Wednesday, 22 March 2017

The Earliest Known Photograph of a Halo

Following the publication of the recent Kertész post, a lively discussion ensued as to what is the earliest known photograph of a halo, either in black and white or colour? This brought to mind Marko's post on his blog submoon, about the first recorded halo from Lowitz orientation with a 315/325 raypath. In that post, he includes a photograph taken by Paul Schultz on a 1905-06 expedition to Alaska and later reproduced in the book Ten Thousand Miles with a Dog Sled by Archdeacon Stuck (Scribner's, 1914),


Very recently, I also had the great fortune to come across a book, Cloud Studies by Arthur W. Clayden, (John Murray, London, 1905) which includes two photographs of halos. The first shows a 22° halo which exhibits a thickening around the area of the upper tangent arc and a second one which shows a section of the parhelic circle. Considering the book may have been in preparation some time prior to publication, these images might even be slightly older.



Now the question I would like to pose is can these really be the earliest photographs of halos ever taken? I have an extremely hard time believing this to be the case. My gut feeling is that earlier examples must be in existence somewhere. Photography had been around for nearly eighty years when these photographs were taken. The first black and white image was produced  in 1826-7 and the first colour image in 1861. The quality of photographic equipment and technique had been refined to such an extent by this time that high quality images were able to be produced by the average photographer. However, in the hands of a skilled practitioner, large format plates coated with slow emulsions were capable of recording some of the finest images that have ever been produced, exhibiting the most exquisite detail and tonality. In the following examples of early photographs, we see that the clouds and the sky play a principal or prominent part in their composition,

Sky Study, Paris, Charles Marville, 1856-7. © Metropolitan Museum of Art.
September Clouds, Roger Fenton, 1859.
Seascape at Night, Henry Peach Robinson, 1870.
So here is where I hand the investigation over to you to play detective. The bar has been temporarily set at 1905, but I am quietly confident that with a little effort we can push the timeline back into the nineteenth century and even further, possibly back towards the 1850's and 1860's. One last sobering thought to bear in mind. The very first photograph ever to be taken was View from the Window at Le Gras by Joseph Nicéphore Niépce in 1826-7 and was taken from a vantage point looking out on to the open sky which could potentially have contained a halo.

View from the Window at Le Gras, Joseph Nicéphore Niépce, 1826-7.
Happy hunting!

Tuesday, 21 March 2017

Pseudo-anthelion

On the evening of 9th February I left my apartment to hunt diamond dust halos, but was also supposed make it to Lappland Chamber Orchestra concert. So with the proper clothing for such an high society occasion underneath the overall and several other layers (it was close to -30° C) I half hoped it would be total crap to allow me to slip to the concert to hear live the Shostakovitch chamber symphony op. 110.

It indeed was quite crappy, or at least I thought so, and after taking some lunar and spotlight shots I was already driving towards the city - only to turn around and come back to do one last check. That settled it: there was an all sky display developing and DSCH was no more on agenda.


Here is highlighted only one set of photos of that display. The three images show an anthelion that moves below the parhelic circle as lunar elevation rises from 30.1 to 30.9 degrees (according to USNO calculator). The images from left to right are stacks of 4, 3 and 4 successive frames with 30s exposures and the values in the upper corner indicate lunar elevation.

In my attempt to simulate the effect with Halopoint there is only one population of column oriented crystals considered with orientations of the crystals restricted to 12 degrees rotation about the c-axis (parameters are shown at end of this post - the last one of the three tables). This, together with plate shape and slightly triangular habit indeed reproduced something that looks like the pseudo-anthelion in the photos.

A look at the raypaths revealed that the effect is an intensified apex of the Tricker arc. This explains the movement as Tricker separates from parhelic circle at light source elevations higher than 30 degrees. To show it in its true form, below left is a filtered simulation that has only the Tricker rays responsible for the effect and for comparison next to it a full simulation with all rays. Further below is depicted the beautiful raypath. This type of variation of Tricker arc raypath which enters and exists through basal face is also drawn in Robert Greenler's "Rainbows, Halos and Glories" on page 85 and Tape's "Atmospheric Halos" on page 26.


The set of simulations below compares two scenarios of traditional diffuse arc anthelion with the Tricker arc pseudo-anthelion. Actually, in the middle simulation both effects seem to be present. Parameters for these simulations are given further below. Left to right order for simulations corresponds to top-bottom order for parameters.


So accepting that this pseudo-anthelion is an anomalously brightened Tricker arc top, I am however less certain about the correctness of the suggested mechanism behind. The simulation does not come out that convincing when you look at the other parts of the display. It seems to me there is going on something that I have no idea of (or then I just didn't simulate enough, like has happened in the past).  

One curious thing is the lack of subhelic arc in the display. Only if I used plates that were h/d 0.2 or thinner could I get rid of the subhelic arc. But that made the simulation in other respects even further from the reality. Such h/d values were also too small for the pseudo-anthelion which seemed to thrive in quite delicate balance around 0.3 value. For reference, see an earlier case where simulation with thin plates in restricted column orientation (or poor Parry orientation) produced a good overall match with spotlight display. I guess next winter I must shape up on crystal sampling to see if displays like this really don't have columns in the dish.

The display itself was rather faint. No hope of seeing, for example, that pseudo-anthelion even though I saw from the camera display that it was there (and thinking it is just a normal anthelion). I'll be posting on some later occasion more photos from this night, including spotlight stuff.

Sunday, 19 March 2017

Riddle from the Past

André Kertész: Boat at Sunset on the Danube. Esztergom, 1917 (1967)
This photo by Hungarian photographer André Kertész taken exactly 100 years ago. Kertész became world-famous for his innovative and ground-breaking photographic techniques and the new perspectives he used in photo-journalism. The image above has created much discussion recently in the Hungarian halo-observers' forum, and generated some international correspondence. 

What can we actually see in this photograph? At the very first superficial glance this is like a solar halo with its reflection in the river. The light also becomes diffuse around it, so had the photo been modified, this would really be a masterpiece of manipulation from 1917. But Kertész was known for his documentary style not for remaking his photos.

However, if it was a halo, the image must have been taken by a lens with ultra wide focal length, which would not be commensurate with the boat in the foreground. The size of the feature could indicate a corona, but would a corona appear like this in a photograph made with a gelatin silver photographic process and the camera Kertész was using at this time: a Voigtländer Alpin 9×12 cm with a 6.3 lens?
 
All ideas are welcome. 

UPDATE:
Nicolas Lefaudeux has given an explanation for the riddle in the comments section. The image (see below) he found of the same Kertész photo with but a different development confirms his point.
 

The photo appeared in maimanohaz.blog.hu in 2015.

Friday, 17 March 2017

Weak odd radius display with possible column arcs


This display occurred on 22th February 2017 in Izborsk (Pskov region, Russia). In the morning it was sunny and the first cirrus started to arrive around 13-00. In that moment, I saw a faint 22° halo, but it was visible because the cloud layer was smooth. Also it seemed to me that I saw a 9° halo through the viewfinder of my camera. The stacks showed pyramidal halos such as 9°, 24° and 35° halo.

The 24° halo looks pretty curious, because B-R processing shows the pause in 24° ring in area of upper tangent arc. It reminds me of 24° column arcs from crystals with big tilts. 9° halo also looks curious, brighter on the sides than on the top, what looks like 9° column arcs.

What do you think of that? 

Thursday, 16 March 2017

Some photos of a Rovaniemi spotlight display


This was seen on 24 January 2017 in Rovaniemi. The image above is a total of 24 minutes exposure (48 frames). It shows all four kaleidoscopic arcs, which is not really that uncommon combo in the beam reality. Just before the diamond dust disappeared I took also a rare positive elevation lamp shot as shown below left. It's got 5 minutes total exposure. Below right is one of the first sets of the evening with 3 minutes exposure. The br reveals the insides of 46° and 22° halos are somewhat reddish.

It was quite cold, I think temperature was somewhere around -28° C towards the end of hunt. Unfortunately my halo hunt diary is no more because the folder called "halo" recently disappeared from the computer desktop without leaving a trace. It seems the universe don't want those notes to exist. Already earlier this season it got corrupted, all letters turned into #s. But I have a safety copy which has last winter's notes. At least for the time being.

Thanks to Panu Lahtinen, who stacked the image above when my Halostack had some mysterious glitch.

Wednesday, 15 March 2017

Artefacts from Hell

At the end of Marko Riikonen’s recent post, we hear a profound crie de couer about artefacts which plague some camera makes and models. For those of you who are blessed with top of the range, state of the art equipment, you might be wondering what all the fuss is about. Can artefacts which plague some cameras really be that bad? The short answer is a resounding yes, they can be horrendous. Moreover, for the type of work serious halo observers are engaged upon, these cameras are virtually useless. Marko mentions that for him the problems are exacerbated when trying to photograph during daylight but ease somewhat at night when recording spotlight displays. From personal experience with my own particular model, I can say that it is equally bad day or night. Here is an example of how bad it can get even at night. The image is of a simple circumscribed lunar halo with a faint 9° odd radius.

The halo is almost obliterated by the artefacts. This is one reason why I very rarely post anything these days because the images are just so embarrassing. 

The consensus amongst seasoned halo observers and professional photographers is that full frame cameras are largely free of this level of artefact or at least they are not affected to quite the same degree. However, sadly for many, myself included, professional full frame cameras are just too expensive and so we have to settle for cheaper consumer models. The problem here is that by and large you select a camera model based on a review you either see online or in a camera magazine. None of the reviewers who write these are engaged in the type of work we do so rarely, if ever, is this problem of artefacts encountered, mentioned or highlighted. Once a budding halo enthusiast has selected his camera on the basis of one of these reviews and splashes out several hundred euros on the latest consumer model, disillusion can very quickly set in when he realises he has bought a complete and utter duff. More than likely, he or she is going to be chained to this millstone for the next four or five years until they can afford something better.



So then, we come to the crux of this post: what to do about this situation? To all those who are in this situation and are experiencing this problem, I want to ask our readers two things.

Firstly, can we compile a list of camera makes and models that are particularly prone to artefact problems? I would like to do this to alert everyone to the problems with those specific models and to try to stop people wasting their money buying them if they are predominantly going to be used for photographing halos. This is not to say that a particular model is “bad” per se, just that it is ill suited for halo photography. Conversely, if you are in the fortunate position of being in possession of a camera which is particularly free from artefacts or one which you could recommend in this respect, we would also like to hear from you. 

Secondly, I would like to ask everyone whether they have any tips or solutions for overcoming or lessening these artefacts if you are unfortunate to have a camera that is beset by them. These tips could either be in-camera or pre- or post-processing. 

After a suitable period of time, once we have received some feedback on this issue, perhaps we can collate the results and do a follow up post. I would also be interested in posting particularly horrific examples of artefacts in halo photographs which would act as a warning to the curious. Please send any images or private correspondence to thehalovault@gmail.com.

Update

To clarify following enquiries, the above image is 8-bit and is used for illustration purposes only. In my experience, 8-bit are always unusable for this type of work. 16-bit are variable and one cannot predict when or why artefacts will appear. When they do manifest, they are every bit as unusable as 8-bit, at least with my equipment.

Tuesday, 14 March 2017

Trying to simulate arcs associated with parhelia in Rovaniemi solar display


Above is a display showing arcs extending outwards from parhelia and an attempt at simulating with Lowitz oriented plates using HaloPoint software. Sun elevation was 14.5 degrees.

In the lower right panel is a simulation with all rays. On the upper right is the same simulation (well, not exactly the same, ray numbers are a bit different) that shows from Lowitz orientation population only rays that experience 3 or 5 hits. This leaves the arcs from 325 and 315 type raypaths (the so called Schulthess arcs) visible while some others, such as Lowitz arcs are filtered out. The Lowitz arcs are seen in the lower left simulation, which has only rays with 2 and 4 hits from Lowitz oriented crystals.

The Lowitz arc scenario is clearly out of question to explain the arcs in the display, there is no match. Then how about the 3 and 5 hit scenario? Comparison is easiest with the flashing image below. The outer arcs fit together quite well but the inner ones don't. The inner arcs are angling too steeply inwards in the simulation.


Did I just do a botched job in matching the simulation to the photo? I admit it is not perfect work, but likely not so bad as to account for the large mismatch of the arcs.

Could it be because of the projection difference between the photo and simulation? I know that my 8 mm Sigma fisheye doesn't align perfectly with HaloPoint fisheye projections. For example, subanthelic arc is always narrower and taller in simulations than in photos. So maybe this too is just down to projection. Some day we might have a simulating tool that allows customization for individual lenses. That would settle the issue.

But even then we would still be long way off explaining these kind of displays. How do you get rid of Lowitz arcs in the simulation? I could not find a way. You have to really burn the Lowitz arcs to get 315 and 325 type arcs. This scorching inevitably gives also 46° contact arcs as is shown by the fuller version of the simulation below. In the fuller version of the photo next to it there are no signs of these arcs. Also, I was not able to simulate the correct length of the outer arcs. Lessening tilts seemed to make them disappear altogether. But I wasn't exhaustive in my attempts, it might have been possible to get them right.

What else? The display has no Kern arc even though cza was quite nice and diamond dust smooth. Clearly Kerns are not to be taken for granted. While observing, I thought there could be a chance here, but at the same time had a feeling that sun is probably too high, the plates too thin (you pretty much can say it without looking at a crystal sample) and tilting too much for the good old H.F.A.


Some words about the hunt itself  - the ryynäys as we say here. I was doing spotlight at the night and things got crappy as supersaturations increased. Diamond dust was everywhere but really poor halos. Expectedly it was no better in the morning. Close to the ski centre, diamond dust was so thick the sun did not shine through. At the edge of the cloud where the sun shone brightly there was quite some crystal glitter in the air, but, as it is with this glitter, it comes at the expense of halos: only pillar and subsun was visible. So I went shopping to a grocery store, hoping that in the meantime warming air brings a positive change.

It got better. However, the display was good only at the receding edge of diamond dust cloud. So I photographed in one place and when it weakened, hopped into car and followed the cloud to a new place to photograph again. I did six such manoeuvres, after which the swarm was soon done away completely by the heating sun. The photo shown here is the best set that I got at the third location.

Some technical info. The display was seen on 7 March 2017 in Rovaniemi. Temperature was probably around -16°C at the time I took the stack. It has 54 photos taken during 5m10s, starting at 10:13. Stacking was done with Registax 5.0. The artefacts seen in the image are a scourge of some series of Nikon cameras, they come in daytime photography and there is nothing you can do about them in post processing. 3000 series is one plagued with this issue (I have 3200 and 3300) and from what I have heard from other people's experiences 5000 series too. Definitely not cameras for halo photography.

Saturday, 11 March 2017

Halo Phenomena in Olaus Magnus’s Historia de Gentibus Septentrionalibus (Part 1)



Parhelia in Historia de Gentibus Septentrionalibus, Bk. 1, Ch, 17.

This is the first post of a three-part series focusing on the rich material that can be found in Historia de Gentibus Septentrionalibus (History of the Nordic Peoples), a popular and influential work of the 16th century. The work was written by Olaus Magnus and was printed in Rome in 1555. Soon after its publication, it was translated into several languages and thus became a “bestseller” of the age.

The author, Olaus Magnus, was a Swedish theologian, cartographer and writer, and the last Catholic archbishop of Uppsala. He maintained good relationship with King Gustav I of Sweden, and partly due to this, he was sent on various diplomatic and ecclesiastical missions around Scandinavia and other parts of Europe. During these travels he recorded his observations and what he had heard from locals, which later gave the basis of his magnum opus. When his country adopted the Lutheran faith, Olaus decided to remain loyal to his Catholic religion, and stayed abroad for the rest of his life. He was issued the title Archbishop during this turbulent period of his life, but the title was only a nominal one, as Olaus had been banned from Lutheran Sweden.

Historia de Gentibus Septentrionalibus is Olaus’s major work, which consists of 22 books divided into chapters, and is illustrated with 481 woodcuts. In his first book, he deals extensively with halos and dedicates 5 chapters to them. Of these, chapters 17 and 18 deal with parhelia and paraselenae. Olaus seems to have personal interest in these phenomena: when he lists occasions of three suns or moons visible in the sky, he mentions his own birthday at the beginning of October in 1490.

Olaus starts his description of parhelia by saying that in the North, around sunset and sunrise, they frequently appear at any location. They are white or rainbow-coloured, there could be two or even more of them, and are “never above or below the true sun, but at an angle to it” (All English translations by: Peter Fisher and Humphrey Higgens). As a 16th century Renaissance scholar, he pays much attention to authenticating his writing, and supports his description by referring to natural historical works of Seneca (Naturales quaestiones), Pliny (Naturalis Historia) and even to the popular 12th century encyclopaedia Speculum Maius, written by the Dominican friar Vincentius Bellovacensis. Thus, in his explanation about the formation of parhelia he relies on earlier sources and theories, most of which would now raise a smile. Although the description is very far from the truth, we must acknowledge that some properties of parhelia are rightly observed. Already in the 16th century it was realised, for example, that their formation is connected to clouds, more precisely to clouds that have specific thickness and uniform nature. 

Olaus Magnus’s description goes as follows: "(…) a parhelion is a rounded shining cloud, similar to the sun; for at the time of an eclipse we set out basins, which we fill with oil or tar, in order to observe how the moon stations itself before the sun, because a viscous liquid is less easily disturbed and retains the images which it receives. Therefore as the images of the sun and moon are viewed like this on earth, so also it happens in the sky that when the air is condensed and pellucid, it takes upon itself the figure of the sun; other clouds catch this up, too, but pass it on if they are moving or if they are thin or contain impurities. For the moving ones scatter the image, the sparse ones let it escape, while the foul and filthy ones receive no impression of it, just as with us things that are stained give no reflection."

A further interesting detail of the text is the idea that if a second parhelion appears in the sky, it is the mirror image or reflection of the first one; “clouds that present this effect are said to be dense, light, brilliant, flat and composed of compact matter.” He also states that parhelia cannot be seen on clouds very far from the sun because the beams of sunlight cannot be reflected from afar. Paraselenae (Chapter 18) depend on the Sun’s brightness as Olaus says, since the Moon “has no power at all to initiate action on inferior bodies, except for reciprocating and receiving light from the sun”.
Paraselenae in Historia de Gentibus Septentrionalibus, Bk 1. Ch. 18.
At the beginning of  Book 1, chapter 17, Olaus notes that the reason why he finds it important to talk about the phenomena is that locals believe they signify upcoming events. For farmers parhelia indicate rain coming. If the parhelia are visible in the South and they last long, farmers in the hills can sow seed safely. If, however, two parhelia are “contending” with one another on the sides of the real sun and then vanish, sailors must beware of severe storms. In wintertime, when there are three moons in the sky, they foretell snow, frost and cold.

By: Ágnes Kiricsi

Sources:
Olaus Magnus, A Description of the Northern Peoples, 1555, Vol. 1. Ed.: Peter Foote, Hakluyt Society, 1996.
Olaus Magnus, Historia de gentibus deptentrionalibus. http://runeberg.org/olmagnus 
Images: Lars Henriksson http://www.avrosys.nu/