Yeah I agree. Nearly all HDR photography is uninteresting to me because I’m attracted to contrasting light in the frame. Having everything in focus looks bland to me.
That is a great photo. To me HDR on the phone is useful for capturing whatever I happen to be doing in a way that is more like how I perceive it in person.
And to generic android as well. I get that they want differentiation, but there's serious lack of other implementation in play store. For actually good hdr it looks like there's pixel or nothing. I'd be happy to pay quite a bit to get their new HDR+ on a OnePlus for example.
There is a hacked Camera APK that restores features and backports new features to old phones. It's not perfectly stable on my Pixel 2 but its close. Restored Burst shots as a feature (my main goal), brought focus tracking and astrophotography improvements. And it can be installed along side the stock camera.
Real cameras have been doing "HDR" for ages, since their sensors have 12-14 stops of dynamic range, but JPEG only has 8. And it works incredibly well, just like the color science Nikon and Canon have figured out, a thing smartphones are lacking as well. With a lot of light smartphones can take very good pictures as far as resolution is concerned, but color and dynamic range rendering are consistently poor. For me it's rare that I need to change the colors my Nikon camera produces, and if I do, it's usually just a slight tweak (a few hundred Kelvin of red-blue shift or maybe a tiny magenta-green adjustment), while the colors in practically every iPhone shot are lacking and require effort to get to a satisfactory level.
That doesn't sound right at all. DSLRs like my Canon do indeed have a larger dynamic range but they are still nowhere near being close to the dynamic range the human eye can capture. Moreover, the native image rendered by DSLRs still has a linear transfer function that still suffers all the issues that HDR tries to solve. This is why auto-bracket exposure is a thing on all DSLRs so you can try to capture high dynamic range scenes in multiple photographs that you then need to combine offline in separate software.
And the sad fact of the matter is that computational photography on phones, especially when it comes to HDR, makes it absolutely no hassle to obtain exceptionally good HDR captures 80+% of the time. I've literally taken back to back comparison shots of my son on a bright sunny day on a boat when on the ocean and my smartphone picture (S9+) was far superior to my DSLR image, even after trying to capture details from highlights/shadows in postprocessing.
Phones these days can perform a lot of neat tricks to reduce noise, capture large dynamic ranges and compress it all into a pleasing HDR image in fractions of seconds that lets you achieve great HDR images even with moving subjects (something notoriously hard with a DSLR).
Not that DSLRs don't have a whole host of other advantages when it comes to image quality and depth-of-focus, etc, but HDR is not one of them. It is almost the sole reason why I've been reaching for my DSLR less and less when on vacation.
The DSLR captures pictures and then you post-process them. The phone can dynamically adjust what it captures, and potentially capture way more data (quickly slurping a gigabyte of image data into RAM) than a DSLR can push to persistent storage in an acceptable timeframe.
Together with the phone always being in my pocket, while a DSLR is bulky, I've gone completely with the phone. I just wish the computational photography developers and the camera engineers would come together and make something that uses the far superior hardware of the DSLR combined with the far superior software originally designed for phones.
Yeah, it's a similar situation for me. Though large prints from phone photographs are pretty poor in comparison to the image quality from even my entry-level Rebel Xsi from 2007. Sports photography with a good lens is still something that a camera phone will never rival, but in most day to day situations, it has surpassed DSLRs purely out of convenience and being good enough (and in the case of things like HDR/low-light photography, better than a DSLR in many situations).
> Moreover, the native image rendered by DSLRs still has a linear transfer function
Capture RAW+JPEG of a scene with dark shadows and bright highlights, the camera clearly isn't using a linear transfer function to get from RAW to JPEG. With something like a D7200 you can literally have the sun in your picture and still get both detail in the sunstar and the clouds, while also having detail in the sun's shade, with an out-of-camera JPEG.
That isn't the same type of HDR that these HDR modes on cell phones are. You seem to be confusing bit's with stops of dynamic range.
To simplify I'll pick a grayscale image so with 8bits you would only have 0-255 as pixel values for the intensity.
With 12 bits you'll have 4096, and so forth.
What cellphone HDR usually does is take the image at a high exposure and a low exposure and combine the result. (Also the sensors inside the cellphone are also more than 8bit)
Even if you take a 12 bit photo if it's overexposed you can't do much. All you get is more play but it doesn't solve the fundamental problem of too much light hitting the sensor, or vice versa if the image is underexposed.
Now there are more advanced camera sensors that let you set the exposure time (or usually the ISO (which just translates to gain) at specific horizontal points of the sensor so that you can get even better images in one frame.
> You seem to be confusing bit's with stops of dynamic range.
This is correct, they seem to be mistaken. I've seen this mistake many times in this thread. I wrote a comment in reply to one of them explaining in some detail what the point of higher bit depths and "HDR" (as a set of technology standards) is: https://news.ycombinator.com/item?id=24044818
Your remark (~"x bits worth of luma doesn't necessarily correspond to x stops of DR on a display") is entirely correct but is tangential to my point. You can't encode a scene with more than 8 stops of dynamic range into an 8 bit JPEG without either loosing details or performing a tone-mapping-like process.
> That isn't the same type of HDR that these HDR modes on cell phones are. You seem to be confusing bit's with stops of dynamic range.
I'm aware of the difference between bracketed HDR and what these cameras do, but that's besides the point. If you capture RAW+JPEG it's pretty obvious that the camera is not using a flat curve, but that it is quite clearly doing something similar to tone mapping around highlights and shadows, and it's not fixed either, but slightly different for each shot.
"HDR images can be challenging to edit, because some decisions are effectively baked into the final JPG. To maximize latitude for editing, it’s possible to save RAW images for each shot (an option in the app). However, this process takes the photographer out of the moment and requires expertise with RAW editing tools as well as additional storage."
I wish at least 12bit (ideally 14 or 16bit) compressed image formats (like HEIF) took over jpeg on cameras. It's great to have raw as an option, but can we please just get rid of 8bit jpg as the default
Part of the underlying challenge is that displays are, at best, 10-bit. Our imaging systems easily handle 14-bit depth, but the display systems cannot.
Yep. But you can do a lot more post-processing to bring all that latitude back to 8/10bit color space, than if you start with a 8bit jpeg. Same as when shooting high bit depth raw files
To me, the biggest limitation is the limited range in luminance. By design, half of my work (ig:@charliehagedorn) is in black and white. The difference in light intensity between sunlit snow and shadowed rock is often far, far more than 8 stops.
While it is the job of the photographer, these days, to collapse the dynamic range enough to get it onto a screen, there is a huge depth of experience awaiting us the day that our displays reach parity with our sensors.
> To me, the biggest limitation is the limited range in luminance. The difference in light intensity between sunlit snow and shadowed rock is often far, far more than 8 stops.
The bit depth of a photo or display device is not the same as the dynamic range at which that photo is displayed. With traditional SDR image formats, on some screens a "0" pixel will be displayed at about 1 nit brightness, and a "255" pixel will be displayed at about 100 nits. But on other screens, the same pixel will be shown at 500 nits or more. Thus with SDR images, the luminance range depends on the characteristics of the display device in use, and not the fact that it's only an "8 bit" photo. "8 bit" ≠ "8 stops". On the other hand, on displays with very high peak brightness, you may get banding even with images that are properly dithered to take advantage of the full capabilities of the 8 bit range.
The point of 10 bit and higher is that you can accurately capture all the details in between a very dark portion of an image and a very bright one without banding. The point of the new HDR standards (which are just now being introduced to images) is that luma is now on an absolute scale, so that you are no longer dependent on the characteristics of the individual display. (You have to have both together for either to be very useful.) But whether you're working with SDR or HDR, 8 bit or 10 bit, fundamentally the question of how many stops you can get (the display's true contrast) is a question of what the display is capable of reproducing, not the underlying technology you're working with.
I'd contend that a display that spans a dynamic range of a factor of 100 is only a 6.7-bit display. It is impossible to calibrate such a display to span 8 bits of intensity.
It isn't the maximal intensity that matters, (to the extent that the viewer's eye can adapt to the differences in intensity between displays), but rather the number of subdivisions available between peak intensity and darkness.
Totally agreed that improved bit-depth improves gradations/banding. An N+1-bit display has N bits between half-intensity and full intensity, twice as many bits as an N-bit display has.
Another way to see that this matters is that imaging sensors are generally linear in their response to impinging light. The optimal way to display the output from a 14-bit sensor is a 14-bit (or higher) display.
> I'd contend that a display that spans a dynamic range of a factor of 100 is only a 6.7-bit display. It is impossible to calibrate such a display to span 8 bits of intensity.
That's not what a nit is. A nit is a measurement of absolute brightness. You can have 256 gradations (8 bits) on a 100 nit display. You can have 1024 gradations (10 bits). You could have 65536. What's being measured here are two different things. Imagine I have a flashlight with adjustable brightness: if I turn it all the way up, that's what we're measuring when we talk about the nits of a display with with all white pixels. The bit depth is how many gradations the flashlight can display between full brightness and no light at all. So in fact a 100 nit display can have any bit depth. A stop is not a nit is not bit depth.
(This is a simplification that is only completely accurate for SDR screens with sRGB gamut. With HDR and tagged images, part of the range created by the extra bit depth is for "impossible" values, stuff that is too bright or colorful for the screen to display, and has to be tonemapped by the display into the possible range.)
First off -- thank you for this conversation. It has caused me to think more-deeply about the meaning of pixel-values in a display context. It has sent me into the standards, too. In particular, I found this document useful:
We agree that bit-depth is independent of maximum light output. Where we appear to disagree is on the meaning of an ideal bit, in particular whether or not it is acceptable for the (gamma-corrected) intensity difference between pixel-value 0 and pixel-value 1 to be greater than the base intensity of the display at pixel-value 0. I believe that I'm arguing for the concept depicted in Figure 3 of the document above (relative colorimetric), while you are arguing for the concept in Figure 4 (black-point compensation).
There is an important pragmatism to your approach -- high contrast ratios are technically difficult, while higher-resolution gradations sitting atop a pedestal of minimum intensity may be more technically-feasible. Increased subdivisions between minimum intensity and maximum intensity do reduce banding, as you suggest. Such a rendering choice can portray the content of an image at the expense of the creator's intended contrast.
A linear display output with no offset will yield an intensity proportional to the intensity value assigned to that pixel. Higher bit-depth does not make for greater intensity, but rather more gradations between maximum intensity and zero.
As a scientist or as an artist, when specifying pixel values I expect the intensity, on a calibrated display, to reproduce a calibrated fraction of the maximum light intensity. It is helpful to understand that not all systems render with this intent.
In the original reply, the thought-experiment display had a minimum brightness of 1 nit and a maximum brightness of 100 nits and 255 brightness levels between them. That spans a factor of 2^6.7. The discrepancy between our opinions represents differences in a choice of rendering intent. If I had to specify the rendering strategy for portraying 8-bit pixel values on such a display, it would have less contrast in the shadows than the highlights but equal contrast in the highlights when compared with an 8-bit display with a minimum brightness of 0.4 nits and a maximum brightness of 100 nits (which is capable of 2^8 dynamic range). Your strategy would yield uniform contrast spanning the shadows and highlights, but less contrast on the 1-100 nit display than the 0.4-100 nit display.
In that situation, I suspect that most people would prefer your black-point compensated rendering strategy, as the shadows would not be crushed. I simply wouldn't market/sell it as a true 8-bit display, though I understand why a manufacturer would choose to do so.
The iPhone defaults to HEIF, and all Android devices running at least Android 9 have the option to save images in HEIF. That being said, I have no idea if you get any of the benefits of a higher bit-depth.
I don't think the iPhone HEIF is 14/16bit. And I'm not sure a single shot on a sensor that small has that much dynamic range anyway, so you'd still want HDR+ style multiple exposures. Just wish the end result wasn't stored 8bit so you have more freedom to change the exposure/shadows/highlights after the shot is saved
Yeah I think the big issue here is that HEIF is typically used to get JPEG level quality at a lower file size. Increased bit depth would negate those file savings, and I bet Apple/Google would just prefer you use RAW.
My camera app (the one that came with the phone) appears to be this one https://play.google.com/store/apps/details?id=com.motorola.c... and my device is a Moto X4 Android One edition on Android 9. Don't see it anywhere in this app. Maybe some manufacturer's default camera apps don't support it, even on Android 9?
Newer Canon mirrorless cameras now support HEIF (R5 and R6), and I think newer Sony ones will as well, so the groundswell might be starting in the higher-end.
But iPhones have defaulted to using HEIF for years now I think, and no browser (even Safari) supports the format yet, so...
Modern smartphone HDR is so insane. I tried replicating it with a tripod and HDR software but I had to apply so much compensation and the smartphones are just point and click. Great stuff.
I am very impressed with the photo AI work people have been doing. Very concrete feature for people to use.
This is really cool. Nit: I find it really unintuitive that 100% is on the left of the slider. "Volume" knobs and sliders are almost always the other way around in my experience.
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[ 3.8 ms ] story [ 108 ms ] threadInterestingly, the final rendering in the Pixel 3 looks better to my eyes.
But it's definitely a great tool. See this HDR photo I made years ago:
https://www.flickr.com/photos/petit_pierrot/3806527134/
Same here.
https://forum.xda-developers.com/apps/google-camera-mods/gca...
And the sad fact of the matter is that computational photography on phones, especially when it comes to HDR, makes it absolutely no hassle to obtain exceptionally good HDR captures 80+% of the time. I've literally taken back to back comparison shots of my son on a bright sunny day on a boat when on the ocean and my smartphone picture (S9+) was far superior to my DSLR image, even after trying to capture details from highlights/shadows in postprocessing.
Phones these days can perform a lot of neat tricks to reduce noise, capture large dynamic ranges and compress it all into a pleasing HDR image in fractions of seconds that lets you achieve great HDR images even with moving subjects (something notoriously hard with a DSLR).
Not that DSLRs don't have a whole host of other advantages when it comes to image quality and depth-of-focus, etc, but HDR is not one of them. It is almost the sole reason why I've been reaching for my DSLR less and less when on vacation.
Together with the phone always being in my pocket, while a DSLR is bulky, I've gone completely with the phone. I just wish the computational photography developers and the camera engineers would come together and make something that uses the far superior hardware of the DSLR combined with the far superior software originally designed for phones.
Capture RAW+JPEG of a scene with dark shadows and bright highlights, the camera clearly isn't using a linear transfer function to get from RAW to JPEG. With something like a D7200 you can literally have the sun in your picture and still get both detail in the sunstar and the clouds, while also having detail in the sun's shade, with an out-of-camera JPEG.
To simplify I'll pick a grayscale image so with 8bits you would only have 0-255 as pixel values for the intensity.
With 12 bits you'll have 4096, and so forth.
What cellphone HDR usually does is take the image at a high exposure and a low exposure and combine the result. (Also the sensors inside the cellphone are also more than 8bit)
Even if you take a 12 bit photo if it's overexposed you can't do much. All you get is more play but it doesn't solve the fundamental problem of too much light hitting the sensor, or vice versa if the image is underexposed.
Now there are more advanced camera sensors that let you set the exposure time (or usually the ISO (which just translates to gain) at specific horizontal points of the sensor so that you can get even better images in one frame.
This is correct, they seem to be mistaken. I've seen this mistake many times in this thread. I wrote a comment in reply to one of them explaining in some detail what the point of higher bit depths and "HDR" (as a set of technology standards) is: https://news.ycombinator.com/item?id=24044818
I'm aware of the difference between bracketed HDR and what these cameras do, but that's besides the point. If you capture RAW+JPEG it's pretty obvious that the camera is not using a flat curve, but that it is quite clearly doing something similar to tone mapping around highlights and shadows, and it's not fixed either, but slightly different for each shot.
I wish at least 12bit (ideally 14 or 16bit) compressed image formats (like HEIF) took over jpeg on cameras. It's great to have raw as an option, but can we please just get rid of 8bit jpg as the default
While it is the job of the photographer, these days, to collapse the dynamic range enough to get it onto a screen, there is a huge depth of experience awaiting us the day that our displays reach parity with our sensors.
The bit depth of a photo or display device is not the same as the dynamic range at which that photo is displayed. With traditional SDR image formats, on some screens a "0" pixel will be displayed at about 1 nit brightness, and a "255" pixel will be displayed at about 100 nits. But on other screens, the same pixel will be shown at 500 nits or more. Thus with SDR images, the luminance range depends on the characteristics of the display device in use, and not the fact that it's only an "8 bit" photo. "8 bit" ≠ "8 stops". On the other hand, on displays with very high peak brightness, you may get banding even with images that are properly dithered to take advantage of the full capabilities of the 8 bit range.
The point of 10 bit and higher is that you can accurately capture all the details in between a very dark portion of an image and a very bright one without banding. The point of the new HDR standards (which are just now being introduced to images) is that luma is now on an absolute scale, so that you are no longer dependent on the characteristics of the individual display. (You have to have both together for either to be very useful.) But whether you're working with SDR or HDR, 8 bit or 10 bit, fundamentally the question of how many stops you can get (the display's true contrast) is a question of what the display is capable of reproducing, not the underlying technology you're working with.
It isn't the maximal intensity that matters, (to the extent that the viewer's eye can adapt to the differences in intensity between displays), but rather the number of subdivisions available between peak intensity and darkness.
Totally agreed that improved bit-depth improves gradations/banding. An N+1-bit display has N bits between half-intensity and full intensity, twice as many bits as an N-bit display has.
Another way to see that this matters is that imaging sensors are generally linear in their response to impinging light. The optimal way to display the output from a 14-bit sensor is a 14-bit (or higher) display.
That's not what a nit is. A nit is a measurement of absolute brightness. You can have 256 gradations (8 bits) on a 100 nit display. You can have 1024 gradations (10 bits). You could have 65536. What's being measured here are two different things. Imagine I have a flashlight with adjustable brightness: if I turn it all the way up, that's what we're measuring when we talk about the nits of a display with with all white pixels. The bit depth is how many gradations the flashlight can display between full brightness and no light at all. So in fact a 100 nit display can have any bit depth. A stop is not a nit is not bit depth.
(This is a simplification that is only completely accurate for SDR screens with sRGB gamut. With HDR and tagged images, part of the range created by the extra bit depth is for "impossible" values, stuff that is too bright or colorful for the screen to display, and has to be tonemapped by the display into the possible range.)
http://www.color.org/WP40-Black_Point_Compensation_2010-07-2...
We agree that bit-depth is independent of maximum light output. Where we appear to disagree is on the meaning of an ideal bit, in particular whether or not it is acceptable for the (gamma-corrected) intensity difference between pixel-value 0 and pixel-value 1 to be greater than the base intensity of the display at pixel-value 0. I believe that I'm arguing for the concept depicted in Figure 3 of the document above (relative colorimetric), while you are arguing for the concept in Figure 4 (black-point compensation).
There is an important pragmatism to your approach -- high contrast ratios are technically difficult, while higher-resolution gradations sitting atop a pedestal of minimum intensity may be more technically-feasible. Increased subdivisions between minimum intensity and maximum intensity do reduce banding, as you suggest. Such a rendering choice can portray the content of an image at the expense of the creator's intended contrast.
A linear display output with no offset will yield an intensity proportional to the intensity value assigned to that pixel. Higher bit-depth does not make for greater intensity, but rather more gradations between maximum intensity and zero.
As a scientist or as an artist, when specifying pixel values I expect the intensity, on a calibrated display, to reproduce a calibrated fraction of the maximum light intensity. It is helpful to understand that not all systems render with this intent.
In the original reply, the thought-experiment display had a minimum brightness of 1 nit and a maximum brightness of 100 nits and 255 brightness levels between them. That spans a factor of 2^6.7. The discrepancy between our opinions represents differences in a choice of rendering intent. If I had to specify the rendering strategy for portraying 8-bit pixel values on such a display, it would have less contrast in the shadows than the highlights but equal contrast in the highlights when compared with an 8-bit display with a minimum brightness of 0.4 nits and a maximum brightness of 100 nits (which is capable of 2^8 dynamic range). Your strategy would yield uniform contrast spanning the shadows and highlights, but less contrast on the 1-100 nit display than the 0.4-100 nit display.
In that situation, I suspect that most people would prefer your black-point compensated rendering strategy, as the shadows would not be crushed. I simply wouldn't market/sell it as a true 8-bit display, though I understand why a manufacturer would choose to do so.
Thank you -- I learned something useful.
Can you tell me how I'd enable this on an Android 9 device? I've looked everywhere, even in the developer options, but I can't find it.
The Play store claims that my device is incompatible with the official Google camera app. https://play.google.com/store/apps/details?id=com.google.and...
But iPhones have defaulted to using HEIF for years now I think, and no browser (even Safari) supports the format yet, so...
I am very impressed with the photo AI work people have been doing. Very concrete feature for people to use.