[HN Gopher] Comparing iPhone 13 vs. iPhone 14 for Astrophotography
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Comparing iPhone 13 vs. iPhone 14 for Astrophotography
Author : mikece
Score : 58 points
Date : 2023-05-28 14:36 UTC (8 hours ago)
(HTM) web link (www.diyphotography.net)
(TXT) w3m dump (www.diyphotography.net)
| ris wrote:
| I guess this is "astrophotography" for the sake of making pretty
| images, because I couldn't imagine the "computational AI"
| features he mentions towards the end of the article doing
| anything but horrify even an amateur astronomer.
| Scea91 wrote:
| What do you mean? Statistics and ML is used in astrophotography
| regularly. For example, the famous black hole "photo" [1].
|
| https://www.nasa.gov/mission_pages/chandra/news/black-hole-i...
| etrautmann wrote:
| Yes, but the computational pipeline is designed and
| implemented by the end user to achieve a scientific result.
| Here, it's a black box where the resulting image cannot be
| treated as raw data.
| chongli wrote:
| Yes exactly. The training set used for the famous black
| hole image was a database of images created using black
| hole simulations based on our best available models. This
| is pretty far away from these consumer ML models trained on
| publicly available images which may as well be consider
| garbage from a scientific perspective.
| astrange wrote:
| Nothing about phone cameras involves "ML models trained
| on publicly available images".
| chongli wrote:
| You haven't been following the story, then, because
| Samsung phone cameras have been accused of doing exactly
| that: using a training set of publicly available images
| to "enhance" people's images by filling in details with a
| ML model.
| empyrrhicist wrote:
| That is completely unrelated to astrophotography as a hobby,
| taking pictures of space objects from the surface of the
| earth. Like, totally and completely not-comparable in any
| way.
| birdman3131 wrote:
| As somebody who has a Pixel 7 I completely agree. The AI makes
| my photos unusable. The worst part is I can see a usable image
| before it finishes processing. But then it turns it into
| pixilated garbage.
|
| I am often taking pictures of small text that is borderline
| unreadable to get part numbers off stuff. The AI processing is
| absolutely a bad idea.
| FridayoLeary wrote:
| On that subject one of the recent samsung models had a rather
| interesting feature, where you could print a blurry picture
| of the moon, put it in a dark room and the camera would
| "enhance" the image adding detail it never had. I think
| smartphone cameras are reaching the limits of their
| potential, the only way forward now is ever protruding camera
| bumps.
| londons_explore wrote:
| You can install an alternate camera app if you just want raw
| rixels with no computetional stuff.
|
| Having said that, I find the computational stuff turns a
| fairly poor sensor and lens into kinda acceptable photos, as
| long as I don't want to zoom in (I can see far further with
| my eyes than the camera can when it comes to taking photos of
| tiny far away things)
| dzikimarian wrote:
| You can disable lot of AI in settings, you can also enable
| saving RAWs.
| vrtnis wrote:
| On that front, there is also one called the vaonis hyperia that
| seems totally automatic, but perhaps we miss out on the
| challenge of amateur astronomy..
| quanto wrote:
| for general users who simply want clearer photos, what are some
| cheaper phones for recommendation?
| [deleted]
| justsocrateasin wrote:
| If you can get your handles on a Pixel 3 for cheap, that took
| simply incredible photos. Even better than my current iPhone 12
| for most purposes (not all).
| habosa wrote:
| Pixel 3 photos continue to be my favorite of any phone I've
| ever owned (had iPhones since then) I thought I was the only
| one
| xattt wrote:
| 1:1 crops still look like a solarized mess. It's nothing than a
| feel-good gimmick ("oh wow, this phone in my pocket can do some
| sort of multi-syllable photography").
| SV_BubbleTime wrote:
| Yeah, I kinda lost me at the end when he's talking about AI
| generated "synthetic skies".
|
| I get it, a ton of photoshops will just drop in a new sky. But
| that's a choice that a user made not a choice that the phone
| manufacturer made for them.
| CharlesW wrote:
| > _Yeah, I kinda lost me at the end when he's talking about
| AI generated "synthetic skies"._
|
| For anyone who didn't read TFA, this is part of an in-story
| quote by Russell Brown (not the author) talking about the
| future of mobile photography. As a long-time Adobe employee
| he's parroting their messaging here, since Adobe's value-add
| is in "what comes after" photography.
|
| Photoshop's new AI-powered Generative Fill is a good example
| of what Russell's thinking of when he talks about
| "computational AI" (a non-sensical name intended to one-up
| "computational photography"):
| https://www.youtube.com/watch?v=uR7j8r-LzQ8
| alexose wrote:
| I've read that CMOS sensors perform better in low light
| conditions if they're kept cold. Curious if anyone has tried this
| with a smartphone...
| wyager wrote:
| > I used the 1x camera, which is 26mm at f/1.5
|
| I find this way of describing the iPhone cameras frustratingly
| misleading. It's not the author's fault; Apple does it in their
| official specs.
|
| The "26mm" rating is "equivalent", meaning "this looks like a
| 26mm lens on a 35mm film camera". It basically tells you the FOV
| angle.
|
| The "f/1.5" rating is _not_ equivalent. It 's very dishonest to
| mix and match equivalent and non-equivalent specs, because it
| makes the lens sound a lot better than it is to non-expert
| readers. If they were being honest, the equivalent aperture would
| be a lot smaller, like f/16 or something.
|
| Every other camera mfg I am aware of will consistently use
| equivalent or non-equivalent for all specs, and make it clear
| which they are using.
|
| For example, most mirrorless camera lenses are spec'd non-
| equivalently, meaning that a "26mm f/1.5" means "if you put this
| lens on a 35mm camera and extrapolated the output to cover the
| whole sensor, that's what you would get". To understand what it
| will look like on a different sensor, you multiply 26 and 1.5 by
| the crop factor.
|
| In Apple's case, it's actually impossible to tell what the image
| will look like from the specs without looking up the crop factor,
| which of course they don't advertise front and center like they
| do this misleading tuple of specs.
|
| In general, lenses with smaller f/N aperture values tend to be
| better and more expensive (because they have a larger aperture,
| let in more light, narrower depth of field), so if you don't mind
| misleading customers, you just pick the smallest denominator you
| can get away with.
| musictubes wrote:
| I hate hate hate "equivalent aperture" specs. I don't mind the
| FOV being equated to 35mm sensor size but give me the actual
| Fstop please. Back in the day I shot formats from 8x10 down to
| 16mm. Nobody ever tried to normalize DOF between formats by
| talking about fstops until digital photography. Trying to
| normalize DOF across formats only obscures and confuses what is
| actually going on optically. No particular fstop (ratio between
| focal length and physical aperture) has a unique look and yet
| that is what people that demand equivalent fstops assume and
| demand.
|
| For exposure purposes, f1.5 is the accurate and most important
| spec for that lens. All mirrorless camera lenses are specced
| accurately with focal length and fstop. Perhaps some of the
| marketing is done with 35mm "equivalent" specs but I've never
| seen a lens that had anything but the actual measurements on
| them. I'm not sure why people are still referring to 35mm focal
| lengths when talking about FOV in any case. Nobody is comparing
| the lens on an iPhone with one on a camera with a 35mm sized
| sensor. Certainly nobody will use the iPhone lens on another
| camera.
|
| The main sensor on an iPhone is larger than most phone cameras
| but still close enough that touting the f1.5 fstop does indeed
| mean that it lets in more light, has a larger aperture, and has
| a narrower DOF than many other phone cameras. The vast majority
| of iPhone users have never shot with 35mm cameras and so
| wouldn't have any idea what you're talking about when it comes
| to 35mm DOF. I wish companies would ditch the 35mm normalized
| specs altogether.
| doodlesdev wrote:
| Every time people tell me iPhone cameras are getting as good as
| dedicated DSLR/mirrorless, I always point this out to them.
| F/16 is absolutely unusable for certain types of photography
| (although quite perfect for landscape), and even worse with
| such a small sensor with that big of a crop factor (3.5x) [0].
| I personally use a f1.8 35 mm on an APS-C sensor for hobby
| photography and I still feel the sensor is too small for
| portrait photography or low light, but then I'm also kind of a
| weirdo since I still use film cameras once in a while (can't
| afford a full-frame lol, so I use it for portraits).
|
| [0]: https://www.dpreview.com/articles/6110937480
| foldr wrote:
| I don't personally care for shallow depth of field (it's
| become a cliche at this point), but the best phone cameras do
| a pretty good job of faking it. It's not yet perfect, but
| it's only going to get better. I also like that I can
| precisely adjust the amount of background blur in post.
| chipsa wrote:
| The f/1.5 is an actual rating. It's the ratio between the focal
| length and the diameter of the pupil. It's important for
| shutter speeds, and relative performance in low light (before
| all the computational duckery). I can compare roughly a phone
| camera that's at f/1.5 vs a phone camera that's at f/2. Making
| a low f/number lens is more difficult than a high f/number
| lens, regardless of actual focal length.
|
| And I've got a non-35mm mirrorless camera. All the lens I've
| got are marked with the true focal length and true f/number,
| not some "equivalent". My iPhone camera photos' metadata show
| the focal length, both true and "35mm equivalent".
| karashi wrote:
| Camera manufacturers do the same misleading marketing too
| right? Here's a video of someone complaining about it.
| https://youtu.be/6Im4W_9blhY?t=7m28s
|
| That said, at least with stand-alone camera manufacturers you
| can usually work out what the real specs should be if you're in
| the know.
| barbariangrunge wrote:
| I like an old camera I have around here with a 50mm lens because
| the photos I take with it resemble what I see better than when I
| use my old smartphone.
|
| Eg, the size of a windmill behind somebody can vary dramatically
| in size depending on this
|
| If I upgraded my phone, do the new smartphones enable you to take
| photos like my old 50mm camera, or will I still need my old
| camera to capture those shots?
| NikolaNovak wrote:
| 50mm on full frame camera is called a "normal lens" precisely
| because for most people it mimics their internal perspective /
| wordlview, so you're not alone:-)
|
| Just look at any given phone specs and see if any of the
| cameras they offer are near "50mm equivalent" (you may have to
| dig because primary specs are usually useless - either the
| completely arbitrary "2x zoom" or the focal length on the
| specific sensor size such as "4.38mm" Which is true but not
| useful).
|
| Most phones come with wide and ultra wide lenses. I'm with you
| and don't like those. Other phones come with zoom lenses of
| various focal lengths. Most of those on the other hand will
| overshoot Into 75mm and higher territory.
|
| Worst case, grab a phone with great lens and sensor and zoom it
| in the store until you get 50mm equivalent... And see if that
| works.
|
| Note though there may be many other subtle and subconscious
| things you like about that camera besides focal length of the
| lens : aperture, bokeh, vignetting, film type, specific
| aberrations, or even the feel in your hand and mechanics of the
| shutter and the optical viewfinder. It's certainly more FUN,
| for me personally, to take a photo with DSLR than an iPhone :-)
| tass wrote:
| On the iPhone at least, all lenses are wide angle equivalent
| (24mm, 13mm) except for the telephoto (77mm).
|
| There might be a lens you can attach that narrows it down, but
| otherwise your old camera will do a better job handling your
| requirement.
| foldr wrote:
| The 2x digital zoom is pretty good on the 14 Pro as it's
| still got 12MP to work with. (I'm guessing that combining a
| stack of slightly misaligned exposures helps it to overcome
| the loss of color information you'd expect from the quad
| Bayer layout.)
| yakubin wrote:
| Digital zoom doesn't fix the distorted perspective.
| foldr wrote:
| The perspective is determined by where you're standing in
| relation to the subject.
|
| If you're talking about wide angle 'distortion', then on
| an iPhone (with the default settings) that's just what a
| rectilinear projection looks like with a wide field of
| view. Zooming in digitally 'corrects' that just as much
| as using a longer focal length would.
|
| You can easily confirm this by taking side by side
| comparisons. There are many of these you can find by
| googling, as this is a popular myth. E.g.
| https://www.photoreview.com.au/tips/shooting/perspective-
| and....
| yakubin wrote:
| Your link doesn't load for me. I'm talking about the
| contraction of depth when using focal lengths greater
| than 47mm and lengthening of it when using shorter focal
| lengths. I guess you can contract depth as well by
| walking backwards, but at this point your subject is so
| small you lost a lot of detail. Also, your subject may be
| gone by then.
| lm28469 wrote:
| Then you mean "depth of field" not "distorted
| perspective"
|
| The perspective will be the same with a 24mm or 200mm (or
| any focal length) as long as you stay in the same
| position relative to the subject, if you crop in the 24mm
| to get the 200mm field of view you'll get the same image
| with a much lower resolution and much wider depth of
| field (ie blurred background)
|
| The perspective distortion happens if you physically move
| closer to your subject to get the same framing on the 24
| as you had on the 200
| yakubin wrote:
| The thing is though that the depth is contracted
| disproportionally much more than width and height, which
| results in a non-linear transformation of perceived
| dimensions. This causes lines to bend. At 47mm straight
| lines aren't bent no matter the distance from whatever
| there is in the picture. At shorter lengths there are
| always regions in your photo which are distorted in this
| way. You can't fix that by changing your position. The
| only thing you'll do is change what object is bent and in
| so doing maybe make it less obvious.
| ricardobeat wrote:
| That's lens distortion, and has nothing to do with depth.
| Phones will correct it in software automatically, and
| Lightroom etc can also do it for your DSLR lenses.
|
| It's not usually a concern until you get to <20mm, and
| especially not if you're going to crop the center of the
| picture to mimic a 50mm perspective.
| olah_1 wrote:
| You basically have to zoom in on the camera app to get a 50mm
| equivalent photo. This isn't as bad as it seems though. The 2x
| quality is quite good on the baseline photos these days.
|
| However, on the "pro" iphone models, they do have a "telephoto"
| lense that is indeed a 50mm equivalent that will get you the
| perspective that you're used to.
|
| Here is the one on the iPhone 14 Pro -> 12MP 2x Telephoto
| (enabled by quad-pixel sensor): 48 mm
|
| Personally, I use an iPhone 8 plus and pretty much always take
| images on 2x zoom. Because yeah everyone looks better on a
| longer lense.
| tass wrote:
| Zooming doesn't correct the perspective though.
|
| I didn't know they blended lenses to create a 50mm, there
| must be some post processing tricks to have it look right -
| are there examples side by side with a true 50mm?
| NikolaNovak wrote:
| I think there's a lot of misunderstanding here and a lot of
| optically correct comments are being down voted.
|
| 50mm is a focal length. If what you like about 50mm is
| indeed the perspective (as opposed to other subtle things
| that may creep like aperture/bokeh or aberration or
| vignetting of the specific lens) then zooming something to
| 50mm effective field of view is exactly what will
| accomplish the goal.
| numpad0 wrote:
| It does. Focal length is just an alternate notation for
| FOV. 2x crop on a "28mm" photo should geometrically match
| that of any 1,2/55, except bluriness(bokeh) effect and
| image quality.
| foldr wrote:
| Perspective is determined entirely by the position of the
| photographer relative to the subject. There will be no
| difference in perspective if you zoom in with the phone to
| get the same angle of view you get with a 50mm lens on a
| full frame camera.
|
| Here is one of many explanations of this you can find
| online:
| https://www.photoreview.com.au/tips/shooting/perspective-
| and....
| rqtwteye wrote:
| I think the time isn't too far away when you don't even have to
| go out for taking pictures but you just tell AI to create a
| perfect image at a certain location with objects or people of
| your choice. That's maybe a good thing because a lot of people
| who just want Instagram shots won't bother going to the places
| anymore so it will be less crowded.
| ccooffee wrote:
| Samsung has recently been caught replacing the moon in pictures
| with a reference image. Discussed on HN less than 3 months ago:
| https://news.ycombinator.com/item?id=35107601
| m463 wrote:
| Reading this it seems their method of doing this is different
| than I expected, but maybe more disturbing:
|
| "In the side-by-side above, I hope you can appreciate that
| Samsung is leveraging an AI model to put craters and other
| details on places which were just a blurry mess."
|
| https://teddit.net/r/Android/comments/11nzrb0/samsung_space_.
| ..
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