Difference between safelights Kodak 13 and Wratten 13??

Is there a big difference between both of these filters? they are both supposed to be used with RA-4 paper in darkroom but the first states to be Amber and Wratten to be Green!!

Thanks evreybody!!

Is there a big difference between both of these filters? they are both supposed to be used with RA-4 paper in darkroom but the first states to be Amber and Wratten to be Green!!

Thanks evreybody!!

 

There is no Wratten 13 in the Kodak filter handbook. Did you perhaps write the wrong number?

 

Fwiw, the Wratten numbers jump from #12 to # 15, both of which are yellow.

There is no Wratten 13 in the Kodak filter handbook. Did you perhaps write the wrong number?

 

Fwiw, the Wratten numbers jump from #12 to # 15, both of which are yellow.

 

 

Thank you.

Can anyone tell me the difference between thses two??? Or is it that the first one is intended only to be used as filter and dnot as a safelight? Some people in the web mentions using Wratten 13 as a safelight filter, or is it pure kodak 13 safelight they are using?.

 

Thanks everybody!!

Edited December 11, 2019 by oskar_romeo

The Wratten 13 green filter is claimed to only have a factor of 2, while I can hardly see through the #13 safelight filter I have for my Kodak 'beehive' safelight. Therefore I'm pretty confident that they're not the same. The only commonality being that they're both vaguely green in colour, but they're vastly different in density.

The Kodak Wratten 13 is a yellow-green optical filter. This filter, also known as the X2 was used when Type C black & white film to grant improved monochromatic rendering when Type C Panchromatic black & white film was exposed under tungsten illumination. This film has increased sensitivity to the red region of the spectrum.

 

When printing color negative films by contact or enlarger, a panchromatic black & white paper is the paper of choice. The Kodak # 13 Ambler safelight, illuminated with a 15 watt bulb can be used, with cares as an aid to inspection developing.

The Kodak Wratten 13 is a yellow-green optical filter. This filter, also known as the X2 was used when Type C black & white film to grant improved monochromatic rendering when Type C Panchromatic black & white film was exposed under tungsten illumination. This film has increased sensitivity to the red region of the spectrum.

 

When printing color negative films by contact or enlarger, a panchromatic black & white paper is the paper of choice. The Kodak # 13 Ambler safelight, illuminated with a 15 watt bulb can be used, with cares as an aid to inspection developing.

 

Thank you for sharing your experince, Mr Marcus!!

I might as well use the #15 Safelight to developing sheets by inspection doing reversal process with RA-4 paper.

It might be usefeull in the B&W first development that should take no more than a 1.5 minutes, maybe less if I switch it on some 15 seconds after starting to develop.

Thanks, Sir

 

romeo

The rest of the story:

 

Frederick Charles Luther Wratten (English inventor 1840 – 1926) Owned one of the earliest photographic supply businesses, along with his partner Wainwright. They made filters and glass plates. Wratten invented “noodling” a method used today to make gelatin film emulsions. Wratten made gelatin filters and maintained a catalog of recipes that specified their color. Essentially, dye was added to gelatin. The gelatin was poured into standing water. The gelatin floated on the water. When the gelatin jelled, a rectangular wire frame captured the floating gelatin, scooped up from underneath. The results were an optically flat gelatin filter called a gel. The firm of Wratten and Wainwright was purchased by Eastman Kodak in 1912. One of their engineers, C. Kenneth Mees moved to Rochester. He was instrumental in the invention of Kodachrome. Kodak retained the catalog numbers of the filters sold as Wratten filters.

Fuji, at least, references a "Wratten Safelight Filter No. 13":

 

https://www.fujifilm.eu/fileadmin/product_migration/generic/files/files/Fujicolor_Crystal_Archive_Paper_08.pdf

 

Kodak documentation I checked (only a few) mentions "Kodak Safelight" filter, but without Wratten.

 

Do all the currently known Wratten filter numbers trace back to before Kodak bought Wratten in 1912?