Literature

A bit more...

The cover from a catalogue and price list dated August 1933 printed in Germany, presumably by Leitz for one of the major UK photographic specialists, Negretti & Zambra, Holborn Viaduct. The cover is carefully designed to allow only a black plate change for different languages.

N&Z216 by dralowid, on Flickr

I remember a Negretti and Zambra shop in Bond Street in the '60s, down towards the bottom.

From the same catalogue the lenses and their prices. Note that although the rigid Summar (the new super lens) is available the collapsible version is yet to arrive.

N&Z215 by dralowid, on Flickr

Other things of interest, a chrome II or III were available for an additional £1.4s.0d and the upgrading of of earlier cameras is also promoted.
 
Interesting how they distinguish between the Elmar and the Hektor 135 mm lenses. I have never understood why they had these two specimens alongside each other in the catalogue ... they seem so similar to my untrained eye.
 
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Here's the other two catalogues needed to start colour photography with the new Leica;

Catalogues-XL.jpg


Both about the same date, the Agfa one mentions the first and then the second version they made.

Regards, David
 
Interesting...do you know why rectilinear focussing was needed for colour photography in 1933? See the bit about the 73 Hektor on the lenses page.

Were they taking an exposure for each colour separation using filters and then combining? A technique I dimly remember being used for pack shots on my first visit to a studio...
 
Dralowid said:
do you know why rectilinear focussing was needed for colour photography in 1933
Click to expand...

For the first Agfacolor system filters were needed with a grid printed on them. These were not usable on lenses with turning lensheads. The filters had to be placed carefully with the grid in the right direction. Therefore the collapsible Summar and the rectilinear Hektor 73mm were created. These lenses had "pips" on them for the orientation of the filters. Only high speed lenses could be used as the filters absorbed a lot of light. I think at least three exposures were made on black and white film, each with a different filter. The three resulting negatives were sandwiched and projected through a similar filter system so a color picture appeared on the screen. Unfortunately I've never seen the set up working. The system died quickly after the invention of Kodachrome in 1936. The set for making these color pictures is nowadays a very expensive collectors item.

Erik.
 
Hi,

I'd love to impress you all by explaining but can't without reading and rephrasing Brian Coe's excellent book 'Colour Photography The first hundred years 1840-1940' - that's not a misprint, btw. ISBN 0 904069 23 0 is the paperback version and change 23 0 to 24 9 for the 'casebound' version; I wonder if that means a slip case?

I think the Dufaycolor was the same system as the first Kodak. I've got some unexposed somewhere with a leaflet wrapped round the film and I'll try and find it.

Regards, David
 
I think we are talking about two different things here...Erik and David are talking about the production of a wet colour print and I seem to have gone off on one (again), talking about producing colour separations for cmyk print (offset litho) in camera...which is a different ball game more suited to 5 x 4 and 10 x 8
 
Hi,

I'm a bit busy at the moment but if you two could keep the row going I might find time to read Coe's book and come back by Sunday, perhaps. ;-)

Glancing quickly at Agfa's catalogue it shows 'Agfacolor Ultrafim' with a mosaic screen in the emulsion and 'Agfacolor' needing a Hektor f/1.9 and a three colour band filter on the lens and later on the projector.

Dufay offered a reversal film Type I and II, type one used without filters and type II described as 'a little more troublesome' but with advantages and a filter was needed. Prices for 35mm 18 exp. 10/=, six refills 51/= and 2/6 processing per film. Also available B&W prints and a 42 page book 'The Dufaycolot Book' for sixpence (by post 8d). Using a x20 I've found a printer's code 7/38 on the accessory book which must be the date.

EDIT; 10/= means 50p, 51/= means £2.55 and sixpence is 2½p and 8d was a fraction over 3p. For our USA friends I'll add that 10/= then was $2 and, luckily, Euros didn't exist.

Regards, David
 
Dralowid said:
A bit more...

The cover from a catalogue and price list dated August 1933 printed in Germany, presumably by Leitz for one of the major UK photographic specialists, Negretti & Zambra, Holborn Viaduct. The cover is carefully designed to allow only a black plate change for different languages.

Click to expand...

This girl seems to be holding my black 1933 III, or something very like it, so thanks for that. Very good memorabilia!
 
Now, finally, I am starting to understand the process a little. Apologies for my slowness and thanks for your patience!

Both Agfa and Dufay processes use separate exposures for which are subsequently combined to produce the colour image. I don't know if this was CMYK or something else. If the kit was three filters maybe there was a fourth unfiltered but screened exposure for black?

Am I right in assuming that by using screened filters at specific angles they are producing a screened image with dots of varying sizes as in litho printing?

It is years since I worked as a designer in publishing but I remember some about screen angles, separations etc etc let alone colour correction!

Michael
 
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Dralowid said:
Am I right in assuming that by using screened filters at specific angles they are producing a screened image with dots of varying sizes as in litho printing?


Michael
Click to expand...

This is what I found on the subject on internet:[SIZE=-1] "Agfa did manufacture a 35mm film in 1933, but this was a Lenticular film, specifically for Leica cameras. The film had minute lenses incorporated into the film base, and transparencies were viewed with a Leitz projector fitted with a three band colour filter. The process was mainly used for cinematography and saw little use in still photography. It was similar to the earliest 'Kodacolor', a 16mm version for home movies made by Kodak in 1928."

Erik.
[/SIZE]
 
Hi,

Now I've got a spare moment and I've started to look at the book by Brian Coe and I think I'll recommend you buy a copy. Absolutely fascinating and shows some prints from Agfa and Dufay. But the earlier stuff is better still. It was a 'Vivex' print btw.

Also in it a picture of the ruled screen up close and a print showing the old-fashioned TV screen effect.

I do hope you all rush out and buy one as I'll never manage to master it all, despite my promise above.

Regards, David
 
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