A single unprocessed subframe of the Rosette Nebula, Canon 6D and TV-76mm, 240s @ ISO6400After solving the little equipment issues, waiting out weeks of bad weather and waiting for the Moon to go away, I finally had a nice photographic night. Setting up at sunset I shot until the Moon rose. Most of the targets I have shot before, Orion, Rosette, Markarian’s Chain. I also shot Melotte 111, an object that has always intrigued me. The full frame camera and the TV-76 has a wide enough field to capture this very large and nearby star cluster.
I want to use this combination camera and telescope with a very wide field to work over the dark nebulae of the Summer Milky Way. With 384mm focal length the full frame camera gives me over 5.35° x 3.56° field of view. The beehive also lent itself to the wide field, another large object that was worth a stop to shoot.
Aside from one little equipment issue to start, more an operator education issue, the gear worked great. Note to self… Must turn off camera WiFi before the camera will link to the computer via USB. I am currently using APT to control the camera, a very impressive bit of software. The auto-guider worked perfectly, frame after frame nearly identical. I can slideshow through dozens of sub-frames and not see any difference, no drift!
A single sub-frame of the Rosette Nebula is shown to the right. The Rosette is an emission nebula with most of the light emitted at the wavelength of Hα 656.28 nm. My Canon 6D is stock, no astrophoto modifications. Despite an IR cutoff filter that blocks much of the Hα light the camera captures a fair amount of the nebula. Perhaps I should get a 48mm Hα filter for the camera to shoot from the driveway.
With everything working so well I really need to haul the rig up to Hale Pohaku for a night of imaging under darker skies than I get down at 1000ft. Next weekend is dark-of-the-Moon weekend. Need to plan an outing?
It will take a bit to process the results of the night. As usual, keep an eye here on Darker View for the finished photos.
The plan was simple. Stay on the summit after work to do some nighttime scenic photography.
I was hesitant in going up after suffering my recent ear infection. The ear is vastly better, no problems with clearing the ear for several days. After two weeks absence the list of things I needed to get done on the summit was getting lengthy and urgent. Yet I worried a bit about going up. An idea… Take my own vehicle. If I have trouble I can go at my own pace without holding up the rest of the guys. If the trouble is serious I can abort and head back down.
If I did bring my own vehicle I could get in a little photography along the way. I had not really had a chance to try out the Rokinon 14mm f/2.8 lens I had bought specifically for starry sky work. Why not stay late, watch sunset and take a few photos after dark? There is snow on the summit, the weather looked promising, the Moon would not rise until after 10pm, all good things.
The plan worked as envisioned. A good day getting stuff done. Actually a rather hectic day. The filter wheel problem of TRICK found and eliminated, the heater circuit at least looked at, I think the problem is still there. Warping data recorded for a segment in Keck 2 for the refurbishment project. Some wiring on TBAD completed, still more to do. An issue with the Keck 2 interlocks that popped up during the day was dealt with. Yes, a very good day.
A minimal dinner of instant ramen, and some paperwork accomplished while waiting for sunset.
Into the cold dark I go… The combination of the Canon 6D and the fast 14mm lens is impressive. This gear will really allow me to step up my game. I was able to shoot great material under very dark conditions. Photos that had been just out of reach for me until now. It will take me a couple days to go through and process the material, but a first look is very pleasing.
Only one problem… What is this red stuff showing up in my photos? Normal airglow is green, but this is crimson red and has very distinct structure? The idea of aurora crosses my mind, almost immediately dismissed as I am standing at 20°N latitude. I step away from the camera and the light for a bit. With some effort I can convince myself that I am seeing red in the sky, at least in the darker areas away from the Milky Way. But it is fleeting, and perhaps just an overactive desire to see something.
I get home and just out of curiosity I check the planetary Kp index… What?!? We have a Kp=6 geomagnetic storm in progress! Beautiful aurora photos are being posted from the upper midwest. Reports of aurora from across much of the United States. There is certainly a dramatic storm in progress. Perhaps this is a low latitude auroral glow!
It is a nice photo. You can see the glow from the lava lake at Halemaʻumaʻu, the winter Milky Way, and a research laser shining straight up from the atmospheric lab atop Mauna Loa.
Airglow or auroral glow? An odd red glow in the photos during a strong geomagnetic storm.
Focus is one of the most frustrating problems when shooting in the dark. The number of astrophotos ruined by poor focus is legion. Worse, the problem is often not found until afterwards, when hours of effort have been wasted. Very slight errors in focus can spoil an otherwise great photo.
Taking photos in the dark creates a situation where the normal solutions do not work… Autofocus simply will not operate without enough light. Taking the lens off and attaching the camera to a telescope results in a completely manual focus. Simply focusing through the viewfinder is not accurate enough.
A Bahtinov focusing mask in use on the front of the AT6RC telescopeThe simplest method of focusing in the dark is to use the live view feature of the camera. By placing a bright star or distant streetlight in the view and magnifying you can achieve a reasonably good focus much of the time. This is not perfect, even the magnified image is a little mushy near ideal focus, making perfect focus difficult to judge. If you find yourself in an after-dark situation, without any special equipment along, this is the method to use.
Do remember to switch off the autofocus feature of your lens. Once you get focus set correctly you do not want to lose it the moment you touch the shutter button. Not that I have ever done that… Never? Well, perhaps maybe.
The brightest nearby supernova in may years is currently visible in the bright galaxy M82. I did want to photograph the supernova before it fades much more. It apparently reached a maximum brightness of magnitude 10.5 a few days ago and is starting to dim. But has so far only slid a few tenths of a magnitude.
So I tried to photograph a supernova, and Murphy came to visit.
The last week has seen me dealing with a sinus infection, which combined with terrible weather has kept me from setting up in the driveway for photography. Taking advantage of a few clear hours last night I did make an attempt. Things continued to go wrong.
A high thin haze would not go away, lit up by the light of a bright quarter moon it created high background and gradients in the imagery that would not calibrate out. I forgot to install the LPS filter, meaning that the low pressure sodium lighting of the village compounded the moonlight in creating a poor signal to noise and bad gradients. The autoguider would not behave. This was eventually solved by adjusting the tuning parameters in PHD guide. Not before ruining most of my exposures, I ended up throwing out 24 of 32 exposures. When I did get everything figured out and corrected, and the Moon had fianlly set, the clouds rolled back in.
The final eight usable exposures did result in a somewhat acceptable final product. It could have been so much better…
The galaxies M81 & M82 with SN2014J seen in the disk M82 at top
All sky-watchers are hoping that comet ISON is spectacular when it emerges from the solar glare. there is no guarantee on this, we just do not know. But it could be as pretty as comet Ikeya-Seki or comet McNaught, both of which became far brighter after perihelion passage.
An ohia tree silhouetted against the dawn in the SaddleIf this does happen the question is where to go to photograph the comet. A week ago I found that ISON was slightly behind the ridge from the Mauna Kea VIS. Not badly, but enough to delay when I could acquire the comet and start taking photos.
This recent Saturday I only went partway up the Mauna Kea access road, just high enough to be clear of the clouds and haze. There is a turnoff on the east side of the road just above the cattle guard at about 8,000 ft, one mile below Hale Pohaku. Plenty of room to park a vehicle or two and plenty of level ground to take photos from.
Astrophotography is not normally a daytime activity, but there are exceptions. If a comet is bright enough, about magnitude -2 or brighter, it is possible to spot the comet in the middle of the day. Comet C/2012 S1 ISON may very well be visible near the Sun in the middle of the day.
C/2006 P1 McNaught while 5° from the Sun on Jan 14,2007The comet will pass through perihelion on November 28th. At a mere 1,860,000km (1,150,000miles) this will be a close pass indeed. As perihelion is measured from center to center, the distance is even closer if you consider the 695,500km (432,200mile) radius of the Sun. Subtracting the solar radius you realize the comet will pass a mere 1,165,000km (724,000miles) above the surface of the Sun. At this distance the intensity of the solar radiation will be nineteen thousand times more intense than a sunny day on Earth.
This sort of solar intensity will cause the comet to emit enormous amounts of gas and dust. It is this cloud of material around the comet, the coma and tail, reflecting the sunlight that makes the comet bright.
Not quite the dramatic comet in the dawn shot I was hoping for. The comet is just barely able to compete with the dawn glow. Still, a beautiful morning.
Waiting to see what fate holds in store for this dirty snowball as it travels through the hell of the solar corona. I will try another photo session after perihelion.
Comet C/2012 S1 ISON, Mercury and Saturn in the dawn over Hilo
