Showing posts with label celestron. Show all posts
Showing posts with label celestron. Show all posts

Monday, February 22, 2021

Field of view 


Orion Nebula imaged at 2030mm with a Celestron Edge HD 8

When I first started looking at getting a telescope everybody was like get a short refractor for wide-field astrophotography. I kept thinking why wouldn't I want the largest telescope I can get? The answer is field of view. 
I have the best of both worlds right now, short 72mm refractor with a 430mm focal length and a 8 inch SCT with a focal length of 2030mm.

Running Man imaged at 2030mm with a Celestron Edge HD 8


Both lenses would benefit from a focal reducer/flattener but the hardest thing is the SCT has such a narrow field of view.
I can encompass both the Orion and the Running Man nebulas with the short refractor but the SCT has a narrow field of view. Coupled with a relatively slow f-stop of f/10 subject selection is kind of critical, I can't get some of the more popular targets in one frame. 

Orion  imaged at 430mm with an Astro-Tech AT 72mm ED II


The reducer will take it down to about a 1500mm focal length which will make shooting some of the bigger targets easier and I will still the ability to try and get to some of the smaller imaging targets as well.

Saturday, February 20, 2021

Guiding star 

Guide scope )n left ready for a debut.


Had my first successful (well actually any) attempt at guiding. The QHY 55L -II -M and matching mini guide scope worked well, even better when I plugged it into the correct port on the camera.

PHD2 guide scope software guiding my CGEM II mount
after out selecting a star near the Orion Nebula

Out of the gate I was able to run three-minute subs, two minutes longer that anything I've been able to do so far with just tracking on the CGEM II or AVX mounts.

A graph charts the corrections to the mount in right ascension
and declination axes during PHD2 guiding of the Orion Nebula

Had some brief hiccups with clouds and high winds trhat led to some not-so-great seeing which probably gave me the crazy graph on the PHD2 software.

Guiding allowed three-minute subs of the Orion
Nebula with a 430 mm focal length telescope

Down the road will be adding guiding to the Celestron Edge HD 8 but I have to have a focal reducer (already on backorder) before I try to guide theat.

Saturday, January 23, 2021

 Gearing up

Celestron Edge HD8 on a CGEM II mount

As the COVID-19 pandemic gripped the nation people who had to shelter in place indoors turned their eyes skyward. Astronomy and astrophotography saw a massive resurgence with retailer's shelves emptied of telescopes and their dedicated accessories. This is where I entered the picture.

Late summer I had lost my father after a short illness and I didn't have the heart to continue, at least for the time being, with the hobby that we had shared for nearly 30 years. So I looked for something new amid the shelter in place.
I had always had an interest in astronomy since a class I took in junior college and the school's planetarium. I had always wanted a telescope and I had photographed every lunar eclipse, partial solar eclipse and comet I could find. But I never took the step into the world of deep sky astronomy until now.

My first piece of astrophotography equipment was the Sky Watcher Pro star tracker.
With a payload of 11 pounds this is really meant for attaching a DSLR with lens for some wide-field photography although light weight refractors also work well on it but I'm getting ahead of myself.

Sky Watcher Pro with a Canon 70D
 and 24mm to 70mm zoom attached

So for a few months I waited for nightfall and carried my tripod and star tracker to the backyard for a an evening of picture taking. Lining up the targets proved to by a little frustrating as I was introduced to the world of "star hopping." Looking back it taught me to appreciate the night sky and always have my phone handy with my Sky Guide app at the ready. Trial and error and I was rewarded with views of the Andromeda Galaxy, the Pleiades Open Cluster and the Orion Nebula. I was hooked.

Way back in October I had put an order in for my first telescope. After hours of reading reviews and watching video tutorials and reports I settled on a Celestron Edge HD8 mounted on a matching Celestron CGEM II computerized "goto" mount. It was more hardware than a beginner needs but my plan was to future proof my purchase and not need an upgrade.

The pandemic played havoc with supplies and as the months slipped by and the backorder notice taunting me I decided to get a smaller telescope and mount with he prospect of nit getting the Edge 8 and the CGEMII mount no earlier that early summer looming large.

People had been recommending beginners get a short focal length refractor so I decided why not and ordered an Astro-Tech AT72mm EDII with a Celestron Advanced VX mount.

Astro-Tech AT72mm EDII on a Celestron AVX mount

So you have to realize buying the telescopes is just half the battle. Time to accessorize.
Polar alignment is such much easier with QHY PoleMaster. Throw in a red dot finder for each optical tube assembly (OTA) camera T-ring adapters, a wireless intervalometer to control the shutter release (thankfully I already had that in my camera arsenal), bahnitov masks for each OTA, red light flashlights, cables, a dedicated power supply, the list just seems to keep going.

As I write this I am getting ready for another night of imaging some distant galaxy, a smudge in my camera's screen . Not sure what my pictures will look like but it is just the fun of looking up to see something that most never do. and I think I have enough tools to get started.









Field of view  Orion Nebula imaged at 2030mm with a Celestron Edge HD 8 When I first started looking at getting a telescope everybody was li...