Monday, January 29, 2018

More Preparation for Wednesday's Total Lunar Eclipse

I needed clear skies to take two more test images of the full Moon in preparation for Wednesday, January 31, 2018 total eclipse of the Moon.

The first image test was to attach my Canon T3i to my Daystar 500mm f/6 scope (from the CATE Total Solar Eclipse Experiment).

This is much nicer image size and better clarity than the 400mm scope I tested yesterday.

The second image test was an early submission for an experiment to make a 3D image of the Moon tonight and (hopefully) for Wednesday morning's total eclipse of the Moon (weather permitting here). Images will be take over 500 miles apart (maybe more) with the exact same experiment by different CATE volunteers, one being in the San Diego, California.

Here are my early submissions to this test. The first is the focus image. The setup was a Daystar 500mm f/6, PointGrey monochrome 5mp camera, Celestron CG-4 mount taken at 8 pm, January 29, 2018.

The second is an HDR composite image. 

The last is a post-processed image to bring out some contrast.

So it appears that my primary scope is going to be the Daystar 500mm f/6, which I will use with both the monochrome PointGrey camera and my color Canon DSLR T3i camera.

I will still take a few image with a second Canon camera for "context" images.

Preparing for the Blue-Blood Moon Lunar Eclipse...

This Wednesday's full moon is unusual:

First, it is the SECOND full moon in the month of January, 2018. As such it is commonly referred to as a "blue moon", where we get the expression "once in a blue moon" because it is a fairly rare event to have two full moons in a given month.

Secondly, this full moon is graced with being a total lunar eclipse, which is when the Moon passes behind the Earth and enters its shadow cast by the Sun.

Here in Oregon it will occur early Wednesday morning from about 4 am until 6 am, due west. You will need to have a fairly clear view of the horizon to see it, though, as it will begin about 30 degrees above the horizon and drop during totality all the way down to about 5 degrees above the horizon.

Thirdly, and here is the "joke":
Question: When is a "blue moon" NOT a "blue moon"?
Answer:   When it is a "blood moon"!
In other words, when the Moon dips into the shadow of the Earth, the color of the light bending will shift slowly from yellow, orange, brownish and even "blood" red.


In preparation for this Wednesday morning's total lunar eclipse I have been testing various lens and telescopes to get a better idea as to how large the Moon will appear in the images I take with a Canon T3i DSLR camera body.

The good news is that the totality of a total lunar eclipse lasts a very long time (up to several hours) compared to a typical total solar eclipse (only about 2 to 6 minutes). This allows one to be able to change the lens/telescope at will once totality occurs.

And it is not always desirable to image the Moon as large as possible in the image. If one includes some foreground objects (trees, buildings, statues, clouds, etc) one may want to use a lens of much lower power to capture the context of the eclipse, as these images (taken by others, not myself) show:

(I would give photo credits but these were posted on the web without them)

Since the Canon T3i is a "cropped sensor" camera, the typical focal length measurements do not line up with what one could expect with an old fashioned 35mm camera lens chart. Hence the need to test my various lenses and telescopes to get a better idea of what size the Moon will appear in the final images.

Here are the 5 lenses and telescopes that I expect to use, weather-permitting, this Wednesday:

250mm focal length: Canon 55-250mm zoom lens (f/4.5-5.6)

350mm focal length: Tele-Lentar film camera telephoto (f/5.6)

400mm focal length: Celestron Short Tube (70mm f/5.7) OTA

750mm focal length: Celestron C-5 telephoto (127mm f/6 Cassegrain) OTA

1,350mm focal length: Celestron NexStar 4 SE (102mm f/13 Maksutov-Cassegrain) OTA

So I tested these in poor weather conditions last night (lots of clouds, but some thin enough to see the Moon) with the camera and lenses/telescope on a stationary tripod: Here are the results without cropping the images:





(the clouds really got thick when I took this shot!)

As you can see, the NexStar 4SE (1,325mm) telescope did not quite take in all the Moon, which may not be useful except in the earlier pre-totality phases of the eclipse.

The 400mm and 750mm images point to the Celestron C5 and the Celestron Short Tube as being the best overall for as telephoto as possible with what I have.

There is one more scope I may use which will be about 500mm, a Daystar telescope used in the CATE project, that I hope to test tonight and update this page afterwards.
Daystar 500mm telescope

However the 350mm, though not as telephoto seemed to create a sharper image with more control over the f/stop by use of its diaphragm settings.

The much wider view that the 250mm telephoto zoom lens offers will likely be the one I use to put the eclipse "in context" of the foreground mountains, trees, etc.

Now I just need clear skies in the area of the Moon on Wednesday from 3 am until 6 pm, though the present weather forecast is foreboding...
Tuesday over night forecast:

Wednesday morning forecast:

Saturday, January 13, 2018

Surprised by mostly clear skies... A Comet and a Nebula

The Flame Nebula (aka NGC 2024 & Sh2-277)
located just to the left of the left hand star (Alnitak)
in Orion's Belt.
Meade LX200GPS 8" f/10 - prime focus- Canon T3i
ISO 12800 - 7 45 sec exposures stacked with DSS
for a total time of just over 5 minutes

Last night was a surprise... the skies cleared up a bit.
So it was out to the obs to do some tests with my Christmas present: a guiding camera.
I still have to find out why PHD2, while recognizing the camera, will not connect to it.
All the same I managed to eck out a few images, though not as many as I needed to get good clean images. Yeah, I was really pressing it to attempt to use the big scope at prime focus instead of using a focal reducer. Live and learn!

A comet is visible in the night sky near the head of Taurus, the Bull, on its way to the Pleiades.
It is Comet PanSTARRS C/2016 R2.

This image is cropped down and tilted so as to compare it with the next image that was taken with a better setup than mine. You will notice that the comet's tail is not in a typical straight line behind the comet's head. This comet is making some unusual tails in the past few days and I was glad to capture it even if it isn't all that well defined.

The next image Amateur astronomer Gerald Rhemann took from his private observatory in Farm Tivoli, Namibia taken the same night as mine. It is a 56 minute guided exposure through a 12-inch telescope that shows the same "dog-leg" break in the comet's tail.

Tuesday, January 2, 2018

2017 Year in Review Photo poster

2017: 47 blog posts

First Full Moon of January 2018

This month is unique in the sense that January will have not one but two full Moons!
Fortunately the skies held clear long enough (January 1, 2018 at 7 pm PST) to take this shot.
Almost immediately after freezing fog began to flow quickly across the sky!
Happy New Year, one and all, and may the Lord bring His blessings into your life!