First Image using NINA, PixInsight

I'm going to start this post with the credits. Usually these are left for the end but the amount of help they've given me earns them top billing.

For using NINA and associated plugins, you could not do better than to watch closely the many tutorials created by Patriot Astrophotography . Chad's presentations are concise and clear; even when he suggests some of the technical portions might be a little on the dull side, they're anything but.

Also well worth viewing are tutorials by the Cuiv, The Lazy Geek . His tutorials are often in demonstration form and tend to be more informal than Patriot's.

You probably already know this great reference for PixInsight, Inside PixInsight by Warren A. Keller. It's been my main resource for starting LRGB processing.

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Although I hated to do it, my first clear night in quite a while was dedicated to playing with NINA's autofocusing (AF). 

AF starts at a good (but not necessarily great focus position). From there it racks your focuser out by several "step sizes," takes an image and analyzes it, then racks in a step size and reimages, continuing until it has taken however many steps you specified. Because every geared focuser has some backlash (which has a first guess value of zero distance), that first inward rack will be soaking up that backlash. If your step size is smaller than the backlash no change in focus will result. Through iteration you work you way to producing a nice bowl-shaped hyperbolic curve with the minimum at the point of best focus.

In doing this you will determine two values: step size and backlash. Patriot Astro has a great video showing you how to do this. I was able to determine the values for my FSQ-106-mounted Pegasus FocusCube and was able to get hyperbolic fits with R^2 values uniformly 1.0. 

A second convenience that NINA provides is the use of filter offsets; these are basically the distance by which your filters are not parfocal with a reference filter (usually taken as the luminance filter). Using filter offsets allows you to move from filter to filter without having to go through an AF sequence. This saves you time that you can use for collecting light frames.The process of measuring offsets is automated by a plugin called Darks Customs, and this video explains how to use it. So how parfocal are Astrodon LRGB filters? Very! 

[Here are the numbers for my FocusCube: step size = 35 and backlash = 450. Filter offsets are luminance = 0 by definition, red = +7 focuser steps, green = -6, blue = -1; The narrowband Baader filter offsets are Ha = -52, O3 = -20, and S2 = -48. For perspective, the FSQ focuser has a travel of about 30mm; this corresponds to about 8000 FocusCube steps. The distance in mm for an offset is therefore equal to 

offset in mm = offset in steps * 30mm / 8000 steps = offset in steps * 0.00375

The largest RGB offset is therefore 7 * 0.00375mm or 0.02525mm. That's 1/38th of a millimeter!

Another way to think about the offsets is to compare them to the step size, which can be thought of as the travel needed to change star diameter by 25 to 50 %. An offset of 7 is just 1/5 of the step size, so using the offset in this case may lead to some improvement over assuming parfocal,  but it probably won't be much.]

Getting AF ready was one night's chore. The second night was doing a trial image using the Advanced Sequencer. Using filter offsets made for a very simple sequence: Cool the camera, unpark the mount, run AF on the luminance, slew and center on NGC 188, start guiding and shoot 20 frames of each filter in the order of offsets from negative to positive: green, blue, luminance, and red. (This ordering means the focuser  only moves in one direction, eliminating the need to deal with backlash.) The triggers for this were AF after a significant change in star width and to dither every third light frame. 

Almost everything worked perfectly. But--it was crazy windy and that gave PHD2 fits while trying to recover from dithers. This resulted in a number of frames that had terrible stars, and those triggered AF runs that wasted time. I need to apply a better settling time the next gusty night. 

AF worked to perfection. Stars for each filter were near perfect. My target was NGC 188, an open cluster near Polaris. Processing in PI resulted in this image.

I had trouble dealing with the light pollution and the end result is a rather blotchy image. I'm sure flats would have helped a lot. 

New moon is coming up, so weather  permitting there will be more imaging!

 

Jumping the APT ship for a ride with NINA

I hopped on the imaging automation wagon reluctantly because I'm very old school. My mounts had go-to that I seldom used; star hopping and a good finder were all I needed, right? Absolutely! I did the H400 pushing a non-electronic 10" Dob from star to star to H object, and it was fun. All I needed was a red light, star atlas, and dew strap for the finder.

Then I started imaging and kept right on hopping. That worked for awhile, but then it became evident (only because someone pointed it out to me) that I spent a lot of time hopping when I could have been collecting photons. Reluctantly I started to move into the 21st Century. A friend suggested a setup that included planetarium and acquisition software. 

The planetarium part was easy enough as I liked Stellarium's simplicity. For acquisition I already had ImagesPlus.  IP and photoshop handled my calibration and image processing needs. After completing the Astronomical League's Bright Nebula list I switched from CCD to DSLR and I changed to BackyardEOS for acquisition.

Then things happened.

I became involved with the creation of a club imaging platform. This brought me into contact with more modern imagers, and they gently suggested I modernize. For the platform I surveyed available acquisition software and put APT and SGP on the short list. APT looked horribly complex (partly due to the clunky interface) and the way SGP worked seemed counterintuitive to me. The decision was made by someone else after I left because of the pandemic, but for myself I decided on APT.

Next, a friend wanted me to learn PixInsight so that I could teach him. I knew PI was a fine package, and that eventually I'd want to wean myself from Photoshop, so PI became the third leg of my imaging tripod: Stellarium, APT, and PI.

Which was how it stood until yesterday when I revisited NINA. In 2019 I had considered NINA briefly but thought it was too new, too undocumented, and too undertutorialed (if that's a word). And since it was Open Source and free, I had concerns that it might wither and have a premature death. Now it's 2022 and none of those concerns are valid. So it is time to revisit NINA. And after a day inside seeing how well it plays with my equipment I'm ready to switch.

First and only somewhat important, NINA looks great. Better yet, the style of NINA complements its large set of features; it seems, at least to me, incredibly intuitive. I've already had a dry run with NINA and my complete imaging setup, and I'm ready to try it out when we have a clear night.

Revised Startup for APT/Stellarium/PHD2 et al.

I've updated all the software I use for image acquisition: APT, PHD2, Stellarium, and ASCOM. 

All the updating went without problems, so Yay!

However, my old way of starting all these in order of APT first, then Stellarium, and finally PHD2 seems to not work well any more. What seems to happen is that APT and Stellarium can't work through ASCOM correctly, and APT sometimes launches an instance of PHD2 out of impatience?

Some experimenting was needed, and the result is that the order of starting now goes like this:

1. Power the mount and allow time for it to boot. My Gemini 2 takes a couple of seconds, most others are probably faster
   
2. Power up everything else and insure it's all running and has made its USB connections.
   
3. Start Stellarium and let it connect to the mount (if all is good it should correctly show the direction in which scope is pointing)
4. Start PHD2 and connect it to the guide camera and mount
5. Start APT and connect it to the camera
6. Start the camera cooling via APT
7. Connect APT to the mount
8. At this point use PoleMaster to do a polar align using the ASCOM hand control, finishing with the scope in its park position (counterweight-down and approximately targeting the NCP)
9. Re-aim the scope far away from the NCP and train PHD2. You can delay this step until after you have pointed the scope at your target.
   
10. Sync the mount using APT's Point Craft (I use ASTAP for plate solving---it's amazingly fast and almost never fails to solve!
    
11. Use either Stellarium or APT's Go-To to acquire your imaging target. Do whatever composing you want.
    
12. Start PHD2 guiding or let APT handle things. 
13. Make sure your focus is perfect and start your exposure plan

Basically: power up, start the helper apps, start APT, start camera cooling, do polar align, sync the mount, acquire target, train PHD2, start imaging. If you're using autofocus, insert its setup where appropriate.

Worth noting is that the use of Stellarium (or any planetarium program) is entirely optional. APT provides extensive object lists and has similar Go-To and Sync features---everything you need to image.

FSQ106 First Light Image; Astronomical League Open Cluster Observing Program: A To-Do list for Astro Photography Tools (APT)

At last! My FSQ system was complete and I could take it out for a first light image. Nothing fancy, just a lot of stars. I also made it a point to process it only with PixInsight, replacing ImagesPlus for calibration and reducing my dependence on Photoshop. The image is here at AstroBin. Below is a preview, along with a 1:1 scale of M13 itself. Click each for larger views.

 

 

The image is based on a bit under three hours of LRGB. There's a lot of room for improvement in this image, I know, but it's wildly better than my previous efforts.

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I think one of my first long-term projects for the FSQ is going to be the AL Open Cluster Program list. The AL provides a PDF document listing the 125 objects in the program along with their coordinates which is helpful because quite a few of the clusters are from obscure catalogs like Berkeley, Trumpler, and Dolidze Dzimselejsvili.

I'm using Stellarium and APT to control the G-11 mount. Wouldn't it be nice if there was an observing list of the AL open clusters for one of those so that I could do simple a simple go-to for each object? Unfortunately Stellarium doesn't seem to support user-defined object lists but APT does. 

Some poking around failed to turn up a list. In APT it's fairly easy to create lists by loading objects into the ToDo list. Start by opening the Object Browser. If a cluster is in the Deep Sky list, find and select it, then click the "Add in ToDo" button. If an object isn't in the list, use the ToDo list's Add New button. When you're done creating a list, just export it. The data is put into an easy-to-read XML file.

This is just what I did! If you use APT and want a copy of the list, click this link:

https://app.box.com/s/l3ji97b1ysm3xxvpve2mgud34nv4x34c

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And now a footnote to my last post in which I was saying goodbye to the Nebraska Star Party for a while. I should mention the same applies to the Iowa Star Party. The last two times I've attended that the heat and humidity were incredible. Those were on the Labor Day weekends, and this year it's a week earlier--meaning the probability of excessive heat is even greater. Much as I hate to give up on ISP, I probably won't go back until they move it into late September or October. 

Yes, I know, I won't be missed by either event, and yes, I'm a weather wimp 😄

Goodbye for now, NSP; Spring of 2022 is a no-show; Destroying pocket watches

 Six Nebraska Star Parties and done (for now)

After attending six consecutive NSPs, I think I'm ready call it a done party. The distance, expense, and vagaries of the weather have led me to explore the alternatives of in-state parks and campgrounds. This is not a knock on the NSP itself or its organizers! The 2014 through 2019 NSPs were splendid experiences (aside from the rainy/cloudy years).

Now that the pandemic is winding down thanks to vaccines (I'm double-boostered) it's reasonably safe to travel, so this year I'll be trying a little gem of a park called Niemackl Lake Park. Drive distance is 3 hours compared to 8.5 for NSP. This means in a worst-case situation, it's possible to do a one-day round trip to home in order to retrieve some crucial forgotten item.

Niemackl has about 25 times as much light pollution as NSP, which sounds bad at first. It's more a case of 25 times almost zero. One place I've imaged with good results is in a yellow zone where the added light is about 12 times greater than at Niemackl, so I think it will be fine. 

One minor concern is horizon glow to the southeast from the town of Morris (population 5,300, distance 15 miles). This is much like the case at another former imaging location near Windom (population 4,400, distance 15 miles). Windom generated discernible glow to the SSE, but it was very tolerable; low targets in Sagittarius were essentially unaffected. Having Morris nearby also means retail services are at half the distance of  NSP to Valentine.

Now When will this start to happen? When Spring finally arrives!

Spring of 2022: Not here yet...

We seem to be trapped in a see-saw pattern of a few days of cloudy, well below normal temperatures, followed by a single average-temperature sunny day followed by a couple of days of rain. The tiresome theme is clouds and cold. This morning it was snowing. It was only a few flakes, but it's indicative of how April has been. Pushing up toward the upper 50s by the end of the week, though. And then, if the European long range model suggests, it will probably leap right into summer, complete with 80s. Typical.

...So the winter hobby continues.

I've been destroying pocket watches and hopefully learning a little as I do so. I started with a non-working Elgin and three non-working cylinder movements. The Elgin actually came to life a little, and ran for 15 minutes. I'll be working on that one more now that I have the proper oils. 

The cylinder movements were a complete loss. People say those are difficult to service, and I was simply unable to get the escapements seated properly. I wasn't duped into buying them, I simply was too ignorant to recognize them for what they were.

After that I moved on to more modern movements, a refurbished wristwatch with an Indian movement and a new 6498 clone from China. The Indian movement ran poorly and on inspection it was dirty inside and had a damaged bridge. Cleaning it and fixing the bridge didn't help much. It still runs poorly. I'll work on that again.

The clone is fine, but I made the mistake of taking apart the shockproof jewels for the balance wheel. I cannot get those back together, so while the balance is still able to oscillate there's a lot of looseness. I've ordered a second identical clone and will use that one for an eventual astronomy large-faced wristwatch. 

I've also got a used wristwatch-sized Chinese skeleton movement that comes in a worn hunter style case and runs very well. I'll eventually strip that down and re-oil it. 

I've been prowling antiques stores for pocket watches but have purchased nothing. The pocket watches they sell are all working and priced like it. This is great for collectors, but I'm still in the non-working realm of watch servicing. Perfectly satisfactory are movements that don't run but have intact balances. My hope is that flea markets and estate sales may prove the best source for these.

FSQ-106 arrives; a new hobby for winter

As the pandemic slogs on with a second flavor of Omicron and war rages (ha ha, I meant of course a "special military operation" per war criminal Putin) there's a little bit of good news.

The FSQ arrived in early January. I'll spare you the unboxing video I didn't make, but I have to say the way Takahashi packages their scopes is nothing short of amazing. Three boxes in one, fitted together with almost surgical precision. Because it's been winter outside I've yet to take the scope out for any sort of star testing. What I am doing is getting it all accessorized. (Pictures to follow eventually.)

First, a Pegasus FocusCube. This went on easily and works just fine. Next, a Pegasus Powerbox Advance riding a dovetail bar fit into a new finder shoe. Finally, the guide scope on a bar that slips into the handlebar spanning the Primalucelab tube rings. 

The next step was putting it on a Losmandy D plate, adding the ASI 2600 + filter wheel combo and getting it to balance on the G-11. This took a little finagling (largely the creation of 1/8th inch risers to provide a touch more clearance between the scope and dovetail).

Once it was balanced it was cable time, so I connected everything through the PowerBox and did a little testing. ASI imaging camera + filter wheel, QHY guide camera, PoleMaster, FocusCube, G-11, PHD2, APT: Everything worked in harmony. The only thing I didn't test were the dew straps, but I'll do another dry run in March and verify their operation.

Lastly, I did some box-crazy myself. I got a Seagull hard shipping cases for the FSQ and the ASI. The old AT65 went into an old tool box, and with the SBIG ST-8300 sold I used its case as home for my modded Canon DSLR.

So basically, everything is boxed and ready for the highway. All I need is warmer weather.

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One problem with winter is that I tend to shut down my astronomy hobby in the cold. When I was younger and doing strictly visual astronomy I didn't mind going out when temperatures were in the teens or single digits F. 

When I started imaging that changed. Cables get very stiff in the cold, and the required fiddling with fingers leaves them stiff, too. I had thought that I might do mirror making during winter, but my work area (at a perpetual 65F during winter) produces hard pitch and figuring is difficult. So this year I decided to make a bold leap and find a non-astronomy winter hobby!

When my mother died in February of 2021, I inherited a couple of family heirlooms. The one I value most is a pocket watch owned by my great great grandfather. Amazingly it still runs, but I knew that it had probably sat in safe deposit boxes for over 50 years and was badly in need of service. I found a watch repair shop ( a real one, not just a place that changes batteries in quartz watches) and set them to work in April 2021. Ten months later the watch has been cleaned and oiled, but the watchmaker has been working on repairing a broken piece that is used for setting the time. Because this watch is very old and of unknown manufacture replacement pieces are impossible to find; instead, pieces must be fabricated.

During the long wait I wondered what was involved in servicing mechanical watches and found some videos on YouTube showing the process. They were fascinating. Many videos later I decided I'd like to try this and started gathering the needed baseline set of tools. I've already dismantled several old pocket watches (none of which were running) for practice, and actually coaxed two of them back to almost running. I know, "almost running" is the same as "not running," but it was fun and I learned some things. Next, I'm going to work on disassembling/reassembling running inexpensive Chinese and Indian movements.

You may think amateur watch servicing is nothing like astrophotography, but you would be wrong. Both:

• Require expensive, specialized, and breakable hardware -- you would not believe how expensive watchmaking tools are
  
• Considerable experience
• Are largely fading hobbies
• Are mainly practiced by older men

There are a lot of differences, of course,  but fun is fun. And so is staying inside during winter.

Canon lens and the ASI 2600MM

In the previous post I suggested a configuration to use in mating DSLR lenses to the ASI 2600MM camera + ZWO 7x36mm EFW. A first test of this has been done, with good results. Here's a simple stack/stretch of some Heart Nebula H alpha data taken using an old Olympus lens with a Canon adapter, mated to the ASI with a thin Canon to M42 adapter + thin spacer rings for 1.4mm

Things to be aware of are 

• The wind was gusting to 30mph the entire time data were being collected.
  
• North is to the right; you can see a substantial drift in RA probably because this is a temporary rig and utterly out of RA balance (PHD was squawking a lot) 
• Focus was far from perfect
• This was 2x2 in-camera binned and roughly calibrated using dark frames from 10C cooler calibration, no flats, no bias. 
• Stretch was just the PixInsight STF
  

Evidence of the drift is seen along the top (west) edge of the image where there is a thin band of partial coverage. As a result of the probable bouncing due to PHD's problems we expect stars to elongate in RA during the ten-minute exposures, and that's just what we see in this composite image of the center and four corners:

 The center shows the poor focus and evidence of the RA drift. (RA drift is in the vertical.) 

Stars at the corners compare well with the center stars. While they show the same soft focus and RA elongation, there's no evidence of aberrations resulting from improper spacing between lens and sensor. 

Sharper focus might well show defects, but this is not bad for a windy night, no balance, and a $40 Olympus 200mm f/4 lens (stopped down to f/5.4).

And one last little observation about the pricing of astro gear. The Canon lens adapter for my SBIG ST-8300 cost me $300. Things were far less expensive for the ASI. The Canon/M42 adapter plus the thin spacing rings came to $75. Over half of that was for the general purpose rings that will see duty in additional ways.