Saturday, February 24, 2018

Dome Automation - Getting Started

Over the last few months I have been working on an automation project for my observatory. I want the dome to rotate automatically so I can image throughout the night without having go out every 30 minutes or so just to nudge the dome. I did some research and I decided to go with LesveDomeNet system. The price is reasonable and the help files that come with it are good for a DIY project. The main components of the system are an electric motor, a drive system, electronic such as a USB I/O board and an encoder to keep track of the dome’s position and the LesveDomeNet software that will monitor the telescope movements and send signal to the I/O board to rotate the dome as needed. The software is ASCOM compliant so that works well with my setup. At the time of this writing I am not done, I am slowly figuring things out. This is a complicated DIY project.

I will post again when I am done to show how the entire system works but the images below show progress so far:

I replaced the nine 3-in caster wheels with three 5-in caster wheels to make the dome easier to rotate, and it worked!

The larger wheels were taller and they raised the dome above the wall! To fix I had to add a skirt to cover the gap (see next pic) 

It might be hard to see but I added a "skirt" to the bottom of the dome using 4" vinyl wall molding. Not bad!

Below you can see the building of the I/O board. I had to learn to solder, I had never done anything like that before. It was much fun.

Here is my first prototype for the drive system. This might work!
I got lucky, went to the local bike store and the guy just gave this sprocket to me!

There is much more to do but progress so far!

Sunday, December 17, 2017

M45 Diffraction Flares and Bad Flats

This image of M45 looks like a Christmas scene with the blue mist (reflection nebulae) and star crosses (diffraction spikes) but all I can see are the diffraction flares that needed corrected. Also, apparently I don't know how to take t-shirt flats because my flats added all kinds of craziness to the image, I used a synthetic flat instead (that was a first for me). There is much room for improvement with this pic but I am happy with it. It was very hard getting the blue nebula to show up. I am using Nebulosity for both pre and post processing so my tool box is limited (for now).

M45, telescope: 8" f/3.9 Newtonian Astrograph, imager: EOS Rebel T5i 700D, optical aid: Coma Corrector, fov: 1.6°, filter: SkyGlow Broadband, subs: 15, exposure: 120s, iso: 800i, temperature: 54f, guiding: PHD2, pre-processing: Nebulosity, post-processing: Nebulosity, start-time: 20171217-01h06m07s

I plan to do some testing to figure out how to correct for the flairs but for now here are some before images for comparison.

Some might like the diffraction flairs in the image of M45 above but I am going for accuracy.  The bright stars should show as a pin point of light at the center of a cross due to the four spider veins that hold up my secondary mirror.  Maybe some day I will shoot M45 with my refactor to see the difference.

Sirius over exposed to show the diffraction flairs 
Sirius over exposed with focus mask over the end of the telescope.
Looks cool but too many spikes!

Saturday, December 9, 2017

Yardwork at Barn Time Lapse

Just having some fun making some time laps clips.

Here I am clearing all the branches after I trimmed the apple trees.

In this second clip I am clearing some honeysuckle but ran out of light.  I will probably be at it again tomorrow and if so I will update this post.

Friday, December 8, 2017

Cassiopeia Setting Over The Barn and Orion

This weekend was a bust, it is snowing and cloudy tonight (Saturday 12/9/2017) but I did manage to set the camera up on a tripod and play around with some time lapse stuff.

Cassiopeia Setting Over The Barn
422 subs taken every 30 seconds from 11:45 PM to 3:16 PM
Canon EOS REBEL T2i, f/4, exposure 10 sec, ISO 400,
35 mm lens at focal length 21 mm

I also made a time lapse move from the same images used to make the star trails. 

Lastly, I decided while I had the camera out I would try a wide field pic.  It was harder than I expected but also fun.  I will be doing more of theses.  I really like the results.  In this pic you can see the constellation Orion.  Orion is the most instantly recognizable of all constellations – the figure of a man represented by the stars Rigel and Betelgeuse, both among the top ten brightest stars in the sky.  If you go out tonight and look to the East you should see Orion rising sometime between 8 and 9 PM.  And as a bonus I was able to catch M45 Pleiades (The Seven Sisters) in the upper right. Very cool. 

constellation Orion, M45, 
35 subs, Canon EOS REBEL T2i, f/4, exposure 10 sec, ISO 800, 
35 mm lens at focal length 18 mm

Sunday, December 3, 2017

Super Moon Time Lapse

I create a time lapse video of the super Moon rising. This is my first time lapse video and it is not very good but I am posting here to document my starting point. I like to see progress.

Here is what I did:

That’s it.

Friday, December 1, 2017

Moon using BYE planetary mode

The Moon is very bright so I decided to take a picture. BackyardEOS has a “planetary” mode where it uses your live view to quickly capture a bunch of jpg files (about 8 per second I think). Here is what I did:

  • took about 400 frames
  • took all the align, stacking and limit defaults in RegiStax 
  • moved the top wavelet sliders to about 15
  • save image, done!

I did not want to overthink this one, I just wanted a quick image with the most bang for the buck. I like the results but I think it is a bit over exposed. Maybe next time instead of using the planetary mode in BYE I will just take a bunch of full resolution images and stack them.  That way I will have full control over the exposure.

Early December Moon taken with 8in Astrograph


  • 8in Astrograph scope
  • 700D-T5i
  • BackyardEOS planetary mode (400 subs)
  • RegiStax (stack,align,limit to 320 subs,process) 

Thursday, November 30, 2017

Workflow practice M42 M45 M52 M81 M82 Horsehead nebula

Here are a few test images taken during a near full Moon. I call them test images because the sky was very bright from the Moon and because of that I do not expect the quality of the images to be the best. My main object is simply to practice my workflow. For the first time I am taking notes on my image processing workflow and hope to become more consistent and to do so I need to practice. Also, I am curious to observe the effect poor vs good seeing conditions. At some point in the future I will image these objects again under good conditions and compare the results.

M81 - Bode's Galazy - top center
M82 - Cigar Galaxy -  bottom center
M81_LIGHT_152s_1600iso_700DT5i+55f_8inAstroGraphSkyGlow_20171130 (12 subs)
seeing: near full Moon, image capture BackyardEOS, image processing: Nebulosity

M52 - Cassiopeia Salt-and-Pepper Cluster (October Salt-and-Pepper Cluster)  - center left
C11 - Bubble Nebula - bottom right (I think)

M52_LIGHT_150s_1600iso_700DT5i+59f_8inAstroGraphSkyGlow_20171130 (20 sub)
seeing: near full Moon, image capture BackyardEOS, image processing: Nebulosity

M42 - The Orion Nebula

M42_LIGHT_120s_1600iso_700DT5i+50f_SkyGlow_20171126 (19 subs)
seeing: near full Moon, image capture BackyardEOS, image processing: Nebulosity

M45 - The Pleiades

M45_LIGHT_180s_1600iso_700DT5i+57f_SkyGlow_20171125 (17 subs)
seeing: near full Moon, image capture BackyardEOS, image processing: Nebulosity

Horsehead Nebula

On this one I did not have much signal to work with and as a result over did it in image processing but like I said, it is a baseline.

HORSE_LIGHT_220s_1600iso_700DT5i+52f_SkyGlow_20171126 (22 subs)
seeing: near full Moon, image capture BackyardEOS, image processing: Nebulosity

Filename Example
I am trying to do what I can to make the process self documenting. For example, I pack a lot into the initial file name, BackyardEOS makes this easy. Then as I process the image with Nebulosity I tack on the last action taken to the front of the filename. In this way you can see my entire workflow just by looking at the filename.
Following the process outlined below you will end up with an image file named like this:
Everytime I peformed an action I save a new copy of the image(s) and tac on a descriptive prefix:

  • M81_LIGHT_152s_1600iso_700DT5i+55f_8inAstroGraph_SkyGlow_20171130 - About 17 to 30 subs named like this:<target>_<frametype>_<duration>_<iso>_<cameraname>_<tempetature>_<scope>_<filter>_<timestamp>
  • pproc - Preprocess subs by applying the calibration frames; flats, darks and bias
  • histm - Normalize subs by matching their histograms
  • recon - Convert RAW subs to color and pixel squaring
  • align - Align subs but do not combine yet
  • stackedstd15 - Combine the stack using a “std dev filter (1.5 - typical)” stacking function
  • crop - Crop the stacked image
  • adjcoloroffset - Adjust Color Background (Offset) to remove skyglow hue
  • ddp - Digital Development Processing
  • levels - Stretch with the levels tool
  • curves - Touch up with the curves tool