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One important point for those looking at smartphones' depth of field despite wide apertures:

Smartphone cameras typically (always?) have *equivalent* focal lengths FAR shorter than the normal lenses DPR readers use on their quality cameras. In my experience, shorter (wider field of view) than typical point-and-shooters.

Crop your photos down to equivalent field-of-view images and you'll see out-of-focus points' area of fuzziness get proportionately larger.

Link | Posted on Mar 15, 2018 at 18:38 UTC as 1st comment
In reply to:

entoman: This concept of "capturing" every single photon is very promising. I found the way that Prof Fossum described everything very easy to comprehend e.g ""For example, if you shoot 100 frames at 1000 frames per second, you get a cube that's x pixels wide by y pixels tall, but also 100 frames deep."

Also fascinating to read "What is the object of photography? Is it artistic or an attempt to perfectly recreate the scene as it was? Some of the things we associate with photography are artifacts of the way we capture them."

A really interesting article explaining a very complex process in a way that the non-scientific community can understand. Thanks you Prof Fossum and thank you dpr.

There are as many objects of photography as there are photographers. More.

But this is technology that goes *into* photography, giving the person pressing the button more opportunities.

Many readers are familiar with aphorisms about art needing limits, but I'll argue that it's best when the artist manages those limits himself, imposing or pushing against them. In that way, better sensor tech will let photographers discover new art by having tools that let him discover new realms, and ignore old, externally-imposed limits that don't help.

Link | Posted on Feb 28, 2018 at 18:07 UTC
In reply to:

utomo99: Sensor technology need a huge improvement. I hope other brand will release newer sensor which work much better on low light

I don't see that this approach improves (low light) sensitivity. In my studies, and what I see online, is that typical sensors capture about 10% of all the photons that strike them, and that with tiny sensors, that number can be counted in the dozens in moderate light levels. Look up “shot noise”—that means more uncertainty, i.e., noise, with such low counts multiplied up to the number you see in the RAW files.

As I look at enhancements over the Canons & Apple cameras I have, the effective sensitivity hasn't seen a LOT of improvements. This announcement is a definite plus, but barking up a different tree.

Link | Posted on Feb 22, 2018 at 19:14 UTC

I looked at the linked shots with a “real” camera. Quite impressive.

Maybe 80% of them would've been just (about) as good, at least at web resolution, on an iPhone.

There's no question a larger sensor gets more information, and that a better picture can result. The only question is the tradeoff of cost/weight/convenience.

Link | Posted on Feb 9, 2018 at 21:20 UTC as 35th comment
In reply to:

matt_j: Taking a smartphone to Nepal as your only camera is just such a waste of "right place right time" opportunities.

What if you're in the mountains and jungle and don't want to recharge your "camera" every day.

We get it, phone cameras with their tiny sensors are "up there" resolution wise, and they don't suck anymore image-quality wise so you can use them exclusively just as I can eat my pudding with a fork. But would I ever eat pudding with a fork if I didn't want to brag about it all over Instagram? Not really.

I bought an iPhone battery pack recently. $14 or something like that, but I haven't had to use it, so can't say whether the extra few ounces are worth it. (I plain forgot to take it on my quick stop in England last week!)

Meanwhile, as the article says and shows, iPhone photos can have all the emotional appeal & technical quality the intended use calls for. You may never sell those photos to National Geographic but you'll get 95% of the shots you want for about 1/4 the effort.

Low-light shots are still a challenge. A tiny sensor may only capture a dozen photons in any given pixel if the light isn't bright, and the resulting “shot noise”—that number being well-removed from the number of photons captured in the adjacent pixel—can be jarring. Of course, the article noted that, too.

Link | Posted on Feb 9, 2018 at 21:16 UTC
In reply to:

Biowizard: #FakeScience alert!

"... can focus the entire spectrum of visible light, including white light ..."

Since when has "white light" been a colour in the spectrum?! It IS the sum of that spectrum, when all colours are present in equal amounts.


Early meta-lenses worked with a tight band of infrared wavelengths, so were not useful for imaging meant for eyes.

While you can use “color” as a synonym for wavelength, most of us perceive *combinations* of different wavelengths as color, and “white” certainly fits that bill.

Link | Posted on Jan 10, 2018 at 20:26 UTC
In reply to:

southwestfilm: Scary the quality of smart phone cameras. Is it time to through away my DSLRs :(

Throw 'em my way. Much as I love MY iPhoneX, the image quality falls far short of a DSLR's.

The article says as much. My take, having just shot a hundred test shots on multiple cameras, is that the tiny sensor records data with almost 5X the noise of a consumer (half-frame, APC) DSLR. That's exactly what the math says you'd expect from a sensor only about 1/22 the size of the SLR's.

In bright light (and the resultant low ISOs), you won't see the noise…much. In dim light, well, you'll want those bigger cameras. Anything dimmer than open shade—and certainly indoor shots without extra lighting, or sports or shows, etc—may be quite noticeable when you're viewing the images at all closely.

Link | Posted on Nov 22, 2017 at 07:10 UTC
On article iPhone X vs. Samsung Note 8 (369 comments in total)
In reply to:

Judy Stone: My $30 brand new Lumia 640 does everything I need and more. Spending over $100 on a disposable device is beyond me

Likewise, putting up with a slow, limited device that is helpful to me for navigation, quick social media updates and a whole lot of other useful & fun things, is incomprehensible to me. ~$50 a month for a speedy, ultra-capable & fun gizmo is a pittance, even if it's one of my bigger spending categories.

Link | Posted on Sep 21, 2017 at 19:20 UTC
On article iPhone X vs. Samsung Note 8 (369 comments in total)
In reply to:

mosc: Too big.

@Mosc, I'll be switching from the 7+ to the X (for just a couple extra $/month on the upgrade program). It'll show a third more pixels on a bigger screen, but be 15% smaller (volume) and 4% lighter.

My iPhone7+ sits nicely in my shirt pocket—I sometimes use the built-in “flash” light when working on my bike in a dim garage. I hope the X is only a BIT smaller that way!

My wife would hate having to use a super-sized phone but since the 7+ has never been too big, the slightly smaller X ought to be great for me. One size does NOT fit all!

Link | Posted on Sep 21, 2017 at 19:18 UTC
On article Canon EOS Rebel T7i / EOS 800D Sample Gallery (110 comments in total)

Maybe I'm a Philistine but it is approximately impossible for me to understand a camera's strengths & weaknesses by looking at a bunch of nice photos.

The contrast of lens-corrected vs out-of-the-camera-JPEGs lets me know there's a tidge of geometric distortion in the lens that was used. Shocking.

It'd be nice to have even a couple of words about what the camera did so well or not so well with a shot. Metering nailed the real subject. Color balance really got the feeling of the scene. Auto-focus struggled. Speed-v-aperture tradeoff was just wrong. Whatever.

As is, the galleries mostly seem to indicate the user's sense of what were interesting photos. Theres's something I could learn from that, but it doesn't seem to say a thing about what the camera did to contribute.

Link | Posted on Apr 13, 2017 at 18:22 UTC as 4th comment
In reply to:

Azathothh: DNG? Who uses that?

A friend frets about being able to archive photos for decades, and the uncertainty of whether subsequent Nikon raw converters will work on the then-old format. DNG at least has a big enough user base that it'd be a bit more likely to survive in a post-Windows, post-Mac, post-Nikon world.

Link | Posted on Jan 5, 2017 at 21:28 UTC
In reply to:

paulkienitz: 3/3: The second approach is a simple sort of switching power supply, with no transformer. Put a silicon switch and a wide resistor between the main bank and a smaller capacitor, and switch the power to that capacitor on and off to keep it charged to a steady level. This would risk introducing interference to the rest of the circuitry so it would need shielding. And if you don't combine it with the banking idea, it would mean that the supercapacitor might be storing dangerously high voltages.

The safety would be a concern anyway. Someone opening up the device would have to tiptoe very carefully around the capacitor's output leads until he makes sure it's discharged. And in the event of a failure it could release energy a lot more abruptly than a burning lithium battery.

Thanks for the ideas. I imagine the HV safety concerns could be addressed by the “battery” modules having both the supercapacitors AND the switched/regulated LV circuits into a single, sealed unit, only allowing current inflows to the HV circuits.

Good sealing w protection should also lessen catastrophic release risks.

Link | Posted on Nov 23, 2016 at 21:31 UTC
In reply to:

JackM: These guys don't exactly sound like rocket scientists. Or even scientists.

Just one word: “Pentaprism.”

Link | Posted on Nov 15, 2016 at 17:28 UTC

<i>“However, currently low light performance is still bad enough for many users to happily sacrifice some resolution for better image quality in dim conditions.”</i>

I've yet to see any evidence that high pixel counts sacrifice more than a little bit of signal/noise ratio. More pixels means overhead circuitry inadvertently blocks a higher fraction of photons from being usefully recorded, but that should be a small fraction.

The real issue is how many photons the sensor can capture during the 1/100 of a second or whatever, and the rumored 1/2" size is approximately 32% bigger, which should more than offset a higher pixel count.

More likely, we aren't seeing small 50MP sensors is that the lenses don't really resolve enough detail to make the quadrupled file size and cost/processing time worthwhile. No sense trying to record detail that's just not there.

Link | Posted on Nov 5, 2015 at 20:09 UTC as 19th comment | 2 replies
In reply to:

Mister Roboto: Cross your fingers that they will put sensor bigger than a pinhead otherwise this will be another setback for iPhone. You can buy a $50 camera and it is far better than what iPhones have nowadays.

Yes, sensor size matters. But a bigger sensor has a wider view, lousy for many purposes, unless the camera is ALSO a lot thicker.

That's why P&S cameras, despite advantages in image quality, aren't selling: they're not as pocketable and not enough better quality.

SLR—higher quality—cameras have ALSO come down in sales, but they still take ENOUGH better pix, especially in dim light or high-speed sports shots, that pros keep buying them.

No reason to worry, I'd say: image quality is important to Apple. Whether they continue the pretty-much-standard sensor size, or have some magic multi-sensor or multi-snap software, nobody expects a regression.

Link | Posted on Jun 29, 2015 at 22:01 UTC
On article Sony debuts 21MP stacked CMOS sensor for smartphones (94 comments in total)
In reply to:

RichRMA: You can't bend the laws of physics. Sensors can be made any which way, but the small ones will never, ever match the larger ones. Back illuminated, electron-multiplying, it doesn't matter. They are modest enhancements that produce a slightly better product, but a 1/2.3" sensor will never be a m4/3, APS, etc.

But that's the point of this advance…by putting circuitry behind the sensor, rather than taking up area that should be capturing photons, you get an all-else-equal bigger sensor.

Then, there's the constant improvement in the physics of converting photons that impinge on a chip, into electrons. And optical improvements that get more photons onto the chip.

Lots of improvements here, and ahead. Hardware. Haven't even touched smart software.

Link | Posted on Jun 18, 2015 at 19:45 UTC
In reply to:

Lhermine: Very interesting article ! Thanks very much DPR.

As many people here, I was wondering if the number of photons can be so low that shot noise would be significant.

Based on the so-called "sunny 16 rule", I've found that for a proper exposition on a 24 MPix FF sensor, around 50,000 photons should hit each pixel. This lead to a shot noise with an amplitude of 1.4 %.

This kind of noise amplitude should to small to be noticed. However, in darker conditions, you may have to increase the ISO speed let's say for instance 6400. It means that you have fewer photons. The corresponding shot noise amplitude will be around 3.5 %. We reach up to 14 % for ISO 100,000!

And that's the bad news: 1,000,000 ISO speed will never be as good as 100 ISO whatever the quality of the sensor because of the shot noise.

So bad...

(for those who are interseted in the computation, please mail me, you may point out some mistakes ;-) )

I can't confirm/deny your calculations but I *WILL* note that it assumes 100% efficiency of capturing incoming photons. That's way too high.

I'm not the expert to describe the percentage that are captured, but in many sensors, a good fraction of photons fall on support electronics that are insensitive, and lost. More importantly, the fraction that hits the sensitive parts may fail to be recorded for a variety of reasons.

Using a SWAG (scientific, wild-assed guess) of 5% detection efficiency, your 1.4% noise rises to 6.3% (the square root of 1/.05). This doesn't seem unlikely for a well-exposed scene.

Note that RAW conversion techniques essentially ALWAYS employ noise-reduction. For example, a green pixel might take the average of the 4 nearest green pixels; this would smush fine details, but reduce the noise by half (again, the square root). In areas with lower signal, the RAW conversion might spread the average further, hoping to create a more acceptable image.

Link | Posted on May 13, 2015 at 19:57 UTC
Total: 52, showing: 1 – 20
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