First Night Shooting at Double the Magnification | 12-13 May Imaging Session

While I had previously done a successful night the previous weekend, a newly arrived 80mm Short Tube Refractor meant I needed to get back out there again!

Date: May 12-13, 2021
Location:Cottonwood Spring, Joshua Tree National Park, CA
Time21:00 – 4:00 (UTC-7)
Weather clear, mostly calm, 75°-60° F (23°-15°C)
Bortle Scale3

Equipment Used

  • 8″ (203 mm) f/4.9 Newtonian Telescope
  • Orion 2″ Barlow Lens
  • Atlas II EQ-G Mount
  • Starshoot Autoguider
  • Nikon d5300

What Did I Shoot?

ObjectCommon NameConstellationFrames
Layered
Combined
Exposure
β CygniAlbireoCygnus48 mins
M 13Great Hercules
Globular Cluster
Hercules628 min
M 22Sagittarius ClusterSagittarius735 min
M 27 Dumbbell NebulaVulpecula842 min
M 29Cygnus726 min
M 57Ring Nebula Lyra 932 min

Notes:

It was not the first time I had tried shooting with a 2X Barlow on my 8″ Newtonian – after all, I’ve had many nights where I learned the hard way how difficult and how precise shooting at f/10 with a 2000 mm focal length must be. Any time I could generate a passable image with high ISO and short exposure time, it always left a lot to be desired, so I spent the entirety of 2020 shooting at the default f/5 setting. After all, if it aint broke, why fix it?

But I knew that eventually I’d start running out of large objects to shoot in the sky, and the need to resolve the smaller objects was always going to hang over my head. Smaller deep sky objects like M57 practically NEED a 2000mm focal zoom to resolve their familiar details better, and certain globulars will either have their individual stars resolved and spaced out a little more. Plus it opens the door for certain double stars to show separation even in long exposure photographs.

At the same time, I always felt the need to improve my guiding capabilities in general, as the photographer in me is always trying to improve the clarity of the images, and keep the background stars as round as possible. So I invested in the Orion 80mm short tube refractor as a piggyback guide scope. More aperture (faster light) and resolution means it can detect the periodic errors and drifts a lot faster than the 50mm guide scope theoretically could.

Of course the main things now were the weight distribution, as the only way I could get the OTA balanced on the DEC axis was to have the camera on the “bottom” parallel to the counterweight shaft. In terms of added weight, it was only a few lbs at the most. and thankfully I didn’t need to invest in a third counterweight.

A huge plus with this refractor was the focuser, making it much easier to get the guide stars in focus.

The night began and… the background stars stayed round?! Hey! So Far So Good!

A little research on CloudyNights’s message board also gave me advice on improving the guiding which was to increase the aggression along the RA axis (if I ever saw “ovals,” they usually were left-right which meant the RA guiding wasn’t always picking up the errors fast enough). That seemed to do the trick, as when I worked on M57, I could tell right away these images were going to be good!

One issue is of course the coma, which did show up near the edges. While working on M13, I could tell that focusing on the stars near the edges made the center out of focus and vice versa.

While I did use a coma corrector inserted into the Barlow Lens, I believe the Coma was more due to the spherical aberrations from 2X Barlow lens itself, and thus if I want “flatter images” with this setup, I need a higher quality 2X Barlow.

Obviously one day I’ll invest in an Edge HD or any type of f/10 long focal length telescope that already has that issue corrected, but for now I make due with what I have!

At least it’s good knowing that I CAN get images of the smaller deep sky objects if the time calls for it! And hey, as long as what I’m shooting can be sharp in the middle, then I can work with that!

I must make a special mention to Darcy and Roy, a couple who reside in Palm Desert and travel together and photograph the sights! They pulled up in the middle of the night, set up on the opposite side of the parking lot, and after closer inspection, I could tell she was getting Milky Way shots and doing various methods to get the foreground and background landscape illuminated. It was nice chatting with them while waiting for my sub exposures, and I do hope when the Observatory reopens, that I’ll be giving them a tour! Here is Darcy’s blogpost on their account of this night! It is another case if you just never know who you meet out in the desert!

And of course, once again to cap off the night, Cassiopeia and Andromeda (and her galaxy) were seen rising North West above the rocky desert landscape!

2 thoughts on “First Night Shooting at Double the Magnification | 12-13 May Imaging Session

  1. Beautiful shots! Keep up the great work. Robert

    On Thu, May 13, 2021 at 7:10 PM ORION BEAR ASTRONOMY wrote:

    > Anthony Perkic posted: ” While I had previously done a successful night > the previous weekend, a newly arrived 80mm Short Tube Refractor meant I > needed to get back out there again! Date: May 12-13, 2021 > Location:Cottonwood Spring, Joshua Tree National Park, CATime21:00 – 4:00″ >

    Like

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