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Author Topic: Uwe Steinmuller of DOP on dynamic range and HDR  (Read 26412 times)
BJL
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« on: December 25, 2010, 02:36:21 PM »
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Given the recent discussions about dynamic range and handling scenes of large subject brightness range, some folks might be interested in a new series of articles by Uwe Steinmuller of Digital Outback Photo (http://www.outbackphoto.com), published at DPR. Here is part 1: http://www.dpreview.com/learn/?/Guides/The_art_of_HDR_Photography_part_1_01.htm
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Ray
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« Reply #1 on: December 25, 2010, 10:19:27 PM »
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Given the recent discussions about dynamic range and handling scenes of large subject brightness range, some folks might be interested in a new series of articles by Uwe Steinmuller of Digital Outback Photo (http://www.outbackphoto.com), published at DPR. Here is part 1: http://www.dpreview.com/learn/?/Guides/The_art_of_HDR_Photography_part_1_01.htm


I read that, BJL, and mostly agree with what has been written so far, except perhaps a minor point about the responsiveness of the eye's pupil to changing levels of light, in the following extract.

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Human vision works in quite a different way to our cameras. We all know that our eyes adapt to scenes; when it gets darker our pupils open, and when it gets brighter they close. This process often takes quite a while (it's not instant). It is said that our eyes can see a Dynamic Range of 10 f-stops (1:1024) without adapting the pupils and overall about 24 f-stops.

I think in most situations, the pupils respond to changing light conditions almost instantly (but not literally instantly, of course).

One can confirm this for oneself by gazing out of the window and focussing on a bright cloud, then suddenly shifting one's gaze to a dark corner of the living room which might reflect about -15EV less light, perhaps more. I'm just guessing. The pupil of the eye opens up so rapidly it would be impossible to time it with a stop watch.

An example of a situation where this process might take quite a while, would be when coming out of a darkened cinema into bright sunlight. It will then take a while for the eyes to adjust to the extreme change in the scale of the brightness range.

It is precisely because of the 'almost' instantaneous nature of the eye's aperture changes, that the limitations of the DR capability of all cameras is so obvious.


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Schewe
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« Reply #2 on: December 25, 2010, 11:25:04 PM »
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Given the recent discussions about dynamic range and handling scenes of large subject brightness range, some folks might be interested in a new series of articles by Uwe Steinmuller of Digital Outback Photo...

Yeah, ok...but ya know, if an image looks surreal, (as in an obviously condensed tonal range) I'm not sure that is particularly interesting (nor useful) for people who want a reasonably realistic representation of the original scene...

Most HDR type stuff looks phony...and while it may be trendy, it's not really all that desirable, is it? Really?

Just saying...

It's ok to look at something and say it looks like crap, if it is...
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JR
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« Reply #3 on: December 25, 2010, 11:45:18 PM »
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Itīs a matter of taste, right? I donīt like extreme HDR as seen in the article but a lot of folks do.
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Ray
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« Reply #4 on: December 26, 2010, 07:42:43 AM »
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Itīs a matter of taste, right? I donīt like extreme HDR as seen in the article but a lot of folks do.

It's not only a matter of taste but a matter of skill in image processing; that is, the ability to adjust the tonality and hues to taste so that the image looks natural. This is something I would have thought Jeff Schewe would have no trouble doing.

It can be a lot of work for those of us who are less skilled, which is why I would prefer a camera with as high a DR as possible to reduce the number of occasions when I might consider merging to HDR necessary.

In my opinion, the purpose of merging to HDR is not to create a surrealistic image but a natural image which is more representative of what the eye saw in the scene at the time the shots were taken.

The result should look like a processed ETTR shot, perhaps the middle exposure or the least exposure of 3 bracketed exposures, but with cleaner shadows as a result of the merger of the overexposed images.
 
Here's an example comparing an HDR merger of 3 exposures with the least exposure of the 3 bracketed shots, which has been processed separately. You can see that the deep shadows are much cleaner in the HDR image, as well as the moderate shadows. The HDR image is a higher quality image.

I haven't bothered to get the tonality and color hues exactly matching in both images. I would do a better job if I intended to print this image. As it stands, the deep shadows are not as clean as I'd like. I feel I should have taken at least one additional exposure 1 EV greater.

The lens, the Sigma 15-30 on the 5D, is also not good at the edges and corners, so I won't be spending too much time on this image. However, I was surprised that an additional 4 stops of dynamic range was still not quite enough, in my view, for this high contrast scene.
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JR
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« Reply #5 on: December 26, 2010, 07:59:24 AM »
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It's not only a matter of taste but a matter of skill in image processing
Here's an example

GīDay Ray!

Of course it is a matter of skills. Totally agree. Steinmuller and his wife are very good at this. However, I find some of their HDR images a little to extreme for my taste. They do not look real to me. But as I said, it is a matter of taste. I donīt agree with Schewe that this is crap. Itīs like art, I donīt like baroque but I like impressionists like Claude Monet. Itīs the same with HDR.

Nice examples you put up. Waiting to see some good examples from your D7000  Wink

- John
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feppe
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« Reply #6 on: December 26, 2010, 08:03:08 AM »
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Yeah, ok...but ya know, if an image looks surreal, (as in an obviously condensed tonal range) I'm not sure that is particularly interesting (nor useful) for people who want a reasonably realistic representation of the original scene...

Most HDR type stuff looks phony...and while it may be trendy, it's not really all that desirable, is it? Really?

Just saying...

It's ok to look at something and say it looks like crap, if it is...

I'm glad I'm not the only one... The very first photo (the arches) has all life squeezed out of it, and scrolling down to one of the originals straight out of the camera is much better. I'm not saying it couldn't benefit from HDR or related techniques (digital blending or exposure fusion), but it's clear that the article is not written with realistic results in mind. Perhaps not surprising since it is DPR, after all.

As a sidenote, I'm currently reading a guidebook for Madrid, and almost all of the photos are done in HDR or emulating the look. Ewww.
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BartvanderWolf
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« Reply #7 on: December 26, 2010, 09:18:27 AM »
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I'm glad I'm not the only one...

Hi Feppe,

In that case the both of you Wink are alone in assuming that HDR images, and more importantly the subsequent tonemapping, are "not interesting (nor useful) for people who want a reasonably realistic representation of the original scene...".

Sure, one can (very easily) produce crappy pictures using these techniques, but one can also achieve realistic results that cannot be achieved with other techniques (unless one does timeconsuming manual exposure blending/masking).

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The very first photo (the arches) has all life squeezed out of it, and scrolling down to one of the originals straight out of the camera is much better. I'm not saying it couldn't benefit from HDR or related techniques (digital blending or exposure fusion), but it's clear that the article is not written with realistic results in mind.

I somewhat agree with your observation about "the life squeezed out of it", but I wouldn't confuse one person's processing preferences with the capabilities to produce vastly different (more to your liking) renderings of the same base images. Tonemapping is as much an Art as it requires technical skill.

Cheers,
Bart
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stever
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« Reply #8 on: December 26, 2010, 01:37:33 PM »
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i agree with Bart - particularly the part about art.  I've read a number of articles and a couple books with descriptions of how to get "natural" results from Photomatix, seen a few examples that looked realistic, and and gotten a couple realistic results myself.  But it always seems to be pretty much trial and error.

There's an article with examples by Tom Till in the Feb Outdoor Photography mag directed towards realistic HDR landscapes with Photomatix and a set of guidelines which i haven't tried yet.  Unfortunately the examples don't look particularly realistic to me.

I believe it can be done, and would love to hear advice or recommended resources for predictable processing to acheive realistic HDR images.
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Schewe
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« Reply #9 on: December 26, 2010, 05:18:02 PM »
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It's not only a matter of taste but a matter of skill in image processing; that is, the ability to adjust the tonality and hues to taste so that the image looks natural. This is something I would have thought Jeff Schewe would have no trouble doing.

Oh, I have no problem controlling scene dynamic range and yes I often blend multiple shots together to extend the limitations of the sensor.

But what I don't do is make images look surreal with obvious tonal manipulations and HDR telltales left in an image.

If it looks phony, it moves out of the photographic realm and into an illustration realm. Just cause modern tools make is "easy" to do something doesn't make it desirable. Actually, the same could be said for a lot of digital imaging techniques...just cause you CAN do it doesn't mean you SHOULD do it, ya know?
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Ray
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« Reply #10 on: December 26, 2010, 06:46:49 PM »
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If it looks phony, it moves out of the photographic realm and into an illustration realm. Just cause modern tools make is "easy" to do something doesn't make it desirable. Actually, the same could be said for a lot of digital imaging techniques...just cause you CAN do it doesn't mean you SHOULD do it, ya know?

I agree that because you can do it doesn't mean that you should. However, to give people like Uwe Steinmuller the benefit of the doubt, I think it's likely that sometimes the photographer may just be demonstrating what's possible with regard to increased DR and lower shadow noise, in the clearest and most obvious manner so all can see, even the untrained eye.

I think it's also the case that some folks are simply not sufficiently well-practiced in the use of the tone-mapping sliders and other controls in programs like Photomatix and Photoshop's Merge to HDR.

I recall the first time Adobe introduced the Shadows/Highlight tool (did that first appear in CS1?), I got some pretty awful results until I experimented a lot with the radius, tonal width, and amount. There are a large number of different combinations just in those 3 sliders.
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Ray
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« Reply #11 on: December 26, 2010, 06:55:30 PM »
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GīDay Ray!

Of course it is a matter of skills. Totally agree. Steinmuller and his wife are very good at this. However, I find some of their HDR images a little to extreme for my taste. They do not look real to me. But as I said, it is a matter of taste. I donīt agree with Schewe that this is crap. Itīs like art, I donīt like baroque but I like impressionists like Claude Monet. Itīs the same with HDR.

Nice examples you put up. Waiting to see some good examples from your D7000  Wink

- John




G'Day John,

I do most of my photography during travels to exotic locations, probably because, when I'm home, I find there are so many chores to attend to, such as slashing grass, mixing concrete, doing home rennovations and improvements, processing some of the hundreds of thousands of images I have stored away on DVD discs and external hard drives, and of course arguing with various people on the internet, who appear to have some wrong ideas on certain topics.  Grin

As Bart would agree, it's better to be prepared beforehand and know what sort of performance your equipment is capable of. From such images I've posted above, in conjunction with an analysis of the comparative test results at DXOMark, I can deduce that the D7000 with a single, correct ETTR shot, will produce shadows as clean as the HDR merger of 3 exposures +/- 2EV, taken with the 5D.

The middle of those 3 exposures was very slightly overexposed, by maybe 1/3rd of a stop. The longest exposure is thus a 2.33 EV greater exposure than an ETTR.

At normalised print sizes, the D7000 has 2.74 EV greater DR than the 5D, according to DXOMark.

Since there are no other image-quality parameters in which the 5D is even marginally better, despite it being full-frame, (such as color sensitivity, or SNR at 18% grey), I can declare that my 5D is now truly, completely and totally redundant. (Anyone like to buy it? Have I done a good job at promotion?  Grin )

Actually, just joking. I probably want to hang onto it for sentimental reasons.
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Schewe
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« Reply #12 on: December 26, 2010, 06:58:41 PM »
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I agree that because you can do it doesn't mean that you should. However, to give people like Uwe Steinmuller the benefit of the doubt, I think it's likely that sometimes the photographer may just be demonstrating what's possible with regard to increased DR and lower shadow noise, in the clearest and most obvious manner so all can see, even the untrained eye.

I know Uwe and it's quite possible he used the opening image in his article as an example, but I saw it as an example of that you SHOULD NOT do not what you would WANT to do. It's a fine example of taking a scene and ruining it by using HDR.

Whether you use ACR's Fill Light and highlight Recovery or Photoshop's Shadows/Highlights tool or blending by HDR or even blending a little bit of a lower exposure in the highlights of a lighter exposure, if it sucks, it sucks, ya know? I don't advocate promoting suboptimal results regardless of who you are.
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Ray
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« Reply #13 on: December 26, 2010, 07:37:04 PM »
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......... but I saw it as an example of that you SHOULD NOT do not what you would WANT to do.

I can't agree with that, Jeff. I always try to do what I WANT to do. I've never considered myself as a conformist. I would have thought you also don't consider yourself as a conformist.   Grin
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Schewe
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« Reply #14 on: December 26, 2010, 09:12:11 PM »
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I can't agree with that, Jeff.

So, you think Uwe's opening shot with the arches is a shining example of a good use of HDR? Hum...we looking at the same image bud?
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JeffKohn
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« Reply #15 on: December 26, 2010, 10:58:17 PM »
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So, you think Uwe's opening shot with the arches is a shining example of a good use of HDR? Hum...we looking at the same image bud?
The way it's captioned, it doesn't look like he meant it to be an example of bad HDR.  If that was the intention, I think it was poorly communicated. Frankly, I'm no longer surprised when I see articles about getting natural results with HDR tonemapping in which the examples look bad. It seems to be the norm, rather than the exception.

It's funny, Tom Till has an article in the most recent issue of Outdoor Photographer about his approach to 'natural' HDR and what a revelation this workflow is after decades of struggling with the limitations of film and grad filters. I personally think he should go back to film, because the HDR photos illustrating the article are terrible.

What a lot of these HDR proponents don't seem to get is that using HDR to reduce the dynamic range between shadows and highlights is not going to change the fact that crappy light is crappy light. The problem with shooting midday with the sun directly overhead is not that our cameras can't handle the dynamic range; the problem is that such light is ugly. It's ugly even to our eyes, and HDR isn't going to fix change that. So while there are times when HDR or other exposure blending techniques can be useful, the simple fact is that HDR cannot save an image shot in crappy light, no matter how much one twiddles with the sliders in Photomatix.
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Ray
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« Reply #16 on: December 26, 2010, 11:22:44 PM »
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So, you think Uwe's opening shot with the arches is a shining example of a good use of HDR? Hum...we looking at the same image bud?


No. I'm just defending a person's right to produce whatever type of image he wants, irrespective of certain peoples' opinions of its merit.
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Ray
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« Reply #17 on: December 26, 2010, 11:28:33 PM »
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It's ugly even to our eyes, and HDR isn't going to fix change that. So while there are times when HDR or other exposure blending techniques can be useful, the simple fact is that HDR cannot save an image shot in crappy light, no matter how much one twiddles with the sliders in Photomatix.

Crappy light is light that has been reflected from crap. I think most people would argue they are not in the habit of photographing crap.

Making the most from the available light is part of the art and craft of photography.
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Schewe
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« Reply #18 on: December 26, 2010, 11:31:26 PM »
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No. I'm just defending a person's right to produce whatever type of image he wants, irrespective of certain peoples' opinions of its merit.

So you are ok with somebody advocating crap, right?

I just want to be perfectly clear here...you think Uwe is doing a public service by teaching people to take a crap image and process it via HDR to get an HDR piece of crap image, right?

I'm fine with people making whatever imagery they want to make in the privacy of their own artwork.

But, I have a problem when somebody touts themselves as some sort of expert and advocates an approach to photography that produces imagery that is, substantially less than useful...or furthers a process that is far more complex and difficult to do well that some tutorial on the web seems to indicate. It takes talent and effort to do a proper tonemapping that doesn't look phony.

Come on, truth be told...do you honestly think his tutorial is really useful or are you simply trying to find some sort of point to argue with me?
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Ray
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« Reply #19 on: December 27, 2010, 08:34:16 AM »
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So you are ok with somebody advocating crap, right?

I just want to be perfectly clear here...you think Uwe is doing a public service by teaching people to take a crap image and process it via HDR to get an HDR piece of crap image, right?

I'm fine with people making whatever imagery they want to make in the privacy of their own artwork.

But, I have a problem when somebody touts themselves as some sort of expert and advocates an approach to photography that produces imagery that is, substantially less than useful...or furthers a process that is far more complex and difficult to do well that some tutorial on the web seems to indicate. It takes talent and effort to do a proper tonemapping that doesn't look phony.

Come on, truth be told...do you honestly think his tutorial is really useful or are you simply trying to find some sort of point to argue with me?


Hey! Jeff,
This is only part one. Part II may be about, 'How to avoid, or fix, crap results when merging to HDR'. Patience, please!  Grin

I take it you are referring to the rather uninteresting image of Fort Point Arcades. Since I'm not American, this image has no particular resonance for me, and therefore I would have no reason to hang it on my wall.

However, if it were my image and if it were to have some special meaning for me, I would do some more work on it in Photoshop.

I notice that Uwe makes the following comment under that final tone-mapped image:

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In this version the highlights show detail, the shadows are not blocked and the flatness is gone. This would be not our final version. We usually optimize the photo in Photoshop CS5:

Did you miss that?
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