July 8, 2017 

July 9, 2017

July 10, 2017

July 13, 2017

All images taken with this setup:

Scope: Daystar 80mm diameter, 500mm focal length APO refractor
Filters: Yellow Filter, IR Cut Filter
Camera: 5 Mpix CMOS MONO camera, by Pt Grey (GS3-U3-51S5M-C)
Solar Filter on scope: by Thousand Oaks #S4250
Post-processing: added color (more pleasing that gray)