Exposure Basics, lesson three?

Started Mar 18, 2013 | Discussions thread
Najinsky Veteran Member • Posts: 5,739
All at once or nothing at all?

As you say, learning is a step by step process. Building foundations, then building on those.

Some people, especially if they are very smart, seem to think learning should be a brain dump, ideally via a plug-in cable with a little flashy 'uploading' symbol the show progress and an alert to indicate the process is finished. Very few of these people become good educators.

These (seemingly endless) discussions are all stemming from the original post about teaching complete beginners the exposure triangle.

A few smart people take objection to including ISO, but they are wrong (in this context) and are not used to being wrong and not handling it too well.

If all comes down to definitions and application.

They believe Exposure has a fixed definition. This is their first error, an error in their foundation on which they are basing everything, and it serves nicely to illustrate the wasted time that can result from a poor foundation.

Exposure has many definitions. Some relate to nakedness or environment, or publicity or the revealing of truths. But even when limited to the photographic context, there are still multiple usages of the term, and phrases based upon. And this is the crux of the 'discussion'. Here are the two key ones in simplified form.

a) The act of exposing.

b) The state of being exposed.

The pro-No-ISO crew use the first as their Bible. But common photography has long since been concerned with the second, as is evidenced by the abundance of terminology relating to it.

Perhaps the most illustrative is the term 'Double Exposure'. This denotes a photograph that results from exposing the film two times. Inherent in this term is the fact the both exposures got recorded. There can be no double exposure unless both exposures are recorded. And this shows quite clearly how the act of recording is inherent in the term Exposure.

The films were sold in rolls that denoted the number of exposures, 24 exposure, 36 exposure, and so forth. Put a 24 exposure film into the camera and you have, for regular shooting, 24 exposures. And most cameras showed a little number that was called 'Exposures remaining indicator' that would keep track of how much film was used and how much is remaining. However, fail to put a film in the camera and how many exposures do you have? Zero. You can still set the Aperture, and release the shutter, but the camera is not capable of making an exposure in the photographic sense. Again, the act of recording is inherent in the term Exposure.

Photographers have always known that the amount of light hitting the recording surface is also a definition of exposure and is controlled by the relationship of the Aperture and Shutter speed. But since the 1950's the term used to describe this is 'Exposure Value' or Ev.

So in common photography the term Exposure is the one that includes the application of recording, and the term Ev is the one that limits itself to just the relationship between the Aperture and the shutter.

For film/JPEG/TIFF shooters, the term 'Exposure Triangle' has to include the three components of Aperture, Shutter and ASA/ISO in order that the photographer can control the appearance of their recordings to their liking. This is the correct foundation for beginners where the overwhelming majority of cameras and photographers shoot JPEG.

What has happened with digital, is the film has been replaced by the sensor and varying ISO implemented via electronics trickery (amplification). For raw shooters and for some sensors, they may indeed be no reason to shoot at anything other than the cameras optimum (base?) ISO, save for the fact that the camera JPEG used to review the image will not look correctly exposed. And this may well be exciting and interesting for some. But it absolutely should not be the foundation of beginning photography. It is way too technical and removed from the act of picture making for the introductory section of a beginners course.

High Key, Low Key, Under exposed, over exposed are all terms that contrast with a normal (or by convention correct) exposure. That is why the exposure triangle is the foundation, to provide the context to relate these too; closely followed by DOF and motion blur as a consequence of the selected values.


Post (hide subjects) Posted by
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow