Xrays and efke Backing Paper Data

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Greg Winterflood
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Joined: Tue Mar 27, 2007 2:11 pm

Xrays and efke Backing Paper Data

Post by Greg Winterflood »

Discussion on other forums indicates that there is a widespread problem with efke R100 127 backing paper data appearing on the developed negative. An initial suggestion was that this was because the backing paper is thin, and that light, getting through the rear red window on some cameras, was the source of the problem. It was recommended that the red window be covered with black tape, and that film advance only be undertaken in subdued light.

However, I have the problem with my Rolleiflex 4x4; which does not have a rear window. Others report it with Yashica 4x4s; and others say it occurs when the film is loaded and unloaded in complete darkness.

Searching for answers, I wondered if x-ray scanning of small parcels of airfreighted film might be causing the problem.

efke R100 127 film does have a tinfoil wrapper; but I doubt it is thick enough to block x-rays.

Could I be on the right track? I have thought of developing an unexposed roll of film by taking it directly from the package into the tank. Would this prove a point?
From the little light I have been able to gather so far, photography was developed by people who, by experimenting in the dark, went against the grain...

Greg Winterflood
Posts: 49
Joined: Tue Mar 27, 2007 2:11 pm

In which he answers his own question....

Post by Greg Winterflood »

Greg Winterflood wrote:Discussion on other forums indicates that there is a widespread problem with efke R100 127 backing paper data appearing on the developed negative. An initial suggestion was that this was because the backing paper is thin, and that light, getting through the rear red window on some cameras, was the source of the problem. It was recommended that the red window be covered with black tape, and that film advance only be undertaken in subdued light.

However, I have the problem with my Rolleiflex 4x4; which does not have a rear window. Others report it with Yashica 4x4s; and others say it occurs when the film is loaded and unloaded in complete darkness.
Even before my first 4 rolls of efke R100 127 film arrived I had read warnings to cover the red rear window of my Baby Brownie to avoid fogging of the film with Backing Paper Data [BPD]

It was explained that the Backing Paper on efke R100 roll film was thinner than the backing paper used 50 years ago, and light, transmitted through the red window, would lead to BPD being fogged onto the negative.

That is a MYTH

I began to question the received wisdom when I experienced the BPD fogging phenomenon with my Baby Rollei. The Baby Rollei does not have a rear red window yet I had BPD markings over nearly every negative.

My investigations have revealed that the problem lies with the Backing Paper Ink. It is being transferred to the emulsion before the film ever sees the light of day. This is known to occur with old or moist film; but should not occur with new film.

You can verify this for youself, for this is a Myth Busting experiment that you can safely do at home.

I sacrificed a roll of film by taking it from its foil wrapper and exposing it directly to daylight. After a few minutes I could see faint BPD images on the emulsion. Their position matched the position of the marks on the underlying backing paper over which the film had previously been very tightly spooled.

In an attempt to enhance the images I developed the film in Rodinal 1:50 for 15 minutes.

I ended up with black on black images; but with the aid of sunlight and the curved surface of my letter box I have managed to capture BPD impressions on the emulsion side of the film, using my Samsung Digital.

The images can be seen here

http://www.flickr.com/photos/94097267@N00/

Another reason I am convinced that the Thin Backing Paper story is a MYTH, is that one can hold a piece of Backing Paper up to an incandescent light globe, and the filament of the globe will not shine through, even with the backing paper held on the surface of the globe. The Backing Paper is light proof.

The ink-emulsion interface is the problem.

MYTH BUSTED
From the little light I have been able to gather so far, photography was developed by people who, by experimenting in the dark, went against the grain...

Digitaltruth
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Post by Digitaltruth »

Hi Greg,

I will contact the distributor and manufacturer and will report back on this forum once I have further information.
Digitaltruth Photo
https://www.digitaltruth.com

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