What is that supposed to mean? Film is either b/w or it is color, right? Well, yes and no. We normally think of film this way, but there are cases where color film is developed in such a way that renders greyscale negatives and there are cases where film is "color" emulsion, but the only color used is black. Let me explain a little. All films use silver to make blacks and greys. This is how we normally think of b/w film. You expose it to light, the silver salts are reduced to varying degrees according to how many photons hit the crystals, the developer then converts those reduced salts to elemental silver which looks black. Ba-da-bing an image is seen in negative. Color film does the very same thing, only it adds layers of color dyes that are developed in similar ways. However, if you don't use the right chemicals to develop the dyes... if you use say Rodinal, you just get a plain old b/w photo. The silver is still developed as normal, but the dyes all wash away, undeveloped. This is the unfortunate fate of anyone still holding on to rolls of Kodachrome. That process is dead and no one is bringing it back. The chemicals and machinery that developed that very special film are gone. So if you have any, it is going to have to be developed as b/w. Sorry Paul Simon.
The other case I mentioned is with what is called "chromogenic" films. These are films that came out in the 80's to take advantage of the explosion in popularity of color negative films. Small labs found it more economical to harmonize on one process and develop everything with it. That is why in the 80's and 90's it got hard to find a lab that would develop straight b/w film in-house. Most small labs would mail it off to Kodak or Ilford or one of the big vendors that was still offering the process. Chromogenic films use black dyes to create the image. The process is just like developing color negative film, just without the colors at the end. I recently acquired some Ilford XP2 Super 400 film that expired in 2007. I exposed it in my Yashica Mat 124G at iso 250 and developed it in Unicolor C-41. Here are a few of the shots I took around the building I work in. Enjoy.
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