Re: Waterhouse Stop Fabrication Alternatives in 2019?
I bought some thin brass at the hobby store.. took some tin snips and a file and created some crude-o stops that work just fine in like 15 minutes.. I only needed two f-stops though - f8 and F16.. so.. my big innovation was to make one long unit with a stop on either end
Re: Waterhouse Stop Fabrication Alternatives in 2019?
I've made waterhouse stops using old darkslides for my Imagon. My library has a very easy to use CNC machine, a Carvey. It's free to use. I bet many of you have something similar nearby. Look for makerspaces. I bring my own bits, which are cheap and easy to buy.
Re: Waterhouse Stop Fabrication Alternatives in 2019?
A tip. If having someone fabricate stops using one of your existing stops, contact-print your stop for him. I use Cyanotype paper rinsed in water to clean it up.
Determining the appropriate diameter for apertures is pretty easy. It is not necessary to make conventional ƒ metrics, just holes proportionally larger/smaller. You can determine effective stop values. I can give the ratios.
Re: Waterhouse Stop Fabrication Alternatives in 2019?
3 Attachment(s)
Re: Waterhouse Stop Fabrication Alternatives in 2019?
Quote:
Originally Posted by
goamules
Good to know there is someone available, thanks for joining. Would you be able to make flanges accurately? We all need those, and the threads are all over the map and 100 years of different types.
Garrett,
I can, I've made many flanges, brass and aluminum mostly.
Attachment 193947
Attachment 193948
Re: Waterhouse Stop Fabrication Alternatives in 2019?
Correct me if I'm wrong here, but quick and dirty with minimal measuring for an f stop the math would be: focal length/diameter of hole = f/stop. So a 12" lens needs a 1.5" hole to get f/8.
When purchasing a lens, isn't the focal length known most of the time?
Re: Waterhouse Stop Fabrication Alternatives in 2019?
Correct me if I'm wrong here, but quick and dirty with minimal measuring for an f stop the math would be: focal length/diameter of hole = f/stop. So a 12" lens needs a 1.5" hole to get f/8.
When purchasing a lens, isn't the focal length known most of the time? So the only measuring left would be the stop dimensions?
Re: Waterhouse Stop Fabrication Alternatives in 2019?
Quote:
Originally Posted by
unimach
Correct me if I'm wrong here, but quick and dirty with minimal measuring for an f stop the math would be: focal length/diameter of hole = f/stop. So a 12" lens needs a 1.5" hole to get f/8.
When purchasing a lens, isn't the focal length known most of the time? So the only measuring left would be the stop dimensions?
The f/number is focal length/hole diameter as measured through the front elements of the lens.
Re: Waterhouse Stop Fabrication Alternatives in 2019?
Quote:
Originally Posted by
unimach
.............When purchasing a lens, isn't the focal length known most of the time? So the only measuring left would be the stop dimensions?
Apart from some process lenses, the use of Waterhouse stops was unusual after 1900, as multi-bladed irises became reliable.
19th century makers were very slow to engrave lens data on their lenses. Even WHStops often had just a number rather than the effective F value. Early lenses, especialy Petzvals, had no information about focal lengths. A list of lens sizes and their respective was often listed in advertising, but this is not always helpful if the size is not is indicated on the lens!
Often we are reduced to measuring the diameter of the front lens (a popular extra data in manufacturers' lists!) or carrying out an approach to getting a measure of the real Focal length.
Re: Waterhouse Stop Fabrication Alternatives in 2019?
Quote:
Originally Posted by
goamules
Good to know there is someone available, thanks for joining. Would you be able to make flanges accurately? We all need those, and the threads are all over the map and 100 years of different types.
what Garret said!
I often make "an alternative solution" when the flange/ring is absent. But need a "real" new flange sometimes.