M92 - The Less Viewed Globular Cluster in Hercules

Messier 92 (M92) is a wonderful globular cluster of approximately 330,000 stars spanning 108 light-years in diameter.  This bright cluster can be spotted without a telescope under dark conditions but is often overshadowed by the bigger and brighter Great Hercules Cluster, M13, which is very close by.  I like the way this one looks when viewing through the eyepiece as it seems more well defined than M13.  Another interesting piece is that M92 is one of the oldest globular clusters in the galaxy at 14.2 billion years (sources: wikipiedia and Messier Objects).

Also, this object is the first color object I stacked using raw frames rather than converted tiff frames.  See the previous post (TIFF vs. RAW: Problem of Stacking RAW in DSS Solved!) for an explanation of why.

Crop

Wide Field

M92
Location: Happy Frog Observatory, Monroe, CT
Date: 06-17-18
Camera: Canon EOS Rebel T3i(a), AstroPhotography Tool APT
Telescope: Orion ED80 80mm f/7.5 Apochromatic Refractor Telescope
Barlow: None
Focal Length: 600mm
f/7.5
Focal Reducer: Orion 0.8x Focal Reducer for Refractor Telescopes
Mount: Orion Sirius EQ (HEQ5)
Filter: Astrodon UV/IR
Autoguiding: QHY-5L-II-M attached to an Agena 50mm Guide Scope with Helical Focuser
Exposure: 50 x 90s
ISO: 1600
Temp: 18 C
Post Processing: Deep Sky Stacker, Photoshop, Gradient Exterminator, Astronomy Tools, StarTools, Lightroom2
https://kurtzeppetello.smugmug.com/

TIFF vs. RAW: Problem of Stacking RAW in DSS Solved!

So, along time ago when I first started out using Deep Sky Stacker (DSS) to stack frames captured with my Canon T3i/600D, DSS would not read the CR2 images generated by my camera so I had to convert them to tiff format.  I read this as a workaround somewhere.  I used Canon's Digital Professional to convert the raw frames.  The Clarkvision website actually recommended converting to tiff on one of the threads and gave some technical explanation as to why but it went over my head. 

After a couple of years and updates, DSS was finally able to stack the raw images. Eureka! It will be much quicker to process, however, when I examined the the stacked image I noticed the stars looked like dim donuts.

For this experiment I used M92 as an example.
- 50 light frames, 90s, ISO 1600
- 10 dark frames, 90s, ISO 1600
- 12 flat frames, ISO 1600
- 10 bias frames, 1/4000s, ISO 1600

Image 1 is the autosave file generated by DSS with the default settings. Notice the poor quality stars.

Image 1 - autosave image stacking raw frames

As I normally do, I converted the raw frames to tiff and the stacked image with the same default settings. Image 2 was the result. Notice the more well defined stars.  This has been my normal procedure for years.

Image 2 - autosave image using converted tiff frames 

I posted the question of why stacking my raw frames gave such poor results on Cloudy Nights and got plenty of reasons why stacking raw frames is much better.  The check out the link to Cloudy Nights to see all of the responses.

Mark summarized it as follows:
"When you stack TIFF files, you are stacking files that have been processed by the raw converter. The data are no longer linear but have been transformed into a non-linear colour space (e.g. sRGB or AdobeRGB). The stacked image is therefore also non-linear. When you subtract light pollution (which is typically high in red and low in blue because it is dominated by sodium street lights) from non linear stacked image, the result tends to have increasing blue with decreasing scene intensity and it tends to have very oversaturated colours."

The original question, however, was answered by another responder.

Wei-Hao summarized it as follows:

"The donut-shaped stars are likely caused by the cosmetic correction or hot pixels removal in DSS. If the setting is too aggressive, DSS would take all stars as hot pixels and remove them, leaving the stacked images no stars or dim stars with funky shapes.

You can first disable all options related to these and see if it solves the problem. Once you confirm the problem is indeed caused by the cosmetic correction, then you can try various settings there to find the best combination for your images."

I did what Wei had suggested and finally, after many years, my stacked raw image looks much better! I wish I posted this a long time ago, I don't know why I did not...

Image 3 - autosave image using raw frames with hot pixel removal disabled

The stars on this image are well defined as they are in the single raw image frames. Although converting to tiff was a pain I don't think my final images were of poorer quality, I believe they were potentially just as good, but I think I had to to a heck of a lot of extra processing in order to accomplish a decent image.  

To end with I have attached final versions of both methods.

Image 4 - Final stacking with tiff

Image 5 - Final stacking with raw (disabled hot pixel)

Hope this helps anyone with similar problems, 

Cheers Kurt

M13 - Hercules Globular Cluster Revisited

Well I finally redid this object after three years.  The old image was so 'good' I must have forgot to put it on Astrobin as a separate image but here is a link to it (https://kurtzeppetello.smugmug.com/Globular-Clusters/i-w5KSQBj).  Like all globular clusters, M13 or the Hercules Globular Cluster (NGC 6205), does not reside in the galactic plane but rather outside surrounding the central bulge.  M13 is considered to be the best in the northern hemisphere and is visible all year at latitudes greater than 36 degrees.  With a diameter of 145 light-years and several hundred thousand stars it certainly does have boasting rights.  Even at 22,000 light years away it it very impressive.  The cluster, like most clusters, contains very old stars on the order of 12 to 13 billion years old, however, this cluster is of particular interest because it produces young blue stragglers - large blue giant stars formed as result of colliding old stars (source: wikipedia and Earthsky).

M13 - Hercules Globular Cluster
Location: Happy Frog Observatory, Monroe, CT
Date: 06-15-18
Camera: Canon EOS Rebel T3i(a), AstroPhotography Tool APT
Telescope: Orion ED80 80mm f/7.5 Apochromatic Refractor Telescope
Barlow: None
Focal Length: 600mm
f/7.5
Focal Reducer: Orion 0.8x Focal Reducer for Refractor Telescopes
Mount: Orion Sirius EQ (HEQ5)
Filter: Astrodon UV/IR
Autoguiding: QHY-5L-II-M attached to an Agena 50mm Guide Scope with Helical Focuser
Exposure: 58 x 90s
ISO: 1600
Temp: 18 C
Post Processing: Deep Sky Stacker, Photoshop, Gradient Exterminator, Astronomy Tools, StarTools, Lightroom2
https://kurtzeppetello.smugmug.com/

M101 - The Pinwheel Galaxy (Finished)

My image of M101 from a couple of weeks ago was not particularly good as it was more of a test using APT with plate solving. I added data from last year and I went out a second night to capture more data.  This time I used my Atlas Pro Mount with APT and Plate Solving. I was very happy as everything worked like perfectly.  This latest colorful image is much better than any other image of M101 I ever did previously and shows the benefit of longer exposure.  I did have one issue with PHD2 with the Atlas Mount in that I had to use the ST-4 cable (phone cable) as I needed to update the Version-4 SynScan Hand Controller like I did with the Sirius Mount.  I updated it the following evening as I did not want to use too much of the clear night doing updates.  Fortunately, the ST-4 cable worked fine.

M101 is a large face-on spiral galaxy located 21 million light-years from us.  It is has a diameter of 170,000 light-years and has around a trillion stars.  It is asymmetrical due to the tidal forces from interactions with its companion galaxies. These gravitational interactions compress interstellar hydrogen gas, which then triggers strong star formation activity in M101's spiral arms that can be detected in ultraviolet images (source: Wikipedia).

I did not crop this much as I like the wide field with all the other galaxies located in the field.  I did not crop this much as I like the wide field with all the other galaxies located in the field. I especially NGC 5422 in the lower central area.

M101 - The Pinwheel Galaxy
Location: Happy Frog Observatory, Monroe, CT
Date: 04-15-17, 05-30-18, 6-11-18
Camera: Canon EOS Rebel T3i(a), AstroPhotography Tool APT)
Telescope: Orion ED80 80mm f/7.5 Apochromatic Refractor Telescope
Barlow: None
Focal Length: 600mm
f/7.5
Focal Reducer: Orion 0.8x Focal Reducer for Refractor Telescopes
Mount: Orion Sirius EQ (HEQ5)
Filter: Astrodon UV/IR
Autoguiding: QHY-5L-II-M attached to an Agena 50mm Guide Scope with Helical Focuser

Exposure: 59 x 90s, 40 x 90s, 72 x 90s

ISO: 1600
Temp: 18 C
Post Processing: Deep Sky Stacker, Photoshop, Gradient Exterminator, Astronomy Tools, Star Tools, Lightroom
https://kurtzeppetello.smugmug.com/

Cygnus & Hints of the Milky Way

I went on a Boy Scout Rafting/Camping trip to a remote area in PA this past weekend so I thought perfect, I will bring a camera.  I looked perfectly clear, however, the 30-second exposure showed clouds all over the place.  I did some processing in PS and LR2 to minimize the clouds and bring out a hint of the Milky Way. Also, I think I stacked two 30-second exposures to enhance the image.  Normally, I do this in DSS but for a small number of frames, like two, PS works.  I used the auto align function in PS to stack them rather than by hand and eye (otherwise I just would have processed one of the exposures).  Lightroom was very helpful especially the vignetting function in removing the light pollution around the bottom edges. 

All I can say is trying to do Astrophotography in the Northeast is ridiculous!  It would be great if I were into clouds!

  

Version 1

Version 2 - Curves Adjust

Location: Hickory Run State Park, PA
Date/Time: 6/9/18 11:37 pm
Camera: Canon EOS Rebel T3i (600D)
Lens: Opteka Fisheye
Focal Length: 6.5mm
f/4.5
Exposure: 2x30

ISO: 3200
Post Processing: Photoshop, Lightroom2

Plate-Solving is Awesome: M101 captured using APT

This image of M101 isn't that great, many more impressive out there, in fact my image from last year may be better.  However, what makes this image special is I used Astro Photography Tool (APT) to  control not only my camera but also my mount.  In addition I used PointCraft, a module of APT which allows the telescope to center on an object by plate solving.  I hate to admit it but this was much quicker and more accurate than I was ever able to accomplish with my normal alignment and centering method.  I can see with people people use this method and why it is especially if you have a large telescope or use a camera with a smaller FOV.

The weather has been horrible for stargazing here lately (the yard is greener than ever) but it has been good enough for me to practice using different software.  In addition to testing APT, I downloaded Sequence Generator Pro (SGP) to give it a try as well.  Warning if you plan on doing this - getting everything to work, i.e. downloading drivers, updating firmware, cabling, and etc. is tedious, time-consuming and frustrating.  Choose week when the moon is out or when you have lots of extra time.

I did a more in depth review of why I chose APT over SGP - Link - (http://astroquest1.blogspot.com/2018/06/why-i-chose-astro-photography-tool-over.html) so no need to go over it here. I liked both programs and SGP does have some advantages but I liked the simplistic feel of APT or maybe it is my personal biased as it looks and works more like BYEOS.

Whatever the reason, I am especially happy about the Plate Solving.  After I got it work I was just bouncing around to different objects taking test photos and I was almost dead on most of the time.  If I wasn't I just pressed solve and I was back on.  If it ever clears up around here I can add more data to M101 and/or I may combine it with last years image.  I chose to crop off center because I wanted to show the NGC 5474 as well as the large stars on the left.  Sort of my artistic finesse on an otherwise not so spectacular image.

Crop

Wide Field

M101 - The Pinwheel Galaxy
Location: Happy Frog Observatory, Monroe, CT
Date: 05-30-18
Camera: Canon EOS Rebel T3i(a), AstroPhotography Tool APT)
Telescope: Orion ED80 80mm f/7.5 Apochromatic Refractor Telescope
Barlow: None
Focal Length: 600mm
f/7.5
Focal Reducer: Orion 0.8x Focal Reducer for Refractor Telescopes
Mount: Orion Sirius EQ (HEQ5)
Filter: Astrodon UV/IR
Autoguiding: QHY-5L-II-M attached to an Agena 50mm Guide Scope with Helical Focuser
Exposure: 40 x 90s
ISO: 1600
Temp: 18 C
Post Processing: Deep Sky Stacker, Photoshop, Gradient Exterminator, Astronomy Tools, Star Tools, Lightroom
https://kurtzeppetello.smugmug.com/

Why I chose Astro Photography Tool over Sequence Generator Pro

The time has finally come for not only controlling my camera but also my mount.
This is by no means a complete review or tutorial.  It is a limited review of things I discovered during while installing and using both Astro Photography Tool and Sequence Generator Pro after a short period.  There much more in depth reviews and tutorials on the web.  At the bottom of the page I listed what I thought were the most helpful links to me to getting started with these programs.

Why Switch From Backyard EOS for camera control?
I absolutely love Backyard EOS (BYEOS) for its power and simplicity, however, I am planning on getting a dedicated astrophotography camera and will need to use a new camera control program as BYEOS works only for specific DSLRs.  I decided on Astrophotography Tool (APT) since it was given high praise, inexpensive ($20), and very similar to BYEOS.  To start, I used APT on a basic level (controlling a camera) only for couple of months.  The other big thing that these programs do on an internal level is Plate-Solving.  Plate-solving is a method that detects the stars from an image you take and then tries to identify them using catalogs of know stars. If successful it is possible to calculate exactly where the telescope is pointing, image orientation, resolution and etc.

Stellarium
I switched gears a bit and I started using Stellarium to control my mount (see Controlling an Equatorial Mount with Stellarium). To do this I had to download the ASCOM driver for my mount.  In my case I have an Orion Sirius EQ-G (HEQ5) so I needed the ASCOM Skywatcher SynScan Mount Controller driver. I also needed the cords to connect the Skyview Hand Controller to the computer.

Sequence Generator Pro (SGP)
Before going directly into into APT I wanted to look into the popular SGP software especially since they give a 45-day free trial. I learned a lot in the first week of getting used to this program and downloading supplemental software as well as upgrading firmware.

The first major hurdle was getting rid of ST-4 telephone wire connection for the autoguider, with SGP and APT you can connect PHD2 using the ASCOM mount driver.  Naturally this did not work with my four-year old Sirius Mount with the Version-3 SynScan Hand Controller.  After more research (another frustrating night) I realized I had to update the V3 - SynScan Hand Controller firmware - that was fun especially because it looked like it did not work.  It was only after I turned the mount off and on did know the new version did install.  When I started PHD2, the Skywatcher slew controller popped on my computer screen.  This was a euphoric moment me!

Next was the plate solving software.  It seems SGP and APT overlap with plate solving software packages in particular PlateSolve2 by PlaneWave Instruments.  In the case of SGP you install it from the SGP button and download the catalogs.  This worked really well and after setting the telescope parameters, you can preview and frame the area you eventually want the telescope to point to.

I did manage to set up a quick sequence between the clouds and take an image of Arcturus, however, I tried to use the Frame and Focus and my computer locked for some reason.  It did this more than once so I decided to go back to APT.

Astro Photography Tool
I had already been using APT on a basic level but I have not used anything else until now.  It was pretty easy connecting everything now since I already connected everything when using SGP.  APT uses the module PointCraft to control PlateSolve2 (PS2) and All Sky Plate Solver (ASPS) for plate solving. The difference is ASPS allows you to do a blind solving, i.e. just take a picture wherever you telescope is pointing and it will solve it whereas PS2 you be in the close by the object you want to solve for.  So far I have only used PS2.

To date I have used PlateSolve2 but had to adjust some of the settings such as Max Star Size (6 to 9) and Detection Threshold (6 to 8).

Upon readjusting the settings, I ran the PlateSolve2 by pressing the solve function and within 20 seconds my image was solved, I synced it to my mount and that was it.  I then bounced around to other objects to see how this worked.  I can tell you it was incredible, I have never been so accurate before and I consider this a crowning achievement.  The next night provided the perfect evening to yield complete control of my camera and mount over to APT and I chose M101 as my test subject.  Needless to say everything worked perfectly, I was zeroed in and framed on the object quicker than I have ever been before.  The whole thing took less the a minute and I just starred at the screen for minute because I could not believe how easy it was.  I'll post the results when processing is complete.

Final Thoughts
SGP has a lot of features that I really liked such as the ability to set up and save equipment profiles as well as the ability to bring up an image from the plate solver atlas and play with framing prior to zeroing in on it for real.  In the end, however, I chose APT mainly because it is a bit simpler to use if you have to make a lot of last minute decisions like I do.

• If you are using BYEOS/Nikon and have no plans to use an astrophotography camera, then by all means stick with it, no need to switch.

• If you are using SGP, by all means stick with it, no need to switch.

• If you are using APT, by all means stick with it.  However, if you have an observatory and/or want to have more computer control over your system, you might consider switching as SGP.

Also, Trevor Jones from AstroBackard gives a more in-depth review of these programs. 

Links I found most helpful for SGP

The First Week with Sequence Generator Pro - Alex's Astro
Sequence Generator Pro Setup - Chuck's Astrophotography 

SGP Manual

Links I found most helpful for APT

Plate Solving with APT - Astropetros.eu

APT Forum - PlateSolve2 settings

APT User's Guide