Snowflake macro photography (2013) | Hacker News Reader

Snowflake macro photography (2013)

chaoticmind75.blogspot.com

517 pointsrunesoerensen67 comments

Feel free to see all of his photos at https://www.flickr.com/photos/alexey_kljatov

I'm more than mesmerized by his work; just stunning, I'm in complete awe!

I forget the name, but there's a great documentary about the man and methods who got it all started. Wilson 'Snowflake' Bentley was the man and, as I recall, he got some help from his wife and went to great lengths to take his pictures.

This was back in the 1860s and very difficult. The Smithsonian has some of his works on display. It is great how accessible this has become. I find them fascinating but I'm very biased. I have quite an extreme love of snow.

I found this short about him, did the job for me, fascinating person - thanks for the heads up.

https://www.youtube.com/watch?v=ptLmA263hlk

I agree!

Going by the Bruce Lee quote "I fear not the man who has practiced 10,000 kicks once, but I fear the man who has practiced one kick 10,000 times". Only in this case kick = photography. There is definitely value in practicing a singular art with focus.

It's nice when people get simple tools to do great work. The PowerShot A650 is a decade old point-and-shoot. He's installed a custom OS to get RAW support, and averaged several photos together to reduce noise, and what a great result. An EOS 5D wouldn't do much better.

Photography seems to be one place where the exchange rate between better skills and better tech favors skills.

I have a friend who makes rock documentaries and his boss will often rent an $8K camera. My friend sometimes shoots on a $500 DSLR, and once mixed in some of his footage. His boss could tell the difference, but it wasn't significant, and it made him wonder why they even rented the nicer camera.

My wife is a good photographer. Not professional level, but pretty good. It always makes me laugh when people say "That's a great picture. What camera do you have?"

You could give me the best camera in the world and my pictures would still be "Meh". It's not the camera that makes the difference.

There's a (British?) phrase for the general phenomenon, especially with recreational sports: All the gear, no idea.

There is a joke: Couple walks into a photo exhibit, and compliments the photographer "these are very nice photos, you camera must be pretty expensive". After an exhibit they invite the photographer to their house for a dinner. Photographer finishes the dinner and says "food tasted great, your kitchenware must be pretty expensive too".

That $500 DSLR can definitely do some impressive work, but the issue is in how it processes the images.

A DSLR will read the sensor progressively, from top to bottom. So if an image changes from the top of the frame to the bottom (if the camera pans or an object moves horizontally) the top is recorded slightly before the bottom, leading to a "tilting" effect. This would be really noticeable if you were to follow someone around with a steadicam, or had objects moving across the screen with any real speed.

When I watch short amateur films on Youtube this effect can ruin the whole experience for me, since I can't stop noticing it. However, a shot of a rock show (crowd or stage) would likely be busy enough to make the effect unnoticeable. There are probably algorithms that fix it too, especially if the film is shot at a higher resolution than is being output (to allow adjustments at the edges of frame).

Is it possible that a high quality camera with a small sensor could actually be preferable to a full frame camera like a 5D in this particular case? My thinking is that it might be hard to get more than a sliver of the image in focus with a full frame camera. Does anyone with more experience know if this is true?

He does mention that, yeah:

> The smaller the focal length of the external lens and bigger - of built-in camera's optics, the greater magnification is achieved, but less depth of field is obtained. Compact camera, with a sensor of small physical size, have an advantage over DSLRs in the depth of field and mobility, allowing you to take pictures quickly and easily change the location and shooting angle. But small sensor have much higher noise level.

The sensor size doesn't change anything. A camera with a larger sensor would have the same image projected on the sensor but it would also capture more around it - basically, you could get the same image by cropping that part out of the larger image.

However, a larger sensor probably would have larger pixels, which would help with lighting and noise reduction.

Focus bracketing could easily solve that problem. In fact, Magic Lantern (the equivalent of CHDK for the larger Canon DSLRs) has a mode to do automated focus bracketing with the electronic focus controls.

I don't really know about focus difficulty, but I calculated the 35mm equivalent of the PowerShot A650 at 6x and it's 200mm. That long of a lens could be pretty awkward to work with, for a start (I still want to try it, my APS-C camera would need only a 140mm lens to get the same zoom, besides the external optics of course).

I used to use a 200mm lens with a reversed 50mm on a Nikon D70, and the focus is difficult. It sounds like the photographer here is using a sort of "spray and pray" technique and using focus-stacking software later.

You actually don't need the telephoto, though. You can get a reversing ring that mounts a prime lens directly to the camera. I took this using a 50mm lens on a full frame body, no focus stacking: https://c1.staticflickr.com/1/498/19387253482_cfdb183b3a_c.j...

If you use a shorter focal length lens, you'll get a higher magnification. I've used a 28mm in the past but wasn't very happy with the image quality.

Question: What makes snowflakes symmetrical?

This is still an area of active research [1,2]. The basic hexagonal symmetry comes from the hexagonal lattice of bulk ice. What is more intriguing is the global symmetry between individual dendrites. From reading some recent papers, I think the mechanism is as follows. The snowflake is small enough that although the temperature and water pressure surrounding it can change quickly, all its dendrites are always exposed to almost identical conditions at a given time, leading to a largely deterministic growth, hence the symmetry.

[1] https://www.nature.com/articles/s41524-017-0015-1

[2] http://iopscience.iop.org/article/10.1088/0034-4885/68/4/R03

but shouldn't then also exist asymmetrical snow flakes occasionally?

First, the symmetry is not perfect with most snow flakes, if you look closely. Second, I guess there are asymmetric flakes, but they are probably rare. I’m sure though that no current model can explain the distribution of the degree of symmetry, perhaps not even an order-of-magnitude guess.

Absolutely.

https://www.flickr.com/photos/alexey_kljatov/11046723195/siz...

"This process is much like tiling a floor in accordance with a specific pattern: once the pattern is chosen and the first tiles are placed, then all the other tiles must go in predetermined spaces in order to maintain the pattern of symmetry. Water molecules simply arrange themselves to fit the spaces and maintain symmetry; in this way, the different arms of the snowflake are formed."

https://www.scientificamerican.com/article/why-are-snowflake...

Nature actually loves hexagons. They are efficient and all over the place. If you blow a bunch of separate bubbles, even they will form into hexagons where they are surrounded by other bubbles.

http://nautil.us/issue/35/boundaries/why-nature-prefers-hexa...

Watch the NASA video linked towards the end. Explains the H2O bonds and how the crystals always form to 6 sides. Temperature, Pressure, etc... trigger different patterns.

Consider a single free water molecule. As it moves around randomly it will hit the growing snowflake on a random side and get stuck to it, jiggling around a bit until it is in a position that is hard to get unstuck from. This creates the basic hexagonal shape of the snowflake.

Because of the huge number of water molecules floating around, it should be statistically likely that all sides of the snowflake will be hit and grow evenly. But the tips of the hexagon will be slightly more likely to be hit since they are protuding a little bit. Thus the tips will grow outwards and will be even more likely to get water molecules stuck to them. Eventually the tips will get large enough that molecules will stick to their sides, creating new growing branches. And those branches will eventually grow other branches and so on in a fractal manner.

The saturation of water molecules and the temperature are the conditions for how often the snowflake is hitnby water molecules and how much they jiggle around before getting stuck. As the snowflake falls through the air, these conditions change, which creates all the varied forms of snowflakes.

There are plenty of "diffusion limited aggregation" simulators around. Has anyone made one using using hexagons, rather than pixels?

https://en.wikipedia.org/wiki/Diffusion-limited_aggregation

I got one implemented in D at https://github.com/olaost/snowflake

Should try to put it up on Shadertoy...

Most snowflakes aren't, the vast majority of snowflakes are of the "irregular" type. And to answer another person's question above "Why are snowflakes 2d", the irregular ones aren't, and there's a lot of symmetric ones that aren't 2D either[1].

The ones people like to photograph are the symmetric 2D ones, so there's just a lot of selection bias going on. But, the ones that are symmetric, are that way because all of the branches experienced the same environment on the way down. Most of them are not perfectly symmetric, and differ quite a bit, but photographers tend to select only the most symmetric ones.

The website in [1] has an overview of how to get started in snowflake photography if you want to give it a try. I've done it quite a bit myself, but unfortunately I don't get the opportunity very often.

[1] http://www.snowcrystals.com/guide/snowtypes4.jpg

Also: What makes such snowflakes largely 2D?

This answers it: https://www.reddit.com/r/askscience/comments/5gae8u/why_are_...

"Ice crystals are like a six-sided prism. This prism grows as more ice molecules stick to its faces. It turns out that under conditions found in common snowstorms, some facets in XY plane tend to grow much faster than the facets along the main axis of the crystal. As a result, snowflakes usually end up looking like flat pancakes with many finger-like branches"

The edges grow much faster because "molecularly flat regions... have fewer dangling chemical bonds and are thus less favorable attachment sites [for condensing molecules]." Also, snowflakes can take on 3D column shapes depending on humidity and temperature. See http://www.its.caltech.edu/~atomic/publist/AmSci2007.pdf

Right, but from that we might also expect very long thin hexagonal crystals. Maybe that is what rime is?

There are some shots of those near the tail end of the article. Both pure cylinders (https://c6.staticflickr.com/9/8240/8661684397_3e2953b2ca_b.j...) and capped columns (https://c8.staticflickr.com/6/5613/29417525663_448be7dac8_o....).

Shooting from the hip here, but another hexagonal crystal, graphite, is strong laterally but not between its lattices.

I was wondering the same thing. Part of it may be selection bias, though.

Snowflakes start from a crystal with hexagonal symmetry and grow via processes that preserve that symmetry. See the top two answers here: https://physics.stackexchange.com/questions/3795/why-are-sno...

I posted this above, but you may not expand the full thread and see it. So, I'll post it again.

http://nautil.us/issue/35/boundaries/why-nature-prefers-hexa...

Sorry for repeating my post, but I figure you may enjoy the linked article.

Additionally, two documentaries spring to mind. Forces of Nature and The Code: Numbers Shape and Prediction.

Sexual selection favors the symmetrical ones?

;)

Selection by the photographer might create the impression of a more prevalent, more perfect symmetry than appears in nature.

Beautiful.

Reminds me of Wilson Bentley's old photos: https://en.wikipedia.org/wiki/Wilson_Bentley

It is incredible how complex water is. Chemically it is a super-simple molecule. For me this is a reminder that in nature even the most simple-seeming "things" will turn out to be unbelievably complex if researched or observed more closely. Like when physicists believed that they solved physics in the late 19th century - b/c it was just about solving some math problems revolving around Newton mechanics. Nature is consistently always being surprising - always.

Wow! These images are perfect for a coffee table book. The thin film interference colors are amazing!

He does sell prints but, as far as I know, doesn't have a whole book out. I suppose you could email him and ask him to consider it?

In the meantime, you may be interested in this:

https://www.amazon.com/Art-Snowflake-Photographic-Album/dp/0...

Such a relief to see the word in a headline with its actual meaning.

Plus, the pictures are sublime.

I wonder if you could improve the pollen image using super-resolution techniques Shouldn't be too difficult, just requires a several images (stacks in this case) from slightly shifted viewpoints.

Kenneth G. Libbrecht snowflake photo collection is another good one: http://www.its.caltech.edu/~atomic/snowcrystals/photos3/phot... ; http://snowcrystals.com/

Incredible pictures, and fantastic to see the method documented so well.

I'd read about doing the reverse-lens thing but never seen a setup and couldn't imagine how it'd work.

Also, the description of his post-processing is revealing. Great to see how much work goes into pictures like that.

affirmative, i see it pass by about every year since 2013, i still look at them with as much amazement as i did in 2013.

A reverser ring for a e.g. 50mm to do macro is quite common in photography. Extender rings work quite nice too, though depth of field becomes mega-shallow, so for any significant object, you will need to resort to image stacking to get a properly focused subject.

I most impressed by the "less is more" category of photos he took. The clean lines, simplicity of shapes while maintaining enough contrast to be beautiful is just astounding. Had no idea that these kind of shapes happened with snowflakes.

If nature had a logo, it must have hexagon.

Or "Enigma".

https://farm8.staticflickr.com/7616/16857912678_239dc8dee5_o...

It's nice when people get simple tools to do great work.

No lie, this was a fantastic way to start my day.

These are just the most beautiful pictures.

I have achieved similar results photographing snowflakes w/ an iPhone 4S and a macro lense I bought for $5 at the Walmart checkout isle.

Show us then.

Here's one from a few years ago:

https://m.imgur.com/a/0PZFM

Wow, beautiful nature.

That is a horrific site to navigate on mobile.