From: hamm@weejordy.physics.mun.ca (Craig Hamm)
Subject: DX code info:
Organization: Ocean Sciences Centre
Date: Tue, 8 Sep 1992 22:21:18 GMT

In article <1VsDaB1w161w@nstar.rn.com> steveh@nstar.rn.com (Steve Heininger) writes:
>A few weeks ago there was a post containing the technical details about the 
>coding on film canisters.  I should have hardcopied the post but didn't and 
>now find that I need the information.  If anyone has this post could they
 

Here is the key to the DX code: 

		 ________________________
		|                        |
		|                        |_
		|________________________| |
		|12 |11 |10 | 9 | 8 | 7  | |
		|___|___|___|___|___|____|_|
		| 6 | 5 | 4 | 3 | 2 | 1  |
		|___|___|___|___|___|____|	
		|________________________|

ISO		SENSING AREA
SPEED		2	3	4	5	6

  25		-	-	-	X	-
  32		-	-	-	-	X
  40		-	-	-	X	X
  50		X	-	-	X	-
  64		X	-	-	-	X
  80		X	-	-	X	X
 100		-	X	-	X	-
 125		-	X	-	-	X
 160		-	X	-	X	X
 200		X	X	-	X	-
 250		X	X	-	-	X
 320		X	X	-	X	X
 400		-	-	X	X	-
 500		-	-	X	-	X
 640		-	-	X	X	X
 800		X	-	X	X	-
1000		X	-	X	-	X
1250		X	-	X	X	X
1600		-	X	X	X	-
2000		-	X	X	-	X
2500		-	X	X	X	X
3200		X	X	X	X	-
4000		X	X	X	-	X
5000		X	X	X	X	X


NUMBER OF	SENSING AREA
EXPOSURES	8	9	10

(non-std)	-	-	-
   12		X	-	-
   20		-	X	-
   24		X	X	-
   36		-	-	X
   48		X	-	X
   60		-	X	X
   72		X	X	X


EXPOSURE	SENSING AREA
 RANGE		11	12

+- 1/2		-	-
+- 1		X	-
+2, -1		-	X
+3, -1		X	X

NOTE:  An "X" under the sensing area indicates an electrically
conductive area.  A "-" under the sensing area indicates an
electrically insulated area.  Areas 1 and 7 are always conductive.

Use electrical tape to insulate; use copper or aluminum tape to
make conductive areas.  Remember that cameras might depend on
conductivity between conductive areas because the cassette is made
of metal.

________________________________________________________________

There is another way to approach the task:  I recently rolled some bulk
Vericolor 400 and Ilford XP-1 for a friend with a Point & Shoot camera.
There were 27 short rolls of each film and I didn't feel like putting
foil tape on each cassette.  Since each of these films is ISO 400 and
my friend wasn't going to shoot anything else in the near future, I 
decided to recode the CAMERA.  Examining the cavity where the cassette
goes, I found contacts for areas 1, 2, 3 and 4 only.  Of course, area
1 is always conductive, leaving only three areas for ISO setting.  
Looking at the ISO table, we see that this camera is not able to
differentiate between the ISO's between multiples of 25; (ISO 80, 64 
and 50 will all set to 50, ISO 160, 125 and 100 will all set to 100,
etc).  This is probably just fine for negative film, but may not be
accurate enough for slide film (ISO 64 would be set to 50).  

Anyway, I put conductive copper tape (sticky side up) between areas
1 and 4, insulating areas 2 and 3, and then covering over that with
insulating tape.  I told my friend that as long as he was shooting my
bulk loaded cassettes, everything would be OK.  If he wanted to shoot
something else, then remove the tapes.  The first couple of rolls look
OK, so I guess this approach works.  Those of you with non-override
cameras might consider this approach.

A couple of years ago, one of the photo magazines had an article on
ways to fool your P&S camera.  Does anyone remember the magazine and the
month?

PS:  I'm glad my camera is pre-DX.

Ron Speirs, Evans & Sutherland Computer Corp., Salt Lake City, UT
	
	Sorry Ron, I kept this way back.  The above is all Ron Speir's!!!!
  ---------
    Craig Hamm, Memorial University, | I don't think the letters which appear
    Newfoundland                     | on your letters page are genuine. I 
    DoD #1500,                       | think you just make them all up.  In
    81 Maxim 650                     | fact you probably made this one up
    ------------                     | too.  -J. Clark, Rotherham (Viz comics)

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