ISO encoding back in the good old days

[movingfinger]

Back a few decades when everyone purchased the image 'sensor' independently of the actual camera, ISO was not simply an independent setting per shutter click. The ISO came hardwired (no pun here) into the purchased sensor which was called 'film'. Here's a fun, and, for those born in the present century, educational, video on how film manufacturers tried to simplify camera functions for the masses, in particular the ISO setting:

Clever Camera Code

[JDMvW]

Yeah, many cameras so "simplified" the process of exposure that it sometimes seemed nearly impossible to actually set a shutterspeed, aperture, and so on manually.

The lower level Contaflex SLRs were especially troublesome to me....

 

Another reason I preferred Jena ("save your East Marks, the DDR shall rise again" sort of thing) 🤤

Edited November 21, 2022 by JDMvW

[Tony Parsons]

Interesting, especially the use of half-frame cameras. As I used to roll my own (mono and slide film), and process them myself, i used the (then) ubiquitous black plastic re-useable cassettes with no coding, setting ASA speeds manually on the camera. To make it easier for myself, I carried 4 film bodies, 2 B & W, one with 125 ASA (FP4), t'other with 400 ASA (TRI-X), and 2 for slides, one Sakura 100 ASA, the other Ektachrome 400 (I think - long time ago !!). I believe some dealers sold adhesive DX coded labels to attach to the canister, but AP warned that positioning had to be accurate. My current film body (Nikkormat, with Tamron Adaptall-2 lenses, has no such 'sophistication' either.

[paddler4]

In years of doing B&W film photography, I never owned a camera that read the ASA code (as it was then known).

It's not quite true that the ASA setting was fixed. You could vary it a little by changing how you developed the film. Increasing the effective ASA was called "pushing". It's now a distant memory, but if I recall right, it was pretty common to push Tri-X up a stop, at the cost of a grainier negative.

The ability to change ISO significantly on the fly is just one of the several reasons why I haven't gone back to film. In the old days, if you had only one camera (as I did), you had only a few choices:

• Stick with the base ASA
• Decide to push the film a bit in development.
• Change the film.

To do the latter without wasting film, you could put the camera in a changing bag, rewind the film (but not enough to put the leader into the cartridge), and insert a different film cartridge. I occasionally did that, but it only works for things like landscape photography, where your subject patiently waits while you spend several minutes changing film. And, of course, it was easy to screw this up, accidentally rewinding the film too far or not remembering correctly how  many frames to advance it when you reinserted the cartridge you removed earlier.

Edited November 22, 2022 by paddler4

[Tony Parsons]

Surely when the film was re-inserted and the incorrect number of exposures (1/1000, f32, lens cap held securely on with gaffer tape) made, the resultant double exposures were described as 'artistic attempts to convey the impermanence of fleeting aspects of life' - or some such twaddle, to avoid admitting a mistake had been made (by the assistant who loaded the camera, naturally !).

I seem to recall that Rollei made a 35mm model designed to resemble a miniature medium format SLR, which had interchangeable backs to avoid this - the 6006, was it? Can anyone confirm, or has my mind slipped yet another cog ?

 

[paddler4]

I believe a number of manufacturers produced cameras with interchangeable backs, but I don't recall details, both because it has been so long and because I never had the $$ back in the day to consider buying one.

[Dustin McAmera]

I have a Sureshot Classic 120 that does DX codes; a nice little tourist compact that served me very well indeed. Most of these have some default speed if you use non-coded film. Or as Tony says, you could buy stickers to add the code yourself. That lets you push film!

The 35mm Rolleiflex is the SL2000F; there are also a Rolleiflex 3001 and 3003.
http://camera-wiki.org/wiki/Rolleiflex_SL2000F
https://www.pacificrimcamera.com/rl/02671/02671.pdf
(pdf brochure for the 3001 at Pacific Rim).

Not in 35mm (and way off topic) but someone designed a camera that lets you load two rolls at once; so you could have B&W and colour loaded, or ISO 100 and ISO 400, and switch between them.
http://camera-wiki.org/wiki/Domnick
His second attempt got as far as a prototype. It uses 127 film!

 

[Dustin McAmera]

More 35mm cameras with removable backs:

The Ektra in 1941: http://camera-wiki.org/wiki/Kodak_Ektra

The Adox 300, in 1956: http://camera-wiki.org/wiki/Adox_300

The Mamiya Magazine 35: http://camera-wiki.org/wiki/Mamiya_Magazine_35

The Contarex I: http://camera-wiki.org/wiki/Contarex_I

Some but not all Contaflex SLRs: http://camera-wiki.org/wiki/Contaflex_(SLR)

The Hologon Ultrawide: made purely as a vehicle for its lens: http://camera-wiki.org/wiki/Hologon_Ultrawide

 

[PapaTango]

On 11/22/2022 at 11:09 AM, tony_parsons1 said:

Surely when the film was re-inserted and the incorrect number of exposures (1/1000, f32, lens cap held securely on with gaffer tape) made, the resultant double exposures were described as 'artistic attempts to convey the impermanence of fleeting aspects of life' - or some such twaddle, to avoid admitting a mistake had been made.... 

 

Or in the case of 120/220 put said exposed roll back in the camera presuming it a new roll...

 

[paddler4]

another wrinkle: to save $$, many of us loaded our own cartridges from bulk rolls of film, so we had no encoding.

[Tony Parsons]

17 hours ago, paddler4 said:

another wrinkle: to save $$, many of us loaded our own cartridges from bulk rolls of film, so we had no encoding.

Please see my post from Monday.

[glen_h]

Instamatic 126 was an earlier method for automatic ASA setting (before ISO did it).

There is a notch in the cartridge, with the position indicating speed.

I believe it is continuous, at least in principle.  The lower models ignored it,

but the higher ones have a sensor that slides along when the back is closed,

and falls into the notch.

 

But yes, as noted in the video, many camera models don't allow for manual setting.