Arrow mark on lens barrel

[Simon Benton]

This is probably a question I should know the answer to but I have a Petzval lens with an arrow marking and don't know if the arrow should point to the film or the sky? Hopefully someone can point me in the right direction pun intended. Thank you!

[DannL-USA]

I believe that to be a projection lens. Arrow to the light source. You might wait to have someone else verify that true or false.

[domaz]

You might be able to verify by seeing which element is the cemented pair and which is the air-spaced pair. In a projection lens I believe the elements are reversed from a taking lens.. but I don't remember which is which.

[maltfalc]

You might be able to verify by seeing which element is the cemented pair and which is the air-spaced pair. In a projection lens I believe the elements are reversed from a taking lens.. but I don't remember which is which.

there's no reason to reverse the elements in a projection lens.

[jnantz]

probably an identifying scar or a "cattle brand" like writing your name in sharpie in your skivvies or shirt collar when you went to summer camp.

[DannL-USA]

https://www.ebay.com/itm/166421209787

Here's a Pathe with a similar arrow. (fourth picture).
There's a couple of these on eBay today.

[djdister]

Just trying to be observant here - wouldn't the focal length markings be on the end that sticks out of the projector? Also, the end that the arrow points to appears more worn like its been rubbed from being inserted into a sleeve multiple times...

[jnantz]

Just trying to be observant here - wouldn't the focal length markings be on the end that sticks out of the projector? Also, the end that the arrow points to appears more worn like its been rubbed from being inserted into a sleeve multiple times...

I don't know man, I hear at the turn of the 1900's there were a lot of parties with Edwardian Freemason chaps dressed like Mr Peanut showing off their projection lenses, and it was an easy way to detect which one was yours in the pile after smoking a giant cigar, consuming too much brandy and a raucous game of Ferris Wheel Goat ( Ferris Wheel Coaster Goat ) was played on the noob ... almost as much fun as that Trick Bottom Chair ..

[Simon Benton]

Thanks for all the comments! I managed to unscrew the lens elements and now have the cemented doublet at the front and the airspaced elements at the rear. Casts a lovely image with swirlies and covers around 6 x 6 cms so will use on old Bronica SLR.
Thanks for the help.