Didy Filter...

I have a lot if friends who work with hot glass, mostly torch work.

They use didymium glasses so that they can "see" the flame. It's purple glass that cuts out the yellow/orange glare.

I know I can get didymium plates that could hold in front of my camera, but is there an actual didy filter that I can put in my hassleblad? How would such a filter reproduce on a B&W negative?

I'm wanting up photograph a friend while he works pretty soon.

Tiffen color enhancing filters are didymium glass. http://www.tiffen.com/displayproduct.html?tablename=filters&itemnum=62WIDEF1

ChristopherCoy said:

I have a lot if friends who work with hot glass, mostly torch work.

They use didymium glasses so that they can "see" the flame. It's purple glass that cuts out the yellow/orange glare.

I know I can get didymium plates that could hold in front of my camera, but is there an actual didy filter that I can put in my hassleblad? How would such a filter reproduce on a B&W negative?

I'm wanting up photograph a friend while he works pretty soon.

Click to expand...

hey christopher

is there a way to borrow their glasses or a spare pair
and just hold it infront of your camera ?

it might be easier ( and less expensive ! ) then buying
photo grade glass that might be a pspecial order ...

have fuN !
john

Didymium filters are a not-uncommon off-the-shelf item sold by a bunch of manufacturers including Hoya. They are a notch filter, i.e. they filter out a very narrow slice of spectrum; the ones used for glass blowing filter out the sodium emission line from high temperature glass.

You can have the notch at different wavelengths, which means for photographic use you can buy red-enhancing, green-enhancing and blue-enhancing filters. B&H sells a B+W Redhancer, for the Hoyas I think you need to get on eBay.

And this dpreview thread contains probably all the info you need for photographing glass blowing.

Didymium filters used to be popular for filtering out the light from sodium (yellow) street lighting when doing astronomical photography. Not a perfect solution since those lights also used cadmium (a sort of dull red colour) as a starter as they warmed up.