Friday, 14 December 2018

Spotlight display with diffuse and Tricker arcs

The diamond dust season has begun in the Czech Republic and on the night between 13th and 14th December it showed what it can do. Temperatures were droping below -10°C in many places, and with a fairly strong temperature inversion (+4,5°C with 300 metres), freezing fogs were forecast - humidity was very high.

The pictures were taken in Velké Karlovice near Kyčerka ski centre. A place I've been to a few times already. And it has its reason. There is another ski centre Karolinka located nearly 4 km from Kyčerka, and while Kyčerka is making halos like crazy, Karolinka is as dry as a bone. This time it wasn't any different. Although it took some time, the snow guns were able to create a marvelous display, one I've never seen in the spotlight before.

I arrived at Kyčerka sometime around 21:00 UTC and until 22:00 UTC, the halo making process was at a threshold. Wind was still blowing a little bit and the halos were changing between beautiful tangent arcs and weak light pillars within minutes. Then the wind calmed down and the valley was beginning to be engulfed in an ice fog.

I set up my spotlight and what I see is amazing. Beautiful and bright upper tangent arc with sharp helic arc is visible. I see Tape arcs as well, though not that well defined. But what I saw in the anthelic region amazed me the most. There was a clear and bright arc hovering above my shadow. Clearly, the Parry oriented crystals made sure the Tricker arc is nicely visible. What I didn't realize was that diffuse arcs were there, too. I saw them after I was looking at the photos in my computer.

It was really freezing and my hands and feet started to feel numb from constantly standing in the light beam. After I took the photos, I sped to my car to warm up, circled the valley for a bit to see if things have changed and then made a decision to go home, because I was tired and slowly transforming into a popsicle.

Next time I plan to place the lamp in a higher elevation for more halo forms to show up. And maybe update my spotlight a little bit, it has too wide beam, which illuminates the snow cover. I wasn't able to find a decent spotlight with a tight beam though, so I'll keep looking.

Diffuse arcs with Tricker arc, helic arc and maybe a hint of Wegener

Diffuse arcs with Tricker arc, helic arc and maybe a hint of Wegener (B-R processed)

UTA, Parry arc, helic arc, Tape arcs etc.


  1. Great work, Matej! You have captured some beautiful images and winter hasn't even arrived yet. Can anyone recommend a spotlight with a tighter beam?

  2. Nice looking display and yes a tight beam will work better

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  4. I have Cyclops Thor. I seem to find for sale now only Cyclops C18MIL Thor X Colossus, which may be a bit bigger than the one I have. You have to get also 75W or so HID for it. That's what I have, and 100W ballast to start it. 6000K temp for the bulb. It is good if the bulb has supporting structures only one side. Less shadows in the beam. My lamp has H4 fitting but there seemed to be no proper H4 bulbs so we modded the lamp to take in H6 bulb. If you do that, make sure you adjust the position of the bulb so that the beam is as tight as possible. The spot in my lamp is really tight. It is also asymmetric and it was really difficult (often next to impossible when the distance was small) to center the camera so that you would get symmetric display.

    And yeah, you need car batteries to power it. You don't want to lose power after 20 minutes when the display has just reached it peak.

    Well, maybe you want to stick with led after reading all that. Led should anyway be the future, while hid is a dying thing. Maybe there are leds with tight beam.

    As for the display you photographed, the Tricker is almost nonexistent loop there. What you have there is a kind of intermediary form of diffuse arc and subanthelic arc. The Parry crystals are rotating some 5 degrees or so. The brightening in the diffuse arc is a sign of subanthelic arc.

    Dress well and be there as long as it lasts. You never know what turn the display takes and even crappy looking display can give out weird stuff.

  5. Would something like this be any use,

    There are several torches now which put out over 50000 lumens but most have a wide beam. The one above seems extremely tight and focussed....and you don't need a car battery!

  6. Guys thank you very much for corrections and new ideas! I think I'll go with the LED Acebeam that Alec send.

    New cold spell is expected to arrive somewhere around 3rd January so I'll be ready to shoot some more halos, still with the old spotlight though. Anyway I will take your advice Marko, and perhaps going to do something different - arrive a little later so I can take photos of spotlight halos and then wait for the sunrise to see if any crystal swarms stay until the Sun rises and take photos of the Sun display, too. And this time I'll take two pairs of gloves with me.

  7. Yeah, if you see the trouble to do it, why not do it well? Make also a blocker so you can breath more. Use the widest lens and nothing else. You don't know in what part of the sky the Grek arc lurks.

    In Finland I would not arrive late as the start is often the best (saturations are not yet too high to crap the crystals). But in Czech mountains rules are probably different.

    Right, hids are dinosaur technology. I'll be interested to see how the led lamp Alec told about works. But it may still be that the lamp battery is not enough. It is cold and batteries go out faster.

  8. Here is my blocker contraption:
    It is a bit modified version of Luomanen's blocker. It's got three parts:
    Car jump starter jaws, a bending thing in between and a telescopic pole.

    In action, at the end of the pole there is a larger disk than what's there now. It was quite handy and the metal jaws grip well onto tripod leg. But reflections from the metal gave lens flares, which is why I painted the blocker matte black. It didn't help, the only way to avoid the flares seemed to be for the blocker to come up from the leg of the tripod quite steeply.

    The bending metal rod was originally a part of magnifying lens that one can attach to a table. It was bought from some cheap items shop.