Grahame N's Web Pages

THE CELLULOID IMAGE


FILM DATA SHEETS

An amalgam of all the data sheets published in previous editions of The Celluloid Image plus new ones

Data Sheet 9: Cine film (acetate only) film cement (June2013)
Data Sheet 8: Cine camera Depth of Field tables (June2010)
Data Sheet 7: Movie film size specifications (April 2010)
Data Sheet 6 : Cine lens mount specicifcations (June 2007)
Data Sheet 5: Top 100 films in the UK (December 2006)
Data Sheet 4: Useful strobe discs (Spring 2006)
Data Sheet 3: Film speed ratings comparison table
Data Sheet 2: Picture width table for various lenses and film gauges
Data Sheet 1: Movie print stock date codes


 

FILM DATA SHEET 9 - June 2013 
Formulae for movie.cine Film Cement (acetate base only)
Years ago movie films both amateur and professional were joined, 'spliced' using a special solvent
known as 'film cement'. It is important to note it is not a glue or adhesive, but a solvent that 'melts'
the two ends of a film together.
These days most film stock is on a polyester type base and has to be joined using special adhesive
tape (no NOT sellotape!) - like PEC tape etc (normally available on my sales lists).
At the moment supplies of commercial film cement are readily available (see my sales list for 'Hama')
However the time may come when a little 'do-it-yourself' may be necessary.  The following formulae
come from various reference books - the chemicals may now be difficult to source legally and some
are highly volatile and flammable - mix in fresh air with no naked flames or cigarettes nearby!!
Formula 1.  This should join both acetate & early nitrate film bases:
Acetone 8 parts
Ether 10 parts
Acetic acid (glacial) 1 part 

Formula 2.

Acetone 15 grams
Acetic acid 15 grams

Formula 3. (from a 1950s 'Amateur Cine World' magazine):

Acetone 80 ml
Chloroform 16 ml
Acetic acid (glacial) 8 ml

Formula 4 (from a French cine book)

Ethyl acetate 200 ml
Acetone 200 ml
Amyl acetate 3 ml
Acetic acid 60 ml

Once the film cement is made, dissolve a short piece of film base (clear film) in the mixture
before pouring it into small glass bottles. Plastic based containers are no use as the cement
will dissolve the plastic! I sourced 12ml nail varnish remover bottles when I sold 'home made'
cement some years ago - these also had a small brush fitted to the screw top. - gln June 2013

 


FILM DATA SHEET 8 - June 2010 
Depth of Field Tables

 

For those still using cine cameras with focussing lenses, it is nice to know
just how much of the filmed image will be in focus when the lens is focussed
on a particular distance.  This range of acceptable focus is known as 'Depth
of Focus'.
The range of acceptable focus increases as the lens aperture is 'stopped down'
so that where a large depth of focus is required, one tries to use a small
lens aperture setting like f8 or f11, whereas if it is desired to just keep 
the subject in sharp focus (head close-ups) for example, then a larger lens
aperture is required - f4 etc.
Short focus (wide-angle) lenses have a larger depth of focus, whilst long
focus (telephoto) lenses have a small depth of focus.  Depth of focus is
greater at long distances, but much less at short distances (close-ups).
One could write a whole book on the subject of depth of focus - one only
needs to look at decent vintage films to see the careful use of this
technique when shots were planned.  These days with automatic digital
cameras, sadly there is far less thought to scene presentation to the 
viewer.
Anyhow., back to the tables - the first are for 20mm lenses, hence most
useful for standard lenses on 9.5mm and 16mm cine cameras.
This first table is for 20mm focal length lenses and is in feet & inches
Top row shows the lens focussing setting, then the nearest & furthest
distances are listed for each lens aperture. H.D. is the hyper-focal
distance - if the lens focus is set at this, everything from half this
distance to infinity will be acceptably sharp.
Aperture H.D. 3' (ft) 4' (ft) 5' (ft) 7' (ft) 10'(ft) 13'(ft) 15'(ft) 20'(ft) 25'(ft) Inf
f1.4 50' 2' 11"
3' 3"
3' 7"
4' 8"
4' 4"
5' 10"
5'10"
8' 9"
7' 9"
14' 0"
9' 6"
20' 6"
11' 6"
28' 9"
12' 8"
35' 6"
14' 6"
88' 0"
35' 0"
inf.
f2.8 21' 2' 10"
3' 5"
3' 6"
4' 8"
4' 3"
6' 2"
5' 6"
9' 6"
7' 3"
16' 3"
8' 8"
26' 0"
9' 6"
35' 6"
10' 1"
87' 0"
11' 0"
inf.
21' 6"
inf.
f4 15' 2' 5"
3' 8"
3' 3"
5' 4"
4' 10"
14' 6"
4' 10"
14' 6"
5' 9"
38' 0"
6' 5"
340'
7' 0"
inf.
8' 0"
inf.
8' 7"
inf.
13' 6"
inf.
f5.6 10' 6" 2' 3"
4' 6"
2' 9"
7' 3"
3' 2"
10' 3"
4' 0"
32' 0"
4' 9"
inf.
5' 4"
inf.
5' 8"
inf.
6' 3"
inf.
6' 10"
inf.
9' 6"
inf.
f8 7' 6" 2' 0"
6' 0"
2' 4"
12' 0"
2' 9"
30' 0"
3' 6"
inf.
3' 9"
inf.
4' 1"
inf.
4' 4"
inf.
4' 8"
inf.
4' 10"
inf.
7' 0"
inf.

 

 

   

FILM DATA SHEET 7 - April 2010 (updated Oct 2011) 
Movie Film Size Specifications
There seems to be much interest recently about actual specifications of the
various cine film sizes - most are available as UK British Standards or the
equivalent overseas.  My main interest is the 9.5mm film gauge and Pathé in
France obviously produced specifications, but oddly there doesn't seem to have
been any 'official' standards set in the UK, and those in France were only
registered in the 1960s when 9.5mm was commercially being abandoned!
9.5mm - below are a few of the published 9.5mm film specifications
 
The original Pathescope 9.5mm specifications printed in UK Pathéscope sales
catalogues from 1928 through to the early 1930s. The 9.5mm (silent) image
is compared to the 16mm image. (Picture size 8.5mm x 6.5mm; pitch 7.54mm)

 

 
This shows the specifications for 9.5mm sound films when they were launched
in the UK in 1938/1939 - (from a UK Pathescope film catalogue)
The sound image was not quite 4x3 on UK optical sound prints as Pathescope
generally tried to fill the frame and hence lost some of the image edges.
After 1944 French Pathé printed a proper 4x3 picture on their 9.5mm optical
sound prints, so the picture height did not extend to the perforations.
Incidentally picture to sound separation is around 26 frames (same as 16mm)
When 9.5mm magnetic sound was introduced in the early 1950s, the magnetic
track occupied the same position as the optical sound track.  Nowadays with
the use of converted 16mm machines for 9.5mm use, the magnetic sound track
tends to be on the oposite side to the optical track - as per 16mm.  The
few printed 9.5mm magnetic sound films issued (by myself - 'Presto Films')
were produced to the 16mm standard with the track on the opposite side to
optical sound track position. Picture to sound separation was 28 frames.
For normal amateur films the magnetic track will be on the film base side
so can be either paste or stripe.  Magnetic track width is around 0.8mm 
to 1.0mm - the same as Super 8mm. For printed films which are contact
printed, the magnetic track has to be on the emulsion side of the film, 
so can only be paste stripe. Because the linear speed of 9.5mm film is
virtually twice that of 8mm, good sound quality can be obtained.
 
 
This shows the 9.5mm film size compared to std 8mm & 16mm. Pathescope
tended to slightly exagerate the potential image width - camera gates
were normally about 8.5mm wide, with projector gates slightly smaller.
(Illustration from UK Pathescope 36 page sales brochure of around 1954)
 
The above comes from "How To Use 9.5mm" a Focal Press book by Dennis Neale
originally published in 1951 and reprinted in 1955.  Sadly there is a
'typo' for the 9.5mm pitch - it should be 7.54mm not 7.45mm!  This error
has caused widespread confusion both in the UK and France where the book
was also published (in French of course!)  
Incidentally the 16mm pitch gives 40 frames to the foot - 9.5mm actually
is about 40.5 frames per foot.
The French 1960s AFNOR 9.5mm film standards can be purchased at:-
www.boutique.afnor.org search under "film cinematographique 9mm5"
or just check out NF S24-201 / NF S24-203 / NF S26-201
The late Alan Lott wrote an article accompanied by a simplified
illustration in an "Amateur Cine Enthusiast" magazine - when I
find my copy I'll add it here (or maybe you can help ....!)

FILM DATA SHEET 6 - June 2007
The specifications for the various cine lens mounts may be useful for experimenters
           ---------------------------------------------------------------- 
                      "C" mount             Pathe               "D" mount   
                     9.5mm & 16mm           9.5mm                std 8mm    
           ---------------------------------------------------------------- 
           Thread:      1 inch           5/8th inch             5/8th inch  
                                       32 T.P.I. USSF         32 T.P.I. USSF
           Register:  0.690 inch         1.000 inch             0.484 inch  
           ----------------------------------------------------------------  
Notes:
 Register: Distance from the flange surface on which the lens screws to the film surface.
           (must be accurate to +/- 0.0005 inch for accurate focus)
 T.P.I.    Threads per inch.
 Pathe:    The Pathe screw mount is used on Pathé and Pathéscope cameras using the 'H' type
           film charger, hence it is often referred to as the 'H' mount.  Cameras include
           the 'H'; 'National 11'; 'Pat' and 'Prince' models.  The 'H' mount lenses were
           usually made by Berthiot in France - 'Cinor' in f2.5 & f1.9 20mm fixed focus
           and f1.9 20mm focussing standard lenses plus a f3.5 50mm telephoto.  In the UK
           a similar range were made by National Optical Company (Dallmeyer?).  The 1959
           'Prince' was originally supplied with a 23mm f2.8 Colotar standard lens, later
           bankrupt stock models were fitted with a f2.8 23mm? Kaydon lens made in Japan
           and later with a decent f3.5 20mm French made Som Berthiot Cinor D lens.

                           FILM DATA SHEET 5 - Autumn 2006                                     
                       THE TOP 100 FILMS IN THE UK
                       ---------------------------
                     (by estimated total admissions)  

     1  Gone With the Wind      Drama    USA 1940  35million
     2  The Sound of Music      Musical  USA 1965  30m
     3  Snow White & the Seven Dwarfs    USA 1938  28m
     4  Star Wars 1V: A New Hope Drama   USA 1978  20.78m
     5  Spring In Park Lane     Comedy    GB 1948  20.5m
     6  The Best Years of Our Lives DramaUSA 1947  20.4m
     7  The Jungle Book         Animated USA 1968  19.8m
     8  Titanic                 Drama    USA 1998  18.91m
     9  The Wicked Lady         Drama     GB 1946  18.4m
    10  The Seventh Veil        Drama     GB 1945  17.9m

    11  Harry Potter & Philosopher's Stone   2001  17.56m 
    12  Grease                  Musical  USA 1978  17.2m
    13  South Pacific           Musical  USA 1958  16.5m
    14  Jaws                    Drama    USA 1976  16.2m
    15  Jurassic Park           Drama    USA 1993  16.17m
    16  Lord of the Rings-Fellowship of the Ring 2001 15.98m
    17  The Courtneys Of Curzon Street    GB 1947  15.9m
    18  Thunderball             Drama     GB 1966  15.6m
    19  Lord of the Rings -Return of the King 2003 15.22m
    20  The Bells Of St Mary's  Drama    USA 1946  15.2m

    21  The Ten Commandments    Drama    USA 1957  15m
    22  Lord of the Rings - The Two Towers   2002  14.4m
    23  The Full Monty          Comedy    GB 1997  14.19m
    24  Harry Potter & Chamber of SecretsUSA 2002  14.18m
    25  Mary Poppins            Musical  USA 1964  14m
    26  The Third Man           Drama     GB 1949  14m
    27  Goldfinger              Drama     GB 1964  13.9m
    28  Star Wars 1 - The Phantom Menace USA 1999  13.59m 
    29  The Blue Lamp           Drama     GB 1950  13.3m
    30  Ben Hur                 Drama    USA 1959  13.2m

    31  ET The Extra-Terrestrial   Drama USA 1983  13.13m   
    32  The Greatest Show on Earth Drama USA 1952  13m
    33  The Bridge On the River Kwai      GB 1957  12.6m
    34  The Spy Who Loved Me    Drama    USA 1977  12.46m
    35  The Great Caruso        Musical  USA 1951  12.4m
    36  Doctor In the House     Comedy    GB 1954  12.2m
    37  Toy Story 2             Animated USA 2000  12.18m
    38  Random Harvest          Drama    USA 1943  12m
    39  The Towering Inferno    Drama    USA 1975  11.78m
    40  Fanny By Gaslight       Drama     GB 1944  11.7m 

    41  The Jolson Story        Musical  USA 1947  11.6m
    42  Picadilly Incident      Drama     GB 1946  11.5m
    43  The Guns of Navarone    Drama    USA 1961  11.4m
    44  Doctor Zhivago          Drama    USA 1967  11.2m
    45  The Sting               Drama    USA 1974  11.08m
    46  The Godfather           Drama    USA 1972  11m
    47  Independence Day        Drama    USA 1986  10.79m
    48  Carry On Nurse          Comedy    GB 1959  10.4m
    49  I Live In Grosvenor Square Drama  GB 1945  10.3m
    50  Mrs Miniver             Drama     GB 1942  10.2m

    51  Superman the Movie      Drama    USA 1979  10.19m
    52  Bridget Jones's Diary   Comedy    GB 2001  10.15m
    53  Monsters, Inc.          Comedy   USA 2002   9.93m
    54  A Clockwork Orange      Drama    USA 1972   9.9m
    55  Crocodile Dundee        Comedy   AUS 1987   9.8m
    56  Finding Nemo            Animated USA 2003   9.79m
    57  Men In Black            Comedy   USA 1997   9.73m
    58  For Whom the Bell Tolls Drama    USA 1944   9.7m
    59  One Flew Over the Cuckoo's Nest  USA 1976   9.65m
    60  High Society            Musical  USA 1956   9.6m

    61  Moonraker               Drama     GB 1979   9.41m
    62  I'm All Right Jack      Comedy    GB 1959   9.41m
    63  49th Parallel           Drama    USA 1941   9.3m
    64  Lost Horizon            Drama    USA 1937   9.2m
    65  Stars Wars 11: Attack of the Clones  2002   9.16m
    66  One Hundred and One Dalmations   USA 1961   9.1m
    67  The Empire Strikes Back Drama    USA 1980   9.09m
    68  Saturday Night Fever    Musical  USA 1978   9.02m
    69  Live and Let Die        Drama     GB 1973   9.0m
    70  The Great Dictator      Comedy   USA 1941   9.0m

    71  The Big Country         Western  USA 1958   9.0m
    72  Bambi                   Animated USA 1942   9.0m
    73  Rebecca                 Drama    USA 1940   8.9m
    74  Oliver!                 Musical   GB 1968   8.9m
    75  Four Weddings and a Funeral Com   GB 1994   8.81m  
    76  Ghost                   Comedy   USA 1990   8.78m
    77  Love Actually           Comedy    GB 2003   8.76m
    78  Reach For the Sky       Drama     GB 1956   8.7m
    79  My Fair Lady            Musical  USA 1965   8.6m
    80  Die Another Day         Drama     GB 2002   8.58m

    81  Close Encounters of the Third Kind US 1978  8.54m
    82  The Citadel             Drama     GB 1939   8.5m
    83  Pinocchio               Animated USA 1940   8.5m
    84  A Bug's Life            Animated USA 1999   8.41m
    85  Lawrence of Arabia      Drama     GB 1962   8.4m
    86  The Dambusters          Drama     GB 1955   8.4m
    87  Stars Wars Vl:Return of the Jedi USA 1983   8.35m
    88  Mr Deeds Goes To Town   Comedy   USA 1936   8.3m
    89  Swiss Family Robinson   Drama    USA 1960   8.3m
    90  You Only Live Twice     Drama     GB 1967   8.3m

    91  The Exorcist            Horror   USA 1974   8.3m
    92  The King and I          Musical  USA 1956   8.2m
    93  Chicken Run             Animated USA 2000   8.12m
    94  The Lion King           Animated USA 1994   8.08m
    95  Notting Hill            Comedy    GB 1999   8.05m
    96  The Matrix Reloaded     Drama    USA 2003   7.96m
    97  The Private Life of Henry Vlll    GB 1934   7.9m
    98  Cinderella              Animated USA 1951   7.9m
    99  Gladiator               Drama    USA 2000   7.8m
   100  The Magnifient Seven    Drama    USA 1960   7.7million


gln/20.12.2004

FILM DATA SHEET 4 - Spring 2006

USEFUL STROBE DISCS

Because of the way that our household electricuty is generated - as 'Alternating Current' - A.C. - the actual voltage level follows a sort of sine wave that has a frequency of either 50 Hz (cycles per second) in Europe or 60 Hz (cycles per second) in the USA. This means that lights actually flicker at 100 or 120 times a second. The most pronounced flicker is obtained from fluorescent type lamps but the usual filament lamps normally flicker enough to use this phenomena to our advantage in the film world.

If we shine a light onto a revolving object, the flicker will have the effect of causing the rotation to be 'snapped' only at the peaks of the electricity supply flicker rate. So for example if something is revolving at 100 times a second - if we light it with a mains electric light it will appear to be stationary. If we make up a disc with alternate black and white segments with the correct number of segments corresponding to the required speed of rotation it will appear to be stationary when rotating at that speed.


9.5mm Pathé Baby strobe

This first strobe disc dates back to an early 1934 issue of "Amateur Cine World magazine. The motor drive pulley of the Pathé Baby 9.5mm projector turns once for 7 frames of film. (Early 9.5mm movies were intended to be shot and projected at 14 frames per second). So for 14 fps it must turn twice per second. For a strobe to be stationary at this speed it must have 50 segments. For a strobe on this machine to be stationary at 16fps it will need 50 x 14/16 = 43.75 segments. The outer ring on this disc has 50 segments and will be stationary when the Pathé Baby 9.5mm projector is running at exactly 14fps. The inner ring has 44 segments and will be stationary at 16fps. The disc can be printed onto stiff paper, cut out and glued to the Pathé Baby main drive pulley.


Strobe for 8 tooth sprocket wheel

This strobe was originally designed for the 9.5mm Pathéscope 'Son' optical sound projector - it is small enough to be fitted to the 8 tooth sprocket that acts as feed and take-up sprocket on this machine and the 'Gem' and 'Mk 9 / 16' silent versions of this machine. In this case the segments are designed to indicate speeds of 16fps and 24fps. The strobe disc will work on any cine projector with an 8 tooth sprocket. I used this on my various 'Son' projectors in my youth to try to set the governor to an accurate 24fps.


Finally if you live in a country which has 60 Hz mains electricity then I'm afraid these strobes will not work. Sadly it will necessary to design something similar using the theory mentioned at the start of this article.


FILM DATA SHEET 3

FILM SPEED RATINGS COMPARISON TABLE

Correct exposure depends on two things: the amount of light that reaches the film via the camera lens when the shutter is open; and the sensitivity or speed of the filmstock. Whilst the light reaching the film is controlled by the size of the hole letting light through the lens (the aperture) and the time that the shutter is open (varied with the filming speed of the camera); the sensitivity of the film stock is normally decided for the user when the filmstock is purchased.

The amount of light reaching the film can be varied by opening or closing the aperture of the lens - f8 will provide twice as much light to the film as f11 for example. Generally when filming at the 'standard' silent speed of 16 or 18 frames per second, a cine camera shutter gives an exposure of about 1/32nd or 1/40th of a second. Some cine cameras are fitted with variable shutters which allow for this to be adjusted over a wide range (usually to a complete closure).

Some filstocks are more sensitive (or 'faster') than others. For example for normal outdoor filming a 25 to 50 asa film stock will be fine in sunny conditions, maybe needing an exposure of f8 say. However in very dull conditions the lens aperture with this film stock might need to be around f2 - not too practical. Hence a more sensitive (or 'faster') film stock would chosen, like 100asa for example. Filming indoors would need an even more sensitive stock - say 400asa to avoid the need for lots of extra lighting.

Today most film stock is advertised with it's sensitivity indicated in ASA (American Standards Association) notation. With this rating system the speed number is doubled when the sensitivity of the film stock is doubled - so that a film rated at 20 asa is twice as sensitive as one rated at 10asa. It follows from this that if a film stock rated at 10asa needed an exposure of f8 then a film stock rated at 20asa would only need an exposure of f11.

Film stocks originating in Europe used to be rated in the DIN notation (Deutsche Industrie Norm / German Industrial Standard) and in the UK a BS Log. (British Standard) notation sometimes turns up in magazines. These film speed notations are logarithmic, the film speed (sensitivity) being doubled when the speed rating number goes up by three. So DIN 18 is twice as fast as DIN 15.

With the Weston exposure meter being considered the standard exposure for many years, the Weston ratings were often quoted - this is ambiguous as the Weston rating became the same as ASA from the Weston model 111 onwards.

Finally it is always best to check indicated exposure settings for a particular film stock using the same exposure meter and camera etc. to see if any variation from the indicated exposure gives improved results.


ASA (& Weston 111/1V etc)   200  160  125  100  80   64   50   40   32   25   20   16   12   10
Weston Master early models  160  125  100   80  64   50   40   32   25   20   16   12   10    8
BS (log.)                    34   33   32   31  30   29   28   27   26   25   24   23   22   21 
DIN                          24   23   22   21  20   19   18   17   16   15   14   13   12   11
Scheiner                     35   34   33   32   31  30   29   28   27   26   25   24   23   22

(A figure in any column represents a film sensitivity of one third faster than that in the next column to the right)


FILM DATA SHEET 2

PICTURE WIDTH TABLE FOR VARIOUS LENSES AND FILM GAUGES

All measurements are in feet (') and inches ("). Lens focal length comparisons are 1" = 25mm; 2" = 50mm etc.
The figures for 9.5mm refer to silent films - 9.5mm sound films have a rather square format as the sound track uses part of the picture area. The picture width for 9.5mm sound films will be perhaps 80% of the width quoted for the silent films.
Remember a sharp bright smaller picture is far better than a larger soft and dull picture!
Always try to show films in a properly darkened room.


FILM DATA SHEET 1

MOVIE PRINT STOCK DATE CODES

(kindly provided by the late Warton Parfitt)

Original 35mm and 16mm movie print stock from the major manufacturers carries a date code along the edge of the film. Although 9.5mm stock came from Kodak/Pathe 35mm stock, the edges were removed when the triple 9.5mm prints were slit, hence losing the original date codes. Later 9.5mm printed films from Walton etc. were printed on 16mm print stock and again the date codes were lost once the edges were trimmed off to make the 9.5mm print.

The data below shows when the film stock was manufactured, and for Kodak stock, the location of the factory. White printing refers to information about the negative stock; black printing about the positive print stock.

For example: The black printing reading left to right on a print of "The Producers" is " ++ ". The chart below tells us the print was struck in 1968, which is indeed when the film was released. Naturally the filmstock date is not always the date of the film - it may be a re-release print printed many years later or a laboratory may have been using older print stock which had been fridge stored etc.

For Fuji professional filmstock there is a 4 digit code on the perforations. The first two numbers are the year the filmstock was manufactured. For example: " 83JM " is filmstock manufactured in 1983.


If you have any film data you would like included or corrected please contact the editor
Grahame L. Newnham, 22 Warren Place, Calmore, Southampton, SO40 2SD, UK
email: cel @ pathefilm.freeserve.co.uk (no spaces in actual address)


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First published March 2004 ........ Last updated: 08 June 2013 ........ cel11.htm .......... ©MM1X-G.L. Newnham