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Author Topic: dynamic range of digital cameras - what does this mean to me?  (Read 512895 times)

Wayne Fox

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Re: dynamic range of digital cameras - what does this mean to me?
« Reply #20 on: September 24, 2017, 02:40:22 pm »

While shooting this weekend, this thread came to mind so I thought I'd take a shot with an iPhone that has relatively limited dynamic range and a Sony a7R Mk II with excellent dynamic range to illustrate what dynamic range really means.  To top it off, I even used the HDR feature on the iPhone and the a7R Mk II still annihilated the iPhone.  Just look at the detail in the buildings and in the iPhone picture and you can't even really see the river boats since they are just silhouetted against the far bank:

iPhone first, then a7R Mk II:
was the Sony shot in raw and then processed or is this an in camera jpeg?  Just curious, since the iPhone software might have made the decision to leave the shadows dark, not necessarily representative of what the HDR process could do if it was left to the photographer.

Not trying to defend the iPhone here, I shoot sony too and the iPhone isn’t any where close in DR.  But it does make me curious how the iPhone would fair if the captures were raw and then went through similar post processing.
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BJL

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Re: dynamic range of digital cameras - what does this mean to me?
« Reply #21 on: September 24, 2017, 03:04:49 pm »

While shooting this weekend, this thread came to mind so I thought I'd take a shot with an iPhone that has relatively limited dynamic range and a Sony a7R Mk II with excellent dynamic range to illustrate what dynamic range really means.  To top it off, I even used the HDR feature on the iPhone and the a7R Mk II still annihilated the iPhone.
Mmmm: this does legitimately illustrate the advantages of high dynamic range capture (whether single shot or via HDR composite) when photographing scenes of high Subject Brightness Range (why have photographic discussions mostly abandoned the old standard jargon of SBR?)

But this reminds me a bit of the notorious article at LuLa some years ago arguing the superiority of medium format cameras by comparing to what turned out to be an iPhone image. Here one missing detail is that this is the four year old iPhone 5S; two years older than the Sony a7R Mk II.

So for more irrelevant fun, let's compare high SBR handling between this year's hottest new toys: the iPhone X and the Nikon D850!


P. S. I should add: thanks to shadowblade for the good explanation, and to Wayne Fox for the illustration of getting an artistically worthwhile result from a scene with way too much SBR for "straight" printing or display.
« Last Edit: September 24, 2017, 03:09:13 pm by BJL »
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E.J. Peiker

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Re: dynamic range of digital cameras - what does this mean to me?
« Reply #22 on: September 24, 2017, 05:25:46 pm »

OK, lots of questions/comments:
- No I am just visiting the STL area
- Sony shot in RAW, even had I shot it in JPEG it would still be very different, in fact the embedded JPEG in the RAW file clearly shows this.
- Yes, my newer iPhone did not survive the Pantanal and I have an 8 Plus waiting at home so I am temporarily using an old phone but even with a 7 Plus, there is absolutely no comparison in dynamic range and remember I shot the iPhone shot with HDR on!
- The benefit is definitely not just noise - it is how many tonal levels the sensor records between solid black and solid white
- Not at all trying to advocate one format over the other, simply pointing out the difference between a sensor that has lower dynamic range with one that has higher dynamic range using what is probably an extreme difference in equipment for illustrative purposes.  I just happened to think of this thread as I was shooting at dusk...

« Last Edit: September 24, 2017, 06:13:34 pm by E.J. Peiker »
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kers

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Re: dynamic range of digital cameras - what does this mean to me?
« Reply #23 on: September 24, 2017, 06:13:29 pm »

to put some numbers to it:
according to    http://photonstophotos.net/Charts/PDR.htm
the Apple Iphone7 has at 25 asa the same dynamic range as the d850 at 2500asa
at 25 asa the iphone has 7.15 stops of dynamic range the d850 has at 64 asa 11.63 stops = about 4.5 stops more.
at asa 200 the iPhone has the same dynamic range as the d850 at 12.800asa= 4.7 stops.

But i think what is interesting is the different approach camera and phone companies have.
The iphone companies are computer based and use advanced software to get the best out of the captured information.
They do a very good job in processing the image to a kind of general taste. Part of the work i have to do myself in photoshop.
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Michael Nelson

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Re: dynamic range of digital cameras - what does this mean to me?
« Reply #24 on: September 25, 2017, 11:53:33 am »

A DR question: (These three images are typical of what I photograph).

For digital images, I use a 9-stop DR sensor camera. If I use a 12-stop DR sensor camera, what differences might I see (other than increase in resolution size)?

Will there be smoother transitions between tonality? A better gradation between colors?

Optimistically...
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kers

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Re: dynamic range of digital cameras - what does this mean to me?
« Reply #25 on: September 25, 2017, 12:36:31 pm »

A DR question: (These three images are typical of what I photograph).

For digital images, I use a 9-stop DR sensor camera. If I use a 12-stop DR sensor camera, what differences might I see (other than increase in resolution size)?

Will there be smoother transitions between tonality? A better gradation between colors?

Optimistically...

In the last photo less noise and more detail in the dark areas...- yes smoother transitions.
This also depends on your way of handling the files
But maybe with an other camera you do not like the colour you now have- always a bit different.
And if you have a controlled environment you just make sure you can arrange you only need 9 stops.

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shadowblade

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Re: dynamic range of digital cameras - what does this mean to me?
« Reply #26 on: September 25, 2017, 04:58:16 pm »

In the last photo less noise and more detail in the dark areas...- yes smoother transitions.
This also depends on your way of handling the files
But maybe with an other camera you do not like the colour you now have- always a bit different.
And if you have a controlled environment you just make sure you can arrange you only need 9 stops.

Not necessarily.

Yes, you will have less noise in the shadows, since they may be six stops above the noise floor rather than two - the SNR in the shadows may be much higher  (and you will be able to capture detail in deeper ones). But transitions and graduations will not necessarily be more gradual - that depends on the bit depth rather than the dynamic range. More bit depth means finer graduations. If you have a sensor with high bit depth but low dynamic range, you may have 32 different levels within the darkest stop, and it only goes up from there. Conversely, if you have high dynamic range but low bit depth, you may have one level at the darkest stop, with no levels at the secomd darkest and only two levels in the third darkest.

And this is all complicated by noise. It's only meaningful to have more levels of tonality in the shadows if there is enough of a difference between the levels to make detail distinguishable from noise. Although having the difference between levels slightly smaller than the noise is, in itself, no bad thing if it's not overdone - it ensures that all recordable detail is captured and helps eliminate posterisation, a bit like adding noise to eliminate posterisation in post-processing, where curves are being stretched and levels pulled further apart.
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ErikKaffehr

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Re: dynamic range of digital cameras - what does this mean to me?
« Reply #27 on: September 27, 2017, 04:17:25 pm »

Hi,

Dynamic range is about recovery of shadow detail. All digital sensor handle highlights the same. If you have a lot of DR you may underexpose to protect highlights and still have clean shadow detail.

I would suggest that DR is somewhat overrated.

Technically, DR is usually the full well capacity (FWC) of the sensor divided by readout noise. So a sensor with a good FWC and low readout noise has a good DR. This is an area where modern CMOS has made great progress. Signal readout is much cleaner compared to CCD or old CMOS technology, at least at base ISO. All CMOS based MFDs except Leica use Sony technology.

Best regards
Erik


hello.  so since i've read about the dynamic range of some of the newer PhaseOne digital systems, i've wondered what exactly this looks like? and what does it mean?  if i take a photograph of scene with bright sky in the background and use my canon 6d, then take the same image with same exposure settings with one of the HDR PhaseOne'rs, the plop both of these image into a raw converter, will the PhaseOne with 10 or 12 stops of DR have that bright sky under control without me having to do any adjustments?

i know for instance, that you can use a highlight recovery slider in a raw converter and get some of that sky back.  or, a shadows slider to increase the visibility of shadow details.

i work in a 3d rendering program that can generate 32bit HDR images.  i can save those out and open in photoshop and use an exposure slider or whatever, to basically set whatever exposure "range" i want for the rendered image.  technically i don't know how to equate the number of stops the image is.  but ultimately i get a nice clear image no matter what.  in addition to the 3d rendering program's simulated sun and sky light, i can use HDR photographs to light a scene... those are typically 10 or so photographs blended together from under exposure to over exposure. but even with these, as i increase/decrease the exposure of the rendered image, i still run into the sky can be over exposed and all "white" or shadows can be all "black".

or, is that not even the issue in digital camera systems? is the issue the noise, "blockiness", lack of details in shadows as you try to "open" them up in a scene that might be exposed for that bright sky.

thanks,
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Erik Kaffehr
 

digitaldog

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Re: dynamic range of digital cameras - what does this mean to me?
« Reply #28 on: November 19, 2017, 11:56:53 am »

Dynamic range is about recovery of shadow detail.

Dynamic range is about the capture of shadow to highlight data/detail.
You can't recover what wasn't captured.
This is a bit like those that state they 'alter' exposure in post'. Not possible. Exposure like DR is an attribute of the capture of the data.
DR isn't at all over-rated IF you desire to capture as much of what you 'saw' and what existed at the scene. More data on this concept:
http://www.lumita.com/site_media/work/whitepapers/files/pscs3_rendering_image.pdf
Page 3-4 but do read the entire piece.
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Andrew Rodney
Author “Color Management for Photographers"

digitaldog

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Re: dynamic range of digital cameras - what does this mean to me?
« Reply #29 on: November 19, 2017, 11:59:33 am »

In the last photo less noise and more detail in the dark areas...- yes smoother transitions.
This also depends on your way of handling the files
Like how you exposed them:
https://photographylife.com/how-to-use-the-full-dynamic-range-of-your-camera
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Andrew Rodney
Author “Color Management for Photographers"

ErikKaffehr

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Re: dynamic range of digital cameras - what does this mean to me?
« Reply #30 on: November 20, 2017, 12:54:33 am »

Hi,

The factors involved are the full well capacity (FWC) , that is how many electron charges the pixel can hold and the readout noise of the sensor. DR is simply FWC divided with the "readout noise" of the sensor. This is a tiny bit oversimplified.

It could be argued that FWC should be utilized fully at exposure, exposing non specular highlights  just below FWC, this is called expose to the right and maximises DR.

Highlights can never go beyond FWC, but you can protect highlights by underexposing the image.

The other end is dark detail. Here noise sets the limit. Engineering DR tells how far the noise floor is from the ceiling defined by FWC.

Engineering DR is plenty on modern sensors, especially with CMOS sensors using column converters doing conversions in parallell. But, you cannot show like 13 EV of DR on a screen especially not in surround light. So, if we want to utilize the DR of a modern camera, we need to map tones.

The images below show a white text over a gradient going from Lab(100, 0,0) to Lab(80, 0, 0), printed on paper. The images were shot on a P45+ (2007 year's CCD) and a Sony A7rII (2015 year's CMOS)
. The text begins with Lorem ipsum and the "m" in Lorem is the first discernible character in the original print.

Getting a scene with a full dynamic range utilizing the sensor is no easy task. In the example below, a tabletop setup was made, illuminated by a single flash with a grid to reduce light spread. The image was split into a highlight/shadow part. An additional flash at minimum power was bounced trough a door to get some fill light. This scene had a luminance range of around 14 stop.

The highlight parts were pretty much similar:


Brightening the shadows was not easy, as I run into the 5EV exposure limitation of Lightroom, combined with the built in exposure bias of LR. So, I resorted to RawTherapee to show shadow detail, where I could adjust exposure at will:

This image shows that the A7rII handles the shadow detail well. The P45+ image is noisy. With the A900, that is the same era as the P45+, the image is blotchy. This is probably in part due to the A900 using a 12 bit file format, 14 bits are needed to handle 14EV of dynamic range.

Some examples are shown in this discussion:

https://www.dpreview.com/forums/thread/4083662

Best regards
Erik
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Erik Kaffehr
 

digitaldog

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Re: dynamic range of digital cameras - what does this mean to me?
« Reply #31 on: November 20, 2017, 11:47:52 am »

Engineering DR is plenty on modern sensors, especially with CMOS sensors using column converters doing conversions in parallell.
Plenty, perhaps. But not enough for many scenes which the Karl Lang article clearly outlined visually and numerically.
The article by the author of RawDigger doesn't appear to believe that getting a scene with a full dynamic range utilizing the sensor is difficult task when the scene DR doesn't exceed the sensor DR.
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Andrew Rodney
Author “Color Management for Photographers"

qwz

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Re: dynamic range of digital cameras - what does this mean to me?
« Reply #32 on: November 30, 2017, 01:09:37 pm »

And what about lens contrast limitations?
Shooting and combining +/- 5EV images can give an enormous 'dynamic range' - but it doesn't at all.
Yes, shadow become less noisy but there not much new details - 'cause camera body and in-lens reflections eats almost all.
Zeiss is better, old zoom lens is worthier but over 14EV is practical ceiling. 
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epines

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Re: dynamic range of digital cameras - what does this mean to me?
« Reply #33 on: November 30, 2017, 06:52:07 pm »

Interesting discussion. Can someone here point me to a good tonemapping tutorial? And software? (And if you have a good technique, feel free to explain it.) I'm a commercial photographer and tend to light everything I shoot, so I'm not usually dealing with images needing HDR techniques or bracketing. But occasionally I do shoot landscapes / found scenes, and I'd like to be more capable when it comes to rendering and processing them artfully.

I shoot predominantly with a Hasselblad H5D-50 (CCD).

Thank you,
ethan pines

shadowblade

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Re: dynamic range of digital cameras - what does this mean to me?
« Reply #34 on: December 01, 2017, 05:06:49 am »

Interesting discussion. Can someone here point me to a good tonemapping tutorial? And software? (And if you have a good technique, feel free to explain it.) I'm a commercial photographer and tend to light everything I shoot, so I'm not usually dealing with images needing HDR techniques or bracketing. But occasionally I do shoot landscapes / found scenes, and I'd like to be more capable when it comes to rendering and processing them artfully.

I shoot predominantly with a Hasselblad H5D-50 (CCD).

Thank you,
ethan pines

You're tonemapping any time you apply a Curves adjustment to an image, a channel or part of an image. In other words, every time you use almost any tool in Photoshop, Capture One or any other RAW converter or editor. It's the same whether it's a regular file or a merged HDR file - just that the HDR file gives you more data to work with.
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epines

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Re: dynamic range of digital cameras - what does this mean to me?
« Reply #35 on: December 01, 2017, 11:05:32 am »

I'm going to rephrase my question in a new thread. Thanks.

digitaldog

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Re: dynamic range of digital cameras - what does this mean to me?
« Reply #36 on: December 01, 2017, 11:16:59 am »

I'm going to rephrase my question in a new thread. Thanks.
Excellent idea considering one can pull a curve without affecting tones;)
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Andrew Rodney
Author “Color Management for Photographers"
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