Cor
9-May-2013, 08:29
Hi,
I have this very old, but in good shape, dark red B + W glass filter, type 40 E. I cannot find any information about it. I want to use it for IR photography.
By looking through it it is definitely darker than a red (wratten 25 filter) and looks quite similar to my Wratten 70 filter, my standard IR filter. It's not as dark/opaque as a 89b (B + W 77E).
I would really like to know at what wavelength it's transmission is 50 %, but any other info is most welcome too.
Long version:
I have this ultra low weight 4*5 kit consisting of a Gowland Pocket, 90mm Angulon (f6.8), 150 G-Claron and 210 G-Claron for travelling. When shooting Maco IR film I use a Cokin type 70 filter (square, P) in front of the lens, which is a nuisance (I hold it infornt of the lens during an exposure), and it gives rise to unwanted reflections as well.
This small 40E filter might fit the bill: it almost fits the Angulon (1mm too small), it's a little bit too big for the 150 Angulon, so I have to find a step up ring. The 40E lens came with a funny brass ring, in which the 40E (about 39mm ) screws, extending its diameter to about 49 mm, which fits into the 210 G-Claron.
I assume that the ring will not cut off too much of the projected image of the 210 G-Claron lens, since this lens is said to almost fill a 8*10 negative.
Or do I make a mistake here ?
best,
Cor
I have this very old, but in good shape, dark red B + W glass filter, type 40 E. I cannot find any information about it. I want to use it for IR photography.
By looking through it it is definitely darker than a red (wratten 25 filter) and looks quite similar to my Wratten 70 filter, my standard IR filter. It's not as dark/opaque as a 89b (B + W 77E).
I would really like to know at what wavelength it's transmission is 50 %, but any other info is most welcome too.
Long version:
I have this ultra low weight 4*5 kit consisting of a Gowland Pocket, 90mm Angulon (f6.8), 150 G-Claron and 210 G-Claron for travelling. When shooting Maco IR film I use a Cokin type 70 filter (square, P) in front of the lens, which is a nuisance (I hold it infornt of the lens during an exposure), and it gives rise to unwanted reflections as well.
This small 40E filter might fit the bill: it almost fits the Angulon (1mm too small), it's a little bit too big for the 150 Angulon, so I have to find a step up ring. The 40E lens came with a funny brass ring, in which the 40E (about 39mm ) screws, extending its diameter to about 49 mm, which fits into the 210 G-Claron.
I assume that the ring will not cut off too much of the projected image of the 210 G-Claron lens, since this lens is said to almost fill a 8*10 negative.
Or do I make a mistake here ?
best,
Cor