Iso film speed ????

[wiltw]

So of I do shoot at 200 iso should I follow the light Metter exactly to not over expose anymore?

Too much worry about +1EV of exposure. Color neg film has been repeated demonstrated thru tests to have an exposure latitude of -2EV to +3EV, and the end print hardly shows deviation from the ideal exposure. Outside that range, the prints may look reasonable, but the excessive deviations (-3EV, +4EV) from ideal exposure will carry consequences of lost detail (Oververexposure) or muddy shadows (Underexposure)
In the past, pros would deliberately and routinely overexpose color neg by +0.5EV to +1.0EV in oder to avoid muddy color in the shadows. I shot weddings with ISO 160 film at ISO 100 ratiing.

 

[MattKing]

No film manufacturer uses, or has adopted the ISO standard that I am aware of.

Kodak and Ilford and Fuji don't count?
For example:

 

[grat]

I'm not aware of any current film that isn't using the ISO nomenclature on their current data sheets.

 

[George Mann]

Kodak and Ilford and Fuji don't count?
For example:
View attachment 271512

I'm not aware of any current film that isn't using the ISO nomenclature on their current data sheets.

The mention of ISO on their datasheets does not prove their adaptation of the ISO rating of their film stock!

ASA is the standard of which film sensitivity is rated, with zero reason to change.

 

[MattKing]

ASA is the standard of which film sensitivity is rated, with zero reason to change.

ISO has replaced ASA when it comes to film sensitivity (in 1991 I believe).
The American Standards Association no longer has any involvement in the film speed standard, even if the organization that took over responsibility, the organization responsible for ISO standards, originally adopted the ASA standard and DIN standard as the combined ISO standard, using the ASA numbering.

 

[mshchem]

Well I remembered incorrectly
View attachment 271489 View attachment 271490 View attachment 271491 View attachment 271492

Those powder kits haven't been updated in some time. Vericolor film is obsolete as well as Kodacolor.

 

[George Mann]

ISO has replaced ASA when it comes to film sensitivity (in 1991 I believe).

Show me a film emulsion that is ISO rated.

 

[MattKing]

Show me a film emulsion that is ISO rated.

Portra 400

 

[Kodachromeguy]

No film manufacturer uses, or has adopted the ISO standard that I am aware of.

You are about 40 years out of date:

https://en.m.wikipedia.org/wiki/Film_speed

Look at a 2016 data sheet for Kodak Ektar 100 film:

https://imaging.kodakalaris.com/sites/prod/files/files/products/e4046_ektar_100.pdf

Come on, cite helpful/valid information on public forums.

 

[BrianShaw]

https://www.iso.org/iso-6-camera-film-speed.html

https://blog.ansi.org/2016/03/iso-speed-standard-for-film-speed/

 

[grat]

Show me a film emulsion that is ISO rated.

ALL OF THEM.

Every single datasheet says "ISO <X>/Y°" where X is a linear value and Y is a logarithmic, with the log being offset by 3° for each stop.

It is true that the ASA scale translates 1:1 for the ISO arithmetic scale, but the ASA log scale (which was dropped) is different, in that it uses +1° for each stop.

 

[MattKing]

ALL OF THEM.

Every single datasheet says "ISO <X>/Y°"

With the exception of the Ilford and Kodak 3200 offerings, which are intentionally referred to with non-ISO nomenclature.
There is a reference though in the materials for them that relates their effective ISO speed.

 

[BrianShaw]

With the exception of the Ilford and Kodak 3200 offerings, which are intentionally referred to with non-ISO nomenclature.
There is a reference though in the materials for them that relates their effective ISO speed.

Actually, Kodak refers to an actual ISO film speed rating in the data sheet: ISO 1000... then they round down to 800 for another processing regime and market up to 3200 under very specific conditions.

“The nominal speed is EI 1000 when the film is processed in KODAK PROFESSIONAL T-MAX Developer or KODAK PROFESSIONAL T-MAX RS Developer and Replenisher, or EI 800 when it is processed in other KODAK black-and-white developers. It was determined in a manner published in ISO standards. For ease in calculating exposure and for consistency with the commonly used scale of film-speed numbers, the nominal speed has been rounded to EI 800.”

https://imaging.kodakalaris.com/sites/prod/files/files/products/F4001.pdf

 

[Autonerd]

So of I do shoot at 200 iso should I follow the light Metter exactly to not over expose anymore?

Shoot the rest at 400 and don't worry so much about the two shots taken at 200.

 

[George Mann]

You are about 40 years out of date:

Which marked the end of the good, sane world we once lived in, and there has been precious little of any real value since then!

Come on, cite helpful/valid information on public forums.

Until I see ISO on a film canister, my info stands as valid.

 

[MattKing]

Until I see ISO on a film canister, my info stands as valid.

It is in white letters surrounded by the turquoise bar at the bottom left.

 

[George Mann]

View attachment 271607
It is in white letters surrounded by the turquoise bar at the bottom left.

Wonderful! The international globalist conspiracy to corrupt and marginalize everything has struck again (excuse me while I puke).

 

[MattKing]

Some 2007 dated Fuji:

CustomColor was the combined lab and store that sold it with processing included.
You won't see ISO on any Kodak film cassettes that I can find an image of - but you also won't be likely to see ASA or DIN on any cassettes from the era that predated the ISO standard. Kodak just put 32, or 125 or 400 or whatever applied on the film itself - no letters attached.

 

[MattKing]

Note the lack of any ASA or DIN reference on a Kodachrome 64 cassette:

 

[MattKing]

And then, into the 1990s, we have ISO showing with (Australian?) Kodachrome:

 

[wiltw]

What is written:

"Current system: ISO
The ASA and DIN film speed standards have been combined into the ISO standards since 1974.

The current International Standard for measuring the speed of colour negative film is ISO 5800:2001[17] (first published in 1979, revised in November 1987) from the International Organization for Standardization (ISO). Related standards ISO 6:1993[15] (first published in 1974) and ISO 2240:2003[16] (first published in July 1982, revised in September 1994 and corrected in October 2003) define scales for speeds of black-and-white negative film and colour reversal film, respectively.

The determination of ISO speeds with digital still-cameras is described in ISO 12232:2019 (first published in August 1998, revised in April 2006, corrected in October 2006 and again revised in February 2019).[36][37]

The ISO system defines both an arithmetic and a logarithmic scale.[38] The arithmetic ISO scale corresponds to the arithmetic ASA system, where a doubling of film sensitivity is represented by a doubling of the numerical film speed value. In the logarithmic ISO scale, which corresponds to the DIN scale, adding 3° to the numerical value constitutes a doubling of sensitivity. For example, a film rated ISO 200/24° is twice as sensitive as one rated ISO 100/21°.[38]

Commonly, the logarithmic speed is omitted; for example, "ISO 100" denotes "ISO 100/21°",[39] while logarithmic ISO speeds are written as "ISO 21°" as per the standard"
​

ISO 6:1974: Photography — Determination of ISO speed of monochrome (black-and-white), continuous-tone photographic negative materials for still photography

https://www.iso.org/standard/3579.html?browse=tc​

 

[George Mann]

Yah, OK. But I don't have to like it.

 

[Don_ih]

If you want, you can start calling it ANSI.

 

[George Mann]

If you want, you can start calling it ANSI.

How about anti-American globalist corruption (aAgc)?

 

[Don_ih]

How about anti-American globalist corruption (aAgc)?

The rest of the world is usually pro-Wherever-They-Are and not really anti-American.