Make a Daguerreotype: Exposure Guidelines
If you have surmounted the various steps of making Daguerreotype plates, equipping your darkroom, buying a buffing machine, rigging your camera, and convincing your friends to stop laughing at you, you may be wandering exactly what to DO with your sensitized Daguerreotype plate once it’s in your camera.
Well friends, I give you this: Becquerel Daguerreotype Exposure Guidelines.
I made this little cheat sheet a couple of years ago and I periodically modify it as my experience teaches me new things about Daguerreotypes. I carry a printout of the cheat sheet for easy reference and I scribble all over it constantly.
The times on this sheet are largely based on my experience with some degree of frightening mathematical calculations that I’m happy to let Microsoft Excel do for me automagically. My crappy camera lens has a maximum aperture of f/6.3 if you’re wondering why such an arcane number is on my reference list.
Keep in mind when you’re making your exposure calculations that Daguerreotypes are orthochromatic, you’ll have to increase your exposure time if you choose to photograph a red subject and potentially decrease your exposure time if your subject is primarily blue.
I rarely make an exposure without these guidelines but I also rarely make an exposure based specifically on what’s on the sheet. I have found that my new polishing routine is improving my exposure times by 1-2 stops!
As with everything with Daguerreotypes, experiment to find the best results!
-Jonathan
What is your new polishing technique versus your old one that has increased the exposure by almost 2 stops, that is a lot of time at f/6.3 on a Dag.
I think that it’s more that I had a problem with both the old and new processes. The new process is vastly superior AND the old process was woefully insufficient.
The new process involves me buffing with red rouge on a stitched wheel then with blue compound on an unstitched wheel, and then hand polishing on a velvet board with black ferric oxide powder. It seems that the shinier the plate is, the faster it is overall.
I should also remind that mine are Becquerel-process dags and are far slower than bromoiodide sensitized daguerreotypes that are developed over mercury.