Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

iPhone Macro: A Big Day for Small Things

lux.camera

Post reply on HN
Print view View original

71–80 of 152 posts

Re: iPhone Macro: A Big Day for Small Things

#71

Post by megablast »

packetslave wrote: post #37

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 le…

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.

Re: iPhone Macro: A Big Day for Small Things

#72

Post by throwanem »

defaultname wrote: post #54
throwanem wrote: post #48

Earlier quoted context omitted.

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.

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.

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.

Re: iPhone Macro: A Big Day for Small Things

#73

Post by defaultname »

foldr wrote: post #63
defaultname wrote: post #53

Earlier quoted context omitted.

"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 phot…

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.html ). 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…

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.

Re: iPhone Macro: A Big Day for Small Things

#75

Post by ImaCake »

packetslave wrote: post #4

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)

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.

Re: iPhone Macro: A Big Day for Small Things

#76

Post by dylan604 »

packetslave wrote: post #69
dylan604 wrote: post #65

Earlier quoted context omitted.

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.

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.

that's not what the person I responded to implied. they specifically called out the keynote

Re: iPhone Macro: A Big Day for Small Things

#77

Post by dylan604 »

marcellus23 wrote: post #66
dylan604 wrote: post #65

Earlier quoted context omitted.

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.

> 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 th…

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.

Re: iPhone Macro: A Big Day for Small Things

#78

Post by sbierwagen »

sudosysgen wrote: post #27
defaultname wrote: post #13

Earlier quoted context omitted.

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…

This is a fixed issue in cameras. Stop down to F16, and use a ring flash, there you go, fixed.

Not on a full frame 35mm sensor it won't.

Re: iPhone Macro: A Big Day for Small Things

#79

Post by defaultname »

throwanem wrote: post #72
defaultname wrote: post #54

Earlier quoted context omitted.

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.

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.

"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.

Re: iPhone Macro: A Big Day for Small Things

#80

Post by foldr »

defaultname wrote: post #73
foldr wrote: post #63

Earlier quoted context omitted.

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.html ). 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…

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 camer…

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.

Post reply on HN