Film-Tech Forum ARCHIVE: Emulsion side

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Posted by Antonio Marcheselli (Member # 373) on 02-04-2002, 06:17 AM:

Hi everyone

I'm teaching to an apprentice the job. Does exist movies with the emulsion side on the opposite side? In other words: are there movies that has to be projected with the emulsion side at the lenses side?
Bye
Antonio

Posted by Leo Enticknap (Member # 534) on 02-04-2002, 07:43 AM:

The only non-standard prints I've come across in terms of the emulsion orientation are 16mm prints designed for back-projection. This was at the Museum of the Moving Image in London, when we were trying to get a 1940s 'video' jukebox called a Panoram, which used 16mm film on a small endless loop platter, to work. The original film that came in it (acetate propionate) was so shrunk and brittle it wouldn't run at all, and we had to get dupes made in a lab. Because it was intended for back projection the running orientation was reversed, i.e. writing in the picture would appear as mirror-writing if you were looking at it from the emulsion side. My boss told me that this sort of element was called a 'DIN print' (DIN = Deutsche Industrie Nummer, i.e. a German engineering standard) but that he did not know why. Presumably this means either that back projection was used a lot in Germany or (and I think this is more likely) that early 16mm German sound projectors had the optical head on the other side of the film from Western ones, thus requiring the film to be printed the other way round.

I've done a bit of research on the use of safety film by the Nazis for distributing propaganda material to non-theatrical venues, and virtually every German technical standard I've come across was in some way different from (and surprise surprise, incompatible with) its SMPE counterpart.

But I've never come across any 'DIN print' elements since, and would be intrigued to know if this was ever done on 35mm and/or in the west.

Posted by Bernard Tonks (Member # 809) on 02-04-2002, 07:51 AM:

I can tell you Antonio that I have witnessed a 35mm print that had to be projected with the emulsion side towards the lens. It was 50 years ago when I was a trainee projectionist at an Odeon cinema, it was a black & white 2nd feature. I assume it was an experiment and I do remember the bold instructions on the film cans. I have never seen a print like this again since. BTW the print was on safety stock, highly inflamable nitrate film had just been discontinued.

There was of course Cinecolor which had the emulsion on both sides, I projected many of these colour prints and I also remember the cyan soundtrack that long ago.

Perhaps John Pytlak could kindly tell us how a print would be struck for a re-issue today from an old Cinecolor original negative(s). I have often wondered.

Posted by Richard Fowler (Member # 893) on 02-04-2002, 09:08 AM:

Their is reversal print film available that is normally used for "dirty dupes" off of a workprint. I have seen these in several occaisions in foriegn locations where the local distributor has bought a print ( legal or illegal ) for his market. The contrast is usually higher and the color off....the last one I saw was a Van Dam movie, two years ago in Latin America, that only played in video in the USA.....with good reason.

Richard Fowler
TVP-Theatre & Video Products Inc. www.tvpmiami.com

Posted by Leo Enticknap (Member # 534) on 02-04-2002, 09:55 AM:

The only Cinecolor rereleases I've projected were done by making b/w panchromatic separation masters and then a combined dye-coupler negative from those. I don't know how the separations were produced, but my guess is that an optical printer was refocused for each of the two layers, or a contact printer was used and the film was simply turned round and printed back the other way (with the raw stock being reversed too).

Presumably you'd have to make preservation dupes of the 20s two-strip Technicolor prints (the ones in which two strips were cemented together) the same way.

Posted by Dave Macaulay (Member # 813) on 02-04-2002, 10:01 AM:

I've never come across a 35 release print like that. It would affect the sound focus for one thing.
Imax 3D comes with assorted emulsion orientatiopns. There are a few camera types, one has one "eye" shooting through a mirror which puts the release print emulsion out. The other 2 camera setup is normal on both eyes, and the single camera (with 2 film paths and lenses) also has emulsions on the normal side. If the movie has used a mix of cameras in production you may get mixed emulsion orientation on one reel of the pair. This makes opticals a bit difficult...
The odd effect of this with early Imax 3D films - which used only the mirror camera setup - is that the film running "emulsion to the lens" fades much slower than the other because the base filters out a lot the ultraviolet light that fades the colour dyes.

Posted by John Pytlak (Member # 331) on 02-04-2002, 10:18 AM:

Standard SMPTE 194 specifies for 35mm release prints that "The photographic emulsion shall be on the side of the film which faces away from the projector lens." Looking at the print on a viewer, it will always "read" correctly with the emulsion facing you. If you have a 35mm print with the opposite orientation, it is likely a reversal "dirty dupe", possibly a pirated copy. Or a lab mistake was made, and the negative was printed through the base.

For 35mm, the system evolved as a camera negative contact printed onto a print film. In the camera, the negative film emulsion faces the lens. When a contact print is made of that negative, the image orientation is "flipped", so the emulsion side of a print faces AWAY from the lens of the projector (towards the lamp).

For 16mm, the system started out with the the same piece of film (reversal camera original) being projected, so 16mm prints made from an internegative often had the emulsion facing the lens, although direct prints from a camera original could have the emulsion facing away from the lens. Some 16mm projectors have easy adjustment of optical sound focus to accomodate the fact that 16mm prints could be oriented either way.

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: 716-477-5325 Cell: 716-781-4036 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion

Posted by Leo Enticknap (Member # 534) on 02-04-2002, 10:55 AM:

Of course, it's so easy to forget that when 16mm was launched in 1923 it was purely as an amateur format (i.e. reversal stocks only) and that no-one envisaged its use for any professional applications (i.e. requiring a negative-positive system of duplication), hence the lack of a clear standard on emulsion orientation.

Posted by Antonio Marcheselli (Member # 373) on 02-04-2002, 02:18 PM:

Thanks to everyone.

So I can tell to my apprentice that:

1. On "regular" commercial films the emulsion will faces the lamp
2. There are however the possibility that emultion will faces the lens, but just with old movies, 16mm movies, pirated movies or for a lab mistake.

Right?

Bye
Antonio

Posted by John Schulien (Member # 215) on 02-04-2002, 03:04 PM:

I can think of two more possibilities ...

A camera-original film shot on reversal stock will project properly with the emulsion oriented toward the lens.

A contact-dupe made on reversal stock from a release print will have the emulsion reversed as well. I understand that this is/was sometimes done legitimately in order to make a one-off copy of a film without the expense of making a new negative and soundtrack. I would imagine that the sound quality on such a dupe would be pretty bad ...

Posted by John Pytlak (Member # 331) on 02-04-2002, 03:53 PM:

Antonio -

Yes. Normal 35mm release print orientation is that the emulsion faces the lamp. This is standard SMPTE 194. Anything else is non-standard and very uncommon.

16mm reversal camera originals have the emulsion facing the lens, as do 16mm prints made from an internegative. 16mm prints may also have emulsion facing the lamp if they are contact prints of the original, or from a Negative --> IP --> DN --> Print system. You may need to refocus picture and optical sound between prints if the orientation changes.

Posted by Phil Hill (Member # 371) on 02-04-2002, 06:37 PM:

Typically large format 3D films, both 870 and 1570, have one eye with the emulsion toward the lamp and the other eye toward the lens.

I've shot several thousand miles of 16mm and 35mm film and the emulsion orientation all depends on how many generations are involved before the final print is released. John is absolutely right about 35mm emulsion being specified as faced away from the lens. I know that seems weird since one would think that the image would be sharper/clearer to resolve directly on the emulsion without going through the base. Oh, Well.... I guess some(?) are smarter than the rest of us.....

>>> Phil

Posted by Antonio Marcheselli (Member # 373) on 02-04-2002, 06:48 PM:

Thanks to everyone.

Antonio

Posted by John Pytlak (Member # 331) on 02-04-2002, 09:55 PM:

Phil said: "John is absolutely right about 35mm emulsion being specified as faced away from the lens. I know that seems weird since one would think that the image would be sharper/clearer to resolve directly on the emulsion without going through the base."

As I noted, camera original negative always has the emulsion towards the lens of the camera. Can't be otherwise with color negative film because of the anti-halation black rem-jet coating on the unprocessed film. Make a contact print, and the orientation is flipped. Likewise go through the normal duplicating system of Neg --> IP --> DN --> Print, and the orientation is emulsion towards the lamp.

The polyester base used for KODAK VISION Color Print Film is really quite transparent and has high optical quality, so light scatter and distortion are minimal, even when the image has to go through the base.

Posted by Phil Hill (Member # 371) on 02-04-2002, 10:01 PM:

Yeah John.... I agree..what's your point? It's what I said...

WTF?

>>> Phil

Posted by Frank Angel (Member # 248) on 02-05-2002, 02:15 AM:

John,

The Eastman 25B (the finest 16mm projectors every made, IMHO) happens to be one of those few 16mm projectors that has a sound focusing design -- smooth as butter too. It's a shame EK stopped stocking parts for it. The intermittent couping which has a rubber center to reduce vibration eventually looses its resiliancy and the intermittent and shutter go out of timing -- shutter ghost gallore, to echo another topic. I wound up fashioning our own replacement out of truck tires.

Posted by John Pytlak (Member # 331) on 02-05-2002, 07:56 AM:

Phil --- I was just answering your rhetorical question regarding whether having the image go through the base degraded image quality.

Posted by Gordon McLeod (Member # 33) on 02-05-2002, 09:56 AM:

Frank I always felt the Prevost/Zies Favorite 16B was the best 16mm followed closly by the hortson