Do we really need bracketed exposures and HDR programs anymore?

[Doug Peterson]

The answer to that depends on the camera used, and the scenes shot.

If you have an IQ4 with Frame Averaging and Dual Exposure+ then the answer is basically: no, you don't.

Except for some *really* contrived situations the dynamic range of that system easily exceeds the contrast of even traditionally challenging scenes (e.g. dark subject matter backlit against bright subject matter).

If you're using a 10 year old Canon Rebel then the answer is basically: yes, you do. Even moderately challenging scenes will easily outpace the range that camera can capture in a single frame.

[assumptions are that you want a file that contains usable detail throughout the subject, leaving it up to you how to render the tonality of the scene, without fear of introducing ugly noise or areas of otherwise poor quality such as banding or lower color fidelity]

[Guillermo Luijk]

Can't colors change as well even at 1/3 over or under exposure? So bracketing at 1/3 would assure the correct colors important for product shoots.

Colours don't change with exposure, unless the original RAW files are processed with poor (very poor indeed) software. In fact the most accurate colours are achieved through ETTR, no matter if the final exposure will be lower. The only difference between differently exposed shots is SNR.

This is a seamless composite made from two RAW files 2EV apart, the joints are undetectable in the whole image because capture exposure doesn't alter colour nor contrast:



And these are the colours on captures taken 4EV apart:




http://translate.google.com/translate?u=http%3A%2F%2Fwww.guillermoluijk.com%2Farticle%2Fettrcolor%2Findex.htm&langpair=es%7Cen&hl=EN&ie=UTF-8

Regards

[Guillermo Luijk]

I wonder how the camera manufacturer would accomplish that.  Would it require demosaicing the scene in the camera?

A histogram is just a count of how many pixels in the RAW file are given each possible numeric value after the A/D conversion. So you can calculate and display a RAW histogram very easily without demosaicing anything. This is IMO the most beautiful, compact and useful to the photographer RAW histogram:



The reason I find it the most useful to the photographer is that it is plotted in log scale, so the width of every vertical division corresponds to exactly 1 stop in exposure. This has the following advantages:
- The histogram doesn't change in shape when modifying exposure, it justs shifts left or right:
   
- It allows to know exactly how much you need to overexpose to achieve ETTR without trial&error (in my example the RAW file is perfectly ETTR'ed, it wouldn't even admit an extra +1/3EV)
- It allows to calculate scene's dynamic range at a glance (even if scene's DR is higher than the sensor's DR!). This scene spreaded over 8 stops of DR.

Regards

[Guillermo Luijk]

Responding to the original question, I think there are still situations where more than one shot are still recommended or even we could say necessary. However in my opinion the limit, i.e. the point at which more than one shot won't be recommended/necessary anymore thanks to sensor's DR is nearing. There will always be real world scenes with more DR than any sensor because real world contrasts can be so huge, but we'll probably won't want to do more than one shot on those scenes because tone mapping such a high contrast in a good looking final image will be very dificult, if not impossible.

- A scene with 12 stops of DR, no matter if it comes from a single shot or more, can be quite easily tone mapped on a monitor or print in a pleasant way.
- A scene with 14 stops of DR starts to be difficult to render on any output device in a pleasant way.
- A scene with 16 stops of DR is nearly impossible to render properly on any output device, the compression will lead to an unreallistic look or loss of local contrast. If our camera has 14 stops of photographic DR, we'd rather sacrifice a couple of the scene's 16 and just render 14 stops, than doing an extra shot +2EV apart with the idea to merge them. So it won't make any difference capturing those extra 2 stops (either with a couple of shots with the 14 stops camera or using a hypothetical 16 stops camera).

Eventually at some point increasing DR on sensors will become useless, and the reason is not we can't find real world scenes with such a high contrast but because it will be almost impossible to map such a large DR on any output device in a pleasant way. The compression required will make those images look dull or unreallistic.

Regards

[rdonson]

Responding to the original question, I think there are still situations where more than one shot are still recommended or even we could say necessary. However in my opinion the limit, i.e. the point at which more than one shot won't be recommended/necessary anymore thanks to sensor's DR is nearing. There will always be real world scenes with more DR than any sensor because real world contrasts can be so huge, but we'll probably won't want to do more than one shot on those scenes because tone mapping such a high contrast in a good looking final image will be very dificult, if not impossible.

- A scene with 12 stops of DR, no matter if it comes from a single shot or more, can be quite easily tone mapped on a monitor or print in a pleasant way.
- A scene with 14 stops of DR starts to be difficult to render on any output device in a pleasant way.
- A scene with 16 stops of DR is nearly impossible to render properly on any output device, the compression will lead to an unreallistic look or loss of local contrast. If our camera has 14 stops of photographic DR, we'd rather sacrifice a couple of the scene's 16 and just render 14 stops, than doing an extra shot +2EV apart with the idea to merge them. So it won't make any difference capturing those extra 2 stops (either with a couple of shots with the 14 stops camera or using a hypothetical 16 stops camera).

Eventually at some point increasing DR on sensors will become useless, and the reason is not we can't find real world scenes with such a high contrast but because it will be almost impossible to map such a large DR on any output device in a pleasant way. The compression required will make those images look dull or unreallistic.

Regards

+1

[MauriceRR]

Colours don't change with exposure, unless the original RAW files are processed with poor (very poor indeed) software.

If noise increases, color sensitivity will decrease. Colors can shift between different exposures, as you wrote in your article, and as you show here .
If it's not so much visible with a big photosites/sensors, it can be quite obvious with small photosites/sensors.
Moreover, a not well controlled denoising or a bad black level substraction can affect linear datas and can be rather harmful for colors, especailly if underexposure is too strong, wich can often happen in high dynamic scenes.

Consequently, multi exposure bracketing will often improve not only exposure, noise and details, but also colors separation, especially in darks.

[Guillermo Luijk]

If noise increases, color sensitivity will decrease (...)

Yes, but this is not the "colours change with exposure" statement under discusion. 4EV is not 1/3 EV:

Can't colors change as well even at 1/3 over or under exposure? So bracketing at 1/3 would assure the correct colors important for product shoots.

Regards

[BAB]

I would say if your shooting for the web and your capturing interior and you charge 5.00 per shot use an IPhone
Any great retouched would love to have 9 images 1 stop. Apart and even more depending on the scene to deliver excellent work that you would hang on a wall.

There is just many more opportunities to pull out detail in the shadows with no noise using feathered luminosity masks.

I also believe under exposing certain colors give the color more saturation.

A raw histogram by channel with a way to correct it would be ideal. For oceanscapes at sundown.

Phptomatrix has its uses for some images as a layer brought back into photoshop and blended.

Hard in Lightroom basically SUCKS!

Certain programs have some really nice feature that do heavy lifting with ease.

But in the end you need to develope your own style it’s more about the finished piece.

Any raw file SOC needs help, but the jpegs are cooked well, ha ha

Best of luck

[Redcrown]

I'm a big HDR fan. Here is an example. When I saw this scene I thought the dynamic range would be great. However, my old Pentax spot meter said the brightest part of the curtains was EV 15.3 and the cat was EV 7. So only 8.3 stops. I made a 5 shot bracket, 1 stop increments.

The first image is an HDR merge by SNS-HDR. The second image is my best attempt at processing only the middle exposure in ACR and Photoshop. The images are from a Canon EOS R. Different sources rate the dynamic range of that camera between 13 and 14.1. It seems to me that there is a big difference between theory and practice.

If anybody is interested, I'll Dropbox the raw files. I'd like to see if anyone can come close to the HDR image using only a single exposure.

[Alan Klein]

The second shot looks like you have a black cat.  The first looks like a gray cat. 

Actually, I think the first would be slightly better if you darkened the shadows a little.  The wood on the furniture seems a little to light for the way the room is lit.  It would be more natural, to my eyes anyway.  Shadows are shadows.  While the 2nd is too dark, we really don't have to see too many details in them.  We don't expect to in real life either.

[digitaldog]

The second shot looks like you have a black cat.  The first looks like a gray cat. 

They both look black to me; is your browser color managed? Anyway, the rendering is subjective and up to the image creator to decide.....

[Redcrown]

These images were made this morning. When I finished the HDR I loaded it onto my tablet and took it to the scene. The cat was still there. I looked back and forth, tablet to scene to tablet. Of course, as I scan the scene my eyes adjust. That's the point. Eyes have a narrow point of view. As I look at the table lower left, my eyes adjust and it looks very close to the HDR image. Ditto the cat.

If anything, the white curtains in the image are a bit darker than I see in the real scene. However, I have a blown pupil in my left eye and it can't close down very much. So bright things always appear brighter unless I close the left eye. Then, the curtains in the scene and the image are much closer.

HDR images, if well done and conservative, are always a better match to what my eyes see.

[mcbroomf]

Very nice shot and a good demo of well executed HDR.  The cat is clearly black in both but with a little more detail in the 1st.  Also more detail in the front/shadow of the dresser.  I much prefer the 1st.

I rely on photonstophotons for dynamic range info and he lists the Canon R as having ~10.5 at base ISO.  You don't mention what ISO you took the images at but PDR drops off very quickly with increasing ISO, by 400 for example it's down to ~9.5

[Alan Klein]

They both look black to me; is your browser color managed? Anyway, the rendering is subjective and up to the image creator to decide.....

Yes it's a NEC PA242W calibrated with Spectraview II.  Sure the 1st cat is black.  But the light in the hairs give a gray appearance.  You can see the whiskers and differentiate the bottom of its chin from its breast.   You don't see those things in the 2nd.

What's interesting is that while the black items are darker in the 2nd, the white sheet is whiter in the 2nd rather than darker than the 1st.    How do you do that?

Of course, the final image is the way the creator wants to present it. It's very individual.

[David Eichler]

The answer to that depends on the camera used, and the scenes shot.

If you have an IQ4 with Frame Averaging and Dual Exposure+ then the answer is basically: no, you don't.

Except for some *really* contrived situations the dynamic range of that system easily exceeds the contrast of even traditionally challenging scenes (e.g. dark subject matter backlit against bright subject matter).

If you're using a 10 year old Canon Rebel then the answer is basically: yes, you do. Even moderately challenging scenes will easily outpace the range that camera can capture in a single frame.

[assumptions are that you want a file that contains usable detail throughout the subject, leaving it up to you how to render the tonality of the scene, without fear of introducing ugly noise or areas of otherwise poor quality such as banding or lower color fidelity]

Can someone who has used the Phase One frame averaging reference above and does not have a stake in selling photographic equipment comment on the effectiveness of this technology?

I will mention that that are other ways to combine a range of different exposures than with an HDR program or some process that is internal to a camera or digital back, and this can provide more flexibility for certain purposes.

[digitaldog]

Yes it's a NEC PA242W calibrated with Spectraview II.

That is your display. I asked about your browser.
Look at the actual RGB values coming off a display with a color managed browser of the black cat. It's damn near as black as black can be, NOT gray:

[David Eichler]

That is your display. I asked about your browser.
Look at the actual RGB values coming off a display with a color managed browser of the black cat. It's damn near as black as black can be, NOT gray:

I think there is some miscommunication here. I think he is saying that the shadows are too open for his taste for the top shot and he would like to see them brought down more. Maybe something between the two shots for the shadows?

[digitaldog]

I think there is some miscommunication here. I think he is saying that the shadows are too open for his taste for the top shot and he would like to see them brought down more. Maybe something between the two shots for the shadows?

Bottom Cat: Black hole, no detail. Top Cat, lots of detail, still looks black to me, not gray. And the output values to my display (Which the Digital Color Meter provides, not the values of the image itself) show the top cat has a very deep black (5/5/5) while still having all kinds of detail invisible on the bottom cat; on this display with a color managed browser. I can't even see the bottom cat's nose but on the top, the nose and whiskers.
IF the desire of the image creator is to show us the black cat, the bottom image doesn't. The top does.
The wood shadow detail of the table (if important) is night and day between the two.

[Alan Klein]

I think there is some miscommunication here. I think he is saying that the shadows are too open for his taste for the top shot and he would like to see them brought down more. Maybe something between the two shots for the shadows?

Exactly.  That's what I was saying.  But as they say in recipes, season to taste.   

[Frans Waterlander]

So, what happens if you pull up the shadows of the second (single) shot? Wouldn't it come close to the first shot? Just wondering. As I said before, when I played around with Christian Bloch's bracketed shots in Photomatix Pro I could make the best single shot look just as good as the HDR rendered bracketed shots.