Terminology question: what is el?

[eharriett]

no matter how much I learn each day, I still find more things to learn. And this time, Google is no help.

What does it mean when film recommendations say to shoot at EL400? At first, I thought it was another way of saying ISO, but I see, for example on Cinestill, they say to shoot their 800t at either EL200-1600 or iso 800. When I noticed it there, I started noticing it other places. What does this mean and how is it different from the iso recommendation?

Thank you.

 

[AgX]

You have been fooled by our shitty computer letter types...

In this case it must be

EI = Exposure Index

( a capital i looks like a small L )

Exposure Index means to expose a film in a standard unit (ASA, DIN, ISO, whatever is stated) with the figure given.
It is applied were the film does not yield a speed established on the standardized process for that unit, but nevertheless when exposed at that film sensitivity (speed) will yield results the manufacturer considers acceptable.

There either is no standard for such film or the manufacturer considers exposing that way more benefitial, like gaining more effective speed even if that does not coincide with the standard.

 

[AgX]

EL may mean Exposure Latitude

(sum of stops of over- and under-exposure a film yield at a given subject contrast)

 

[RalphLambrecht]

no matter how much I learn each day, I still find more things to learn. And this time, Google is no help.

What does it mean when film recommendations say to shoot at EL400? At first, I thought it was another way of saying ISO, but I see, for example on Cinestill, they say to shoot their 800t at either EL200-1600 or iso 800. When I noticed it there, I started noticing it other places. What does this mean and how is it different from the iso recommendation?

Thank you.

You probably mean'EI' not 'EL"<which is a personal film speed rating different from ISO, depending on personal processing techniques that may differ from the ISO standard.Yes, in a way your personal ISO, giving you better results than shooting at box speed. Mine is typically 2/3 of a stop lower than box speed and gives me better shadow detail than shooting at box speed.

 

[MattKing]

As posted above, when you meter at a setting different than the ISO speed of the film, you are using instead an Exposure Index or EI.
The ISO (or older ASA and DIN) light sensitivity ("speed") standards are a measure of how a film responds to light under certain defined circumstances, which are process related. If your meter is working properly, your metering technique is a standard one, you use commercial processing and have machine prints made, there is a good chance that the best setting for your meter will be the ISO speed for the film. For most films, that ISO speed is the "box" speed.
Some films are frequently used under circumstances that are significantly different than the ISO standard circumstances. The Ilford and Kodak films with "3200" in the name are examples of that. They do have ISO ratings (800 - 1000) but they are designed to respond well to less exposure than would normally be given to film metered and exposed at the ISO standard, with a corresponding increase of development to improve rendition even if shadow detail is still less than ideal.
In addition, many people use film in circumstances where they have more control of the results than is provided by traditional commercial processing and machine prints. Ralph Lambrecht is certainly an example of that! His choice to use an EI that is 2/3 of a stop lower than ISO gives him results that take advantage of the additional control available to him. Those who use the Zone System to expose and develop film are using criteria for development that mandates a result that is 2/3 stop less.
Some photographers also prefer results with non-standard rendition of tones. Examples would include photographers who feature deep shadows and hard contrast. They achieve those results through a combination of controlling light, modifying exposure (through choice of EI and metering technique) and modifying development.
Referring to the Cinestill materials will tend to confuse the issue. They are motion picture negative film that has had the anti-halation remjet removed. The material is originally designed for ECN process, not the C41 that people are generally using to develop their still shots. All of those factors make discussions of ISO at best, problematic. There are ISO speed standards that apply to the original motion picture stock, but the removal of the remjet and the change in process essentially make that ISO speed rating nearly irrelevant.

 

[eharriett]

Ah. That answers it. Thank you.

 

[Irrev.Rev.]

Had a Nikon EL lens...Enlarger?
PJ