Imaging Saturn

One of the things I’m learning is that it is hard to keep up with processing images when one collects 10GB in one night, and does not have the right tools (computer; stacking software) to do the job best. The other thing I’m coming to terms with is that despite having spent several years working against technique in photography and camerawork, this project simply demands that I pay closer attention (than, say, Blurry Canada demanded).

I spent 5 days at the CAO last weekend, driving up on Thursday to join Millie and Dietmar, then Ian. Before night fall I played with the Arduino and since the skies weren’t too clear we watched Hugo and I did my best to stay up late so that I wouldn’t be foiled by midnight on Friday, which had a really good forecast. I managed to sleep in until almost 11am, and once Blake arrive we walked part of the Lorree Forest Bruce Trail.

Friday night was busy. Ian started up the 14″ and opened the DBO roof early and I managed to capture some hand-held projection images during dusk with Saturn against a pretty blue sky [not sure which eyepiece was used].

These above are the same shot, horizontally flipped and rotated to match the real position of the planet in the sky, and the bottom one modified in Pshop to bring out some planet detail.

Ian and Blake helped set me up to shoot on the 14″ in the DBO, and I captured a lot of footage using my dSLR and CCD cam. I haven’t come close to processing any stacks, but here’s one dSLR still that I captured, with little modification:

And another, the the luminance, colour temperature, and levels modified, with a crop and flip:

I set up my 8″ behind the 14″ and jumped back and forth to observe (Millie and I had quite a time trying to identify which moons we saw; there was a lovely triangular formation, but we figure one point must have been a star). Blake brought his dew heaters for me to use (thanks!), and rightfully because it was just soaking wet out there. I’ll have to buy some when I visit KW scope next week (I’m giving a presentation, Sketching Saturn and the Milky Way, at the KW RASC club on Friday, June 28th, in lieu of making it to the General Assembly in Thunder Bay).

I spent a bit of time yesterday with a short dSLR video clip and Keith’s image stacker, and while Keith’s served me well for my 2012 image, I really truly need a PC so that I can use Registax. So, no sample stacks just yet, though as I mentioned I have several GBs worth of footage to work with in the dead of the SK winter….

Steve McKinney inspired me to try some wide-field dSLR photos of the milky way, and also some time lapse. I need to play closer attention to all my settings, obviously, but I spent all day Monday reading the manual and playing around. I am still quite annoyed by the new Nikon lenses and cameras: there is no subject distance focus ring on the lens, and while the metadata will record details on subject distance that can be read after shooting (I use Bridge), there is absolutely no way, while shooting, to learn this figure in-camera. The focus ring doesn’t just ‘go beyond infinity’ – there is no infinity. The ring spins freely and endlessly in both directions, and the small catch, which can by spun over, changes position between AF and MF, i.e. the AF does not have a zero ring position which can be physically inferred when manually focusing. It’s really annoying. So, as you can see, none of the shots that I took are anywhere near in-focus. The solution is either: set focus to infinity in a lighted environment, and tape the lens in place; or shoot, view the metadata (power down, remove the card, put it in my mac, open the file) on successive files to try to get closer to infinity in the moment. Another possibility is to buy Lightroom (which I am uncertain will show me this information, anyone?) or, more expensive, the Nikon Camera Control 2 Pro software (can anyone explain why Capture NX 2 is preferable?), to control the entire camera using the laptop, including, presumably, focus.

So, here are the two ‘best’ galaxy shots (one unmodified, one slightly tweaked). Dietmar suggested a colour temperature for shooting this kind of subject, but I forget (3400k??). He also suggested stacking. And a fun one of Ian and me in the GBO.

Finally, for those who didn’t see my links on the list-serves, I saw an amazing storm Monday evening.

I didn’t manage to capture any images using my 8″ at the CAO, but I did set up at the DDO last night and collected a lot! That’s for another post….

Okay. The parallel circuit. The switches must be on the same row as the LED. The LED cathode is ground, and the ground is on the same row as the parallel circuit and the resistor. The resistor is connected to the switch, which is connected to the front foot of the 2nd switch, the back foot of which is connected to the LED anode:

I’ll try to make a second pair of parallel circuits…. nothing out of the ordinary (just don’t forget the 2nd ground)….

Project 2: Spaceship Interface. AKA making LEDs blink and change states when controlling an input sensor.

Instead of being instructed to download the code, or merely open it from the available sketches that come with the application, this starter kit book of projects walks the user through writing the code itself. Guard against inserting extra spaces, or using a – instead of a =. Since this wordpress site won’t permit video, click here to see the results. I inserted a standing HIGH delay for one of the red LEDs as well.

Up at the CAO I did Project 3, love-o-meter, but no pics. I had to tweak the temp baseline in the code, and used the pre-made code because I didn’t have enough time to correct my hand typed code before the sun went down and it was time to go outside to look up. That’s the next post… [will do Project 3 again more slowly].

Blake spent some time on Saturday movie night (007 Skyfall) to play with the Arduino himself: CAO Astro Arduino Rainy Day Crafting Group. Yup.

In any event, my SSHRC grant received 4A status (recommended but not funded), so I’m glad I’m self-learning Arduino as a start, and still hopeful the CCA grant will come through so that I can hire Rob and John to help, and be able to pay for my Video Pool residency next year.

After six days of travel by car my body is a right mess, but I made it to the Blue Mountains of Ontario in one piece (dodged four moose on the drive between TBay and the Soo!). The E.C. Carr Astronomical Observatory (CAO) is owned and operated by the RASC Toronto Centre, and fully accessible to all members with nominal day rates or a really inexpensive yearly pass of $75.

I worked out my first visit from afar, thanks to Blake N, and Phil and Lora C, who have been wonderfully welcoming! Let me just say this place is fabulous, and exactly what I needed to wind down such a busy academic year and begin my summer of Saturn chasing.

Phil offered that I set up my CGEM in the main observatory, since noone last night was using the scope in there, and there was plenty of room. Phil confirmed that probably I am being too finicky with polar alignment given that the computerized mount will run an efficient routine – but darn it, now that I know how to use that polar finder scope, I’m being stubborn about using it. Phil also gave me some tips on general handling and maneuvering, which is extremely helpful.

Everything was fine until I powered up the mount to run through the 2-star alignment routine. The scope kept slewing to nothing (thinking it was slewing to something), and this reminded me of my Wrong Silo Blues experience. Turns out I had both the time zone and standard/savings settings mixed up, and with that sorted out, all was well. I didn’t manage to post two weeks ago when I visited the URegina Lifelong Learning Centre and gave a lecture on astro-sketching to Chris Beckett’s class. Mike O and I each set up outside and I managed to run through the whole routine on my own without assistance, so that was a huge breakthrough for me.

Saturn is so pretty. Dietmar and Phil joked with me about how *not* good the viewing conditions were, but everything is such a wonder to me that I don’t quite care yet. I could make out banding on the planet, and the Cassini Division would pop in and out of resolution, with the 24mm, and the 12mm (though too much magnification for the skies). I thought I could make out the subtlest hint of ring shadow on the planet, just a subtle and thin dark line, but Dietmar was unconvinced (averted imaginary vision is what I think he called it :)).

Millie suggest some Messier objects; we began with M13, with the 12mm, but quickly changed to the 24mm for more context, as Phil suggested. What a pretty sprinkling of globular nebular stars! We also looked at M57. In the picture linked < M57, a planetary nebula, is quite contrasty, but in the scope it was diffuse and really flat. The first glimpse I took I could make out the donut shape and inner circle with great clarity, but the more I looked, the harder it was to see (a very odd characteristic of vision, might as my optometrist about this).

I attached my camera at prime and took a couple of snaps (will go grab the card…not worth posting), and by the time I re-attached the hyp24 and camera the clouds rolled in. I am very frustrated with the Nikon T-ring: it does not attach/unattach from the bayonette mount as easily as it should and I worry that I might be damaging the camera. Will need to take a better look in daylight.

I learned how to hybernate my cgem, and I suppose I’ll find out tonight how well that works, if I don’t need to relocate my scope (since more members are joining us here today).

All that in a day, from the Soo to the CAO. It is fantastic here. And I wonder what the seeing will be like tonight!

Anyone who has been following my blog, or the CGEM yahoo group, might know that I have had a really tough time comprehending polar alignment – both the full principles, and the actual technique.

I mean – it’s not hard to comprehend the part about the mount needing to be aligned with the north celestial pole in order for the scope to be able to track in compensation for the earth’s rotation. But what this means, fully, for a german equatorial mount is another thing, and understanding the various techniques and their different functions and applications can be really, truly hard for a newcomer.

I think I’ve got it, though, and the key is summed up in this: The entire purpose of Polar Alignment is to get the altitude and azimuth axes into position. Thus, the  ‘home position’ for RA/DEC (i.e. those lined up arrows) becomes relevant for tracking only relative to accurately positioned alt/az axes.

The Polar Axis Finder instructions are fine – if read and re-read thoroughly. But it leaves out the most important step/concept in being able to move to the Hand Controller (HC) and run through the 2-star alignment procedure (with however many calibration stars), or the “All-Star” procedure (p37 of the manual) once Polar Alignment has been achieved using the polar finder scope: Return the RA/DEC axes to the ‘home position’ i.e. with all the arrows aligned.

The alt-az axes need to be in position for the home position to be useful.

So the step by step routine (assuming that the Optical Axis of the Polar Scope has been aligned already):

1. Rough align the tripod north, and level.
2. Many recommend against assembling the OTA fully at this point: for both weight and range of motion. Some suggest a full assembly to avoid messing up polar alignment, since the full weight can cause bowing in the tripod legs. I’ll have to see which works for me.
3. The Latitude Scale should be set to your latitude.
4. Rotate DEC so that you can see through the bore hole.
5. – rotate the RA axis until the big dipper (northern hemisphere) is in the same orientation within the polar axis finder scope reticule as it is within the sky. This is a nice video.
   – Another method is to control the rotation of RA according to the RA setting circle and polar finder scope metal collar with hour angles on it. My scope does not have an RA setting circle, so the collar is useless. Here is a good link that Gary A. emailed that describes it, along with the rest of the routine.
   – Yet another method is the Kochab’s Clock method, described here. With this method, line up Polaris and Kochab along the unloaded counterweight bar.
   
6. Adjust the alt/azimuth axes until Polaris is within the small circle meant for it. Then lock them down.
7. Return the RA and DEC to home (in bold because this is the part that kept tripping me up). Power up the scope, and run through the 2-star alignment, and then, if preferred, the “All Star” procedures.
8. (Kevin adds something about re-calibration at this stage, and ‘display align’, but I’m not there yet in my learning curve!)

That is it. Of course, I’ll post again on the topic when the snow melts and the temperature is above freezing.