|Kodak/Eastman Plus-X in 16mm, 35mm, medium format and large format sheet film|
"To reflect our enduring commitment to black-and-white photography, black-and-white film production will take place in an even more advanced film-coating facility. New technology applied to these superior, time-tested emulsions will result in slightly different processing times for the film family. But the same great films—those you've known and trusted for years—will still deliver the same breathtaking results."One notable difference between the two versions was the new Plus-X was provided with development times for a three-stop push to EI 1000, while the earlier film was only recommended to be pushed no more than two stops; both films' data sheets stated that a one-stop push to 250 could be achieved without a change to development times. In my own tests below, I did not attempt more than one-stop push, given that I was working with discontinued film, although the 35mm motion picture film was manufactured in 2010, not old enough to really be concerned with increasing exposure to compensate for a loss of sensitivity with age; in some other formats, the Plus-X film I shot was much older.
In the Kodak Reference Handbook from 1946 it is described under 'General Properties' for Roll Film and Film packs as being:
"High speed, fine grain, excellent gradation, wide exposure latitude. The speed and balanced color sensitivity make this film particularly suited to a wide range of outdoor conditions. It also has ample speed for well-lighted indoor subjects. The low graininess and high resolving power permit high quality enlargements many times the size of the original negative."While for 35-mm and Bantam (828) films:
"High speed and fine grain. For general miniature camera work this film should be used unless light conditions are very adverse or unless a very high degree of enlargement is intended."Plus-X was originally rated 50 ASA, but at some point in the 1950s this was increased to 80 ASA (this thread gives some information on Plus-X ratings). When speed ratings were changed for black and white films in 1960, Plus-X was rated at 160 ASA for a time, before gaining its 125 ISO rating, which it retained for nearly fifty years (Kodak's reference hand book implies the presence of the one-stop safety factor in the statement about Plus-X that, "When it is desired to reduce the exposure to a minimum, these values can be doubled with little danger of serious underexposure..." ). Additionally, the motion picture stock was recommended to be shot at a slower speed, 80 ISO in daylight and 50 under tungsten, which may just reflect the process of striking a positive from motion picture negative film, rather than a slower emulsion.
Eastman Plus-X was discontinued in 2010, with the notice for the still camera version announced the following year - although the production runs may have both stopped at the same time if the emulsion itself was the same. Incidentally, the Massive Dev Chart still has Plus-X on its main chart, not on its discontinued/unlisted page. Kodak's rationalising of the film stocks it produces in recent years has meant the discontinuation of many of its classic films. This does leave Kodak without a medium-speed traditional emulsion film (Ilford's FP4 Plus being the closest equivalent still available). Kodak suggests TMax 100 as a replacement for Plus-X; this film uses a modern T-grain emulsion. For most of the period that Kodak was manufacturing Plus-X, it also produced Verichrome Pan, another still picture film with a traditional cubic emulsion at the same speed as Plus-X, only discontinued in 2002; Verichrome Pan does appear to have been available in some formats (126, 127) that Plus-X was not, but both were available in the most common formats - 35mm, medium format and sheet film.
|Minolta 16QT with 16mm Kodak Plus-X, develop before date Sept 1971|
|MPP pinhole with 4x5 Kodak Plus-X, develop before date July 1972|
|35mm Kodak Plus-X motion picture film latitude test|
|Canon A-1 with Plus-X rated 40|
|Canon A-1 with Plus-X rated 200|
|Mamiya-16 Automatic with 16mm Eastman Plus-X|
|Pentax Auto 110 with 16mm Eastman Plus-X|
|Agat 18K (35mm half frame) with Kodak Plus-X motion picture film, developed in Ilfotec LC29|
|Kodak Retina IIa (35mm) with Kodak Plus-X motion picture film, developed in Ilfotec LC29|
|Kodak Retina IIa (35mm) with Kodak Plus-X, rated 200, push processed in Ilfotec DD-X|
|Kiev-4 rangefinder (35mm) with Kodak Plus-X motion picture film, developed in Ilfotec LC29|
|Ikoflex Ic (medium format 6x6) with Plus-X, develop before date of 03/2006, developed in RO9 One Shot|
|Zodel Baldalux (medium format 6x9) with Plus-X, develop before date 02/2007, developed in Ilfotec DD-X|
Kodak's history of motion picture film stocks
Plus-X Pan (PXP) tech sheet on 125px.com
Plus X (PX125) tech sheet on 125px.com
Kodak Reference Handbook 1946