There is already someone working on a line of wet plate lenses
There is already someone working on a line of wet plate lenses
Names, please.Originally Posted by 8x10 user
In any case, historical reproductions should be hand - made. It's a job for an artisan, not a state-of-the - art lens designer. You only need the one set of stones to grind petzvals of any size.
Please do not grind me or family against Petzval glass... Not nice :whistling:
Jody come on. That's insulting. It's also humorous because in my circles I'm considered an "old school" designer. While there's nothing state of the art about any of these lenses, you still need the know-how to make a good lens (and there is an art to good lens design...like anything else). Otherwise anybody could make them. Just push the green button on the software! Right? If you think it's just a matter of copying an old design....where do you start? Is the glass types called out still available? Can you substitute? Which type? How do you calculate the radii? How thin can a lens be? How thick? What are the tolerances? How do you calculate that stuff? And then what are reasonable answers?
In any case, it sounds like the desire for wet plate lenses is being fulfilled.
Newly made large format dry plates available! Look:
https://www.pictoriographica.com
Today I got my order of glass grinding grits from https://gotgrit.com/. He sells glass grinding supplies cheap and in small quantities. It's my second order. At first I bought coarse grits to make GG's. Now I plan some experiments.
Make your own, if you dare.
Tin Can
I did, and it sucked!
“You often feel tired, not because you've done too much, but because you've done too little of what sparks a light in you.”
― Alexander Den Heijer, Nothing You Don't Already Know
I'm not going to make a lens, but I am experimenting with finer grits for GG to see where the 'Satin Snow' quality comes in.
I may try the finest grits and polish on some fungus...nothing to lose with some of these ruined lenses.
Tin Can
I deeply appreciate that.
Over decades I, as many here have shot with progressively corrected lenses. Today there are in the small format lenses designs that may satisfy purely metric oriented photographers but produce truly ugly outcomes that offend the eye because they do not at all create what our human eye-brain perceive.
Gotgrit.com is a great resource for amateur telescope and lens making. It was a big deal in the ATM world when the website was established.
The finest grit will give you a finish like you find on the back of telescope mirrors. To polish it out the rest of the way you'll need to buy pitch and polish, make a pitch lap and polish out the gray. You'll want a harder pitch, like a Gulgoz 74 and 82 mix for the size lens you'll probably work on. Recommend you use cerox as the polish: it won't stain as readily as red rouge although your glass may stain regardless if it's a soft flint...and it's a bit more forgiving for sleeks. I prefer zirconium oxide but I'm not sure if gotgrit supplies that. It has the feel of rouge but polishes like Cerox.
If you don't polish out the surface you'll get horrible scattering and veiling glare.
To maintain a spherical surface you'll want to get the polishing stroke down. If you've ordered from gotgrit before then you may know what I'm talking about. But if not, get a copy of Texereau's How to Make a Telescope. The first half of his book is pure gold....like Adams' books for fabricating an optical surface. Polishing ain't anything like grinding (which is 95% grunt work) and easy to screw up. It's all technique. Luckily you don't have to have any sort of accuracy on your surface. You only need maybe like 2-4 waves of accuracy.
Good luck and holler if you have any questions.
Newly made large format dry plates available! Look:
https://www.pictoriographica.com
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