Pages: 1 2 [3] 4   Go Down

Author Topic: Skies and high dynamic range images  (Read 22117 times)

ronkruger

  • Jr. Member
  • **
  • Offline Offline
  • Posts: 88
  • Outdoor writer/photographer for over 30 years.
Re: Skies and high dynamic range images
« Reply #40 on: March 04, 2011, 06:43:25 pm »

I'm not some old-timer stuck in the past, suffering from dementia. Well, I am an old-timer, but I've been on computers since the early 1980 Macs, both for work and pleasure. I've worked in computer design with Photoshop for years and with PageMaker and Quark before that, plus a couple of programs designed specifically for newspapers. I've served as an editor, photo editor and published my own magazine. I don't claim to know it all, and I will admit I haven't kept up with that end for the past few years, concentrating mostly on photography, but I still have friends who do it for a living, and every one of them has told me often that "the less one does in PhotoShop the better." The common tendency is to overdo it, and the most frustrating part of their job is correcting all the click and slides others make, even professionals.
Yes, the idea of underexposing comes from Kodachrome days, but I rarely underexpose more -1/3 with digital, bringing it back during PP. I do this most of the time and print at 30X40 with no noise at all. If you think it doesn't make a difference, conduct the test I described. I will add that with the Nikons I shot for decades, one needs to underexpose more than with the Pentax I now use. I don't expect anyone to take my word for anything, because I don't either, especially across the internet. What I suggest is that you conduct your own tests and make up your on minds.
Again, this look is not for everyone. Many prefer the more plastic look of digital, which I think is great for product photography, but not landscapes. Why do some want to expose more detail in the shadows than the human eye notices, or even wants to notice, in a landscape anyway? Shadows in landscapes add drama. That's why we wait for low light angles and avoid shooting at mid-day.
Logged
In the end, the only things that matter are the people we help and the people we hurt. Google Ron Kruger and click on any link to Photoshelter

LKaven

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 1060
Re: Skies and high dynamic range images
« Reply #41 on: March 04, 2011, 07:13:36 pm »

I'm not some old-timer stuck in the past, suffering from dementia. Well, I am an old-timer, but I've been on computers since the early 1980 Macs, both for work and pleasure. I've worked in computer design with Photoshop for years and with PageMaker and Quark before that, plus a couple of programs designed specifically for newspapers. I've served as an editor, photo editor and published my own magazine. I don't claim to know it all, and I will admit I haven't kept up with that end for the past few years, concentrating mostly on photography, but I still have friends who do it for a living, and every one of them has told me often that "the less one does in PhotoShop the better." The common tendency is to overdo it, and the most frustrating part of their job is correcting all the click and slides others make, even professionals.
Yes, the idea of underexposing comes from Kodachrome days, but I rarely underexpose more -1/3 with digital, bringing it back during PP. I do this most of the time and print at 30X40 with no noise at all. If you think it doesn't make a difference, conduct the test I described. I will add that with the Nikons I shot for decades, one needs to underexpose more than with the Pentax I now use. I don't expect anyone to take my word for anything, because I don't either, especially across the internet. What I suggest is that you conduct your own tests and make up your on minds.
Again, this look is not for everyone. Many prefer the more plastic look of digital, which I think is great for product photography, but not landscapes. Why do some want to expose more detail in the shadows than the human eye notices, or even wants to notice, in a landscape anyway? Shadows in landscapes add drama. That's why we wait for low light angles and avoid shooting at mid-day.
Certainly nobody thinks you're stuck in the past, and even less, suffering from a brain disorder.  :-)  And certainly nobody thinks one should over-do work in post, by definition.

Think of it this way.  What happens in your camera after you press the shutter release /is/ photoshop in essence.  The raw capture, applying curves, white balance, sharpening, saturation--this is your camera on photoshop (cut to shot of fried egg in a hot skillet).  I can't help but think that you yourself would choose and apply filters of your own with more finesse.  Cool?  Call it a hunch. 

Schewe

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 6229
    • http:www.schewephoto.com
Re: Skies and high dynamic range images
« Reply #42 on: March 04, 2011, 07:30:17 pm »

Yes, the idea of underexposing comes from Kodachrome days, but I rarely underexpose more -1/3 with digital, bringing it back during PP.

Never shot many negs huh?

In point of fact, when shooting raw, you are better off exposing to the right if the scene's contrast range fits inside the dynamic range of your sensor. Controlling the image's tone curve (and whatever color saturation you may want) is easy to accomplish in the raw processor way before you ever have the image open in Photoshop. You are indeed leaving potential image quality on the table when you intentionally under expose. Since the raw capture is linear, you have tones of levels in the highlights and far less in the shadows. By under exposing and then lightening the image, you are indeed getting more noise in your shadows which you might be compensating for by darkening the tones.

Just how much potential image detail is their in the extreme highlights with digital? A lot...see Un-debunking ETTR for both an explanation of ETTR and how much image detail you can tease out of even over exposed images.

In point of fact, digital capture is a bit more like shooting negs than chromes–lot more dynamic range with digital than chromes.
Logged

ronkruger

  • Jr. Member
  • **
  • Offline Offline
  • Posts: 88
  • Outdoor writer/photographer for over 30 years.
Re: Skies and high dynamic range images
« Reply #43 on: March 04, 2011, 10:04:21 pm »

I'm tired of defending myself, and fell like what I'm saying challenges some pecking order here or something. I've been shooting professionally for almost four decades. Of course, I've shot negs.
This is about getting more out of skies at time of capture. I guess you expose that to the right too.
If you can't even listen to a different approach without inuendos, never mind.
Logged
In the end, the only things that matter are the people we help and the people we hurt. Google Ron Kruger and click on any link to Photoshelter

LKaven

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 1060
Re: Skies and high dynamic range images
« Reply #44 on: March 04, 2011, 10:22:27 pm »

I'm tired of defending myself, and fell like what I'm saying challenges some pecking order here or something. I've been shooting professionally for almost four decades. Of course, I've shot negs.
This is about getting more out of skies at time of capture. I guess you expose that to the right too.
If you can't even listen to a different approach without inuendos, never mind.
All I care about personally is whether you get the best information available for what you want to do.

Schewe

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 6229
    • http:www.schewephoto.com
Re: Skies and high dynamic range images
« Reply #45 on: March 05, 2011, 12:00:32 am »

I guess you expose that to the right too.

Yes...where...appropriate...

You really need to understand what digital capture does and doesn't give you...

When you are in the field, you must decide what the optimal raw capture exposure will be...

If you are habitually underexposing, then yes, you are leaving IQ on the table. That's easy to prove.

On the other hand, if IQ is important to you, then it makes sense that the digital capture is optimally exposed. If you, by nature, under expose by 1/3 of a stop because of some sort of film based experience, then yes, I would say that you are producing images at less than an optimal raw exposure.

Sorry to break your bubble...

Do you want optimal results or do your want to force fit your images to your expectations?

There is nothing ethically wrong with post processing images to meet your visual expectations. Assuming you know HOW to do the post processing...that's the real challenge...apparently your post-processing skills are lacking.

That's all I'm saying...if you habitually under-expose raw captures, then you are leaving IQ on the table. As long as you understand and accept that, fine. Otherwise, you might want to adapt your approach to raw captures.

For other people, I would caution that there is a better way...

And if time in the industry is any sort of criteria, I think I may have you beaten...been there, done that, got the TEE-shirt and the scars...
« Last Edit: March 05, 2011, 12:05:41 am by Schewe »
Logged

ErikKaffehr

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 11311
    • Echophoto
Re: Skies and high dynamic range images
« Reply #46 on: March 05, 2011, 02:01:18 am »

Jeff,

I don't take your point. It may be a question of definition but in my view we would always expose to the right, thus maximizing the number of photons detected by the sensor. In essence ETTR means that the histogram is moved to the right but not allowed to clip nonspecular highlights. In what situation would it be preferable to expose less than maximum possible?

Best regards
Erik

Yes...where...appropriate...
Logged
Erik Kaffehr
 

uaiomex

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 1211
    • http://www.eduardocervantes.com
Re: Skies and high dynamic range images
« Reply #47 on: March 05, 2011, 12:48:59 pm »

Excellent thread guys! Every post counts though not all the words in them. However, I need to say that you are here a little anal about the issue. At some point, reading some of these posts seemed like you were discussing exposure of 8X10 chromes. It is digital, isn't? Can't anybody do a "free" brief bracketing of 3 exposures and get the best part out of the 3 to pp? Am I missing something here?
Great thread anyway and thanks.
Eduardo
« Last Edit: March 05, 2011, 12:51:53 pm by uaiomex »
Logged

Schewe

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 6229
    • http:www.schewephoto.com
Re: Skies and high dynamic range images
« Reply #48 on: March 05, 2011, 01:10:47 pm »

In essence ETTR means that the histogram is moved to the right but not allowed to clip nonspecular highlights. In what situation would it be preferable to expose less than maximum possible?

The key word is clip. If the contrast range of the scene is greater than the dynamic range of the sensor, by definition you can't capture the full range without clipping. If highlight detail is important to a shot, the you have to expose for the highlights and let the shadows go. In this case, ETTR isn't a good idea. I agree that whenever the scene range is within the dynamic range of the sensor, it's a good idea to ETTR as long as doing so doesn't interfere with the needs of F stop or shutter speed.
Logged

Nick Rains

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 705
    • http://www.nickrains.com
Re: Skies and high dynamic range images
« Reply #49 on: March 05, 2011, 04:11:39 pm »

It's a bit of a generalization but camera manufacturers own software is rarely in the same league as the offerings from Adobe, Apple, Iridient etc. I used the Sony software when I had a Sony Alpha 900 on test and it was not very inspiring, sorry. Give the others a go, you might be pleasantly surprised.
Logged
Nick Rains
Australian Photographer Leica

ErikKaffehr

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 11311
    • Echophoto
Re: Skies and high dynamic range images
« Reply #50 on: March 05, 2011, 04:39:39 pm »

Hi,

I don't think that you get the idea. The idea with ETTR is that you maximize exposure, so that you get least possible noise. So even if you bracket you would not process the image that looks good but the one which is near clipping. It's essentially very similar to exposing for the shadows with negative film. Just an example, blue sky. You can expose blue sky for natural look, but you can also increase exposure one step extra. In postprocessing you would than reduce "exposure" by one step, so you get the sky right, but you would gain one stop in dynamic range and reduce noise in the shadows.

Best regards
Erik


Excellent thread guys! Every post counts though not all the words in them. However, I need to say that you are here a little anal about the issue. At some point, reading some of these posts seemed like you were discussing exposure of 8X10 chromes. It is digital, isn't? Can't anybody do a "free" brief bracketing of 3 exposures and get the best part out of the 3 to pp? Am I missing something here?
Great thread anyway and thanks.
Eduardo
Logged
Erik Kaffehr
 

Ray

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 10365
Re: Skies and high dynamic range images
« Reply #51 on: March 05, 2011, 04:46:51 pm »

Excellent thread guys! Every post counts though not all the words in them. However, I need to say that you are here a little anal about the issue. At some point, reading some of these posts seemed like you were discussing exposure of 8X10 chromes. It is digital, isn't? Can't anybody do a "free" brief bracketing of 3 exposures and get the best part out of the 3 to pp? Am I missing something here?
Great thread anyway and thanks.
Eduardo

I agree. Memory is so cheap nowadays there should be little risk of running out of memory during a day's shooting. This was not the situation when I bought my first DSLR about 7 years ago. I recall I paid about A$ 800 for a 1GB compact flash card. On accasions, realising I would run out of memory before the end of the day if I continued shooting in RAW mode, I would switch to jpeg mode.

Nowadays I frequently bracket 3 exposures, not necessarily for merging to HDR but to provide a choice for slection of the best one for processing.

Skies can be a problem when there's a deceptively bright patch where the sun is trying to break through the cloud cover but not quite succeeding. In such circumstances the choices seem to be, (1) a totally blown patch of sky, (2) a correctly exposed sky but noisy shadows on the land, (3) bracket exposures for merging to HDR, (4) buy a Nikon D7000 or Pentax K5  ;D .
Logged

ErikKaffehr

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 11311
    • Echophoto
Re: Skies and high dynamic range images
« Reply #52 on: March 05, 2011, 04:57:10 pm »

Hi,

Personally I hate bracketing. The reason is really that when I work trough a days shooting I end up with 600 pictures instead of 200. Doing the job right at capture time just takes a glance at the histogram but saves a lot of PP time.

Just my 2 cents...

Best regards
Erik

I agree. Memory is so cheap nowadays there should be little risk of running out of memory during a day's shooting. This was not the situation when I bought my first DSLR about 7 years ago. I recall I paid about A$ 800 for a 1GB compact flash card. On accasions, realising I would run out of memory before the end of the day if I continued shooting in RAW mode, I would switch to jpeg mode.

Nowadays I frequently bracket 3 exposures, not necessarily for merging to HDR but to provide a choice for slection of the best one for processing.

Skies can be a problem when there's a deceptively bright patch where the sun is trying to break through the cloud cover but not quite succeeding. In such circumstances the choices seem to be, (1) a totally blown patch of sky, (2) a correctly exposed sky but noisy shadows on the land, (3) bracket exposures for merging to HDR, (4) buy a Nikon D7000 or Pentax K5  ;D .
Logged
Erik Kaffehr
 

Ray

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 10365
Re: Skies and high dynamic range images
« Reply #53 on: March 05, 2011, 06:31:31 pm »

Hi,

Personally I hate bracketing. The reason is really that when I work trough a days shooting I end up with 600 pictures instead of 200. Doing the job right at capture time just takes a glance at the histogram but saves a lot of PP time.

Just my 2 cents...

Best regards
Erik



Erik,
That seems a trivial problem to me. Make the normal exposure the first one in the series of 3. Spend as much time as you like getting it right. The other two bracketed shots simply become a sort of insurance.

When sorting through the images at the end of the day, it should not be necessary to examine all 600, just the first image of every group of 3. It's only in the event of a miscalculation that you might choose to use one of the other two exposures.

Bracketing also provides the advantage of it being less likely that one 'misses the moment' as a result of spending too much time trying to get a good ETTR.

Cheers!
Logged

ErikKaffehr

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 11311
    • Echophoto
Re: Skies and high dynamic range images
« Reply #54 on: March 06, 2011, 02:41:32 am »

Hi!

I see your point, and you are of course right. For me, with my way of working, it is causing a mess.

Best regards
Erik





Erik,
That seems a trivial problem to me. Make the normal exposure the first one in the series of 3. Spend as much time as you like getting it right. The other two bracketed shots simply become a sort of insurance.

When sorting through the images at the end of the day, it should not be necessary to examine all 600, just the first image of every group of 3. It's only in the event of a miscalculation that you might choose to use one of the other two exposures.

Bracketing also provides the advantage of it being less likely that one 'misses the moment' as a result of spending too much time trying to get a good ETTR.

Cheers!
Logged
Erik Kaffehr
 

ErikKaffehr

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 11311
    • Echophoto
Re: Skies and high dynamic range images
« Reply #55 on: March 06, 2011, 02:53:38 am »

Hi,

Phase One owners are happy...

I use Adobe Lightroom and I love it. Won't say it's the best raw processing engine, I simply don't know (before defining best you need to define good). For me it's a workflow solution taking care of the image from the cradle to the grave. I don't really now about the grave part ;-)

I also tested Iridient Raw Developer from time to time, it's good but I'm pretty much sold on Lightroom. At a time I was considering writing image management software for my own needs, but when Aperture came out I realized that the software was there, but I was on PC and that Microsoft OS (and Linux). So when Lightroom came out I jumped on it. Later I switched to Apple but stayed with Lightroom.

Best regards
Erik

It's a bit of a generalization but camera manufacturers own software is rarely in the same league as the offerings from Adobe, Apple, Iridient etc. I used the Sony software when I had a Sony Alpha 900 on test and it was not very inspiring, sorry. Give the others a go, you might be pleasantly surprised.
Logged
Erik Kaffehr
 

Nick Rains

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 705
    • http://www.nickrains.com
Re: Skies and high dynamic range images
« Reply #56 on: March 06, 2011, 03:50:48 am »


I also tested Iridient Raw Developer from time to time, it's good but I'm pretty much sold on Lightroom. At a time I was considering writing image management software for my own needs, but when Aperture came out I realized that the software was there, but I was on PC and that Microsoft OS (and Linux). So when Lightroom came out I jumped on it. Later I switched to Apple but stayed with Lightroom.

Best regards
Erik


I'm a Lightroom affectionado too, but have you tried the highlight recovery tools in Aperture? Seems to be able to pull more back than LR for some reason. These is even a histogram opion that shows you how much raw data exists above 255. I still prefer LR but that might be something to do with familiarity too!
Logged
Nick Rains
Australian Photographer Leica

uaiomex

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 1211
    • http://www.eduardocervantes.com
Re: Skies and high dynamic range images
« Reply #57 on: March 09, 2011, 07:16:31 pm »

That's is exactly what I do. I call my workflow the "in situ-lazy brain". At least for my way of shooting it is easier for me to do "the thinking" in front of the computer when usually I have time to my heart's content, not so the same while shooting outdoors. It can be pedestrians, animals, vehicles, extreme weather, darkness, sunshine, stylists, posers, AD's, you name them! - What I mean, I hate to be waited of or wait!  :'(
Yes I come home with 3X the pictures to download and review. Small nuisance!
Thanks guys for all the good posts.
Eduardo


Erik,
That seems a trivial problem to me. Make the normal exposure the first one in the series of 3. Spend as much time as you like getting it right. The other two bracketed shots simply become a sort of insurance.

When sorting through the images at the end of the day, it should not be necessary to examine all 600, just the first image of every group of 3. It's only in the event of a miscalculation that you might choose to use one of the other two exposures.

Bracketing also provides the advantage of it being less likely that one 'misses the moment' as a result of spending too much time trying to get a good ETTR.

Cheers!
« Last Edit: March 09, 2011, 07:20:13 pm by uaiomex »
Logged

bjanes

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 3387
Re: Skies and high dynamic range images
« Reply #58 on: March 13, 2011, 12:28:27 pm »

I don't think Mike "coined" the term but he sure popularized the concept. The concept actually was told to Mike by Thomas Knoll, the co-author of Photoshop and founding engineer for Camera Raw as explained in this article.

Thomas Knoll is an iconic figure in digital photography, but the rationale given in the quoted article is incorrect. The brightest f/stop of a 12 bit digital capture contains 2048 possible levels, but the actual number of perceivable levels is drastically limited by noise. Shot noise increases with exposure, but the signal:noise is highest in the brightest f/stop. For example, here is a 200x200 flat frame of the green1 channel of the Nikon D3. The mean pixel value is 8296, but the standard deviation is 175.

.

As explained by DXO in their tonal range evaluation, it makes no sense to have a quantization precision much smaller than noise:



The actual tonal range for the D3 is 8.72 bits or 422 levels, much smaller than 16183 levels implied by the 14 bit readout.



Nonetheless, ETTR is a valuable procedure since it increases signal:noise and the effect is most dramatic in the darker tones than the highlights as explained by Emil Martinec in his excellent post on noise, where he specifically refers to Micheal's article.

Regards,

Bill
Logged

Schewe

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 6229
    • http:www.schewephoto.com
Re: Skies and high dynamic range images
« Reply #59 on: March 13, 2011, 03:11:08 pm »

Thomas Knoll is an iconic figure in digital photography, but the rationale given in the quoted article is incorrect.

Actually, I think it would be unfair to paint Thomas as the author of the "rationale" written about in the article...the article was written by Michael not Thomas. I'm pretty sure Thomas knows that the reason ETTR works is that more photons = better signal to noise.
Logged
Pages: 1 2 [3] 4   Go Up