[HN Gopher] iPhone Macro: A Big Day for Small Things
___________________________________________________________________
iPhone Macro: A Big Day for Small Things
Author : lalmachado
Score : 158 points
Date : 2021-10-11 10:22 UTC (3 days ago)
(HTM) web link (lux.camera)
(TXT) w3m dump (lux.camera)
| sudosysgen wrote:
| My Poco F3 does that too - it can actually focus even closer.
| It's quite useful for reading markings.
|
| That said, I often break out my camera and use it's macro lens
| when I need serious resolving power.
| throwanem wrote:
| I've tried this functionality in Halide on my 12 mini, and it's
| not half bad in good light. No doubt the 13s with built-in macro
| do better, and it's certainly nowhere near the same realm as the
| D850 and 105mm macro lens I use for real [1] work [2], but it's
| not a bad capability to have in a device that fits in a pocket.
|
| [1] https://aaron-m.com/wp-content/uploads/2021/01/DSC1250-1.jpg
|
| [2] https://aaron-m.com/wp-
| content/uploads/2020/08/DSC0772-240dp...
| uuddlrlr wrote:
| Content warning: bug on bug violence
|
| Gorgeous shots tho
| packetslave wrote:
| Here's the thing about iPhone photography (and Android too, I
| suppose): if you know what a DSLR is, or the difference between
| DSLR and mirrorless bodies, _you are not the target audience_.
|
| Apple isn't trying compete with a $3500 Sony A7R4 with a $1000
| 90mm macro lens. They're aiming for people who see the example
| "macro" photos and say "neat! I want to try that". Or the people
| who have already bought a Moment macro lens (or one of the other
| clip-on/screw-on iPhone macro lenses) and are tired of carrying
| it around.
|
| _edit: formatting_
| marcellus23 wrote:
| Also always worth bringing up in these discussions: the best
| camera is the one you have with you. A DSLR is obviously a
| better camera, but you usually don't have one on you 24/7.
| packetslave wrote:
| The best camera you have with you _with the lens you have on
| it at the time_.
|
| If I have to pick which of my heavy glass to carry around
| with me on a regular basis, the 90mm macro is going to stay
| on the shelf most days unless I'm specifically going out to
| shoot macro photos.
|
| My iPhone Pro 13 is always going to be in my pocket.
| matwood wrote:
| > if you know what a DSLR is, or the difference between DSLR
| and mirrorless bodies, you are not the target audience.
|
| I disagree. I have both a dslr and mirrorless bodies and love
| that my 12pro also takes great pictures. Anyone who enjoys
| taking pictures should be excited about the cameras improving
| on an always with you device.
| megablast wrote:
| What are you talking about??
|
| Sole us continuously improving their cameras on every iPhone
| release. They spend a lot of money on doing it.
|
| They don't care about competing with anyone. That is not their
| mindset. They just get better every year.
|
| You are making up a rivalry that doesn't exist.
| amelius wrote:
| It's the other way around. People with iPhones look at
| professional photography and will say "I want that too", and
| they're disappointed if their iPhone can't do it, so Apple
| makes sure it can.
| [deleted]
| PragmaticPulp wrote:
| I think the cellphone versus DSLR/mirrorless debate is largely
| an artificial internet debate.
|
| Every real-world photographer I know is very happy that they
| can have both a cellphone and a full-size camera and choose
| appropriately for the situation.
| lm28469 wrote:
| > Apple isn't trying compete with a $3500 Sony A7R4 with a
| $1000 90mm macro lens
|
| tbh something like a Nikon d300 with a 200$ lens does a better
| job in good light
| mithr wrote:
| I think that's largely true -- if you frequently need to take
| professional macro shots, you'll already have your own, better
| setup anyhow, and won't be switching to a phone camera anytime
| soon. However, somewhat surprisingly (for me at least), this
| seems to actually be good enough to _also_ satisfy those that
| do carry fancy cameras, but don 't need to take macro shots
| that often... from https://austinmann.com/trek/iphone-13-pro-
| camera-review-tanz...:
|
| > As a photographer passionate about the natural world, I carry
| a macro lens with me no matter what project I'm working on,
| just because I never know what tiny detail of interest might
| present itself. Now with the macro capability of the iPhone 13
| Pro, I feel like I have my "in-a-pinch" macro shots covered and
| I can leave the rarely-used macro lens at home.
| tshaddox wrote:
| I would have guessed quite the opposite: that people who know
| about and use DSLRs would be particularly interested in
| advancements in smartphone photography. I would have guessed
| that such people probably use their smartphone cameras more
| often (and more deliberately) than other people use their
| smartphone cameras. Heck, I bet a lot of these people even use
| their smartphone cameras more often than they use their DSLRs.
| Someone wrote:
| I think the group of people who know about and use DSLRs is
| too small to be the target audience of any of Apple's
| smartphones.
|
| Other smartphone manufacturers might be willing to do a
| product for, at best, a few million users, but Apple thinks
| focusing on fewer products is the better choice (for them,
| and, possibly, for all users because Apple can spend more
| effort on each design)
|
| I would guess Apple's target audience is everybody who wants
| to make better photos, whether they know about DSLRs or not.
|
| Yes, they have RAW support, but I think they find that a nice
| to have, not a must for their product.
| fastaguy88 wrote:
| It is may be worth mentioning that it is very difficult to get
| such amazing pictures without a very stable setup -- both for the
| subject and for the camera. Even if you have enough light for a
| high shutter speed, it can be difficult to compose a macro shot
| if there is any motion at all. And, as was pointed out,
| lighting/shadows can be tricky when the "camera" lens is just a
| few inches away.
| ip26 wrote:
| Forget about composing the shot, it's often even a struggle
| just to keep the depth of field centered where you want it.
| (Apple might be handling that via smarter autofocus, though)
|
| A little sway left or right can be cropped away, but missed
| focus ruins the shot.
| throwanem wrote:
| Halide does focus peaking, albeit only in manual-focus mode.
|
| In general, though, you're right - I wouldn't want to try for
| the same kinds of shots with a phone that I get with a DSLR. My
| macro rig weighs about five pounds, which sounds like a lot and
| _is_ in comparison with a phone, but between the damping effect
| of all that mass and the ability to get a good grip with both
| hands, it makes for a much more stable platform overall.
| brudgers wrote:
| Yes. "Use a friggin tripod" still applies. So does "bring your
| own damn light."
| CharlesW wrote:
| Also, you can avoid touching the iPhone when you shoot by
| using a timer, a Bluetooth shutter remote, or your Apple
| Watch (Halide has a watchOS companion app).
| fudged71 wrote:
| Surprised to see zero mention of ring lights. A small ring light
| would be perfect for iPhone macros.
| jagger27 wrote:
| That's a neat idea for an accessory. I bet you could make a
| little stick-on or clip-on light pipe that redirects the built-
| in flash to a tiny ring diffuser around the macro lens.
| slowhand09 wrote:
| Google it - theres about a million...
| smoldesu wrote:
| I see a Lux article, I almost always skip it. Fair warning,
| basically every article I've ever read from this site was a fluff
| piece intended to take a hit for Apple, promote their iOS-
| exclusive app or both.
| renewiltord wrote:
| The iPhone lens swap trick that it does can be triggered by
| holding your fingers over the lenses. You'll see that as your
| finger approaches the lens, it will get bigger until it suddenly
| disappears when it covers the lens! Very cool!
| wyldfire wrote:
| This company makes a software product called "Halide" for your
| mobile camera, AFAICT it is an iOS app [1].
|
| But interestingly enough there's an image processing programming
| language called halide, too [2].
|
| [1] https://halide.cam/
|
| [2] https://halide-lang.org/
| [deleted]
| sandofsky wrote:
| This comes up every time a post makes it to Hacker News. I can
| only speak for the camera app, but I assume the language also
| refers to silver halide, a chemical used in film photography.
|
| https://en.wikipedia.org/wiki/Silver_halide
| novok wrote:
| Apple's crop / digital zoom with the 1x camera vs using the
| telephoto camera has been pretty annoying with the new iPhone 13
| pro. It fails in many cases it's not supposed to, like zooming in
| at 3x in a bright day trying to take a picture of a flying bird
| or similar in the sky.
| shoto_io wrote:
| _Wow. I can see every detail of every scuff and scratch. I need
| to take better care of my stuff._
|
| "Wow," was exactly what I thought when I saw the third crown
| image. Incredible.
| opensmtpd wrote:
| My problem with smartphone cameras(including iPhone) is that they
| completely misrepresent the scene. They try to make the colors of
| your photos as punchy as possible even when that's not actually
| what you're seeing. Older iphones used to capture accurate colors
| (which is why I preferred iphone cameras in the past) but now
| they produce the same over-saturated, over-sharpened images as
| every other phone these days.
|
| If I want to make my photos punchy, I can do that in lightroom.
| For those who don't use lightroom, you can do that in the built-
| in photos app. My old iphone 6s produces much accurate colors
| than my iphone 11. On the iphone 11, colors are way off and
| images are so over-sharpened that I can see severe haloing around
| high-contrast areas.
|
| And those awful noise-reduction watercolor textures... I wish
| they would just leave some noise as-is. Get rid of chroma noise
| (which is relatively easy), and leave some luminance noise
| around. I mean, luminance noise are actually quite nice as they
| are similar to film grain.
|
| I can get pretty close to what I want with raw(not ProRaw), but
| you know, I can't even capture raw with their default camera app
| even when they are bloating it with useless(IMHO for a stock
| camera app) features like portrait mode, cinematic mode,
| photographic styles, filters etc.
|
| I mean, I get why they are doing it; obviously because people
| like over-processed photos for their instagram. But it's my pet
| peeve...
| packetslave wrote:
| While this is obviously a promo for the Halide camera app (which
| is awesome, mind you) it's full of useful information on macro
| photography, regardless.
|
| This bit in particular caught my eye: "What makes Halide 2.5's
| Macro Mode so special? For one, it brings Macro capabilities to
| all iPhones." (not just the iPhone 13 Pro)
| ImaCake wrote:
| I am always happy to defend an advertisement that has
| informative content and is up front about it's true nature as
| an ad. An honest ad would be a win-win, consumers understand
| things more and the product, if its good, gets increased sales
| or awareness.
| dkonofalski wrote:
| I will admit that I got a little tinge of resentment when I
| realized it was an ad/announcement for their app but that
| quickly subsided when I realized that I would much rather have
| educational/informative ads like this than the alternative.
| Even if I don't download their app, I got something useful from
| this and that's ok with me.
| packetslave wrote:
| yeah, content marketing doesn't annoy me nearly as much when
| it's this good (and this isn't technically CM since they're
| open about the fact that they're announcing their new app
| version)
| flyinglizard wrote:
| Going be amazing for people working on PCBs, to read difficult
| package markings and to inspect solder pads instead of using a
| microscope.
| jkestner wrote:
| It's nice to have a do-all device, but a head-mounted dental
| loupe is hands-free and can light up your subject.
| macintux wrote:
| Or just old people like me trying to read serial numbers on
| electronics hardware.
| noneeeed wrote:
| Honestly, as someone who is starting to go long-sighted, this
| is tempting me towards getting a 13 pro (or Pixel 6 i it is
| similarly good).
|
| I frequently find myself using my phone camera to zoom in on
| ridiculously small text on things, but my phone has always
| struggled with it. Good phone macro will be a feature I would
| use all the time.
| gnicholas wrote:
| I've heard of people who are very near-sighted using their
| smartphones to help them find their glasses. Just hold the
| phone close to your face, so you can see it in focus, and
| open the camera app. Voila, you can see the whole room in
| focus!
| Tagbert wrote:
| The iPhones have a special magnifier feature specifically for
| this purpose. With one tap it opens the camera, focuses close
| and does a little digital enlargement on a live image. It
| will be interesting if they incorporate the Macro mode in
| that feature soon.
| mhb wrote:
| I don't want to interfere with a rationalization for a new
| phone, but how does your phone struggle? I use my iPhone SE
| (Gen 1) for this all the time.
| gnopgnip wrote:
| You can't really use machine learning based image upscaling for
| that type of work
| bwanab wrote:
| I feel the need to point out that Nikon has always called extreme
| closeup lenses micro instead of the oxymoronic macro the rest of
| the industry uses:
| https://imaging.nikon.com/lineup/lens/f-mount/#special.
| cfjgvjh wrote:
| That's because the original micro lenses were commissioned to
| resolve images of microfilms iirc[1] (See under 1962), and
| doesn't really have anything to do with the macro/micro
| relationship.
|
| [1] -
| https://www.nikon.com/about/corporate/history/chronology/194...
| dkonofalski wrote:
| These kinds of comments are what I miss seeing in the
| majority of posts on HN. Thanks for this esoteric bit of
| knowledge!
| lostgame wrote:
| This is a fantastic nugget of info, thank you!
| rrreese wrote:
| There is a well understood difference between macroscopy and
| microscopy. Naming macro lenses micro might be helpful to the
| layperson but not the subject expert.
| pdpi wrote:
| The name Macro makes perfect sense. It doesn't refer to the
| size of the subjects being shot, but rather to the
| magnification factor. Macro lenses are capable of preserving
| 1:1 scale between the subject and film/sensor
| marban wrote:
| While the 13 Pro's lens is undoubtedly a marvel of engineering, I
| feel like all those 'mind.blown' reviews must have been written
| by youngsters who never used a dedicated macro lens on a (D)SLR.
| throwaway81523 wrote:
| I've never been able to get good macro shots on a DSLR, despite
| decent optics and lighting, and an ok-for-most-purposes tripod.
| I eventually decided that to do it really right takes a massive
| copy stand, maybe on a concrete slab. Stuff wobbles too much
| without it.
| arrrg wrote:
| It's different and each has its own qualities.
|
| I noticed it during my vacation in Italy. Yeah, I still run
| around with a big mirrorless camera with a huge zoom lens
| (Fujifilm's weird X-H1 absolutely no one bought but I still
| love very much with the very large and heavy 16-55 mm F2.8
| lens) and I'm sure I will only use its photos for my 2022 week
| calendar or whatever else photo projects I will do - but the
| photos from my iPhone still provided an instant satisfying
| value in the way in which they are instantly and easily
| shareable and just immediately can populate my digital live
| (even if I have the huge camera with me - which I don't always
| have!).
|
| These are two different ways of using photography and both are
| valid. More importantly, both benefit from any new capabilities
| you gain.
|
| I guess what I want from my Fuji is to integrate itself more
| tightly and easily with my smartphone, something they really
| suck at. And I want my smartphone to be good enough in more
| situations. Like macro photography.
|
| And the weird thing about macro is that even if you do have a
| big camera and great lenses (I have the 35mm F1.4, 23mm F1.4,
| 16-55mm F2.8 and I sometimes rent the 90mm F2.0) you might not
| prioritize macro photography, so if you just get a new thing
| that's pretty good at it that just very cool to play around
| with. And I don't think your sneering attitude is justified ...
| alistairSH wrote:
| Certainly not the case for this review. Lux produces several
| well-reviewed iOS camera apps and regularly publishes articles
| about the iPhone camera hardware and software.
| defaultname wrote:
| Having that functionality in your pocket, instantly usable,
| beats having an SLR in the closet at home with a macro lens
| that you can switch to for a passing need.
|
| And FWIW, the curse of SLR macro lenses is _minuscule_ depth of
| field, so much so that many take many photos (presuming a
| perfectly stationary subject), bracket the focus, and stack by
| sharpness. It 's a hugely involved process. A macro lens with a
| tiny focal length instantly has a big advantage, though depth
| of field is still going to be a problem given the fixed
| aperture.
|
| It most real world scenarios I think the average person will
| have a much better chance of successful results.
| sudosysgen wrote:
| This is a fixed issue in cameras. Stop down to F16, and use a
| ring flash, there you go, fixed.
| ValentineC wrote:
| Wouldn't this also involve needing to use a tripod?
| sudosysgen wrote:
| Not necessarily, no. If you want a pin-sharp image at
| 48MP yes, but if you want something comparable to the
| iPhone jacking up the shutter speed to 1/400 makes it
| manageable handheld with good stabilization.
| bosie wrote:
| i assume fixed at 24mm because at 90mm, stopping it down to
| f16 won't do you much good?
| sudosysgen wrote:
| Yes, somewhere around 24mm. You'd need to step down a bit
| more at 90mm.
|
| However, at 90mm the object would also be farther away,
| so you wouldn't need to stop down a lot more than you'd
| expect.
| defaultname wrote:
| Few who have ever taken macro photographs would claim this
| is a "fixed issue". Macro photography is a giant pain.
| Further the difference between a 4mm focal length and a
| 50mm focal length, as a function of DoF, is massively
| larger than that 50mm going between f2.8 to f16. You'd have
| to go to a hypothetical F/512 to get the same advantage in
| that particular realm (though in reality small apertures
| suffer from their own problems).
|
| This is basic math. It's interesting that someone else
| claimed it's "physics" as a retort, when yes indeed it IS
| physics. It's why you can make a tiny lens fixed focus
| camera that seems to have everything in focus, from near to
| far, because the DoF becomes enormous.
| throwanem wrote:
| I usually work around f/22, at 1/250 and of course with
| flash. I shot this handheld, about a year ago:
| https://aaron-m.com/wp-
| content/uploads/2021/01/DSC1250-1.jpg
|
| It's a fixed issue.
| defaultname wrote:
| Do you think that photo demonstrates that it's a fixed
| issue? You seem to have around 3mm of depth actually in
| focus, and even with a very, very shallow subject, parts
| are unpleasantly out of focus.
|
| I don't think that is the demonstration you think it is.
| Most macro photographers would not rack that up as a
| successful photo.
|
| And again, focus stacking is what everyone does to
| compensate for the DoF weakness.
| throwanem wrote:
| If you know a way to focus-stack a live and highly active
| subject, I'm all ears. But where's your work? To judge by
| your response here, you must certainly be much better at
| this than I am, and I'd like the opportunity to derive
| some small benefit from the extensive experience that
| gives you so confidently to take such a superior tone.
| defaultname wrote:
| "If you know a way to focus-stack a live and highly
| active subject, I'm all ears."
|
| You don't, which is why higher depth of field is the
| golden standard. See: The entirety of this discussion.
|
| "so confidently to take such a superior tone"
|
| To be clear, you dismissed my post by claiming that it's
| a "fixed" issue, then posting proof that doesn't show it
| to fixed. I don't believe I'm the one who attempted a
| superior tone.
|
| Depth of field is *THE* issue in macro photography. Small
| focal length cameras are at an advantage in that regard.
| It's pretty simple.
| sudosysgen wrote:
| Small focal length cameras only have an advantage when
| the sensor size is the same. If you are decreasing the
| sensor size and keeping the resolution constant, the
| "small focal length" camera has zero advantage. There is
| no difference between a 4mm lens at f/2 that is a, say,
| 30mm FF equivalent and a 30mm full-frame lens at f/15.
| Precisely zero difference.
| sudosysgen wrote:
| I don't see anymore than 3mm in focus in the images of
| the post.
| sudosysgen wrote:
| I have a macro lens in my hands and a stabilized sensor
| camera. I can take a picture of the crown of my watch
| with a fair amount of detail.
|
| You have a 4mm lens at f/2. To get the same depth of
| field you'd need a 50mm lens at f/25, not f/512.
|
| You don't need to use a 50mm lens though. Macro lenses
| are typically 24mm or so. So you need to shoot at F12 to
| have the same depth of field in reality, certainly not
| f/512...
|
| And my camera actually moves the sensor AND the lens
| instead of just the lens. Because of that it can
| stabilize in the near field MUCH more efficiently than an
| iPhone ever could.
| defaultname wrote:
| "You have a 4mm lens at f/2. To get the same depth of
| field you'd need a 50mm lens at f/25, not f/512."
|
| Humorously years back I had authored a giant depth of
| field essay with online calculators specifically because
| so many people just _couldn 't understand_ why their
| iPhone couldn't get bokeh. Yes, f/512 would be the
| impossible equivalent. This is easily calculated.
|
| Regardless, the lens Apple uses for macro mode has a
| 1.54mm focal length. The 4mm example was just
| demonstrating how _fundamentally_ small cameras win on
| depth of field, at least if you want maximal depth of
| field. Conversely they lose when you want to limit depth
| of field, which is why we have computational bokeh.
|
| "Macro lenses are typically 24mm or so."
|
| The smallest from most makers is 35mm, but the majority
| are 50mm+.
|
| This conversation has turned weird. As someone who has
| had many SLRs, and _many_ lenses, and has taken thousands
| of macro photos, I know that in the real world macro
| photography is a massive pain. That DoF is by far the
| number one obstacle (which is why focus stacking is
| simply _necessary_ , often with ten or more varied
| focuses). Physics benefits small camera systems for that
| specific scenario.
| sudosysgen wrote:
| That's just not how lenses work, fundamentally. Bokeh is
| determined by two things, and two things only - the
| diameter of the aperture and the distance to the object.
| That's it.
|
| Also yes, the wide angle of the iPhone 13 is much
| smaller. Just stop down even further then.
|
| Cheap macro lenses in 2021 are typically around 24mm. I'm
| talking about the Mitakons and the Laowas of the world.
|
| Focus stacking is needed when you're trying to take very
| high detail pictures with 60, 70, 90mm lenses on high
| resolution sensors. You don't need anywhere near as much
| to take an image with the same magnification as a 13mm
| equiv. 2cm away.
| defaultname wrote:
| "That's just not how lenses work, fundamentally."
|
| Go to the wikipedia page on depth of field and see how it
| is calculated.
|
| "Cheap macro lenses in 2021 are typically around 24mm"
|
| You claimed they were the norm. Now it's that they simply
| _exist_.
|
| "Focus stacking is needed"
|
| Focus stacking is needed when the depth of field is so
| small that the resulting photo would be unpleasant. This
| is the case for almost all macro photographs shot on
| SLRs. It's interesting that someone else claimed this is
| a fixed issue and posted a photo that looks like it was
| taken with one of those terrible lens adapter kits. If
| that is one's standard for "fixed", then sure, but most
| of us have higher standards.
| sudosysgen wrote:
| 24mm is a normal focal length for entry level macro
| lenses nowadays, yes. They don't just exist, they are
| very common in the entry level market. If you want to get
| those kinds of macro shots that's what you'll get.
|
| If your goal for macro photography is to take a picture
| that is reasonably sharp at 12MP 2cm away with a
| magnification of less than 2, then yes, getting
| acceptable depth of field is a solved problem. Set your
| wide angle macro lens to F/22 and there you go.
|
| If you have higher standards, then the problem is not
| fixed on DSLRs. But the iPhone doesn't do it either.
|
| If you don't understand why using the CoC criteria for
| depth of field is incorrect on two cameras with vastly
| different sensor sizes, I can't help you. The only
| measure for depth of field that works across cameras with
| two different sensor sizes is the ratio of distance and
| aperture diameter, which determines the solid angle of
| light capture. You're the one that brought up physics, so
| actually look at the physics instead of using
| photographer's ready-made formulas without actually
| understanding them and where they break down.
|
| As for the image that you replied to, it doesn't look any
| worse at all to the images in the post technically. If
| you look at the image of the lightning connector, it
| doesn't even have 2mm of depth of field at a pretty low
| actual resolution. You can say whatever you want as for
| the composition and artistic value, that's not what we're
| talking about.
| defaultname wrote:
| "I can't help you"
|
| No, you can't, because you are painfully ignorant on this
| topic.
|
| Literally, spend 30 minutes with an iPhone and an SLR and
| you'd be illuminated. Instead you seriously argue that I
| need to look at the "physics" (which is farcical when you
| ignore the most important part of a camera, which is the
| focusing from the lens to the sensor. Dismissing that
| betrays a complete misunderstanding of optics).
|
| This conversation is clearly futile, but again - spend 30
| minutes and actually test your theories. Or, you know,
| read _any_ single article on the tubes.
|
| Or how about simply ask yourself "why does the iPhone
| need to do computational bokeh"? 65mm equivalent lens,
| f/2.2...should be the easiest thing in the world. In SLR
| world that is bokeh gold.
| sudosysgen wrote:
| I have a phone with a macro lens. I have a mirrorless
| camera. As I told you, what matters for bokeh is the
| distance to the object and the diameter of the aperture.
| The iPhone needs computational bokeh because the aperture
| is 2.4mm wide, whereas one of my lenses has a 40mm
| aperture. That's why my camera produces more bokeh - the
| aperture has a wider diameter while the distance to the
| object is the same.
|
| That is literally the one and only thing that matters.
| The diameter of the lens, and the distance from the
| object. Take a piece of paper, draw the lens as a slit,
| draw the object as a point, and make a line from the two
| edges of the slit to the point, that continues furhter
| back. You'll get two triangles. Everything that is
| contained in those two triangles will be focused to the
| same point on the sensor. That's why the ratio between
| the two is what matters. That's why closer objects
| produce a more out of focus background than objects
| farther appart. That's what I'm trying to explain to you.
|
| The DoF formula that photographers use _does not_ work
| for comparisons across two different film sizes.
| defaultname wrote:
| You understand that cameras don't use a slit, right? Do
| you understand the optics in a modern camera?
|
| Further my 70mm lens has a _smaller_ aperture than my
| 35mm f1.4 lens. Yet it has a much smaller depth of field
| for a given distance. Weird! Lens makers must not know
| your remarkable "slit lens" trick.
|
| At this point I'm convinced you are either trolling, or
| have dug so far into the depths of wrongness that you're
| dedicated to sticking with it. So good luck with that.
| I'm out of this conversation.
| sudosysgen wrote:
| Revolve the entire setup around the axis perpendicular to
| the slit and you will have a very accurate representation
| of how a camera-lens system works.
|
| The ratio between distance and focal length only works if
| the focal lengths are equivalent across the two cameras.
| Otherwise it doesn't work. That's to say, a 70mm f/2.8
| has the same depth of field as a 35mm 1.4 lens if the
| second is on a camera with 2x crop factor.
|
| Try it out, crop the image of your 70mm lens at f/2.8 and
| compare it to the image of your 35mm f/1.4 lens and you
| will get exactly the same image with the same blur
| (assuming the lenses are exactly 70mm and 35mm at the
| focus setting, which is not guaranteed due to focus
| breathing and manufacturers rounding off their focal
| lengths)
| foldr wrote:
| I think you are right if you hold constant the CoC. In
| that case the DoF is proportional to the f number but
| inversely proportional to the square of the focal length
| (http://graphics.stanford.edu/courses/cs178/applets/dof.h
| tml).
|
| However, for a smaller format, we arguably ought to
| reduce the CoC proportionally. And I think that reduction
| will end up canceling out one factor of f, bringing us
| back to the ratio of the focal length to the f stop (i.e.
| the absolute diameter of the aperture).
| defaultname wrote:
| The focal length input is squared, but the CoC impact is
| linear. The iPhone has a small CoC compared to SLRs, but
| its input on the calculation is undersized relative to
| focal length.
|
| The iPhone is widely assumed to have a CoC of 0.004mm
| (this actually increases on the most recent iPhone,
| though it's tough to get precise numbers). A Nikon D5000
| (going with an equivalent resolution -- larger pixels --
| on an ASP-C camera) has a CoC of 0.020.
|
| So let's calculate hyperfocal distance of the two systems
| for the same effective focal length (but obviously very
| different real focal lengths)-
|
| iPhone 12 telephoto lens - 65mm (7.5mm real) equivalent,
| f2.2.
|
| Nikon D5000 equivalent lens - 65mm (43mm real)
| equivalent, f2.2.
|
| For the iPhone, the HF is 6.4m. For the Nikon, it is
| 54.3m. For those who don't know, hyperfocus is the point
| where everything from 1/2 of that distance to infinity is
| in focus if you set the focus to that magical point. It's
| a proxy for the other depth of field calculations, and is
| the simplest to demonstrate.
|
| Anyone who owns an iPhone w a "telephoto" and an ASP-C
| SLR w/ a 50mm lens needs to try to replicate bokeh at
| various distances without the computational bokeh. Focus
| on a subject at 1m, 2m, 4m, etc at the same aperture.
| Close down the aperture on the SLR even.
| foldr wrote:
| Holding constant the target resolution, you need a
| smaller CoC in proportion to the difference in focal
| lengths (assuming the viewing angle is also held
| constant). That removes one of the factors of f.
|
| I think it makes sense to assume the same target
| resolution for the iPhone and the DSLR, even though this
| isn't true in practice. The DSLR user is obviously free
| to downsample their photo to a lower resolution and
| thereby (in a rather uninteresting way) gain more depth
| of field. We shouldn't be giving the iPhone extra DoF
| points just because it happens to have a lower
| resolution.
|
| So we are not talking about any empirically derived value
| for the iPhone's CoC. The CoC here is a value derived for
| each format from an arbitrarily chosen target resolution.
| defaultname wrote:
| "I think it makes sense to assume the same target
| resolution for the iPhone and the DSLR, even though this
| isn't true in practice"
|
| It yields a practically perfect comparison of focus. This
| isn't a trick or handicapping, and the degree of
| focus/defocus is identical whether that SLR had 10x the
| resolution. There is utterly nothing arbitrary chosen
| here, and the amount a tree 10 feet outside the focus is
| out of focus will be identical on a 12MP SLR or a 24, 48,
| or 96MP version with the same focal length / f / sensor
| size.
| foldr wrote:
| My point was that it doesn't matter what resolution we
| choose as long as we do the calculations based on the
| _same_ resolution for both the iPhone and the DSLR (and
| hence with different values for the CoC in each case,
| given the different sensor sizes). Thus your value for
| the iPhone's CoC derived from its pixel size is
| irrelevant. We can choose any target resolution we like
| to make the comparison and get the same result
| (comparatively speaking).
|
| By resolution here I'm talking about what we could
| crudely measure in megapixels. Say for example that we
| have a target resolution of 5MP. We then calculate the
| corresponding CoC for both cameras based on their
| respective sensor sizes. You'll find that the CoC for the
| iPhone will be smaller in proportion to the difference in
| focal lengths between the iPhone and DSLR. That cancels
| out one of the factors of f.
|
| Sudosysgen is saying the same thing, but without going
| indirectly via the DoF formula that you've been using.
| defaultname wrote:
| The CoC for the iPhone is smaller than the ASP-C given
| the smaller sensor. By choosing the same resolution of an
| ASP-C sensor, we are calculating for a given level of
| "good enough for that resolution". It is perfectly
| comparable level of focus. I have no idea why you are so
| caught up in distractions.
|
| I calculated the hyperfocal length for an iPhone and an
| equivalent zoom SLR, at the same aperture. These yield
| effectively identical degrees of focus from 1/2 the HF to
| infinity. The iPhone is from 3.2ft to infinity, the SLR
| is from 27 feet to infinity.
|
| Nothing else matters if you can't _tell me why that 's
| wrong_. Because it isn't wrong. It's absolutely right.
| The same zoom level and cropping. MASSIVELY larger focus
| zone.
|
| If we doubled both dimensions of the sensor, thus
| doubling the CoC, it would halve the HF. If we instead
| doubled the focal length it QUADRUPLES the HF. The focal
| length is a squared factor and outweighs any other
| component. For a reason.
| foldr wrote:
| If you double the focal length you also have to double
| the sensor size (to get the same angle of view) and hence
| double the size of the CoC - so you end up with f*f/f =
| f.
| sudosysgen wrote:
| You can't use the same aperture. The SLR has to be at a
| smaller aperture so the diameter of the lens is the same.
| That way both will gather the same amount of light and
| have the same amount of bokeh.
|
| That's your issue - you need to use equivalent apertures.
| defaultname wrote:
| At this point I'm sure you must be joking.
| sudosysgen wrote:
| The CoC refers to the circle in the pixel that a point
| will be focused to. The pixels on an iPhone are much
| smaller than the pixels on a camera. If you use the same
| CoC for the iPhone, you are referring to many more pixels
| than on a DSLR.
|
| Therefore, when you use the same CoC, you are asking the
| DSLR to be dozens of times closer to perfect focus, in
| pixel terms, than the iPhone, which is why you are
| calculating outlandish f stop values.
|
| If instead, you have a target that the object must
| resolve to a pixel with the same resolution on both, you
| will arrive to an f stop linearly proportional to the
| sensor size, instead of proportional to the square of the
| sensor size.
| defaultname wrote:
| I _clearly_ used completely different CoCs, factoring in
| the different sensor sizes.
|
| At this point I feel like you are just posting things
| hoping some future visitor will think that your
| commitment must demonstrate that you are right. I guess.
| sudosysgen wrote:
| You clearly did not. If you scaled the CoC _exactly_ with
| the crop factor, we would find exactly the same numbers.
| [deleted]
| angst_ridden wrote:
| The most popular macro lenses for dSLRs are 60mm, 90mm,
| and 105mm. Of course, there are other focal lengths. I
| don't think I've ever seen a 24mm macro lens, unless
| we're talking micro 4/3 or some other non-35mm sensor
| size.
| sudosysgen wrote:
| If you want to replicate the effect in the article, you'd
| be using a 24mm macro lens, yes. Mitakon makes multiple,
| and laowa makes multiple for all mounts.
| angst_ridden wrote:
| I didn't argue that 24mm macros don't/can't exist, I'm
| arguing that they're vanishingly rare in the grand scheme
| of 355mm photography.
| sudosysgen wrote:
| I really don't think they are. The 24mm "probe" lens is
| pretty famous and widespread, and it's actually the #2
| item for the query "macro lens" on Google shopping and
| it's the first macro lens you'll see on Google images.
| Beyond that, there's a whole plethora of ~24mm macro
| lenses and they're pretty dominant in the budget side of
| macro lenses nowadays.
| sbierwagen wrote:
| Not on a full frame 35mm sensor it won't.
| dylan604 wrote:
| But that's how physics work. If iPhone Macro doesn't suffer
| the same issues, then it's a software trick
| packetslave wrote:
| I wouldn't call it a "trick" but I suspect Apple is doing
| some focus stacking under the hood.
|
| The image pipeline in the iPhone gets more and more
| advanced with every IOS release. The state of the art for
| computational photography is pretty amazing.
| dylan604 wrote:
| If you're doing something under the hood without
| disclosing it but calling it something else, it's a
| trick. It doesn't have to be nefarious, but you are
| tricking the user into thinking they are doing something
| which they are not actually doing.
| marcellus23 wrote:
| How are they not disclosing it? They talk at length,
| every single keynote, about all the software they build
| to process iPhone photos.
| dylan604 wrote:
| Do they really? I only ever hear about how its the best
| iPhone camera they have ever made. Yes, they talk about
| how their AI is able to adjusts exposure, color tone,
| etc. Do they actually talk about how a macro is taken in
| such detail as focus stacking etc? I tend to nod off
| during these videos, so I might have missed something.
| packetslave wrote:
| They tend to have sessions at WWDC about the underlying
| camera pipeline, for developers who care. Product launch
| keynotes are the wrong forum for deep technical talks.
| dylan604 wrote:
| that's not what the person I responded to implied. they
| specifically called out the keynote
| marcellus23 wrote:
| > Yes, they talk about how their AI is able to adjusts
| exposure, color tone, etc. Do they actually talk about
| how a macro is taken in such detail as focus stacking
| etc?
|
| Is that moving the goal posts a bit? Your point was that
| Apple is somehow pretending they're not using software to
| create this effect -- if they say they're using AI/etc.
| to do it, it seems to me like they're not misleading
| their customers. I don't think the requirement is that
| they explain exactly how it works in technical detail.
|
| I don't think they did any sort of deep dive on their
| macro tech, but in the past yes, they have gone into some
| detail about how their image processing works behind the
| scenes.
| dylan604 wrote:
| There's a difference in macro being 1:1 ratio (as
| understood in photography) vs having an AI do something
| to make something small look big in the image. So if
| their lenses are not delivering 1:1 but use some sort of
| algo, then it's misleading.
| packetslave wrote:
| I see where you're coming from, but here's the thing:
| every single photo taken on a modern phone goes through a
| pipeline of 10+ stages of image processing, including
| multiple exposure merging. The iPhone isn't even taking a
| single photo... it's picking the best frame(s) out of a
| running buffer of video.
|
| (unless you shoot in raw, and I haven't read enough yet
| to know what processing, if any, Apple does to ProRes/RAW
| photos).
|
| Call it "tricks" if you want. I call it using technology
| to give the non-professional camera user the best photo
| possible at the time. If that bothers you, pull out the
| DSLR, shoot in RAW, and spend time afterwards in
| Photoshop/Lightroom.
|
| _edit_ this is also why apps like Halide (or ProCamera
| or Filmic Pro) exist... if you want to control more of
| the options instead of letting Apple choose, the
| capability is out there. Most users probably don 't care.
| They just want a good photo of their kids to post on
| Instagram.
| renewiltord wrote:
| DSLRs use extensive such tricks to process the image.
| Enthusiast groups will show the pathological cases for
| the image processing that happens. Ultimately, ceci n'est
| pas une pipe applies to the picture. It's a
| representation and it is meant to evoke the scene.
| dylan604 wrote:
| What DSLRs use AI or other software based tricks to
| perform macro photography?
| defaultname wrote:
| Depth of field is a direct function of real-world focal
| length. An iPhone has camera systems with a focal length in
| the 1.4mm - 5mm range (the equivalent framing is not
| relevant to the impact on DoF). Most SLRs have lenses with
| focal lengths from 35mm - 100mm.
|
| https://www.photopills.com/calculators/dof
|
| (That site has different camera selections purely because
| the circle of confusion differs based upon the sensor size
| / resolution, so it's the relative values that you should
| pay attention to)
|
| Take a gander at the DoF variations for a 4mm versus a 35mm
| FL system.
|
| This is the reason why iPhones have to implement fake bokeh
| -- because the depth of field on tiny cameras is so much
| larger, even with a wide open aperture. But the inverse is
| that where you want a wide depth of field it is a feature
| of the size. It's also why people seem to be much more
| successful taking photos on smartphones, because the focus
| is much more forgiving.
|
| A wide DoF is a function of those physics.
| zippergz wrote:
| I've been seriously into photography since well before usable
| digital cameras were a thing. I have used very expensive
| cameras, lenses, and lighting rigs with 35mm, medium format,
| 4x5 and pro-level digital. I am under no illusions about the
| difference between a high end dedicated rig and what my phone
| can do. But I still find it amazing and delightful to be able
| to get such great results from a device that fits in my pocket,
| I have with me all the time, and also does so many other
| things. It's all about context.
| GoodJokes wrote:
| Youngsters or people who don't want to and should not spend big
| money to carry around a bulky camera to take a picture 1
| million other people have taken a picture of. One always see
| people in these threads projecting their insecurity with having
| forked over a $1,000 on a bulky camera that is nearly bested by
| a multi-purpose phone.
| 153957 wrote:
| So this is just a digital zoom (crop) with Super
| Resolution(tm)-like (machine learning) upscaling...
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