8 ms·

Flipped an element in an old lens and got 'magic' bokeh (2018)

181 points by colinprince 6y ago

gerikson 6y ago
Here's hoping the swirly/crazy bokeh phase is soon over.
dusted 6y ago
that's interesting, especially interesting that nobody has done it before, considering the amount of money there are in specialty lenses.. This is somewhat an example of "if that was a dollar, someone would have picked it up already"
- Arainach 6y ago
  The money in lenses goes towards more predictability - sharper, wider aperture, faster to focus, smooth bokeh for portraits - or technical achievements like ultratelephoto lenses. The people who can pay are looking for those features, not random effects. The value here is in novelty - it doesn't look like anything else. If it was mass produced, demand for the effect would likely go down, not up. And it's certainly not without compromise - sharpness across the entire frame in those example shots is worse than your average plastic 18-55mm kit zoom.
  - wlesieutre 6y ago
    There are lenses made for unusual effects rather than optical quality, but it's more of a niche market https://microsites.lomography.com/petzval-58-bokeh-control-lens/photos/ https://microsites.lomography.com/petzval-58-bokeh-control-l... https://lensbaby.com/products/composer-pro-ii-with-sweet-50-optic https://lensbaby.com/products/composer-pro-ii-with-sweet-50-...
- Sebb767 6y ago
  From the sample photos it seems like the lens is rather useless this way. While some bokeh is awesome, this looks more like someone applied an LSD-filter and called it a day; nothing that you could use for a portrait. It also seems the pictures are not too sharp. Therefore, there's probably not too much money to be made. If this could be a bit smoother in the background, on the other hand ...
  - Applejinx 6y ago
    I dunno. I'd buy a micro 4/3 one like a shot. I'm already using lenses from SLR magic that aren't THE sharpest possible things, but have really good bokeh and pleasing departure from perfect focus outside perfect focal distance.
- dylan604 6y ago
  I'd be surprised if this is truly the first time. I'm guessing that there is someone that was assembling a lens and did this by mistake. After seeing the results, saw it wasn't right, and then went back in to see what needed to be corrected.
- ska 6y ago
  > especially interesting that nobody has done it before I'd be astonished if this hasn't been done before, at least several times in variations. However, someone having done it, and you and I finding out about it, are very different things. And the latter is much, much easier today than it was for most of the life of this lens.
- lm28469 6y ago
  > especially interesting that nobody has done it before I know a few people who toy with lenses and very often remove, invert or replace elements (with elements from other lenses) This is making the "news" because today everyone is looking for that sweet sweet internet karma Explore a few hobbyist forums and discords and you'll find plenty of crazy modifications that aren't talked about on petapixel
imwillofficial 6y ago
Seriously cool. I love creative accidents like this. True hacker culture.
- dylan604 6y ago
  I'd love to see video recorded this way. Looks like it has lots of potential for those "characters take psychedelics" parts of the script.
  - imwillofficial 6y ago
    I love where your head is at. That instantly reminded me of this clip. I adore this song because of it. https://www.youtube.com/watch?v=oNHP5Z7RZcA https://www.youtube.com/watch?v=oNHP5Z7RZcA
wingspar 6y ago
(2018)
echelon 6y ago
At some point all of these effects would probably be better to produce computationally. Lens hacks result in lost signal. You're sending fewer photons to less surface area, and you're losing readings. The cameras of the future might look a lot less like the ones we have today: stereo and light field capture, explosion of sensors, and design that incorporates both advances in optics as well as ML-assisted optimization. edit: -3 :( I've got unpopular opinions as always, I suppose. We'll see how it pans out in ten years. I predict we're in for a sea of changes. Photogrammetry is going to be huge.
- postalrat 6y ago
  Most information is lost when light hits the sensor. You mentioned a few ways we might be able to capture more of that. But until we get all that we can play with that information through lenses.
- nomel 6y ago
  Many of these effects cannot be produced without a depth map, since distance to the lens is part of the maths.
IgorPartola 6y ago
As an amateur photographer… can someone smarter/more educated than me explain to me why practically I would prefer this over a computational solution? This looks really cool, but there are dozens of apps and filters out there that do stuff like this, no? That’s not to take away from how cool this is, just asking as a practical thing why someone else beside the person in question would buy another lease and do this vs use a digital solution to get a similar effect.
- taeric 6y ago
  Same reason folks generally like kaleidoscopes, but I don't see as many of those in screen savers anymore. That is, I don't think there is an objective answer. A lot of the fun in this is the unexpected and unrepeatable nature of the results.
- udev 6y ago
  An extreme version of your question: Why even bother taking pictures? Just ray-trace or otherwise render your images.
- LASR 6y ago
  It’s same reason you’ve already outlined. It’s cool. With computational capabilities these days, you can really get whatever look like purely through software.
- dv_dt 6y ago
  Serendipity in the real world can produce effects that you may not think to work to create digitally. On the flip side, digital processing can do things that would be a pain to do with a physical pipeline. Imho more possibilities from all avenues makes for a richer world.
- dylan604 6y ago
  Why would anybody do anything in camera vs digital? Because somethings just aren't the same when done in post. Is this one of them? Maybe the person doing something physically isn't a software person to make something that doesn't exist now, but they have old lenses laying around and are not afraid to tinker. Much faster results. The "bokeh" from these smart phone cameras are still annoyingly not right, so there's that aspect as well.
mmastrac 6y ago
Better title might be 'A "Magic Bokeh" Lens Modification' - from the original YouTube video.
Sharlin 6y ago
The Zeiss, like the huge majority of ~50mm lenses in existence, is a so-called Double-Gauss design [1] (yes, that Gauss [2]). The role of the interior doublet is mostly to reduce aberrations, so reversing it basically has the opposite effect (at least spherical and chromatic aberration appear to go crazy). Would be interesting to see some raytrace diagrams of the modified lens. [1] https://en.wikipedia.org/wiki/Double-Gauss_lens https://en.wikipedia.org/wiki/Double-Gauss_lens [2] https://en.wikipedia.org/wiki/Carl_Friedrich_Gauss https://en.wikipedia.org/wiki/Carl_Friedrich_Gauss
- formerly_proven 6y ago
  Even the most modern "ultra high performance" 50 mm lenses still have a Double Gauss lens at their core. For example, here's the Nikon Z 50/1.8S: https://imgsv.imaging.nikon.com/lineup/lens/z-mount/z_50mmf18s/img/lensconstruction.png https://imgsv.imaging.nikon.com/lineup/lens/z-mount/z_50mmf1... Doesn't take much guessing where the aperture is in this lens.
nsxwolf 6y ago
I'm not seeing any photos on that article. Server load issue?
deleted 6y ago
[deleted]
JohnMalkovite 6y ago
How could I recreate this effect with an app/website ?
- vipa123 6y ago
  1. Buy two of those lenses, modify one to cause this effect. 2. Take tens of thousands (possibly orders of magnitude more, possibly less) of photographs of the exact same scene with near identical lighting conditions. 3. Use both sets to train a deep learning algorithm to take input photographs and produce the same output. 4. Grow dataset until reached desired look for general input photograph.
- ska 6y ago
  > How could I recreate this effect with an app/website ? Poorly, if experience with similar things has anything to teach us.
dukeofdoom 6y ago
This is actually probably more useful for video. Many story lines contain a dream outer world sequence. Or just a romantic interlude of a flower. Lots of applications, this could be use to create a certain feelings and emotions.
- techrat 6y ago
  My first thought when I saw the images... Drug sequences in Dredd. Very similar soft and slightly haunting quality.
Eric_WVGG 6y ago
Funny… just thirty minutes ago I was giving a sort of guest lecture to some UX students, one of my key talking points was that old “should designers learn to code?” chestnut. (If you're not familiar, and want to see dozens or hundreds of people instantly start arguing on Twitter, go ahead and ask.) I come down firmly on the side of “yes,” and started my explanation of why with the photographic work of Salvador Dali. The guy was an absolute darkroom master. He wasn’t just a person who had a vivid imagination and could paint, he had an engineer’s understanding of optics, physics and the chemistry of photography. This led into a sort of point about programming not being an end to itself, but that programming is a part of of the toolbelt of a modern digital designer. ANYWAY. This guy, not just busting out a camera and photoshop, but actually taking apart and rebuilding lenses, more of this. Get dirty with your tools.
- shahar2k 6y ago
  100% correct, I am an artist working in realtime visual effects (previsualization) and it's surprising how often knowledge of how realtime 3d works on the hardware and software end enhances what I can do with my art! (and how little fellow artists want anything to do with anything technical) there's so much you can do if you realize how textures are mapped or what gets affected by polygon sorting order...
  - paulmd 6y ago
    I don't work in computer graphics, but I've always gone the other direction and been amused by the analogies of digital image processing to the physical ones. An example is the "contrast-adaptive sharpening" that AMD introduced a while back in their driver. I've been using contrast-adaptive sharpening for a long time in my film development. I use a developer (Agfa Rodinal, with many clones such as Compard R09) with a solvent effect that tends to increase edge sharpness. If you use it in high dilution without any agitation then highlights or sharp edges will tend to "locally deplete" the developer and reduce the rate of development. In combination with the edge-enhancing nature, this compensating effect tends to help reduce the haloing from the sharpening (and of course it also helps pull your highlights back a bit in general). Which is basically what contrast-adaptive sharpening does! And of course there's all those skeumorphic terms we've adopted that we no longer consciously think about the origins of. Dodging and burning, unsharp masks, and airbrushing are all real things that people used to do by hand!
deleted 6y ago
[deleted]
supernova87a 6y ago
I would love to know from someone knowledgeable -- How is a new lens design made nowadays, and is there much innovation still in lens design? I mean, seems like aside from zoom lenses, the designs were done (by hand! and slide rule) 100 to 50 years ago. What do you do now? Have a ray tracing linear solver with constraints about refractive index, desired weight, number of elements, distortions, etc. (and cost!) factor all these things in and see what multiple lens stack it comes out with? Or is it just small variations on known proven designs now?
- paulmd 6y ago
  (I don't work in the field, I just do photography as a hobby, but as let's say an "advanced amateur" interested in lens design and history:) CNC optical design really hit big in the 90s. The problem space for lens design is obviously high-dimensional and large (number of elements, element composition, element placement, element size, curvature of each optical surface, cement between the elements...) and that made it possible to just brute-force a bunch of different lenses and tune it all. For prime lenses, that pretty much solved "reasonable" lenses for "reasonable" angles of view, "reasonable" aperture/intensity, and "reasonable" numbers of elements. A 7 element lens of a particular focal length, designed in the 90s, is significantly better than one designed in the 70s, but probably about the same as today. There has still been significant progress made on the "unreasonable" lenses. For example f/1.4 lenses from the 50s were poor wide open, from the 70s they are mediocre, in the 90s they were decent, modern lenses they are excellent wide open. Superfast lenses, superwide lenses, super-sharp lenses, and lenses optimized for beyond-visual light or wide-spectrum photography (IR or UV at the same time as visible light) have all benefited significantly since the 90s. Lenses have been moving to more and more elements over time, as well as using more exotic shapes and materials, all of which gives more ability to correct the image. A lens from the 50s would have been around 5-7 elements, all spherical (all surfaces are a sphere of some radius), using basic types of glass. A modern superlens will incorporate several ultra-low dispersion elements (typically grown fluorite crystals) and use at least one aspherical element, on top of having a significantly higher number of elements in general (7 elements was a lot in the 70s, modern prime lenses might have 12-14, with 3-4 of them being exotic). This may seem like an obvious statement but optics are a very complex materials science problem and on top of the optical design the materials and manufacturing have become much more advanced over time. At the dawn of photography, basic crown glass and flint glass was about all that was available. The coatings are also very important - every time a beam of light goes from air to glass or vice versa, it refracts a bit. Many of the modern optical designs used in the 70s to 90s were actually known quite early - the Planar lens type (used in your standard 50mm f/1.8 lens) was invented in 1896, and the Plasmat type was invented in 1918, but the number of air-glass interfaces meant the contrast was very low on those early lenses and it was not practical. Instead, fewer elements produced more contrast (because of fewer air-glass interfaces) and elements were often cemented together with balsam pitch so that you didn't have to have an air-glass interface between them (for example in the Cooke Triplet or Zeiss Sonnar designs). More advanced designs had to wait for the advent of coatings just before World War 2, and then there was an explosion of designs after the war. And multi-coatings (Pentax SMC was the early winner) did the same in the 70s, and the expiration of the SMC patents enabled another explosion in the 00's. The same applies to glass types and other components of the lenses, most recently aspheric elements and fluorite. And yes as you mention it has always been hard to design good zoom lenses, they are as complex as a "super" prime lens even with a relatively modest zoom range and relatively slow aperture. "Superzoom" lenses covering a giant zoom range are even harder to do. The 70-200mm type has been around a long time and good 70-200 designs were available in the 70s for the professional market, then in the 2000s the pro market got 24-70 f/2.8 and 24-105 f/4 types, and more recently there's been some good consumer ones like 17-50 f/2.8 or 18-35 f/1.8. So the field of zoom lenses is still very much advancing. so tl;dr basic prime lenses were "solved" in the 90s, really high-end prime lenses that do exotic things and zoom lenses are still making progress by increasing numbers of elements and using more exotic elements.
towergratis 6y ago
Magic bokeh? No offense, but it's horrible and nothing magic about it.
bdamm 6y ago
Kinda neat. Many of these remind me of observing a solar eclipse, where trees cast shadows with zillions of little crescents. Fun to experience in person, but distracting to see in an image because I get the distinct "something is not right here" feeling. Now to really make it art, figure out how to say something with the effect. A portrait would have been a nice addition to the collection. How would it change the feeling of looking at a face?
rozab 6y ago
It seems like this type of lens has been available since the 1920s, and there would have been nothing stopping, say, the German Expressionists from using this sort of technique? I love seeing this sort of thing, it's part of why I find modern demoscene so fascinating.
mrwh 6y ago
Reminds me of realising years and years ago that one can make a macro lens by reversing a normal prime. (Which I know! Everyone knows that, you can even get proper adapters for it, but it was a genuine discovery for me at the time.) Doing things in camera, rather than later in software, just is more enjoyable for a lot of photographers. I know I find it more fun.
- paulmd 6y ago
  even better, you can use a reversed prime as a loupe to view slides!
- ksml 6y ago
  I've been shooting for 10 years and didn't know this at all!! I just saw a photo of a lens mounted in reverse and my mind is blown. Time to go down a rabbit hole trying to understand why this works...
  - paulmd 6y ago
    lenses pass light in both directions, if you flip it around then it bends the light the opposite way ;) http://hyperphysics.phy-astr.gsu.edu/hbase/geoopt/image.html#c1 http://hyperphysics.phy-astr.gsu.edu/hbase/geoopt/image.html... the lens is designed to take rays traveling from optical infinity, and converge all those rays at a focal plane that's (eg) 30 millimeters away, right? well, if you flip the lens around backwards, then it will send out rays towards optical infinity from a focal plane that's 30mm away... which is what a macro lens is. in fact in the old days people used to use their camera as an enlarger to expose their negative onto prints. The theory was that using the same lens that took the image in reverse would help to correct the abberations of the lens... I am not sure that's actually supportable compared to using a real enlarger lens that's optimized for high-magnification work but it's a neat theory, and possibly better than just using a random crap enlarger lens ;) now if you really want to have fun... ever wonder why diffraction makes your image softer at smaller apertures? ;) https://www.cambridgeincolour.com/tutorials/diffraction-photography.htm https://www.cambridgeincolour.com/tutorials/diffraction-phot...
  - michrassena 6y ago
Scene_Cast2 6y ago
So most lens design software I've seen is optimized for a "scientific instrument" workflow - optimizing for sharpness across spectrum and angle. Is there software that helps with artistic lens design?
- paulmd 6y ago
  "perfect" optical performance is something that you can mathematically express, while whether an abberation is "pleasing" depends on the person and the scene it's used on. There is no mathematical formula that says a Petzval portrait looks nice and many people would say they don't. I think the three easiest factors in a "pleasing" image are spherical abberation, apodization, and field curvature. Spherical abberation is what makes a soft-focus lens soft, and a slight amount of spherical abberation is responsible for the famous "Leica glow". People generally find at least a small amount of this abberation to be pleasing. "Bokeh" is the rendering of the out-of-focus areas of an image, and it's the combination of a number of optical factors. Highlights in the bokeh area will take on the shape of the aperture. Crudely, if you cut a dick shaped hole in a piece of paper, then tape it over your lens, you will have dick-shaped highlights. Apodization basically is the idea that if instead of a hard aperture, you use a neutral-density filter that gets darker at the edges, then your bokeh won't have hard edges, it'll have a gradient. STF lenses use a separate aperture with one of these gradient filters to alter the edges of the bokeh so it's smooth. Other abberations also manifest in the bokeh - uncorrected sagittal field curvature will result in the "swirlies" of a Petzval lens, and spherical abberation likely helps smooth out the bokeh a bit as well. if your software gives you metrics for these optical abberations... that would be a good place to start. tbh someone else mentioned Lytro and this is something they would have been good at. Take an "accurate" lightfield image and you could reproject it as if it had come through a different (not accurate) lens. From what I know the resolution on Lytros was never that great, but maybe you could do something similar with a custom Reshade filter in video games, change the rendering characteristics of a game in accordance with the optical characteristics of some lens. Perhaps raytracing might be useful to model the exact optical behavior of the rays inside the lens in realtime... (what software are you using btw? anything available for free / at a semi reasonable cost? I've always thought it would be interesting to try single-point-turning custom elements and building my own custom lenses... completely absurd idea but neat to think about.)
hatsunearu 6y ago
I wish there was a way to learn more about photographic lens design. Seems completely inaccessible. I wanted to create some basic lenses from scrap parts (this has been done before by others)
smcameron 6y ago
He can flip a lens, but he can't rotate his phone 90 degrees?

181 points by colinprince 6y ago

Here's hoping the swirly/crazy bokeh phase is soon over.

that's interesting, especially interesting that nobody has done it before, considering the amount of money there are in specialty lenses.. This is somewhat an example of "if that was a dollar, someone would have picked it up already"

Arainach 6y ago
The money in lenses goes towards more predictability - sharper, wider aperture, faster to focus, smooth bokeh for portraits - or technical achievements like ultratelephoto lenses. The people who can pay are looking for those features, not random effects. The value here is in novelty - it doesn't look like anything else. If it was mass produced, demand for the effect would likely go down, not up. And it's certainly not without compromise - sharpness across the entire frame in those example shots is worse than your average plastic 18-55mm kit zoom.
- wlesieutre 6y ago
  There are lenses made for unusual effects rather than optical quality, but it's more of a niche market https://microsites.lomography.com/petzval-58-bokeh-control-lens/photos/ https://microsites.lomography.com/petzval-58-bokeh-control-l... https://lensbaby.com/products/composer-pro-ii-with-sweet-50-optic https://lensbaby.com/products/composer-pro-ii-with-sweet-50-...
Sebb767 6y ago
From the sample photos it seems like the lens is rather useless this way. While some bokeh is awesome, this looks more like someone applied an LSD-filter and called it a day; nothing that you could use for a portrait. It also seems the pictures are not too sharp. Therefore, there's probably not too much money to be made. If this could be a bit smoother in the background, on the other hand ...
- Applejinx 6y ago
  I dunno. I'd buy a micro 4/3 one like a shot. I'm already using lenses from SLR magic that aren't THE sharpest possible things, but have really good bokeh and pleasing departure from perfect focus outside perfect focal distance.
dylan604 6y ago
I'd be surprised if this is truly the first time. I'm guessing that there is someone that was assembling a lens and did this by mistake. After seeing the results, saw it wasn't right, and then went back in to see what needed to be corrected.
ska 6y ago
> especially interesting that nobody has done it before I'd be astonished if this hasn't been done before, at least several times in variations. However, someone having done it, and you and I finding out about it, are very different things. And the latter is much, much easier today than it was for most of the life of this lens.
lm28469 6y ago
> especially interesting that nobody has done it before I know a few people who toy with lenses and very often remove, invert or replace elements (with elements from other lenses) This is making the "news" because today everyone is looking for that sweet sweet internet karma Explore a few hobbyist forums and discords and you'll find plenty of crazy modifications that aren't talked about on petapixel

imwillofficial 6y ago

Seriously cool. I love creative accidents like this. True hacker culture.

dylan604 6y ago
I'd love to see video recorded this way. Looks like it has lots of potential for those "characters take psychedelics" parts of the script.
- imwillofficial 6y ago
  I love where your head is at. That instantly reminded me of this clip. I adore this song because of it. https://www.youtube.com/watch?v=oNHP5Z7RZcA https://www.youtube.com/watch?v=oNHP5Z7RZcA

wingspar 6y ago

(2018)

echelon 6y ago

At some point all of these effects would probably be better to produce computationally. Lens hacks result in lost signal. You're sending fewer photons to less surface area, and you're losing readings. The cameras of the future might look a lot less like the ones we have today: stereo and light field capture, explosion of sensors, and design that incorporates both advances in optics as well as ML-assisted optimization. edit: -3 :( I've got unpopular opinions as always, I suppose. We'll see how it pans out in ten years. I predict we're in for a sea of changes. Photogrammetry is going to be huge.

postalrat 6y ago
Most information is lost when light hits the sensor. You mentioned a few ways we might be able to capture more of that. But until we get all that we can play with that information through lenses.
nomel 6y ago
Many of these effects cannot be produced without a depth map, since distance to the lens is part of the maths.

IgorPartola 6y ago

As an amateur photographer… can someone smarter/more educated than me explain to me why practically I would prefer this over a computational solution? This looks really cool, but there are dozens of apps and filters out there that do stuff like this, no? That’s not to take away from how cool this is, just asking as a practical thing why someone else beside the person in question would buy another lease and do this vs use a digital solution to get a similar effect.

taeric 6y ago
Same reason folks generally like kaleidoscopes, but I don't see as many of those in screen savers anymore. That is, I don't think there is an objective answer. A lot of the fun in this is the unexpected and unrepeatable nature of the results.
udev 6y ago
An extreme version of your question: Why even bother taking pictures? Just ray-trace or otherwise render your images.
LASR 6y ago
It’s same reason you’ve already outlined. It’s cool. With computational capabilities these days, you can really get whatever look like purely through software.
dv_dt 6y ago
Serendipity in the real world can produce effects that you may not think to work to create digitally. On the flip side, digital processing can do things that would be a pain to do with a physical pipeline. Imho more possibilities from all avenues makes for a richer world.
dylan604 6y ago
Why would anybody do anything in camera vs digital? Because somethings just aren't the same when done in post. Is this one of them? Maybe the person doing something physically isn't a software person to make something that doesn't exist now, but they have old lenses laying around and are not afraid to tinker. Much faster results. The "bokeh" from these smart phone cameras are still annoyingly not right, so there's that aspect as well.

mmastrac 6y ago

Better title might be 'A "Magic Bokeh" Lens Modification' - from the original YouTube video.

Sharlin 6y ago

The Zeiss, like the huge majority of ~50mm lenses in existence, is a so-called Double-Gauss design [1] (yes, that Gauss [2]). The role of the interior doublet is mostly to reduce aberrations, so reversing it basically has the opposite effect (at least spherical and chromatic aberration appear to go crazy). Would be interesting to see some raytrace diagrams of the modified lens. [1] https://en.wikipedia.org/wiki/Double-Gauss_lens https://en.wikipedia.org/wiki/Double-Gauss_lens [2] https://en.wikipedia.org/wiki/Carl_Friedrich_Gauss https://en.wikipedia.org/wiki/Carl_Friedrich_Gauss

formerly_proven 6y ago
Even the most modern "ultra high performance" 50 mm lenses still have a Double Gauss lens at their core. For example, here's the Nikon Z 50/1.8S: https://imgsv.imaging.nikon.com/lineup/lens/z-mount/z_50mmf18s/img/lensconstruction.png https://imgsv.imaging.nikon.com/lineup/lens/z-mount/z_50mmf1... Doesn't take much guessing where the aperture is in this lens.

nsxwolf 6y ago

I'm not seeing any photos on that article. Server load issue?

deleted 6y ago

[deleted]

JohnMalkovite 6y ago

How could I recreate this effect with an app/website ?

vipa123 6y ago
1. Buy two of those lenses, modify one to cause this effect. 2. Take tens of thousands (possibly orders of magnitude more, possibly less) of photographs of the exact same scene with near identical lighting conditions. 3. Use both sets to train a deep learning algorithm to take input photographs and produce the same output. 4. Grow dataset until reached desired look for general input photograph.
ska 6y ago
> How could I recreate this effect with an app/website ? Poorly, if experience with similar things has anything to teach us.

dukeofdoom 6y ago

This is actually probably more useful for video. Many story lines contain a dream outer world sequence. Or just a romantic interlude of a flower. Lots of applications, this could be use to create a certain feelings and emotions.

techrat 6y ago
My first thought when I saw the images... Drug sequences in Dredd. Very similar soft and slightly haunting quality.

Eric_WVGG 6y ago

Funny… just thirty minutes ago I was giving a sort of guest lecture to some UX students, one of my key talking points was that old “should designers learn to code?” chestnut. (If you're not familiar, and want to see dozens or hundreds of people instantly start arguing on Twitter, go ahead and ask.) I come down firmly on the side of “yes,” and started my explanation of why with the photographic work of Salvador Dali. The guy was an absolute darkroom master. He wasn’t just a person who had a vivid imagination and could paint, he had an engineer’s understanding of optics, physics and the chemistry of photography. This led into a sort of point about programming not being an end to itself, but that programming is a part of of the toolbelt of a modern digital designer. ANYWAY. This guy, not just busting out a camera and photoshop, but actually taking apart and rebuilding lenses, more of this. Get dirty with your tools.

shahar2k 6y ago
100% correct, I am an artist working in realtime visual effects (previsualization) and it's surprising how often knowledge of how realtime 3d works on the hardware and software end enhances what I can do with my art! (and how little fellow artists want anything to do with anything technical) there's so much you can do if you realize how textures are mapped or what gets affected by polygon sorting order...
- paulmd 6y ago
  I don't work in computer graphics, but I've always gone the other direction and been amused by the analogies of digital image processing to the physical ones. An example is the "contrast-adaptive sharpening" that AMD introduced a while back in their driver. I've been using contrast-adaptive sharpening for a long time in my film development. I use a developer (Agfa Rodinal, with many clones such as Compard R09) with a solvent effect that tends to increase edge sharpness. If you use it in high dilution without any agitation then highlights or sharp edges will tend to "locally deplete" the developer and reduce the rate of development. In combination with the edge-enhancing nature, this compensating effect tends to help reduce the haloing from the sharpening (and of course it also helps pull your highlights back a bit in general). Which is basically what contrast-adaptive sharpening does! And of course there's all those skeumorphic terms we've adopted that we no longer consciously think about the origins of. Dodging and burning, unsharp masks, and airbrushing are all real things that people used to do by hand!

deleted 6y ago

[deleted]

supernova87a 6y ago

I would love to know from someone knowledgeable -- How is a new lens design made nowadays, and is there much innovation still in lens design? I mean, seems like aside from zoom lenses, the designs were done (by hand! and slide rule) 100 to 50 years ago. What do you do now? Have a ray tracing linear solver with constraints about refractive index, desired weight, number of elements, distortions, etc. (and cost!) factor all these things in and see what multiple lens stack it comes out with? Or is it just small variations on known proven designs now?

paulmd 6y ago
(I don't work in the field, I just do photography as a hobby, but as let's say an "advanced amateur" interested in lens design and history:) CNC optical design really hit big in the 90s. The problem space for lens design is obviously high-dimensional and large (number of elements, element composition, element placement, element size, curvature of each optical surface, cement between the elements...) and that made it possible to just brute-force a bunch of different lenses and tune it all. For prime lenses, that pretty much solved "reasonable" lenses for "reasonable" angles of view, "reasonable" aperture/intensity, and "reasonable" numbers of elements. A 7 element lens of a particular focal length, designed in the 90s, is significantly better than one designed in the 70s, but probably about the same as today. There has still been significant progress made on the "unreasonable" lenses. For example f/1.4 lenses from the 50s were poor wide open, from the 70s they are mediocre, in the 90s they were decent, modern lenses they are excellent wide open. Superfast lenses, superwide lenses, super-sharp lenses, and lenses optimized for beyond-visual light or wide-spectrum photography (IR or UV at the same time as visible light) have all benefited significantly since the 90s. Lenses have been moving to more and more elements over time, as well as using more exotic shapes and materials, all of which gives more ability to correct the image. A lens from the 50s would have been around 5-7 elements, all spherical (all surfaces are a sphere of some radius), using basic types of glass. A modern superlens will incorporate several ultra-low dispersion elements (typically grown fluorite crystals) and use at least one aspherical element, on top of having a significantly higher number of elements in general (7 elements was a lot in the 70s, modern prime lenses might have 12-14, with 3-4 of them being exotic). This may seem like an obvious statement but optics are a very complex materials science problem and on top of the optical design the materials and manufacturing have become much more advanced over time. At the dawn of photography, basic crown glass and flint glass was about all that was available. The coatings are also very important - every time a beam of light goes from air to glass or vice versa, it refracts a bit. Many of the modern optical designs used in the 70s to 90s were actually known quite early - the Planar lens type (used in your standard 50mm f/1.8 lens) was invented in 1896, and the Plasmat type was invented in 1918, but the number of air-glass interfaces meant the contrast was very low on those early lenses and it was not practical. Instead, fewer elements produced more contrast (because of fewer air-glass interfaces) and elements were often cemented together with balsam pitch so that you didn't have to have an air-glass interface between them (for example in the Cooke Triplet or Zeiss Sonnar designs). More advanced designs had to wait for the advent of coatings just before World War 2, and then there was an explosion of designs after the war. And multi-coatings (Pentax SMC was the early winner) did the same in the 70s, and the expiration of the SMC patents enabled another explosion in the 00's. The same applies to glass types and other components of the lenses, most recently aspheric elements and fluorite. And yes as you mention it has always been hard to design good zoom lenses, they are as complex as a "super" prime lens even with a relatively modest zoom range and relatively slow aperture. "Superzoom" lenses covering a giant zoom range are even harder to do. The 70-200mm type has been around a long time and good 70-200 designs were available in the 70s for the professional market, then in the 2000s the pro market got 24-70 f/2.8 and 24-105 f/4 types, and more recently there's been some good consumer ones like 17-50 f/2.8 or 18-35 f/1.8. So the field of zoom lenses is still very much advancing. so tl;dr basic prime lenses were "solved" in the 90s, really high-end prime lenses that do exotic things and zoom lenses are still making progress by increasing numbers of elements and using more exotic elements.

towergratis 6y ago

Magic bokeh? No offense, but it's horrible and nothing magic about it.

bdamm 6y ago

Kinda neat. Many of these remind me of observing a solar eclipse, where trees cast shadows with zillions of little crescents. Fun to experience in person, but distracting to see in an image because I get the distinct "something is not right here" feeling. Now to really make it art, figure out how to say something with the effect. A portrait would have been a nice addition to the collection. How would it change the feeling of looking at a face?

rozab 6y ago

It seems like this type of lens has been available since the 1920s, and there would have been nothing stopping, say, the German Expressionists from using this sort of technique? I love seeing this sort of thing, it's part of why I find modern demoscene so fascinating.

mrwh 6y ago

Reminds me of realising years and years ago that one can make a macro lens by reversing a normal prime. (Which I know! Everyone knows that, you can even get proper adapters for it, but it was a genuine discovery for me at the time.) Doing things in camera, rather than later in software, just is more enjoyable for a lot of photographers. I know I find it more fun.

paulmd 6y ago
even better, you can use a reversed prime as a loupe to view slides!
ksml 6y ago
I've been shooting for 10 years and didn't know this at all!! I just saw a photo of a lens mounted in reverse and my mind is blown. Time to go down a rabbit hole trying to understand why this works...
- paulmd 6y ago
  lenses pass light in both directions, if you flip it around then it bends the light the opposite way ;) http://hyperphysics.phy-astr.gsu.edu/hbase/geoopt/image.html#c1 http://hyperphysics.phy-astr.gsu.edu/hbase/geoopt/image.html... the lens is designed to take rays traveling from optical infinity, and converge all those rays at a focal plane that's (eg) 30 millimeters away, right? well, if you flip the lens around backwards, then it will send out rays towards optical infinity from a focal plane that's 30mm away... which is what a macro lens is. in fact in the old days people used to use their camera as an enlarger to expose their negative onto prints. The theory was that using the same lens that took the image in reverse would help to correct the abberations of the lens... I am not sure that's actually supportable compared to using a real enlarger lens that's optimized for high-magnification work but it's a neat theory, and possibly better than just using a random crap enlarger lens ;) now if you really want to have fun... ever wonder why diffraction makes your image softer at smaller apertures? ;) https://www.cambridgeincolour.com/tutorials/diffraction-photography.htm https://www.cambridgeincolour.com/tutorials/diffraction-phot...
- michrassena 6y ago

Scene_Cast2 6y ago

So most lens design software I've seen is optimized for a "scientific instrument" workflow - optimizing for sharpness across spectrum and angle. Is there software that helps with artistic lens design?

paulmd 6y ago
"perfect" optical performance is something that you can mathematically express, while whether an abberation is "pleasing" depends on the person and the scene it's used on. There is no mathematical formula that says a Petzval portrait looks nice and many people would say they don't. I think the three easiest factors in a "pleasing" image are spherical abberation, apodization, and field curvature. Spherical abberation is what makes a soft-focus lens soft, and a slight amount of spherical abberation is responsible for the famous "Leica glow". People generally find at least a small amount of this abberation to be pleasing. "Bokeh" is the rendering of the out-of-focus areas of an image, and it's the combination of a number of optical factors. Highlights in the bokeh area will take on the shape of the aperture. Crudely, if you cut a dick shaped hole in a piece of paper, then tape it over your lens, you will have dick-shaped highlights. Apodization basically is the idea that if instead of a hard aperture, you use a neutral-density filter that gets darker at the edges, then your bokeh won't have hard edges, it'll have a gradient. STF lenses use a separate aperture with one of these gradient filters to alter the edges of the bokeh so it's smooth. Other abberations also manifest in the bokeh - uncorrected sagittal field curvature will result in the "swirlies" of a Petzval lens, and spherical abberation likely helps smooth out the bokeh a bit as well. if your software gives you metrics for these optical abberations... that would be a good place to start. tbh someone else mentioned Lytro and this is something they would have been good at. Take an "accurate" lightfield image and you could reproject it as if it had come through a different (not accurate) lens. From what I know the resolution on Lytros was never that great, but maybe you could do something similar with a custom Reshade filter in video games, change the rendering characteristics of a game in accordance with the optical characteristics of some lens. Perhaps raytracing might be useful to model the exact optical behavior of the rays inside the lens in realtime... (what software are you using btw? anything available for free / at a semi reasonable cost? I've always thought it would be interesting to try single-point-turning custom elements and building my own custom lenses... completely absurd idea but neat to think about.)

hatsunearu 6y ago

I wish there was a way to learn more about photographic lens design. Seems completely inaccessible. I wanted to create some basic lenses from scrap parts (this has been done before by others)

smcameron 6y ago

He can flip a lens, but he can't rotate his phone 90 degrees?