Comparison of the Celestron C5 telephoto and the Bushnell Northstar 90mm telescope

As I look forward to the solar eclipse in August, 2017 which passes through central Oregon I have been wondering how each scope's view will make the eclipse appear. 

Having just purchased an old school Celestron C5 (previous blog entry) 

and the Moon being visible last night, I mounted it and my Bushnell Northstar 90mm telescope

on tripods and using the same camera (Canon t3i) at prime focus I imaged the Moon for comparison shots. Here are the results:

                           Bushnell Northstar 90mm                             Celestron C5

Not only does the Celestron C5 have a wider view but the exposure difference was significant.

At ISO 100 the Bushnell required 1/5 sec exposure due to the fact that it is a f/14 lens

whereas the Celestron C5 only needed 1/20 sec because it is an f/6 lens.

That means that under low light the C5 will be easier to focus and can use a shorter exposure time than the Bushnell. However, the Bushnell gives a closer view of the subject, nearly twice the magnification of the C5.

Conclusion: 

As there is no such thing as a telescope that can be "all things to all people" it appears that, if possible, I will use both scopes during totality (if I have sufficient help from others).

The Bushnell might work well for a closer view of any prominences that may appear on the edges of the Sun during the eclipse and for imaging the Baily's Beads.

The red around the edges are prominences

and Baily's Beads (on the right hand side)

result from the Sun peeking through the

mountain peaks of the Moon during a solar eclipse.

The Celestron C5 will capture more of the surrounding corona due to a larger field of view. The fact that the corona is so dim will also play to the C5's ability to let more light come to the sensor in a shorter period of time.

Comet 41P/Tuttle-Giacobini-Kresak

With windy and clear skies (a first for many moons) I was able to capture Comet 41P/Tuttle-Giacobini-Kresak just west of the "Big Dipper" aka Ursa Major ("The Great Bear") constellation.
This was taken with a Canon t3i and is made up of five -30 sec exposures at f/5.6 and 250mm telephoto - ISO 3200 stacked with DeepSkyStacker Live. No tail is visible though larger telescope can image a slight one.

"New" scopes waiting for clear skies!

When the skies aren't clear my eyes go to craigslist to see if anyone has a scope I can't live without. And today I found another!

I picked up an old school Celestron C 5 telephoto 750mm f/6 (black version) for $90 off craigslist today. The previous owner has chased solar eclipses all over the world! Jealous!

I had to clean the backside of the front plate (no problem, it seemed to have gotten 'smokey'). 

Works great... now just have to get a mounting plate and a couple of rings and it is good to go for the eclipse in August!

And yet another crescent Venus

It is March 12, 2017 and 7:45 pm DST in La Pine, Oregon and Venus is still shining brightly in the west.   I broke out my little Bushnell NorthStar 90mm Catadioptric Telescope (OTA) and mount my Canon t3i to capture yet another crescent Venus (skies still mirky).

Compare the above recent image with this one that I took 11 days earlier (March 1, 2017)
and you will see that the crescent is getting thinner and thinner:

And then this one taken back on January 30, 2017 in broad daylight. (The poor quality of this image is due to atmospheric conditions).

A Cresent Moon and A Crescent Venus

If you go out tonight (March 1, 2017) or the next few nights you will see the crescent Moon and then to the right of it what appears to be a bright star. But that "star" is the planet Venus, which orbits the Sun closer than Earth does.

Though the skies were murky (as evidenced by the unsharpness of the Venus photo) I broke out my little Bushnell NorthStar 90mm Catadioptric Telescope (OTA) and mount my Canon t3i to capture these two crescents in the evening sky. The first image is Venus (cropped). The second image is the Moon (of course!)

Venus is working its way between the Earth and the Sun and as it does so the thickness of the crescent will decrease each evening and Venus will drop lower and lower in the evening sky, drawing nearer and nearer to the Sun (from our perspective) until we will not be able to see Venus due to the glare of the Sun.

Compare the above shot to the one I took (in broad daylight) back in January (Jan. 30, 2017) and you will see the difference over time. (The distorted view is due to being out of alignment with a different scope.)

Crescent Moon (Mar. 1, 2017)

No, Venus is NOT that large compared to the Moon! In fact, the smallest crater you can see in the Moon shot is larger than Venus was in the frame of the camera!

A little clearer sky for a change

January 30, 2017

Viewed Mars, Venus and the Moon in the evening sky. Venus is so bright that I was actually able to see it with the unaided eye long before sunset!

The crescent moon (short exposure) and the crescent moon with "earthshine" (the Sun reflects off the Earth's clouds and water, then the Moon reflects the light back to Earth! - longer exposure.

2016 Year's End - Work and Photos in Review

Well, 2016 is in the photo bucket and there are not a lot of photos in that bucket due to health, home projects, and the darned cloudy and extremely cold weather. The transit of Mercury (in photo below the Moon) was a first for me!
As far as observatory modifications, I added another set of rails (to the left of the observatory) so now I can run the roll-off roof in both directions. I have installed one of two power winches to aid in rolling of the roof.
Equipment-wise, I sold the NexStar 8i SE and the Meade LXD-75 6" achro refractor. In their places I purchased a NexStar 4 SE and a High Point 6" f/4 reflector (for astrophotography).
The total number of hours in the observatory took a hit compared to the past two years, probably down 50% and the total number of posts on this blog is also down. Please, just some clear skies when I am not busy, weatherman!
2017 has a lot of projects in the observatory that need reworking or completing as well as photography I am looking forward to doing and perfecting.
Check back throughout the year and Happy New Year!