oldtigger Loc: Roanoke Virginia-USA

One of the benefits of this trchnique is that it does not compress the darker end of the range the way EBTR does.
You get the full range of black from edge to edge.

rmalarz Loc: Tempe, Arizona

OT, This technique reminds me of a comment made by Nigel Tufnel in the movie "This is Spinal Tap". When viewing their new album, he remarks, "How much blacker could this be"? I think this technique answers that question.
--Bob

rmalarz Loc: Tempe, Arizona

Though possibly directed at Uuglypher, I'll put my 2 cents in here. The white egrets would have been little problem with ETTR/EBTR. I'd have spot metered on the white feathers and then increased exposure 2 - 2-1/2 stops. That would have placed the light values in Zone VIII and given me lots of detail in the shadows with which to work. I'm not saying these aren't good. I'm saying I'd have done the initial exposures differently.
--Bob

selmslie Loc: Fernandina Beach, FL, USA

The only quibble I have with your statement is that when you meter something as middle gray, you are finding the middle of exposure Zone V. Half a stop higher is at the top of Zone V (the bottom of Zone VI). One stop more is the top of Zone VI (the bottom of Zone VII) and one more puts it at the top of Zone VII (the bottom of Zone VIII). That is your 2-1/2 stops. If there were precisely 2.5 stop from middle gray to the top of Zone VII then a JPEG would probably have made the egret feathers come out OK.

What I have observed with egret feathers is that their reflective properties are high enough to place them slightly above the top of exposure Zone VII but not out of reach for post processing. There are not many other naturally occurring objects that are that have such a high reflectance. There are very few blinkies on my camera for those images and the camera's histogram indicates that it's a very close call whether the feathers would actually be blown out in a JPEG.

But why take a chance with the highlights? For egrets, highlight rendition is the goal, the intent being to have them contain texture and detail.

As you have now seen, underexposing is not a mortal sin. You can easily recover enough shadow information if you don't underexpose too much. So neither ETTR nor ETTL can be taken very far without risk. What I am advocating is simply ETTM - expose to the middle.

rmalarz Loc: Tempe, Arizona

Scotty, the situation you describe here leaves out one major component...the sensor/camera as a unit and how it handles exposure. Through testing, the camera's capabilities to expose beyond what the blinkies indicate and still extract meaningful information is critical in using ETTR/EBTR. So, when I mention upping the exposure by 2-2-1/2 even 3 stops, I'm still within my camera's ability to capture, and render useable, the brightest portions of a scene without loosing details in highlights, barring specular reflections. As we know, specular reflections are extremely bright and contain no detail.

Most of my images, when chimped, are more blinkies than subject matter. That's fine. I know the camera's capabilities and still work within them. To illustrate the point, perhaps more for those reading this thread because you've, more than likely, have seen these before, here is an SOOC and processed image to illustrate the placement of the highlights such that they contain image detail. The SOOC is a screen capture of the image in ACR. The reason for the screen capture is to illustrate those areas that are supposedly overexposed.

I don't know how else to point out that knowing what one's camera is capable of producing is paramount to producing images without having to guess or "fudge" downward to insure maximum use of a camera's DR. Don't fear the blinkies.
--Bob

SOOC

(Download)

Post Processed

(Download)

selmslie Loc: Fernandina Beach, FL, USA

I am very familiar with all of that. I have examined many images using RawDigger and I know when highlights become irretrievably blown.

To recap, testing with RawDigger on two cameras (D610 and A7 II) has shown me that both of them place the raw values for middle gray (the middle of exposure Zone V) between raw values of 1000 and 2000 on a 14-bit scale. That means that the top of exposure Zone V is at about 2000 (note that these are exposure zones, not print zones, which range from 0, maximum black, to X paper white) Zone VI reaches 4000, Zone VII to 8000 and Zone VIII to 16000. If there were a usable Zone IX it would reach 32000 but a 14-bit raw file blows out at 16383. For all practical purposes there is no exposure Zone IX in either of these cameras. That leaves only 3-1/2 stops of latitude above middle gray. I would be surprised to come across any other Nikon or Sony camera that behaves differently. I don't have access to a camera with a 16-bit raw file but I bet it would have more latitude on the high end.

The bottom of exposure Zone V is 1000, Zone IV is 500, Zone III is 256 (switching to powers of 2), Zone II is 128, Zone I is 64, Zone 0 is 32, Zone -1 is 16, Zone -2 is 8, Zone -3 is 4 ... This explains why there are a lot more zones available below middle gray than above it. It also explains why ISO Invariant cameras can handle a great deal of underexposure before the darker portions become irretrievable banded and ugly.

So there is more latitude for underexposure than for overexposure in in the raw file of a digital camera just as there is more latitude for overexposure than for overexposure with negative film.

Of course, underexposure followed by a correction in post processing is likely to magnify the visibility of noise. But we both know that the visibility of noise is a function of exposure, not ISO. If you expose normally at a reasonable ISO, noise is not the issue.

I realize that not every image includes something as reflective as an egret and that there are cases where you can get away with moving the histogram to the right until the JPEG looks somewhat washed out (and maybe even greenish) only to move it back to the left in post processing to restore a more natural looking image. I prefer to be able to review the image on the LCD while it is still in the camera.

ETTR begs the question, "Why bother?" We have seen all the demonstrations we need of how it is done. I am still waiting to see a demonstration of a visible benefit.

rmalarz Loc: Tempe, Arizona

Scotty, it's my humble opinion that no matter what examples are displayed to illustrate the benefits of ETTR/EBTR, you will not accept them. Continue on determining exposure however you wish. I'll continue with my approach. Just keep in mind that exposing your procedures as if they were gospel is unfair to those wishing to learn how to maximize the capabilities of their equipment.

RAW Digger is a fine tool. But like any tool, the outcome is based on the skill of the user. I sincerely wish I could put my finger on the one thing that seems to be eluding you, but as of this moment, I can't. You can use RAW Digger all you want. The determination of your camera's right exposure boundary is still eluding you, most likely due to a reluctance to actually test it. I tested mine, both the D700 and D800e. Though different from each other the application of what I've learned from those tests was paramount in obtaining "no guess work" exposure settings.

The critical value is the high end, not Zone V. That is the portion of the scene that one wishes to maintain controlled settings to place that value in the higher Zone of one's choice and in doing so, not destroy the highlights of the scene. Knowing that most exposure meters are reading for Zone V makes it simple to adjust for just the right amount of additional exposure to capture, but not over saturate the highlights of the scene. The additional benefit is the signal to noise ratio for the lower zones inhibits the appearance of noise.
--Bob

selmslie Loc: Fernandina Beach, FL, USA

Neither you nor Dave has ever demonstrated the benefits.

You have demonstrated how you use it but never why. A proper demonstration entails: 1- this is the result without ETTR (exposed normally the way anyone might do it), 2- this is the better result with ETTR. That has never happened.

Dave has demonstrated only noise reduction but it is always at an absurdly high ISO. The noise reduction is always accomplished by increasing the exposure.

I think I described above very clearly how I tested my two digital cameras to determine the exposure boundary. Take another look at how I determined the distance from middle gray that all meters measure to the 16383 limit.

selmslie Loc: Fernandina Beach, FL, USA

I just reviewed all 58 of the images that I captured in the session on Friday*. In every case where I strictly followed the Sunny 16 rule the highlights for the green channel reached about 11000 or less, about 1/2 way into exposure Zone VIII, The blue channel reached generally reached the 8000 level and the red channel about 1/3 stop lower than blue. If I had attempted to increase the exposure by as much as 1/2 stop I would have blown the green channel. The only time I got into trouble was when I increased the exposure because I thought I was shooting into the shadows.

So ETTR would not have only been more difficult to execute, it would have certainly led to blown green highlights if I was off at by a half stop.

* See http://www.uglyhedgehog.com/t-453302-1.html and http://www.uglyhedgehog.com/t-453150-1.html

rmalarz Loc: Tempe, Arizona

Scotty, likewise, I've reviewed every image I photographed since I learned about ETTR and ETBR. Likewise, I've found that in EVERY case, I've captured the dynamic range that was there in the manner that I felt expressed the emotional sensation I viewed. You can analyze all you want. I've done the same with the same tools. I've come out ahead due to the capture of far greater data and greater tonal capture than a hit and miss approach. I can predictably place my high end tonal values where I want them, as opposed to fudging by reducing the optimum exposure.

It's amazing to me that this post, which was done in somewhat tongue in cheek manner, brought about this discourse, which again shows a limited experience with knowing the camera's limits and working within those limits.
--Bob