Dupont Defender 16d Developer

[jayabbas]

Does anyone know the chemical make up of Dupont 16d developer? My 1946 Dupont formula book shows formula for 15d but not 16d. I have a can of the stuff I'm itchin to mix up and soup some film. Perhaps it was a proprietary blend that came out later in time. I'm guessing a comparable product would have been Kodak DK-50. Also anyone can chime in with thoughts on using old powdered developers in sealed metal cans -- stuff seems to last forever if kept dry. Thanks

[David Lindquist]

Does anyone know the chemical make up of Dupont 16d developer? My 1946 Dupont formula book shows formula for 15d but not 16d. I have a can of the stuff I'm itchin to mix up and soup some film. Perhaps it was a proprietary blend that came out later in time. I'm guessing a comparable product would have been Kodak DK-50. Also anyone can chime in with thoughts on using old powdered developers in sealed metal cans -- stuff seems to last forever if kept dry. Thanks

It looks like you are right about this being a proprietary formula. Information in my Photo-Lab-Index dated 1972 says "Du Pont 16-D is a prepared developer, the formula for which is not available for publication." It's further described as a "Versatile General Purpose Film Developer" and "...recommended for use with Du Pont 'Cronar' photographic sheet films." ("Cronar" was Du Pont's name for the base their sheet film was coated on, I expect it was similar to Kodak's "Estar" base.) In addition 16-D is described as a "fast, clean working developer with a long tank life. Negatives developed in 16-D have a neutral colored image of medium-fine grain." The developer was to be used full strength. It came in units to make 1 gallon or 3 1/2 gallons of working solution.

I suppose one risk of using it is that you might find it's the most wonderful film developer you've ever tried and you'll have no way of reproducing it.

David

[Merg Ross]

It looks like you are right about this being a proprietary formula. Information in my Photo-Lab-Index dated 1972 says "Du Pont 16-D is a prepared developer, the formula for which is not available for publication." It's further described as a "Versatile General Purpose Film Developer" and "...recommended for use with Du Pont 'Cronar' photographic sheet films." ("Cronar" was Du Pont's name for the base their sheet film was coated on, I expect it was similar to Kodak's "Estar" base.) In addition 16-D is described as a "fast, clean working developer with a long tank life. Negatives developed in 16-D have a neutral colored image of medium-fine grain." The developer was to be used full strength. It came in units to make 1 gallon or 3 1/2 gallons of working solution.

I suppose one risk of using it is that you might find it's the most wonderful film developer you've ever tried and you'll have no way of reproducing it.

David

Ah, good answer. I thought that 16-D sounded familiar and that there would be more information about it; being a proprietary formula explains why that is not the case. I used 16-D in the late 1950's and early 60's with Cronar Press sheet film (Du Pont). I was shooting 8x10 and contact printing, so grain was not a concern. I don't recall anything remarkable about 16-D, but it worked fine and yielded good negatives. I assumed that it was a typical MQ developer. I recall that it came in a red can (how's my memory?).

[Drew Wiley]

I've seen the forumla somewhere, but don't think I kept it. It was a fairly ordinary MQ tweak of limited interest to me personally. My older brother once used it in tanks for
Super-XX.

[Lynn Jones]

As several of you note, it was an unpublished propietary formulary. I dug through three Photo Lab Index books that were 50 and more years old. It was intended as a standard large format film developer. I have used it a few times in the 1950's but is about the same as DK50/DK60A as I recall it.

Lynn

[jayabbas]

Ah, good answer. I thought that 16-D sounded familiar and that there would be more information about it; being a proprietary formula explains why that is not the case. I used 16-D in the late 1950's and early 60's with Cronar Press sheet film (Du Pont). I was shooting 8x10 and contact printing, so grain was not a concern. I don't recall anything remarkable about 16-D, but it worked fine and yielded good negatives. I assumed that it was a typical MQ developer. I recall that it came in a red can (how's my memory?).

The cans I have are the 3.5 gal mix and are the Dupont green. I also have the 1 gal replenishment can and that is the familiar red though much smaller in size. Thanks for your input on this developer.