question for you wet platers

[h2oman]

I've currently got a book checked out from the library, "Wild Beauty: Photographs of the Columbia River Gorge, 1867-1957." It is a really nice book. The photography is broken into four parts, the first part devoted exclusively to images by Carleton Watkins, all of which I assume is wet plate. In most of the images, water, or smoke from steam engines, smokestacks, etc., is blurred as I would expect it to be - I had assumed wet plate required fairly long exposures. But there is one image of a rapid, and another of a blast, where the motion is fairly "frozen." I guess wet plate exposures can, in fact, be fairly short?

As an aside, the most lovely, in my opinion, images in the book were made by two women, Lily E. White and Sarah Hall Ladd. The one flaw in the book is that there is one set of 13 pages missing, and a few duplicated. I'd suggest anyone interested in the history and/or photography of the region request the book on interlibrary loan. Apparently copies were donated to every public library in Oregon.

[paulbarden]

I've currently got a book checked out from the library, "Wild Beauty: Photographs of the Columbia River Gorge, 1867-1957." It is a really nice book. The photography is broken into four parts, the first part devoted exclusively to images by Carleton Watkins, all of which I assume is wet plate. In most of the images, water, or smoke from steam engines, smokestacks, etc., is blurred as I would expect it to be - I had assumed wet plate required fairly long exposures. But there is one image of a rapid, and another of a blast, where the motion is fairly "frozen." I guess wet plate exposures can, in fact, be fairly short?


In very bright sunlight, with a large=aperture lens used wide open - say maybe f3.5 - you can get away with exposures as short as 1 second. Maybe a skilled wet plater, using less well known techniques (like slightly faster collodion and using the "double dip" silver nitrate bath method*) could get much faster emulsions and maybe able to make a plate with speeds like 1/2 or even 1/4 second, but it would have to be very bright light.

*washing the plate in distilled water after the first dip removes byproducts of the sensitization process, which increases the speed of the collodion by about a stop.

[Two23]

Wet plate seems to be about ISO 2 with fresh collodion. Using the Sunny 16 rule we get 1/2s @ f16. Reciprocity brings us to 1/32s @ f4. About the fastest I can shoot is 1/2s. They did use crude shutters back then and I'm assuming 1/30s was about their limit.


Kent in SD

[paulbarden]

Wet plate seems to be about ISO 2 with fresh collodion. Using the Sunny 16 rule we get 1/2s @ f16. Reciprocity brings us to 1/32s @ f4. About the fastest I can shoot is 1/2s. They did use crude shutters back then and I'm assuming 1/30s was about their limit.


Kent in SD

Bear in mind that Watkins was making collodion negatives, which require 2 to 3 times as much exposure compared to a positive on metal or glass.

[Two23]

Bear in mind that Watkins was making collodion negatives, which require 2 to 3 times as much exposure compared to a positive on metal or glass.


That would make a difference.


Kent in SD

[Mark Sawyer]

Keep in mind Watkins used Rapid Rectilinears (maximum aperture f/8) for his smaller plates. He only had one lens for his mammoth camera, a 16-inch Globe lens, which was only sharp between f/36 and f/72.

[h2oman]

Keep in mind Watkins used Rapid Rectilinears (maximum aperture f/8) for his smaller plates. He only had one lens for his mammoth camera, a 16-inch Globe lens, which was only sharp between f/36 and f/72.

How do you know such things? I'm not questioning your answer, just wondering what resources there are out there. I'm kind of diving into Watkins, O'Sullivan, and the other survey photographers.

[Mark Sawyer]

How do you know such things? I'm not questioning your answer, just wondering what resources there are out there. I'm kind of diving into Watkins, O'Sullivan, and the other survey photographers.

I've been following Watkins for decades, and have a special interest in historic lenses, so I've accumulated some notes through the years. Watkins also used a Grubb C Aplanat, (a single doublet), and a Triple Achromat by Dallmeyer. A couple of threads you might find of interest:

https://www.largeformatphotography.info/forum/showthread.php?139981-Carlton-Watkins-Equipmwnt-and-In-General

https://www.largeformatphotography.info/forum/showthread.php?158212-Which-lenses-did-Carleton-Watkins-use-in-1861-for-his-mammoth-plate-camera