Doctorpepe

Thanx. Except I am one of those people who has been around for more than 30 years (I'm 68) and have been tinkering with photochemistry (monochrome developers of all kinds, C-41 & E-6 as well and alt-processes, palladium, platinum, kallitype, cyanotype and carbon) for at least 40 of my nearly 70 years. The smallest format I use in film is 120, otherwise using 4x5, 5x7 & 8x10. I sold my custom-made (by me) 11x14 some years ago as it was too expensive to feed. I recently reverse engineered the original HC110 formula (since current iterations have lousy keeping qualities) and use it regularly. I have used ABCPyro or some variant of it for years on and off, but hadn't stumbled onto this 510 pyro until recently. The stain parallels the places where silver is deposited and the effect was used with great success to enhance sharpness and color with the now defunct Kodachrome, albeit not with pyrogallic acid. If I play with any additives to the 510-pyro, I will report my findings to the group and let others have at it as they wish. Of course, I could just shoot digital, but that wouldn't be any fun now, would it! Stay well, all.

Hi. I was wondering why the current formulation did not include a small amount of Benzotriazole (as in previous formulations) to reduce the inherent fog (FB+Fog) levels to a minimum, or was it found ineffective? Also, other highly concentrated liquid developers use a small amount of polyvinylpyrrolidone for the same purpose. Any thoughts on these? Pyro imparts a unique stain concurrent with the image which is exactly what we need to add to enhance the low-density areas of the image and to enhance detail. It is most effective when there is a minimal amount of sulfite present...which is exactly what we have here! Any thoughts to adding Catechol to the concentrate to further enhance this stain, since low sulfite also promotes the staining effect of Catechol? Thank you in advance. Kevin Pernicano San Antonio, TX

I know this is an old thread, and the Boss screen may no longer be available, but I am making one with a slightly different set of materials. IMPORTANT: Work under subdued light that has no known UV in it. Materials: 1. Purchase a sheet of clear glass that fits into the frame of the view camera, just as the original ground glass. 2. Purchase a sheet of clear glass that fits into the INSIDE of the frame, just against the first one above. 3. Obtain a bottle of Optical UV curing cement (I get mine from Thor Labs, it is the one used to cement lenses, glass to glass, hard bonding. 4. Buy a Bottle of titanium dioxide pigment (finely ground, obtain from artist painter's supply house like Kremer in NYC). Procedure: 1. Mix a small quantity of TIO2 with the optical cement in low light. Mix thoroughly to disperse pigment thoroughly. The amount you use will depend on how much opacity you want, but it should look about as translucent as paraffin (which is what the Boss screen uses to create the focusing layer). The actual amount of pigment will probably be determined by the size of your GG and the amount of optical cement you use. (Optional: If you have an ultrasonic cleaner, sit the entire container of optical cement plus TiO2 into the cleaner and let it run for about 5-10 minutes more or less until any of the air bubbles disperse.) 2. Set the camera viewing frame and insert the top (larger) glass (where the groundglass would have been) and clip it in with the GG clips. 3. Turn the frame over and carefully pour in the mixed optical cement and TiO2 on one side of the glass in the frame. Might work best to pour a line along the short side of the glass (8" side of an *x10) about an inch from the edge. Take the smaller clear glass and, starting at the edge where the optical cement has been poured, "tip" the smaller class in from the cement side to the other side. 4. Allow the smaller glass to "settle" onto the larger glass. You can gently push about and if any cement leaks over the top, you can just wipe it off with a paper towel. Excess cured cement will clean up easily later. The optical cement should flow smoothly underneath the smaller glass, much like when you put a glass cover on your cell phone. 5. When you are satisfied that the cement is equally distributed and you have a "hazy" layer between the pieces of glass, then... 6. With the back of the frame (Clip & GG) facing DOWN, your smaller piece of glass facing UP, expose the sandwich to your UV light source for 10-30 minutes. 7. Once cured, your sandwich is complete, you have a focusing screen that will not melt in the heat. Cleanup: 1. Take a razor blade and remove any excess cement from the inside of your frame and you can use acetone on the glass to clean up any other residuals. 2. Windex front and back of your new screen and install the frame back onto your camera. I can send some pix later on.

Does anyone know the thickness of the glass optical plate?