Saturday, August 01, 2015

trails - behind the scenes

Readied for my double star "streak" experiments...

Earlier today I had tested the new custom focuser cable, with the USB-serial adapter. It worked! It was still through the portal between the observing floor and Warm Room of the Geoff Brown Observatory. It was still connected to the Dell mount control computer.

Also in the day time, I had put some red film pieces (thank you Babybel!) on various objects and now, in the dark, I was able to assess. The Pyramid DC power supply with green power-on LED looked good. The Paramount RA and Dec motor indicators I had covered. It was hard to tell if this was better with the stupid bright Moon... The UPS and power supply at the pier looked fine. The surge protector in the Warm Room looked good.

Spent about 15 or 20 minutes preparing for photography. Some of the steps were the same; some were new. Connected the camera to the USB-ethernet adapter using the Warm Room portal. Had the camera powered with the DC coupler. I had the Canon EOS software up and running. Created a new image storage folder. Slewed to Albireo, centred, and was ready to capture. Camera tethered.

Fri 31 Jul 2015, 11:22 PM. Somewhat clear, patchy clouds, lightly scattered clouds here and there.

While I had added some red film to the USB-ethernet adapter, it was still not enough. Crazy bright blue LED! I made a note to add another layer.

Did a quick check of the focuser: launched the Optec app and saw it reading the hand box. Issued some commands. All was well. This will be a first! Focusing from the comfort of the Warm Room. I was excited.

Performed a crude centering with the refractor and focusing at the SCT.

Checked the east-west orientation. It was off, about 45°. I wanted to turn the camera, one way or another. That being said, it was not my objective to make it perfect. Turned it counter-clockwise. Oops. Now it was up and down. Turned 90°. Looked nice. Sheesh. Nearly perfect! OK. Turned on the gridlines in EOS Utility and saw it rising slightly.

Warmer tonight. Too many layers?

11:27 PM. Readied to time the drift. Considered the using the tablet when I remembered I had not yet cut a piece of red film. Rasalgethi was about 1 minute 20. Opened the Windows clock. Turned off the tracking in TheSky 6. Oops. Placed the star on the wrong edge of the frame. Test time. Viewed the star, stopped tracking, and it drifted to the right. Drifting to the west. Confused the Motion Control buttons. When I press the on-screen button, I'm telling the mount the direction I want to go. W means go west. Tried again. Nothing showed up. Something wasn't right. It looked like the tracking had turned itself back on... Moved west again, star just off the edge, started, saw the stars. OK! At 45 seconds, it looked like it was about half way; I predicted 90 seconds for the entire drift. First star gone, second star gone, 92 seconds. Turned tracking back on. Moved west again, this time at 8 times.

Centred the stars and zoomed for focusing. 200%. Stars looked out of focus. Maximised on the large monitor. I had pre-set the Optec TCF-S in the middle of its range, i.e. 3500 of 7000. Step the jump to 100 units. Focused in. The image was worse. I could see the central obstruction at 3200. Focused out. 3300, 3400, it was better. Lovely not having image shift! Then 3600. 3700 improved. 3800 looked better still. 3900 was worse. Made the step more granular, 50 units. 3850. Then 10 units. Bad seeing. I was starting to have a hard time telling the difference. This is where Backyard would be good, measuring it mathematically. Getting worse. Switched to in. 3840. Back to 3850. Hard to tell. Good enough. Turned the focuser to automatic mode. It showed the temperature was 15.8.

I was worried about now changing the focus but the In and Out buttons deactivate in Auto mode. Good.

Zoomed out in EU and slewed west.

Turned off Live View. Programmed an imaging run. Didn't bother with a Delay value. Entered a capture duration of 1 minute 40. Of course, EU wanted me to set a minimum of two runs. The Interval time was a high value so I left it. Started the capture run. Turned off tracking.

I didn't see any image. Huh. I thought I had been able to do this before... A mirror-up setting somewhere? So I was blind. Anyhoo...

I was happy. It was real neat doing all this work in one spot!

11:51. Checked how close I was to the meridian. Shot ended. Downloaded. I spotted the imaging run. Wild! Other stars too! Was hoping that would happen. It was awesome. A lot of noise. Changed the ISO from 1600 to 1000. Forgot to turn the tracking on, in all the excitement. On. Panned west. Readied for the next run.

Looked around for the camera Live View or mirror setting...

I loved the angle. Painting with light. Light that was coming from light years away.

11:56. Finished capture. The 1000 ISO was good. Darker sky. Still some noise but much better. Could still see other stars. Decided to try ISO 800.

Considered the next targets. Coloured doubles. That were really high. Reviewed my SkyTools list for the RASC Observer's Handbook.

Hey! Suddenly noticed that there were a lot of unobserved objects. Over two dozen. Huh. I better get crackin'!

Sat 1 Aug 2015, 12:00 AM. The shot looked good. Darker again. Field stars still visible. Possible more interesting as the main stars in Albireo were burnt out before; now the streaks were thinner. The slight oscillations were more obvious is the 800.

Considered the brightness. That would be a factor in these exposures. 3.1 and 5.4.

Applied aggressive filtering. 57 Aquilae was next.

12:05 AM. Oh. Well left of the meridian. Near the Moon.

Wondered about pointing. If the star was not visible, I'd have to run out to the 'scope. Oh. Wait. I could use the spiral search! Slewed. Nothing obvious. Couldn't remember how to do the spiral search... Well, not in the regular mode. I had used it with the Satellite mode. Checked the Help. Looked in the Telescope, Options. There it is: Star Search... I had the word "spiral" in my mind. Chose the command and the Star Search dialog appeared. Left it at the default settings: Width and Height at 10 arcminutes and Speed at 8 times. Clicked the Start Search button and hovered over the Stop button. Ha. Saw the app drawing a little box pattern... Watched the Canon app. Spotted something. There they are! Brill.

Noted the software pointer at the 2 o'clock orientation and the target just outside the target circle.

Disappeared. Clouds. Stepped out to find a clear patch. Lots of clouds there. Cassiopeia looked good. HR 9094 aka SAO 10937 was an option. Slewed. Watched for cable wrap.

Started the timing run. 30 seconds, 1/6th of the way. Not halfway and over a minute. A slower part of the sky. Half way and 90 seconds. Three minutes. 3:05. 3:10 and it's gone. Back to the west. Programmed a 3 minute 15 shot with a 4 minute interval.

The Aquila region was clear. Could return to it for 57. Headed to the house for a glass of water.

12:22. Finished shooting. Viewed the image. The two lines were close together. Noisy. 800. But a longer time.

Slewed to 57 (via its SAO number). Readied Live View. Readied the Star Search. Tried to find the stars by a visual offset. It worked although I had not consider the zoom level. Started timing. Quicker this time. Really bookin', in fact. 2/3rd and 1 minute. 1:15. 1:20. Tracking on. West. Hurry. Programmed 1:25. Shooting, tracking off.

12:30. Downloaded and viewed. Washed out with the goofy Moon. Fun!

Wondered if I should redo without the Moon. I wondered how that might affect the colours... Certainly it would allow more field stars to show.

Slewed to 59 Ser.

Did some more EOS Utility searching...

Did a Star Search. Brightness OK. But they are really close. What the hell. Nothing to lose. Slewed west—whoa! Other way. Camera upside-down. Started drifting. Looked quick. Half way around 45 seconds. 1 minute. Played with the grid. A minute, 20. EU was already programmed for 1:25. Imaged at 85 seconds.

I wished there was a button in TS6 to turn on or off tracking...

12:44. Downloaded and viewed the next image. Ooo. Nice. Dark sky. Tight. Wow, interesting, with a third star starting (or ending) part-way.

ST3P suggested 11 Aquilae. OK. A wider triple. Slewed.

Still bugging me, the Live View issue. Did some more digging. Tried setting the mirror lock at the camera. Did I have that already in C2? Didn't look right on the computer. Spotted clouds in my target area. In my research, learned that there was a version 3.0 of EU while I had 2.8. Resigned my probing, feeling confused.

1:00. Was having a hard time confirming I was on the right target. Discovered that the secondary was very dim. Oh. OK. Let's see what will happen. Did a timing run. Looked quick. Did not like the 4x6 grid so turned on the 3x3. Looked like it was going to be 90s total. 1:10, 1:15, 1:20, gone. Shooting, tracking off. Considered 90 Her. Green and blue they say. Ha. Slewed to next.

1:06. Previewed 11 Aql. Grey! Ha. Clouds. Reminded me of vapour trails following aircraft... Interesting how it faded in and out... I like it!

Manually repositioned with the offset. Didn't find it. 'Cause there were clouds. Slewed back. Time to kill...

1:10. It was driving me crazy, the Live View matter. Google searches were not working. Looked for the PDF manual in the Canon items folder. Found the quick guide and the full manual. There was a reference to double-clicking in the top-left region of the EU app, a little icon for the mirror up, but it didn't seem to work... A camera-specific option, the full guide suggested. Checked the mirror lock state in the 40D camera. Gah. Can't do anything when Live View is on. Turned it off. Enabled lock-up in the camera proper. Now EOS Utility showed a message, in red print no less: Mirror Up Now Set. Tried Live View. A note in the guide made me wonder if it would not work in the C custom modes; I switched to M. Live View on, again. But I could not program the interval timing option! It was locked out...

Light bulb! I could shoot immediately. OK, good. But not exposures longer than 30 seconds. And then it hit me. The double star images from a couple of weeks back I had been shooting fast, typically fractions of a second or just a few seconds. Here, now, tonight, I was going minutes, well over 30 seconds, which is, obviously, beyond the camera body's capabilities. Disappointing but now I knew why it was acting that way.

Headed back to the camera and put it back in C1. Reset. Back to ISO 800. But still no stars.

Similar brightnesses. One magnitude different. I noted these stars would be on top of one another. Tight. Almost horizontal or inline with my long edge. I realised I would not get the full effect with the traces. I went out to rotate the camera, gently turning it about 45°.

There was still a big cloud in my target area.

Ah. I goofed. Of course, turning the camera doesn't do anything! That is the position angle in the sky. All I did was change the streak angle on the camera chip.

Tried a timing run but clouds blotted the star part way. I was blind. Stopped the test. Did a another test, almost 1½ minutes. Started shooting for 90 seconds.

Another idea I considered was an open cluster, with lots of brighter stars. That could be very interesting. Used SkyTools Pro Power Search: open clusters greater than 5. The short list had three. Ah, Stephenson 1 in Lyra.

1:36. Nice. Freaky. Cool! I liked it. Lots of jiggling in the wind. Wow.

Slewed to the area. I presumed I landed on the δ (delta) 2 star. Turned the camera back a little bit. Programmed a 1 minute 30 run.

Was feeling a bit tired... Oh. The multi-star system in the Trifid.

1:43. Amazing. Fantastic, rich colours. So fun. The parallel patterns, if that's the right way to describe it.

This was a really interesting thing. I knew what to expect, in terms of the general appearance, from the drift aligning process. And I had a sense that coloured doubles would be interesting. But my expectations were exceeded. I look forward to do some more of these, with more coloured stars, perhaps some M-class targets, like μ (mu) Cephei, and some denser clusters. And without the imposing Moon. I haven't had this much fun ever during a full Moon!


During this session, I kept hitting the incorrect button on the Sony. I ended up not splitting the single 3 hour audio record! Oops.


Add the "spiral" star search to the TheSky software page.

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