Rongnongno Loc: FL

Bob, I made my test and posted it. If interested I can give you the URL.

selmslie Loc: Fernandina Beach, FL, USA

I suggest that you learn how to read a histogram. Spikes at the end mean that there are maxed out pixels. An abrupt end to the histogram means that there is probably a lot of information that has been truncated.

I was born in West Virginia, lived in Canada for a year and Maryland for five. I know what snow is. It's why I have spent most of my life in Florida and Cuba.

Download RawDigger and read the documentation. It's all explained there. You can use it for free for a month if you are too cheap to buy it. It's on sale for $14.99 until Feb 20.

You will learn a lot more about ETTR and raw files than you know today.

Report back what you have learned, if you have the honesty and courage to do so.

Scotty

PS: Speaking of honesty and courage, I am still on your Ignore list. You are not on mine. Don't you think you are taking unfair advantage of that?

imagesintime Loc: small town, mid-America

"There's no <auto> button that will "recover" the original from the post at the top."


Actually, if you are a Canon owner using the latest DDP4 software you can click on the <auto> button to have the software make the changes. If you are not satisfied with the results you can then use the sliders to make additional adjustments.

Rongnongno Loc: FL

You are just an idiot.

selmslie Loc: Fernandina Beach, FL, USA

I think we all know what an invaluable and erudite contribution you are making to this thread.

Do you have your free copy of RawDigger yet? A couple of hours (maybe a couple of weeks in your case) and you might figure out the function of ETTR and why you can't get UniWB to work on your camera - possibly why you should not even bother to try.

While you are at it, you might also want to look into Learning How to Use Your Camera's Histogram. Scroll to where the RGB histogram is shown. You will learn that, whatever you do to change the white balance of the JPEG, you will not change the fact that the red, green and blue histograms that represent the raw file are ever likely to agree. If you could get them all to line up for the JPEG you would never be able to tell which channel is going to get blown first. This will become clear to you when you see them on the RawDigger display.

Maybe you and Dave can study this together. Enjoy your homework.

I am leaving open the possibility that you are not an idiot. Your next post here might decide that one way or the other.

Uuglypher Loc: South Dakota (East River)

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You need a bit of remediation; that little spike at the end of the "snow mass" of correctly exposed bright values represent the specuar reflection expected in any scene containing sun-lit snow.
Get some experience using Raw Digger (which I've long used to good advantage) on EBTR raw image captures of sun-lit snow scenes; it'll be educational for you!
But that's right....you are fervently opposed to the concept of using your camera's full allotment of DR...because you "can't see the benefits" of EBTR. Your visual defect are yours to deal with, but don't assume that others are similarly encumbered.

You have yet to show any evidence that you have determined the extra raw-accessible DR of any camera you use. That's the first step you must take to get to the point that you can talk about proper raw image data exposure with any experiential knowledge.
You really do need to photograph some snow scenes using competent EBTR and then analyse those image file with Raw Digger! It will be an eye-opener.

You've much to learn about EBTR...including why you should not confuse it with ETTR (for starters). The non-sensical tripe you introduce into threads such as this one is the reason you remain on my ignore list.
The only reason you jumped into this thread was that you noticed it was a good demo of the value of EBTR, and you just cannot STAND that! Your incessant hijacking of threads on proper exposure of raw image data captures is tiresome and I see no reason to subject interested participants in threads I initiate to your bothersome hijacking habits.

So, yes, you will remain on my ignore list, and, out of fairness, I shall continue to refrain from participating in the threads you start and in which you present much firmly held ( but sadly uninformed) personal opinion. But when, as you have done here, you try to spread your misinformation in threads others initiate, I'm glad to participate to provide a counterpoint to your ill-informed opinions.

So, Selmslie/Scotty...if you wish not to be confronted with knowledge borne of considerable objective, practiced experience presented by me and others similarly experienced and knowledgeable, stick to your own threads. Otherwise,
expect to be countered at every mis-step and mistaken opinion.

You need to catch on, Selmslie, that JPEG files and Raw image data captures are two different digital imaging media, and they require very different exposure techniques.

So, to get back to the original purpose of this thread, the OP has, indeed and unarguably, demonstrated the benefits of using at least some of the extra raw-accessible DR that every digital camera has to offer.

Dave

selmslie Loc: Fernandina Beach, FL, USA

That is absolutely not a true statement. I can use most or all of my sensors DR because I normally have my ISO set to 100 or not much higher. You still do not recognize the difference between the sensor's physical capacity and the raw file's numeric capacity.

I just don't buy into your convoluted methodology. I don't need to know my exact ERADR because it simply does not need to be known that precisely. Besides, it is not constant for all ISO levels and that's something you learned from me. If I miss it by 1/3 or 2/3 stop on the safe side it's not going to have a visible impact. It's a lot easier to simply watch for blinkies and take evasive action if necessary. That's pretty rare.

Are you admitting that it is useless for those of us that don't suffer from snow blindness?

It actually caught my attention because it was clear that the highlights were accidentally blown. I could see it but neither you nor Bob recognized it until I directed your attention to the raw histogram. Bob finally saw what the histogram made obvious.

It's not just the little spike. It's the abnormal termination of the right end of the histogram that makes it clear to anyone who is not turning a blind eye. You are still in denial.

And he also clearly demonstrated the danger in overdoing the ETTR by offering this clear example.

I am still waiting for you to offer us a demonstration of a normal scene taken at a reasonably low ISO with a current camera where ETTR provides any benefit over watching for blinkies. You have never done it and you can't do it because 14-bit cameras are better today that the 12-bit cameras from 15 years ago.

You are living in the past. It's time you stored your buggy whips and Power Point charts in the attic next to your obsolete digital gear.

Scotty

amfoto1 Loc: San Jose, Calif. USA

This is an interesting "image rescue" and demonstrates (with that particular camera) how much safer it is to overexpose then pull back exposure in post-processing, than it is to accidentally under-expose and have to push up exposure in post.

However, it's far more over-exposure than I'd normally do using ETTR (which I do)... I usually set about +1/3 or +2/3 stop. I'd guess you have at least two full stops of over-exposure in that first shot.

You're probably losing more to the tiny f25 aperture and diffraction, anyway, than you are to the accidental massive over-exposure.

Any discussion of ETTR seems to bring out the same few people who think it's their job to debunk a well-proven and useful technique.

Truth is, if you have time to "nail exposure" in every shot, then you really don't need ETTR and your images will likely be all the better for taking the time to really dial in an exact exposure.

But I very often don't have that luxury. I frequently have to use an auto exposure mode because my subjects are moving through variable lighting conditions. If my subjects were evenly illuminated all the time it would be great and I'd have a precise exposure set in advance, ready for them. But that's not the case.

And I have automatic image review turned off to preserve battery charge and because it's a distraction when shooting fast and furious sports action. I don't have time to take the camera away from my eye and chimp very much, let alone look for "blinkies". I do occasionally review one or a few shots, during a pause in the action.

So I have to rely upon the AE system and "tweak" it appropriately so that the odds are in my favor that as many shots as possible are as close as possible to "correct" exposure, in spite of the variable lighting. This is where ETTR comes in... I know from having taken tens of thousands of shots with my cameras and hundreds of thousands of shots with various cameras using ETTR, that it will increase the odds I'll get a usable exposure. When you post-process 1000 images taken using any of the auto exposure modes and you find that you need to boost exposure on the vast majority of them, it's fairly obvious that ETTR would be useful.

ETTR is only my "base" AE setting. Even using it, darker than average subjects are still going to want to over-expose and lighter than average subjects are still going to tend to under-expose. Because of that, I still need to use Exposure Compensation, too, and it's pretty easily set without moving the camera from my eye. Any E.C. that I dial in is "on top of" ETTR, which just serves as a starting point.

For some types of shooting, ETTR isn't necessary... such as when you have time to set an accurate exposure, such as when I switch to M and use a handheld incident light meter... or possibly take some test shots, review the histograms and make any necessary adjustments before reshooting. It's great when there is time for that. But other times, with other types of shooting that I do a lot, ETTR is an essential tool. Not perfect, but helpful.

rmalarz Loc: Tempe, Arizona

This is NOT and image rescue. It is the application of the extra dynamic range available when shooting RAW as opposed to the limits imposed by shooting jpg.
--Bob

selmslie Loc: Fernandina Beach, FL, USA

There is another rational reason why I have not bothered. Your method for measuring ERADR is fatally flawed.

You can see why in my RawDigger histograms. The three colors do not reach the 16,000 level at the same time. That's because the cloud I was looking at was not pure white - it is deficient in red.

This means that the amount of ERADR needs to be based on the worst case among the three colors. In other words, the color of the highlight needs to be accounted for, almost impossible to see in a washed out JPEG. RawDigger can tell you something about this but it is after the fact.

The only way to beat this is to hedge your bet. Start with an exposure with no blinkies and capture a series of images at progressively higher exposures. Then use FastRawViewer (same company, same price) to weed out the images where the raw file is overexposed. Then compare the last good exposure to the one with no blinkies.

But I can assure you, under different lighting conditions (different time of day or year, different color of highlight, different ISO, etc.) you are not going to get a consistent result.

And you are still left with a difference of only a couple of thirds of a stop. It's just not going to be enough to matter and it's not going to be worth the effort.

selmslie Loc: Fernandina Beach, FL, USA

It is never safer to overexpose than to underexpose.

You can often rescue an image underexposed by 2 or 3 stops. You are not going to get away with that much error when you overexpose.

rmalarz Loc: Tempe, Arizona

Agreed, but ETTR techniques are not overexposure. They are, with knowledge of one's camera, putting the highest light values at the very top limit of the camera ability without going into blownout mode.
--Bob

selmslie Loc: Fernandina Beach, FL, USA

I agree. To be fair, we should call it adjusted or altered exposure. We can't even call it extra or additional exposure. After all, it might go the other way.

In order to keep the highlight detail (that you want to keep) from being blown it is as likely that you will want to reduce exposure for a scene with a wide DR as increase it for a scene with a low DR.

But even when you do it right the benefit will not be seen in the highlights (if you do not blow them). It has to show up in the shadows.

Low ISO takes care of noise. So what are we left with?

Uuglypher Loc: South Dakota (East River)

Wake up and smell the coffee, Selmslie. The OP sent you the raw digger histogram of the non-normalized raw data. Those little one-pixel-wide spikes at the right end of the bight data represent the specular reflection at the brightest, right end of a well-exposed raw image data capture. Lotsa bright values to the left of the specular reflections!

it's a snow scene in bright sun. Tonally normalize that raw data and you get the nicely exposed image you see in #2.

After normalization by left-sliding the "Exposure" slider in the raw converter, the histogram will assume the configuration appropriate to a more tonally normal image.



Get a grip, Selmslie. Take deep breath....relax...and think about that histogram again. It's exactly what should be seen of raw data exposed for the brightest possible image. Can't you see that?

You really ought to quit pretending that you know the slightest thing about proper raw image data exposure.

Your problem is that you somehow expect that the histogram of correctly exposed raw image data should bear some semblance to the JPEG histograms you are used to.

This seals it! You have confirmed that you have never made a proper, full DR raw exposure. If you had, you'd have recognized what is to be seen in the SOOC raw digger multi-channel histogram and would have recognized the specular reflections.

Stop your masquerade,Selmslie! Congratulate the OP on a well-exposed raw capture; apologize to those you've tried to mislead with your ignorant nonsense, and quit your act! You really are a spiteful piece of work, Selmslie!

selmslie Loc: Fernandina Beach, FL, USA

Still in denial?

The raw data ends abruptly at 16,000 because everything above that level got truncated! It is not because the snow only got that bright and quit on its own right at the end of the brightest zone. Histograms don't work like that. You are the only one who refuses to admit that.

The OP did not come that close to the ETTR limit. He went past it.