Vintage Filter?

[pgk]

I recently bought an 1880s lens which came with a yellow filter fitted into the hood. Ingeniously, it uses 3 short lengths of spring steel screwed onto the rim to hold it in place. Not sure of date (later than 1880s I guess as its a contrast filter?) or rarity of such items but thought it interesting enough to post. Any comments on date, etc.?

[Two23]

I'm just going purely by guess here, but I didn't think filters appeared until after the invention of pan film. Wouldn't a yellow filter cancel out a lot of the UV that the ortho emulsion of the 1880s relied on?


Kent in SD

[pgk]

My thought too, but that said it was clearly designed to fit inside a hood so works perfectly on vintage lenses without filter threads. I'm just intrigued by its date and what it might have been intended to fit.