It seems that, the 8th of inch difference doesn’t effect the edge to edge coverage of the plate, however my 1st test, using using the alpha 4×5 model it did basically work except that my dark slide apparently isn’t as opaque as it visually appears, however for this model that’s ok in that the final materials haven’t been decided on, for the next model, I have to make some adjustments, and will likely use an original dark slid, at least until I can replace it with the correct materials.
as labeled this is an alpha version I’m still resolving some of the details.
I spend most of Tuesday the 3rd of August 2016 working out details of the universal plate holder. and cutting out via a laser cutter a working model to to test some different idea’s.
At present time the working model is made of a couple different types of plastics – partly due to the thicknesses of the said plastic as well as availability, I’m presently undecided as to what type of plastic will be used if not a combination. My principle reason for using a plastic is based upon assemble, general durability and resistance against the silver used in wet-plate photography.
Sadly, one of the biggest issues I’ve run into is a true edge to edge sized image as
traditional with a wet-plate images taken using a specific wet-plate camera. the majority of plate holders were a fixed sized, with corner tabs to support the plate many of those tabs were made from glass or wood, to change size of the plate the photographer would typically use a insert to down size the plate size.
Whereas with the introduction of dry-plate and film the industry stared becoming more standardized, through size of plates, film and camera while increasing the number of shots that could taken via a dry-plate/film holder, this changed how plates and film where held in place, within the holder, it also increased the ability to carry two plates/film per plate holder and later process the plate/film. During this transition from wet-plate to dry-plate/film a number of photographers still used their big camera’s and simply used inserts or a new concept, adjustable plate holders. the insert or adjustable plate holder was soon dropped in exchange for fixed camera sizes in relation to film size. and as roll film quality started increasing the size and weight of the camera decreased.
Today designing, rather than modifying a film holder for a view camera, I’ve encountered the previously described design change from wet-plate edge to edge image to one with boarder, this change is universal to the camera’s rather than being limited to just the film holder. Thus a fixed size modified film holder may not have a boarder, if the holder has been modified to support a plate that is smaller than the said film holder. but if the plate is at the maximum size of the holder, it will always have a boarder of about 8th of an inch. my plate holder are designed to support the true size of the said plate . However based upon the sizing of the camera they will always have a boarder when the maximum sized plate to plate holder is used. this is an unfortunate side effect, that can be used to one’s advantage.
Here’s inside of the back from our 4×5 mid 1920’s Ansco Universal, note the space is not a true edge to edge 4×5 – the standardized film holders with with a spring back were designed to fit a 4×5 sheet of film, but also created a boarder on the film – this boarder offers several advantages and is typically cropped when printing