Various A36 red filters… more details and info needed

[MrRom92]

Does anyone know anything about the various Leica red A36 filters? I have been having some difficulty finding details about them online. I would particularly like to know their filter factor or how many stops to compensate exposure by when using them. It might be cool to know which wavelengths they pass through as well, if this info is available somewhere. There were 3 of them, they are:

• FEDOO - filter is marked Rh, for “rot hell” or light red.

• FIKYB - filter is marked Rm, for “rot mittel” or medium red

• FEOOG - filter is marked Rd, for “rot dunkel” or dark red

I believe the Rh filter is more for general purpose photography, and the darker 2 filters are more intended for infrared photography, but this is just my understanding. I still don’t really know much else about them beyond this. I would’ve assumed these are more well documented than they seem to be since they aren’t exactly obscure Leica accessories, but clearly I am mistaken on that… Any help would be greatly appreciated!

 

[peterm1]

I think from memory, that all can be used for ordinary photography - depending on the strength of the effect sought. For example a light red filter will produce a light to medium grey sky and a dark red one will produce a near black sky. I have at least two Leitz red filters (plus yellow, orange apple green and dark green) but have not used them since giving up on film about a decade ago. (I keep them through inertia initially and I now keep them now just in case I buy a Monochrom). I may still own (I certainly used to own) a dark Leitz IR filter and from memory this is almost totally impermeable, if not completely impermeable to visible light.

 

[MrRom92]

I think from memory, that all can be used for ordinary photography - depending on the strength of the effect sought. For example a light red filter will produce a light to medium grey sky and a dark red one will produce a near black sky. I have at least two Leitz red filters (plus yellow, orange apple green and dark green) but have not used them since giving up on film about a decade ago. (I keep them through inertia initially and I now keep them now just in case I buy a Monochrom). I may still own (I certainly used to own) a dark Leitz IR filter and from memory this is almost totally impermeable, if not completely impermeable to visible light.

Thank you for this, do you happen to know the filter factors used for any of them or do you rely on the metering on your newer cameras?

 

[Dralowid]

The filter factors were printed in most of the old Leica guides from Focal Press etc. Also in 'The Leica Way', if I find my copy I'll have a look but it has been a while since I last saw it.

 

[pete hogan]

For the light red Fedoo Rh filter the Focal Press 1953 “LEICA GUIDE” lists a filter factor of 20 for panchromatic film in daylight. No values are listed for the medium and dark red filters for panchromatic film, only for infra-red film.

Theo Kisselbach’s 1953 “POCKET LEICA BOOK” lists a corresponding range of filter factor of 10-25 for the light red Rh with panchromatic film. It notes medium and dark red filter factors for use with infra-red film only.

Morgan’s 1962 and 1955 “LEICA MANUAL” don’t list filter factors for Leica red filters.

I have a Fedoo Rh filter and add 4 stops with Tri-X.

 

[Dralowid]

Here goes, hope it helps. Factors for light and medium red. Shame the redesigned site hasn't made uploading things any easier...but maybe that is intentional?

filter factors578 by dralowid, on Flickr

 

[MrRom92]

For the light red Fedoo Rh filter the Focal Press 1953 “LEICA GUIDE” lists a filter factor of 20 for panchromatic film in daylight. No values are listed for the medium and dark red filters for panchromatic film, only for infra-red film.

Theo Kisselbach’s 1953 “POCKET LEICA BOOK” lists a corresponding range of filter factor of 10-25 for the light red Rh with panchromatic film. It notes medium and dark red filter factors for use with infra-red film only.

Morgan’s 1962 and 1955 “LEICA MANUAL” don’t list filter factors for Leica red filters.

I have a Fedoo Rh filter and add 4 stops with Tri-X.

Here goes, hope it helps. Factors for light and medium red. Shame the redesigned site hasn't made uploading things any easier...but maybe that is intentional?

filter factors578 by dralowid, on Flickr

Thank you both a ton for these!! I may have to make an effort to locate some of those books/guides…

it is interesting to me that there is a discrepancy between the factor for the light red filter, though only by about 1 stop. I have the feeling it is closer to 4 stops and with modern emulsions, close enough often does the trick anyhow… I have one of those light meter apps on my phone, I will try to use that with a grey card and the filters to get a reading as well.

 

[Dralowid]

There were an lot of titles published that covered the Leica range in detail. Unlike the internet many of them were accurate.

 

[oftheherd]

There were an lot of titles published that covered the Leica range in detail. Unlike the internet many of them were accurate.

Always a problem on the internet.

Do you have any idea how differences in films from the 40's, 50s,and 60s might affect the filter factors use these days?

 

[pete hogan]

And besides film response changing over the years, we may wonder about the filter’s characteristics aging too. My Fedoo Rh is a red-box model, so it’s probably 80 years old.

 

[MrRom92]

And besides film response changing over the years, we may wonder about the filter’s characteristics aging too. My Fedoo Rh is a red-box model, so it’s probably 80 years old.

I do wonder specifically when the packaging styles changed over. My Leitz NY FIGAM is in the red box however my Wetzlar FEDOO is in the clear case. It would be one way to somewhat narrow down the date of manufacture for any given filter.

Personally I haven’t seen any these filters age poorly. Except the UVa (FIOLA) seems there are many slightly yellowed examples of this one. But I also read the early ones were intentionally yellowed, even when new. Don’t know how much truth there is to that.

 

[pete hogan]

More filter info comes from the Hove 1996 “Leica Accessory Guide 2nd Edition” but nothing on packaging, pp108-111.

Medium red No. 2 for infra-red was the first red in 1933. Light red No. 1 and Dark red No. 3 were in 1935.

Hove says Leitz New York produced its own engraved line of filters “from about 1945”.

Rogliatti’s 1977 “Leica The First Fifty Years 2nd Edition” p 149 says FEDOO light red in 1936, FIKYB medium red in 1933, and FEOOG dark red in 1936.

 

[Dralowid]

The glass in medieval churches lasts quite well even in sunlight so I wouldn't worry too much about a little filter that spends most of its life in a box.