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Chloride papers are lower in sensitivity than are bromide papers, but they are faster to develop. Silver chloride papers usually are fully developed in 60-75 seconds, while typical bromide enlarging papers develop to the same level in 120-140 seconds.
Chloride papers are ‘contact’ speed. They are used under a bright light, not an enlarger, with a negative in contact with the paper. The final image size is the size of the negative, which, probably, means you are working with a large format film.
Current chloride papers are the revived Azo styled “Lodima” and the newly introduced Adox “Lupex.”
Adox announced Lupex with a very considerate offer of free shipping, so I bought a sample pack, and then a box of 8×10. I like the paper. The shipping from Germany to Texas takes 10 days — be patient. Lodima shipment takes only 4 days.
I have seen posts (apug) that Lupex is slower (not much) and warmer than Lodima. That isn’t what I see.
Lupex. Lodima Scan
both papers exposed to same light, for same time. Both papers were developed in the same developer at the same time. To compare color of emulsion, I’ve scanned the papers against a Kodak grey card.
Lupex Fomabrom Scan
Foma makes 2 papers which provide distinct differences between warm and neutral images. Lupex is closer to the Fomabrom 111.
Exposure Setup
Exposure is set using a Gossen lightmeter in diffusion mode. The ASA is set to 320. The lamp is raised to a point where the EV is 10. With the lamp at that height, exposure is 25 seconds for the Stouffer TP 4×5 wedge.
Developer
I use different developers, depending upon the image requirement. Many current users follow the Amidol road (spell lodima).. my preferred formula is in my ‘formulary’ section; also Lupex responds well to variable contrast developers, even more so using the 2 tray method.
More recently, I’ve souped both in Lith developers — they each offer brilliant color ranges in both Fotospeed and Moersch developers. I will probably use Lupex and Moersch later for more than just verification and idea generation.
Notes: See Easy Amidol for developer notes
Resources for making emulsions:
https://www.processreversal.org/public/workshops/handmade_baltimore/HandmadeEmulsionResources.pdf
Kodak Publication AJ-12, “Making a Photographic Emulsion.” https://unblinkingeye.com/Articles/Emulsion/emulsion.html
EJ WAll
The Light Farm: http://thelightfarm.com/Map/ContactPaperDev/ContactPaperPart3.htm
1996, Kodak: Process for making high chloride tabular grain emulsion using multiple stream addition of iodide. Patent
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