Sorry, I did miss your question. I suppose that it's easy for me to do this because that's the way that I was taught many years ago and it comes 2nd nature. I can explain it to you, but I can't make you understand it. This concept is a reliance upon incident light falling on a subject and not reflective light, which is always at least ½ stop off under difficult lighting. You don't have to use this method if you don't want to---it's just a different way to "read" light and set your camera manually based upon several decades of tried and true physics.

Obviously you did not read where I already responded to his comment.

The problem is that your "simple" explanation was totally wrong and it revealed that you do not understand the concept of exposure value at all.

If you expose at 1/1000 sec and f/16 it does not matter whether the camera is aimed directly at the sun of if the lens cap is still on. It's the same exposure value. The presence of light has nothing to do with it.

Now go back to my first post and try to understand the subject. Until you have mastered that, please refrain from any further comments.

Completely wrong.

Higher EV means less exposure - faster shutter speed and/or smaller aperture. You only need to look at the table to see that this is obvious:



Higher EV means you are letting in less light.

It seems that this concept is over your head.

Leave you camera set on Auto everything, go to the back of the class and put on your dunce cap. You are not qualified to participate in this thread.

There are several factors that influence the brightness of an image:

1. The brightness of the light
2. The reflective properties of the subject
3. The aperture
4. The shutter speed
5. The ISO

The first and most important is the brightness of the incident light. It can be quantified as Light Value (LV). For example, the brightness of full sunlight during the middle of the day in temperate or tropical latitudes can be considered nearly constant. For reasons that will soon be apparent, let’s assign it a value of 15.

* Taken from the Wikipedia article on Exposure value where you can find additional information.

The second factor is the reflective properties of the objects in the scene, how much of the incident light is reflected. This ranges from very high (for snow, white clouds, white paint or white feathers it can be 90% or more) to very low (a pile of coal might reflect 10% or less). But you want to render these subjects as bright and dark. Your camera's meter will try to render them as middle gray. That would be wrong.

Here is how we end up at LV=15.

Shutter speeds starting at 1 second are given a value of 0. Each doubling of the shutter speed increases that value by one:

For longer shutter speeds the value becomes negative.

Apertures starting at f/1 are given a value of 0.


When you combine the value for the shutter speed with the value for the aperture you get the Exposure Value (EV):


ISO values starting at ISO 100 are given a value of 0.


When you combine exposure value with value for the ISO you get the Light Value (LV).

LV 15 is substantially in agreement with Sunny 16 which recommends 1/ISO sec @ f/16 - LV=14.67.

Since the value for ISO 100 is 0, the exposure value table for ISO 100 can be used as a light value table.

Knowing all of this you can learn to set your ISO and exposure without looking at your meter.

One of the benefits of film, especially negative film, it that does not blow out the diffuse highlights abruptly like happens with digital capture.

I cover this difference in Film vs. Digital Characteristic Curves

Both film and digital have a great deal of latitude for exposure. Digital can be underexposed by one stop and negative film overexposed by one stop without doing any visible harm to the recorded image. On the contrary, this may actually be beneficial since it gives you cleaner digital highlights and more shadow detail with film.

But you need to be more careful with transparency film or when you want a good JPEG straight from the camera.

Slide film was designed to be projected onto a good screen in a darkened room. Scanned and displayed it looks almost as good.

Most of us shot Kodachrome at 1/3 stop darker than the box indicated to bring down the highlights a little and make the mid-tones just a little richer.

We didn't obsess over shadow detail. It was usually there if we looked closely but often pure black was a better background.


Athens, July, 1980 - late afternoon sunlight - Kodachrome 25 (Sunny 16 exposure for ISO/ASA 32)