Photographing the hidden world of slime mould(bbc.com)
bbc.com
Photographing the hidden world of slime mould
https://www.bbc.com/news/articles/c9d9409p76qo
30 comments
You don't even need a macro lens. I used a kit zoom lens and some lens spacers, bought used for £60.
(I did my post-doc on slime mould decision-making)
(I did my post-doc on slime mould decision-making)
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).
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.
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.
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.
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).
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).
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.
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?
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?
> "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?
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...
Can you leverage focus stacking on a mobile camera? I poked around a bit for relevant apps but didn’t see anything credible.
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.
Can any mobile cameras focus close enough to be useful for macro? Maybe you can buy a third party add-on lens?
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!
I've personally found this little hack useful, but then again I don't have a DSLR and macro lens!
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!
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!
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!
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.
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
Cameras and Lenses – Bartosz Ciechanowski https://ciechanow.ski/cameras-and-lenses/
Depth of field - Wikipedia https://en.wikipedia.org/wiki/Depth_of_field
> My, that was a yummy slime mold!
This is a NetHack reference for anyone unfamiliar.
This is a NetHack reference for anyone unfamiliar.
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.
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.
>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).
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).
>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.
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.
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
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
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.
Slime molds are really amazing; large patches spring up overnight and they are so vibrant in color.
>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
Thanks for explaining the concept of close-up photography in terms I can understand. :D
If you saw a movie with an alien landscape with these appearances, you might think it's too far fetched.
I realize that that these photos are for looking at but it irks me when there is never a size scale.
it irks me more that they are super tiny low resolution. where are the originals?
A couple years ago I became obsessed with getting slime mold to grow on a cast 3-dimensional substrate. I finally got it working on an agar mold of Donald Trump's face, which you can see here: https://youtu.be/pxEN-YKDDVM.
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.