Well, I sure didn't mean to take so long to write another post...but as you know, life happens! I have a kid to care for and spend time with (it's summer vacation), a house to manage, part-time work to complete, and of course, alumitypes to make!
Steinheil Gruppen Antiplanet 43 mm Series II, No. 4,
My primary lens, the one that came with my camera, is a Steinheil Gruppen Antiplanet 43 mm, Series II No. 4. It likely dates to the 1890s and probably came with the camera when it was originally purchased. Manufactured in Munich, Germany, this rectilinear barrel lens has a pair of non-symmetrical lenses. Steinheil promoted this as a sort of all-purpose lens, good for taking portraits, group portraits, and landscapes. Here's a link to an 1892 advertisement for this lens.
Closeup of Steinheil marks and slot for waterhouse stops
The Steinheil lens came with what appears to be a complete set of waterhouse stops--these are thin pieces of metal with different apertures; they have numbered tabs to help tell them apart. Inserted into a slot on the top of the lens, they stop, or close down, the amount of light entering the lens. Modern film cameras have a small lever or ring that adjusts the f-stop, opening or closing down the aperture and of course, digital cameras can be similarly adjusted. From what I've read, there was no standardization of f-stops in the 19th century, so every lens and stop system was different.
Waterhouse stops that came with the Steinheil lens
I've measured mine, just to have an understanding for comparative purposes, and I came up with these approximations: no stop - f/6.57, stop ½ - f/6.97, stop 1 - f/9.2, stop 2 - f/12.78, stop 4 - f/19.17, stop 8 - f/25.56, and stop 16 - f/38.33. As you can see, this is a pretty slow lens! That said, depending on the available light, I've been able to get pretty quick images (under 10 seconds) with stop 2. When I was making my first wet plate images, I wasted a fair bit of time and resources trying to use some of the slower stops, but now I know that they are more ideally suited to landscapes, or still lifes. I use no stop when my subject is at a distance, is pretty much on one focal plane, or I want to have a bit of bokeh. When I need more depth of field, I use stop 2. It's pretty clear that I need another, faster lens--I really want to do some closer work and have more speed in the portraiture.