via the lens Loc: Northern California, near Yosemite NP

Hi Dan De Lion,

ETTR is intended to be used with RAW images and is not about shadows, it's about highlights. When shooting JPG one would try to go as far to the right as possible but not get anywhere near blown-out as it is difficult to retrieve data with JPG files, so staying in the midtone-low white range. So, why would anyone want to shoot to the right anyway? The answer is to obtain all of the data needed to get the absolute most color tones in the photo (and this is why some people choose to shoot RAW images as JPG images only have 255 tones of color). If you recall, a histogram is a statistical bar graph of a frequency distribution (tones), going from 0 to 255 for an 8-bit file (JPG), and helps us to know if we are exposing correctly. It also relates back to how sensors capture data, in a linear fashion. ETTR means the image histogram is skewed to the right as a slight overexposure but without blowing out the highlights. Most camera histograms show only five stops of tonal value, but many cameras can actually capture 7 stops of tonal value (know your specific camera). In RAW shooting exposing for the highlights is standard practice. Since a 12-bit RAW file (sensor data is commonly quantized to 10, 12 or 14 bits) contains 4096 tones (212 ) and the number of stops (tones) are halved (cameras tend to do this!) you will get 1024 tones in the far right of the RAW histogram. Then the 1024 tones are halved again, giving you 512 tones in the next section, and 256 tones in the next section, and 128 tones in the next section. This breakdown gives you the five sections of your camera and post-processing histogram: Using Lightroom language this equates to the following RAW histogram zones or tones (color or BW):
Whites-2048
Highlights-1024
Exposure-512 (Mid-tones)
Shadows-256
Blacks-128
By exposing to the right you obtain the highest degree of color tones and thus get brighter and/or deeper colors in your image. This is why you can retrieve a slightly blown-out sky with a RAW file but not with a JPG file. Shooting to the right also allows you to take high-key photos, where the image is in the mid-tone range but the background is actually blown out and white, often done in fashion photography. If you want to know more about this you might purchase The Manual of Photography or other books that explain this. This is about actual results.

catchlight.. Loc: Wisconsin USA- Halden Norway

Light equals detail.

I think the combination of information on your Histogram and blinkies can be a great tool time permitting...I mostly keep tabs 10x on the camera jpeg for detail, blinkies and compare to what I see in real life. I mostly use the histogram in post .

Extreme highlights under reflective conditions or sunny sky's I find better remedied with bracketing and shadow detail, noise is based on how much light is actually available and ISO... Photo shop I use to stack, align, mask, adjust and blend bracket combinations that can't be had in one shot in camera.

In reality I think any smart photographer knows to lean right instinctively. A histogram is an information quantity gauge rather than a quality quantifier and the endless combinations of conditions tend to make it more of a warning device most times.

Thanks for your thoughts Dave,

Dan

Uuglypher Loc: South Dakota (East River)

[quote=via the lens]Hi Dan De Lion,

Hi, via the lens,

You make entirely valid and useful points throughout your post.

However, having initiated this thread to distinguish between, and to reduce confusion of ETTR (Expose to the Right) and EBTR (Expose Beyond theRight) I'll point out that ETTR, as first described by the late Michael Reichmann in 2003, is exposing a raw image capture to utilize all the dynamic range represented by the width of the JPEG histogram frame, if not a small bit more relying on the un-quantitated "some headroom" to permit recovery of some clipped highlights.

EBTR is the practice of utilizing the full complement of extra raw-accessible dynamic range (beyond the right side of the JPEG histogram frame that may be as little as 1/3 stop to two and 2/3 stops (or more...)

(That's right; each camera must be tested for its particular allotment of DR "beyond the right")

Failure to use that full, available, dynamic range results in wasting of a considerable proportion of an image file's potential tonal and chromatic spectra.

Best regards,

Dave

altheman Loc: Christchurch, New Zealand

There is simple and perhaps lazy way of ETTR/EBTR and that is to set your exp comp to +1.3 ev and the shoot a .7ev three shot bracket and this is what I do most of the time unless I think that the dynamic range of the scene is very wide then I will shoot a .7ev 5 shot bracket.
When I first tested this it was in the middle of the afternoon on a bright sunny day with lots of bright white clouds in the sky. I set the camera opened my front door and and took three shots as described with a bright white concrete driveway in the foreground and bright white clouds in the sky green grass etc in the rest of the scene. I came inside and processed the image by first evaluating the highlights in each image this is done by hovering the mouse pointer over highlights in lightroom. The brightest highlights should read between 99 and a 100 on the histogram if they are a 100 then they are blown out and you use the image in which they aren't blown out. I find that 99% of the time this system works although with my camera I will sometimes get colour shifts which will need some extra processsing. I do 90% of processing in Lightroom and really only use Photoshop for remove stuff etc.

rmalarz Loc: Tempe, Arizona

I'll chime in here and say, yup that's the lazy way. Ideally, you could test your camera and determine the amount of additional exposure you can use to take your image. Then, it's one shot, one photo. I rarely shoot multiple exposures of the same scene in an effort to make sure I got something. It's usually one exposure, done properly.
--Bob

rmalarz Loc: Tempe, Arizona

Dave, after reading through the entire set of posts and replies to this thread, all I can say is well done.
--Bob

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

You obviously "own" the concept!

Dan De Lion Loc: Montana

-----

Hi Dave - Thanks for doing a really nice job with the ETTR approach to exposure.

Dan

-----

Uuglypher Loc: South Dakota (East River)

Bob, Gene, Dan, Catchlight, altheman and all others,
Thanks so much for your comments in contribution to this discussion.

Dave