[HN Gopher] Photographing the hidden world of slime mould
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Photographing the hidden world of slime mould
Author : 1659447091
Score : 97 points
Date : 2026-01-02 05:56 UTC (7 days ago)
(HTM) web link (www.bbc.com)
(TXT) w3m dump (www.bbc.com)
| jl6 wrote:
| My, that was a yummy slime mold!
|
| > "You take multiple pictures, sometimes over 100 and it takes
| tiny little slivers of focus, and then you put all those into
| software, and that creates your final image."
|
| Is this a workaround to let us see "what it would look like", or
| are there optical reasons why this produces an image that is
| inherently artificial, and could never really be perceived that
| way?
| pcdevils wrote:
| It's focus stacking so basically just compensating for the way
| macro lenses and large apertures work. There's nothing
| artificial about it, the software is just layering the sharpest
| parts into the photo. It's a common technique, heavily used for
| things like astro photography and landscape photography as
| well. https://www.canon.co.uk/get-inspired/tips-and-
| techniques/foc...
| pbronez wrote:
| Can you leverage focus stacking on a mobile camera? I poked
| around a bit for relevant apps but didn't see anything
| credible.
| azath92 wrote:
| My understanding is that modern mobile phone cameras do
| heaps of "stacking" across multiple axes focus, exposure,
| time etc to compose a photo that saves onto your phone. I
| believe its one of the reasons for the multiple cameras on
| most flagship phones, and then each of them might take many
| "photos" or runs of data from their sensors per "photo" you
| take. id love to see a good writeup of the process, but my
| gut says exactly what they do under the hood would be
| pretty "trade secret"ie.
| hermitcrab wrote:
| Can any mobile cameras focus close enough to be useful for
| macro? Maybe you can buy a third party add-on lens?
| Zababa wrote:
| Depends on what level of macro you want, but with modern
| phones you can get pretty close, usually with the wide
| angle lens.
|
| On iPhones: https://support.apple.com/guide/iphone/take-
| macro-photos-and...
|
| On Pixel:
| https://store.google.com/intl/en/ideas/articles/pixel-
| macro-...
|
| I'd recommend playing around with it, it's a lot of fun!
| hermitcrab wrote:
| Had a quick play with my iPhone 15. It doesn't give the
| sort of magnification you would need for insect close-
| ups. I will stick with my Nikon DSLR + 100mm macro lens!
| Zababa wrote:
| Yeah it's far from being as good as a DLSR or mirrorless
| with a dedicated macro lens. Still, most people reading
| HN have one in their pocket and it can be a good test to
| see if you like the idea of macro. It does work with
| larger insects, on a pixel 10 pro my mantis fill most of
| the frame.
| khr wrote:
| You can, depending on your definition of "useful". You
| can buy a cheap laser pointer, take out its lens, and put
| it over your camera lens. Tape it onto the lens for a
| temporary janky version or make a 3d-printed mount for
| something much better that you can easily take on/off.
|
| I've personally found this little hack useful, but then
| again I don't have a DSLR and macro lens!
| jcynix wrote:
| Optical reasons, aka depth of field. Exceptionally well
| explained in
|
| Cameras and Lenses - Bartosz Ciechanowski
| https://ciechanow.ski/cameras-and-lenses/
|
| Depth of field - Wikipedia
| https://en.wikipedia.org/wiki/Depth_of_field
| Zababa wrote:
| >Is this a workaround to let us see "what it would look like",
| or are there optical reasons why this produces an image that is
| inherently artificial, and could never really be perceived that
| way?
|
| Both in a way. When you look at a landscape, your eyes and
| brain are constantly adjusting everything so what you look at
| "directly" is sharp, and you don't really realize most of what
| is in your field of view is low resolution, maybe a bit blurry.
| Same when looking at something really close.
|
| When you look at a picture, if some parts of it are blurry,
| your eyes/brain can't adjust so that it becomes sharp, because
| it was captured blurry. Even if you had a camera that exactly
| reproduces your eye, the pictures would look nothing like what
| your eyes see, because your eyes and brain are a very different
| system from a camera.
|
| In photo there is something called "depth of field", which is
| "the distance between the nearest and the farthest objects that
| are in acceptably sharp focus in an image captured with a
| camera" [1]. You can see on the wikipedia page that there's an
| equation for approximating depth of field, that has in it 2u2,
| where u is the distance to the subject. That means the closer
| the subject, the smaller the size of depth of field. You can
| test this with your eye. Take an object 30cm away, put your
| finger between your eye and the object, and you can change the
| focus of your eye between your finger and the object. When you
| focus on your finger the object is a bit blurry, when you focus
| on the object your finger is a bit blurry [2]. Now take two
| object that are 15cm away from each other, but 2m or more away
| from you. Changing the focus from one object to the other won't
| make the first object as blurry as when you did that close.
| This is because your depth of field is larger, as the distance
| increases.
|
| Finally macro. In macro photography, you're often extremely
| close, so depth of field is extremely thin. When I say
| extremely thin, I mean "it can take 10 or more pictures to
| cover a whole fly". A solution in that case, to get all your
| subject in focus (sharp), is to take lots of different
| pictures, focusing a tiny bit closer/farther away each time,
| and then taking all the sharp parts of each picture. That's the
| technique used here, often called "focus stacking".
|
| [1]: https://en.wikipedia.org/wiki/Depth_of_field
|
| [2]: This might be harder if you're older, as we age we slowly
| lose the ability to adjust focus, hence the need for reading
| glasses (cameras can also use "reading glasses" when they can't
| focus close enough, they're called "close-up filters" and work
| the same).
| pixl97 wrote:
| >and you don't really realize most of what is in your field
| of view is low resolution, maybe a bit blurry
|
| PBS did a great video on this
|
| https://www.youtube.com/watch?v=HU6LfXNeQM4&t=514s
|
| This links to the section in question, but it's well worth
| watching all of it to see and example of how your brain
| tricks you. The computer doing eye tracking and blurring
| everything else out to the user really points out how much
| your brain lies to you about reality.
| sevg wrote:
| > My, that was a yummy slime mold!
|
| This is a NetHack reference for anyone unfamiliar.
| tristor wrote:
| When you take macro photos with close focus, your depth of
| field is like a very thin slice of the scene, you can think of
| it of having a plane of just a millimeter or so deep that you
| are scanning through the subject, taking a frame each time. So
| if your subject is something like a monarch butterfly which is
| generally around 30mm in length of body and close to 55mm
| considering both wings and body, you might need to take 60-70
| frames then focus stack them afterwards to get critical focus
| on all parts of the subject.
|
| I'm not sure what folks use now, but Zerene Stacker (
| https://zerenesystems.com/cms/stacker ) was the gold standard
| when I was doing serious macro photography about ten years ago.
| hermitcrab wrote:
| Macro photography is a fascinating hobby, revealing a whole new
| world under your nose. And you don't have to go any further than
| your garden or local park to go on safari.
|
| It requires a bit of kit:
|
| -digital camera (I use a Nikon D7000)
|
| -macro lens (I use a Laowa 100mm). A standard lens won't be able
| to focus close enough.
|
| -flash (I use a Godox). You need a decent flash to get enough
| light for a sharp photo. Ambient light won't cut it.
|
| The main issue is that the depth of field (the area in front and
| behind the bit your are focussing on) is _tiny_. Usually well
| under a millimetre. Which makes focussing quite a challenge.
| Thankfully digital photos are effectively free and you can just
| delete the blurry ones.
|
| It is also quite challenging to get close enough to insects to
| photograph (you need to be within a few mm).
|
| There are plenty of good videos on YouTube to get you started, if
| you are interested.
| JR1427 wrote:
| You don't even need a macro lens. I used a kit zoom lens and
| some lens spacers, bought used for PS60.
|
| (I did my post-doc on slime mould decision-making)
| hermitcrab wrote:
| Yes, you can use spacers. That is probably a good way to get
| started. I believe you can even use kits to put a standard
| lens on 'back to font'. I prefer a dedicated macro lens
| personally. Lenses like the Laowa 100mm for Nikon are fairly
| decent and not _that_ expensive (note it is manual focus - in
| macro you generally move the camera rather than changing the
| lens focus).
| EvanAnderson wrote:
| Just to echo what you said:
|
| The "reversing ring" trick does work, (mounting a lens
| backwards) but the ergonomics are shit. I bought one to
| play with and tossed it in a drawer after only using it
| once. A real macro lens is so much better.
| tristor wrote:
| I used to have a macro lens, and while I quite enjoyed it, I
| found that since I primarily do wildlife photography I could
| use a longer focal length telephoto lens at distance to get
| nearly as much detail by filling the frame with the subject. I
| have quite a few butterfly photos that were taken with a 300mm
| or 400mm telephoto prime, not a macro lens, and you'd be hard
| pressed to know the difference.
|
| That's not true of /all/ macro photography, it depends on the
| specific details of the subject you're most interested in
| capturing. Without a macro lens you aren't going to capture the
| subtle textures of a butterflies wing, but you can certainly
| get a good photo of the entire butterfly including the textures
| of its eyes without a macro lens.
|
| That said, I love doing proper macro photography. It does
| require a bit more kit though, you really need a ring light or
| a dual-flash, and a tripod and focus rail to support doing
| focus stacking to get extremely detailed shots. Agreed though
| with your sibling comment that manual focus is fine. There's
| really no reason to worry about refocusing on a subject once
| you get initial critical focus, it makes more sense to move the
| camera/yourself (which is the way a focus rail works).
| roughly wrote:
| I picked up a binocular microscope a bit back and it's one of
| my favorite nerd purchases - it's 20x, which is enough to be
| interesting, but not enough to require a lot of sample prep,
| and the binocular setup gives you depth perception, so it feels
| like you're "there" with whatever you're looking at. I've
| mucked around with microscopes in the past, but the binocular
| is genuinely just fun.
| tristramb wrote:
| Many years ago (or so it seems now), I was turned on to slime
| moulds by the photos of Kim Fleming on Flickr
| (https://www.flickr.com/photos/myriorama/albums/1271006/). The
| undersides of logs can be a good place to find them.
| CheeseFromLidl wrote:
| I've occasionally found them, but only when their color
| contrasts with the background during walks. Can they be found
| year round? Do they have a preference for logs?
| analog31 wrote:
| I realize that that these photos are for looking at but it irks
| me when there is never a size scale.
| dinkblam wrote:
| it irks me more that they are super tiny low resolution. where
| are the originals?
| pixl97 wrote:
| https://www.barrywebbimages.co.uk/Images/Macro/Slime-
| Moulds-...
| scrollop wrote:
| If you saw a movie with an alien landscape with these
| appearances, you might think it's too far fetched.
| adregan wrote:
| When I was a young urbanite, I might not have believed you if you
| told me that one day I would gain great pleasure in discovering
| large blooms of Dog vomit slime mold in the garden, but here we
| are.
|
| Slime molds are really amazing; large patches spring up overnight
| and they are so vibrant in color.
| bondarchuk wrote:
| > _If you shrink yourself down to the size of a mite, and take a
| walk through the forest, this is how you would see slime mould._
|
| Thanks for explaining the concept of close-up photography in
| terms I can understand. :D
| DonHopkins wrote:
| One of my favorite Facebook groups is "Slime Mold Identification
| & Appreciation", which has some spectacularly talented and
| prolific professional slime mold photographers posting to it.
| Including Barry Webb, the subject of this article, who is an "all
| star contributor" and posts frequently.
|
| https://www.facebook.com/groups/1510123272580859
|
| https://www.facebook.com/groups/1510123272580859/user/100041...
|
| And then there's this guy:
|
| Harvesting, cooking and eating Dog Vomit Slime Mold:
|
| https://www.youtube.com/watch?v=KfbLSl_4o78
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