ETTR is a fallacy.

The thinking is that because each successive f/stop records double the number of photons recorded during an exposure, by overexposing the image, (OK then, subjecting the sensor to a greater number of photons than is normally necessary to accurately register any given light value in order to record an image), we gain the advantage of doing our image processing using a vastly greater volume of data.

Utter nonsense.

The facts………

The camera sensor converts the quantity of photons striking it during the exposure and stores the result as a voltage.

That voltage is read and converted to say, a 12bit binary number.

A binary number is to the base 2 which means that there are only two possible values for each successive entry.

Each entry is a multiple of 2, or double the value of the previous one in the line.

A 12 bit number is equal to 4096 to the base 10.

Consider a 12 f/stop sensor.

Each successive f/stop represents a doubling of the light that “it” will pass.

F/stops are not values. An f/stop in isolation is not quantifiable; it has relevance only when in reference to a known value.

Each successive f/stop represents a doubling, (or halving, all else being equal), of the volume of photons that it will pass reference its neighbor.

Voila! That’s the same deal as that binary number….Isn’t it?

Well, no, it isn’t.

The numbers of photons passed by different f/stops increases logarithmically whereas the binary description of the equivalent tonal values the progression is linear.

By the time we can gain access to the data recorded by the sensor it has been irreversibly divided into 4096 steps of tonality ranging from black to white.

There is now the same number of steps for each of the f/stops regardless of where they “fall” and the actual number of photons involved takes no further part or has any further influence.

In RAW PP all you are doing is changing the value of the binary number which describes the tonal value of each pixel in the image.

The notion that by ETTR we gain the advantage of doing our image processing using a vastly greater volume of data is therefore invalid.

Rob.

hi all, i have a canon 7dm2, today i was just playing with the white balance shift, in camera and noticed something, hoping anyone can elaborate on what i saw. i was in my kitchen and took eleven pics in the cameras high speed capture with no flash. In the eleven shots which took just over one second i noticed a blue led night light going from full brilliance in the first pic to no illumination at all in the last pic. i'm assuming it has to do with the 60 cycles in the ac sign wave. hopefully the three of the 11 pics i added i did correctly so you can see it, (1st 5th and last in the series) if so the blue led light is on the left of pics. is this this the same premus as fluorescent lighting has on flashless photography. or is my house possesed :) wondering what all the new led bulbs commimg out what will this do to flashless photography. thanks for any input info on this. bill

I've used Helicon, and my husband has used Helicon Remote, and the interface for both is pretty straightforward, KM. With Helicon Remote, you focus on both the nearest and farthest focal points, and Helicon calculates the number of shots between the two points. Like you said, Helicon is pricey, but I would choose it (Helicon Remote in particular) for its ease of use if I was going to be stacking a lot of images. You're probably aware that you'll have ghosting when you use a stacking program, but Helicon provides the tools to remove ghosting and any other artifacts.

My computer says this is page 11! I've never started a topic here that lasted that long!

My sense is that the vast majority of Lightroom users like it and don't have problems.

At the same time I think Adobe causes user issues in several ways.

1. "Import" is a bad choice of words. It should be "Locate" or "Register". Users coming from Apple software seem to have a habit of thinking photos are somehow "in" their Apple software, so it can be more confusing for first time Apple users.

1a. Related is that a lot of digital photographers have trouble with the basics of computer management. They simply don't understand files, folders and drives. Perhaps they come from work environments where someone else does that for them.

2. The concept of what is kept in the "Catalog" versus what is kept in the image file is hard for beginners. It is worse for beginners that have learned digital photography with JPEGs that can store changes in the image files. Lightroom protects the original.

3. Beginners have trouble because their experience with all software from word processing to other photo processing software because you have to "Save" or "Save As" to keep your work. Lightroom is different!

4. Beginners have a lot of trouble understanding how to keep both their image files and Lightroom develop work safe with backup procedures.

5. Beginners with Lightroom can have a preconceived notion of how they want to work. They want Lightroom to do things their "intuitive" way instead of the Lightroom way.

5a. Related is that some only want and expect to work single files at a time. They want to open it, adjust it and close it. Anything else is not intuitive and can bother the heck out of them.

6. Even installation can cause trouble. Adobe has it's routine and it can be different from user habits. The badly named "Creative Cloud" causes people to think something is somewhere instead of on their computer.

7. The difference between the perpetual license version and the rental license version can confuse people too.

The majority of the frustrated soles that they are having trouble with Lightroom will fall into one of the above. So often, the answer to a user issue has to start with "Lightroom doesn't work that way."