reality check

[ann]

i read the following statement (elsewhere) and in over 60 years of photo education and work i have never heard or read anything like this statement.

was i out of the room when the fax was sent :rolleyes: :o



"See, it's not the film that the camera detects to determine film speed. It's that little black and silver box code (DX code) on the side of the cannister. The house brand ISO 400 film has cannisters with a ISO400 DX code on them. The house brand ISO 800 film has ISO 400 film in the cannisters marked with an ISO 800 DX code. The ISO 200 house brand film has ISO 400 film in the cannisters that are marked with ISO 200 DX codes.

See, some photographers mess with push/pull processing which means that they intentionally increase or decrease exposure for a given situation. And since film has this ability to be pushed and pulled they have made cannisters that fool your camera into thinking it has three ISO rating's to choose from, taking this forgiveness of film into consideration"

i am certainly willing to learn new things and in fact try something new everyday, but perhaps i best turn in my insturctor's badge if the above is true and i am clueless.

i am asking here , as there tend to be very few "bs fools" on this site with a high ratio of those who know what they are doing.

[Don Bryant]

i read the following statement (elsewhere) and in over 60 years of photo education and work i have never heard or read anything like this statement.

was i out of the room when the fax was sent :rolleyes: :o



"See, it's not the film that the camera detects to determine film speed. It's that little black and silver box code (DX code) on the side of the cannister. The house brand ISO 400 film has cannisters with a ISO400 DX code on them. The house brand ISO 800 film has ISO 400 film in the cannisters marked with an ISO 800 DX code. The ISO 200 house brand film has ISO 400 film in the cannisters that are marked with ISO 200 DX codes.

See, some photographers mess with push/pull processing which means that they intentionally increase or decrease exposure for a given situation. And since film has this ability to be pushed and pulled they have made cannisters that fool your camera into thinking it has three ISO rating's to choose from, taking this forgiveness of film into consideration"

i am certainly willing to learn new things and in fact try something new everyday, but perhaps i best turn in my insturctor's badge if the above is true and i am clueless.

i am asking here , as there tend to be very few "bs fools" on this site with a high ratio of those who know what they are doing.

This maybe true Ann, especially with color negative films (that is color neg having a two stop latitude.) I think this maybe the result of some camera bodies not being made smart enough to read DX codes uniformly or properly.

I vaguely recall reading about this some where. It had no significance to me since I don't have cameras that read or use DX codes. My wife once had an Olympus Stylus that did that but we gave that to one of our nieces so I can't test for that condition now.

Don

[Jordan]

Ann -- DX-coding is certainly well-known -- I'm not sure there are any large commercial manufacturers who sell film without DX codes. Whether store-brand film is really all ISO 400 film loaded into 200-, 400- and 800-coded cartridges, I can't say.

[ann]

interesting, thanks don.

as i don't use color film nor use dx coded cameras.

so does that mean the "lab" does the correction for development, or with color does it make a difference?

[Don Bryant]

interesting, thanks don.

as i don't use color film nor use dx coded cameras.

so does that mean the "lab" does the correction for development, or with color does it make a difference?

The wide latitude of modern color negative film made by Fuji and Kodak virtually assures over exposed negatives will be printable with acceptable quality, requiring only standard film development. Since virtually all of the processed films are printed by machine, computerized printers easily handle the density ranges of the negatives. Of course modern color paper plays a role as well.

Don

[ann]

jordan

i am well aware about dx coding, what i am not aware of would be the loading of the same film in different canister coded with a different iso than what the film was intended .
i over ride the coding as my EI is never the same as the box speed. I have tested all equipment to come arrive at my specific needs.

[jd callow]

Ann,
None of my cameras read the DX code. I don't know of any colour 400 iso film that won't be noticeably under exposed at an ei of 800 (most 400iso film pushed 1 stop would, in my world, equate to an EI of ~640 with 1 push in dev time), but then I test for my equipment and it must be that all of my meters and camera's are and always have been at least a stop off. Or at least that is what I am lead to believe by the experts found elsewhere.

[ann]

well, i am still amazed that a standard 400 film would be dx at what ever except 400. that is all i was trying to find out as i found the statement made by the quote i posted as very unusal. But as i am not a color person i thought perhaps i really was out of line thinking this is crazy.

[livemoa]

I find it hard to believe that a company would run the risk. To easy to check by standardised checking. Think of the opportunities for legal actions by consumers.

I do know photographers who use dx cameras and reuse film canisters for bulk loading and take advantage of the dx code to "fool" the dx system for plus or minus zone system stuff in 35 mm.

[Rick-in-lb]

If I remember correct, age showing here, when you look at the sprocket of the film it has the ISO printed there. I do not think that the companies would go and spend extra money to have this here if they were the same. But I don't know what big business thinks these days.