Editing DX encoding

{{Short description|Standard marking on film cartridges}}
{{Use dmy dates|date=June 2019|cs1-dates=y}}
[[File:Kodak DX Logo.png|thumb|DX Encoding Logo]]
[[Image:Dx135can.jpg|frame|right|135 Film Cartridge with ''DX barcode'' (top) and ''DX CAS'' code. The CAS code shows this is (top row) ISO 125 film, (bottom row) 24 exposures, +3/−1 f-stop exposure tolerance.  The DX barcode reads 017563, showing [[DX number]] 109-12, 24 exposures.]]
'''DX''' ('''D'''igital inde'''X''') encoding is a standard for marking [[135 film|35&nbsp;mm]] and [[Advanced Photo System|APS]] photographic film and film cartridges, originally introduced by [[Kodak]] in 1983. It includes multiple markings, which are a [[latent image]] [[barcode]] on the bottom edge of the film, below the sprocket holes, a conductive pattern on the cartridge used by automatic cameras, and a barcode on the cartridge read by photo-finishing machines.

The DX encoding system was incorporated into [[American National Standards Institute|ANSI]] PH1.14, which provided standards for 135 film magazines for still picture cameras and was superseded by [[I3A|NAPM]] IT1.14 in 1994; it is now part of [[International Organization for Standardization|ISO]] standard 1007, whose latest revision was issued in 2000.

== History ==
[[File:Kodak 400 color film DX code.jpg|left|thumb|Codes on Kodak ISO 400 color negative film]]
In order to simplify the handling of 35&nbsp;mm film in 135 format cartridges, Kodak introduced the DX encoding method on 3 January 1983.<ref name="Kodak_1983_Press1"/><ref name="Kodak_1983_Press2"/> In contrast to the [[film speed]] encoding method developed by [[Fuji (company)|Fuji]] in 1977,<ref name="Fuji_Patent_4024557"/> which used electrical contacts for film speed detection on 135 format cartridges,<ref name="AP_1977_Fuji"/> Kodak's DX encoding system immediately met success in the marketplace.

The first DX encoded film to be released was the [[color print film]] [[Kodacolor (still photography)#Kodacolor VR 1000|Kodacolor VR&nbsp;1000]] in March 1983.

The first [[point-and-shoot camera]]s to use DX encoding to automatically set film speed were released in 1984, including the [[Pentax]] Super Sport 35&nbsp;/ PC 35AF-M<ref name="Pentax_PC35AF-M"/> and Minolta AF-E&nbsp;/ Freedom II.<ref name="Minolta_AF-E"/> The first [[single-lens reflex camera]]s to take advantage of DX encoding were released in 1985, including the [[Konica Autoreflex|Konica TC-X]] SLR (1985),<ref name="konfiles-TCX">{{cite web |url=http://www.konicafiles.com/slr-bodies/-konica-tc-x-1985/ |website=konicafiles.com |title=Konica TC-X (1985–1988) |access-date=7 November 2020}}</ref> Pentax A3 / A3000,<ref name="Pentax_A3000"/> [[Minolta 7000]]<ref name="Minolta_7000AF"/> (February 1985) and [[Minolta 9000|9000]] (September 1985), and the [[Nikon F-301]] / [[Nikon N2000|N2000]].

''DX-iX'' (data exchange - information exchange) is an expanded DX encoding system introduced in 1996 which was released as part of the [[Advanced Photo System]] (APS), which use a different cartridge and film size, also known as IX240 film. APS film and cameras were marketed with numerous brand names, most including an "ix" to emphasize the information exchange aspect, including Advantix (Kodak) and Nexia (Fujifilm).

{{anchor|Barcode System}}In 1998, [[Fujifilm]] introduced a film identification system for [[120 film|120]] and [[220 film|220 format]] [[roll film]] called ''Barcode System'' (with logo "|||B"). The [[barcode]] encoding the film format and length as well as the film speed and type is located on the sticker between the emulsion carrying film and the backing paper.<ref name="Paul_2008_Fuji-Barcode"/><ref name="Fujifilm_5845869"/><ref name="Fujifilm_6050489"/><ref name="Fujifilm_6208812"/><ref name="Fujifilm_6052538"/> This 13-bit barcode<ref name="Paul_2008_Fuji-Barcode"/><ref name="Fujifilm_5845869"/><ref name="Fujifilm_6050489"/><ref name="Fujifilm_6208812"/><ref name="Fujifilm_6052538"/> is optically scanned by newer [[medium format]] cameras like the Fujifilm GA645i Professional, GA645Wi Professional, GA645Zi Professional, GX645AF Professional, [[Fujifilm GX680III Professional|GX680III Professional]], [[Fujifilm GX680IIIS Professional|GX680IIIS Professional]], [[Hasselblad H1]], [[Hasselblad H2|H2]], [[Hasselblad H2F|H2F]] and [[Hasselblad H3D|H3D]] Model&nbsp;I with HM&nbsp;16-32 as well as by the [[Contax 645&nbsp;AF]].<ref name="Paul_2008_Fuji-Barcode"/>

==Implementation==
===DX cartridge barcode===
[[File:Agfaphoto APX 400 (new emulsion) 135 film cartridge 04.jpg|thumb|right|upright|Agfa APX 400, cartridge number 017712]]
Next to the film exit lip is an [[Interleaved 2 of 5]] [[barcode]] and a printed number. The six digits represent the I3A assigned [[DX number]] (middle four digits), the number of exposures (last digit) and a proprietary manufacturer's code (first digit). The DX number identifies the manufacturer, film type, and by inference, the necessary developing process type. This is used by automatic photo-finishing machines to correctly process the exposed film.<ref name=":0" />

===DX film edge barcode===
[[Image:Dx-film-edge-barcode.jpg|thumb|left|DX film edge barcode; data track decodes to [[DX number]] 47-1 ([[Agfa-Gevaert|Agfa]] [[Agfa Perutz|Perutz Primera 200]]), frame 22A]]
Below the sprockets under each frame of 135 film is the DX film edge barcode. The barcode is invisible until the film has been developed. It is optically imprinted as a latent image during manufacturing. The barcode is used by photo finishers to identify each frame for printing. It consists of two parallel linear barcodes, one for a synchronizing clock called the "clock track", and the other encoding film data such as type, manufacturer and frame number, called the "data track".<ref name=":0" />  The barcode nearest the film edge (away from the sprocket holes) contains the data track.  The data track sequence repeats every half frame, beginning with six start bits, followed by seven bits of DX Number Part 1, one unassigned bit, four bits of DX Number Part 2, a seven-bit frame/half-frame number, one unassigned bit, one parity bit, and finishes with four stop bits.<ref>{{Cite journal|last1=Gschwind|first1=Rudolf|last2=Zbinden|first2=Erwin|last3=Trumpy|first3=Giorgio|last4=Delaney|first4=John|date=2017|title=Color negatives at the demise of silver halides|url=https://doi.org/10.5167/uzh-142330|journal=ICOM-CC 18th Triennial Conference Preprints, Copenhagen, 4–8 September 2017|volume=|pages=188–191|doi=10.5167/uzh-142330 |via=[[University of Zurich]]}}</ref>  The seven-bit frame/half-frame number is called the "DXN" number (different than the [[DX number|"DX Number Part 1" and "DX Number Part 2"]]), and is an extension on the original DX edge code, patented by Eastman Kodak in 1990.<ref name=":0">{{cite patent|country=US|number=4965628|title=Photographic film with latent image multi-field bar code and eye-readable symbols|status=patent|pubdate=1990-10-23|gdate=1990-10-23|inventor1-last=Olliver|inventor2-last=Johnson|inventor3-last=Patton|inventor1-first=Richard|inventor2-first=Cortlandt|inventor3-first=David |assign=Eastman Kodak Company}}</ref><ref>{{cite patent|country=EP|number=0838718B1|title=Method of printing frame numbers from DX-coded photographic film not having frame number codes|status=|pubdate=|gdate=|invent1=|inventor1-first=}}</ref>

Some image processing software utilized by [[Film scanner|film scanners]] allow selection of film manufacturer and type to provide automatic color correction.  Interpreting the DX film edge barcode may provide this information, permitting accurate color correction to be applied.

===DX Camera Auto Sensing===
[[File:Codage DX.jpg|thumb|right|upright=1.5|DX CAS code positions; this film is rated at ISO 400/27°, has a 24-exposure length, and an exposure tolerance of ±1 stops.
<ul>
<li>1: Ground</li>
<li>2–6: Film speed</li>
<li>7: Ground</li>
<li>8–10: Film length</li>
<li>11–12: Exposure latitude</li>
</ul>]]
The outside of film cartridges are marked with a DX Camera Auto Sensing (CAS) code readable by many cameras. Cameras can then automatically determine the [[film speed]], number of exposures and exposure tolerance. 

With 135 film cartridges, the DX Camera Auto Sensing code uses a 2×6 grid of rectangular contact areas on the side of the metal cartridge surface; these areas are either conductive (bare metal) or non-conductive (painted). The left-most area of both rows (with the spool post on the left) are common (ground) and are thus always bare metal. Electrical contacts in the camera read the bit pattern. Diagramatically (with spool post to the left):

{| class="wikitable"
|-
| bgcolor="#7fff7f" | G
| bgcolor="#ff7f7f" | S1
| bgcolor="#ff7f7f" | S2
| bgcolor="#ff7f7f" | S3
| bgcolor="#ff7f7f" | S4
| bgcolor="#ff7f7f" | S5
|-
| bgcolor="#7fff7f" | G
| bgcolor="#ffff7f" | L1
| bgcolor="#ffff7f" | L2
| bgcolor="#ffff7f" | L3
| bgcolor="#7fffff" | T1
| bgcolor="#7fffff" | T2
|}

In this scheme:
* "G" are the two common-ground contacts
* "Sx" are the film speed contacts
* "Lx" are the film length contacts
* "Tx" are the exposure tolerance contacts

Most cameras read the film speed only, which is in the first row. Some cameras aimed at the consumer market only read enough bits in the first row to distinguish the most common film speeds. For example, 100, 200, 400, and 800 can be distinguished by reading only S1, S2, and ground.

====Film speed====
The five bits after the ground contact in the top row can be encoded to a maximum of 32 different film speeds, but only the 24 speeds from ISO 25/15° to 5000/38°, inclusive, spaced in intervals of {{frac|3}} step, are used.

The film speed codes are in binary order if the first three bits (S1, S2, S3) are considered to identify a trio of film speeds and the last two bits (S4 and S5) are considered an adjustment of +0, +{{frac|3}}, or +{{frac|2|3}} stops within that trio. For example, ISO speed 25/15° is encoded as 00010, while 32/16° is 00001 and 40/17° is 00011. These share a common encoding of 000xx for the first three bits, differing only in the last two bits, so 000xx designates the trio of speeds (25-32-40). Similarly, the next group of three speeds are encoded 10010 (50/18°), 10001 (64/19°), and 10011 (80/20°); it is clear from examination these all (ISO 50-64-80) share the same 100xx encoding for the first three bits. By comparison to the preceding set of three speeds, the encoding for 25/15° (00010) and 50/18° (10010) have the same xxx10 encoding for the last two bits; likewise, 32/16° (00001) and 64/19° (10001) share the xxx01 encoding, which indicates +{{frac|3}} stop compared to the xxx10 encoding, and 40/17° (00011) and 80/20° (10011) share the xxx11 encoding, which indicates +{{frac|2|3}} stop compared to the xxx10 encoding.

====Film length====
In the second row, the first three bits represent eight possible film lengths, although in practice only 12, 20, 24 and 36 exposures are encoded.

====Exposure tolerance====
The remaining two bits of the second row give four ranges of exposure tolerance, or latitude.

The complete encoding scheme is illustrated in the truth table below using letters and color.
* "G" is ground.
* "T" means the contact is connected to ground.
* "F" means the contact is disconnected from ground.

<div>
{| class="wikitable" style="text-align:center;font-size:90%;"
|+Standard film speed encoding
! rowspan=2 | [[Film speed]]<br/>(ISO)
! colspan=6 | 1st row DX contacts
| style="font-size:15%;background:#448;" rowspan=10 | &nbsp;
! rowspan=2 | [[Film speed]]<br/>(ISO)
! colspan=6 | 1st row DX contacts
| style="font-size:15%;background:#448;" rowspan=10 | &nbsp;
! rowspan=2 | [[Film speed]]<br/>(ISO)
! colspan=6 | 1st row DX contacts
|-
| style="background:#7f7;" | G
| style="background:#f77;" | S1 || style="background:#f77;" | S2 || style="background:#f77;" | S3
| style="background:#f77;" | S4 || style="background:#f77;" | S5
| style="background:#7f7;" | G
| style="background:#f77;" | S1 || style="background:#f77;" | S2 || style="background:#f77;" | S3
| style="background:#f77;" | S4 || style="background:#f77;" | S5
| style="background:#7f7;" | G
| style="background:#f77;" | S1 || style="background:#f77;" | S2 || style="background:#f77;" | S3
| style="background:#f77;" | S4 || style="background:#f77;" | S5
|-
! 25/15°
| style="background:#7f7;" | G
| style="background:#000;color:#fff;" | F || style="background:#000;color:#fff;" | F || style="background:#000;color:#fff;" | F
| style="background:#fff;color:#000;" | T || style="background:#000;color:#fff;" | F

! 32/16°
| style="background:#7f7;" | G
| style="background:#000;color:#fff;" | F || style="background:#000;color:#fff;" | F || style="background:#000;color:#fff;" | F
| style="background:#000;color:#fff;" | F || style="background:#fff;color:#000;" | T

! 40/17°
| style="background:#7f7;" | G
| style="background:#000;color:#fff;" | F || style="background:#000;color:#fff;" | F || style="background:#000;color:#fff;" | F
| style="background:#fff;color:#000;" | T || style="background:#fff;color:#000;" | T

|-
! 50/18°
| style="background:#7f7;" | G
| style="background:#fff;color:#000;" | T || style="background:#000;color:#fff;" | F || style="background:#000;color:#fff;" | F
| style="background:#fff;color:#000;" | T || style="background:#000;color:#fff;" | F

! 64/19°
| style="background:#7f7;" | G
| style="background:#fff;color:#000;" | T  || style="background:#000;color:#fff;" | F || style="background:#000;color:#fff;" | F
| style="background:#000;color:#fff;" | F || style="background:#fff;color:#000;" | T

! 80/20°
| style="background:#7f7;" | G
| style="background:#fff;color:#000;" | T || style="background:#000;color:#fff;" | F || style="background:#000;color:#fff;" | F
| style="background:#fff;color:#000;" | T || style="background:#fff;color:#000;" | T

|-
! 100/21°
| style="background:#7f7;" | G
| style="background:#000;color:#fff;" | F || style="background:#fff;color:#000;" | T || style="background:#000;color:#fff;" | F
| style="background:#fff;color:#000;" | T || style="background:#000;color:#fff;" | F

! 125/22°
| style="background:#7f7;" | G
| style="background:#000;color:#fff;" | F || style="background:#fff;color:#000;" | T || style="background:#000;color:#fff;" | F
| style="background:#000;color:#fff;" | F || style="background:#fff;color:#000;" | T

! 160/23°
| style="background:#7f7;" | G
| style="background:#000;color:#fff;" | F || style="background:#fff;color:#000;" | T || style="background:#000;color:#fff;" | F
| style="background:#fff;color:#000;" | T || style="background:#fff;color:#000;" | T

|-
! 200/24°
| style="background:#7f7;" | G
| style="background:#fff;color:#000;" | T || style="background:#fff;color:#000;" | T || style="background:#000;color:#fff;" | F
| style="background:#fff;color:#000;" | T || style="background:#000;color:#fff;" | F

! 250/25°
| style="background:#7f7;" | G
| style="background:#fff;color:#000;" | T || style="background:#fff;color:#000;" | T || style="background:#000;color:#fff;" | F
| style="background:#000;color:#fff;" | F || style="background:#fff;color:#000;" | T

! 320/26°
| style="background:#7f7;" | G
| style="background:#fff;color:#000;" | T || style="background:#fff;color:#000;" | T || style="background:#000;color:#fff;" | F
| style="background:#fff;color:#000;" | T || style="background:#fff;color:#000;" | T

|-
! 400/27°
| style="background:#7f7;" | G
| style="background:#000;color:#fff;" | F || style="background:#000;color:#fff;" | F || style="background:#fff;color:#000;" | T
| style="background:#fff;color:#000;" | T || style="background:#000;color:#fff;" | F

! 500/28°
| style="background:#7f7;" | G
| style="background:#000;color:#fff;" | F || style="background:#000;color:#fff;" | F || style="background:#fff;color:#000;" | T
| style="background:#000;color:#fff;" | F || style="background:#fff;color:#000;" | T

! 640/29°
| style="background:#7f7;" | G
| style="background:#000;color:#fff;" | F || style="background:#000;color:#fff;" | F || style="background:#fff;color:#000;" | T
| style="background:#fff;color:#000;" | T || style="background:#fff;color:#000;" | T

|-
! 800/30°
| style="background:#7f7;" | G
| style="background:#fff;color:#000;" | T || style="background:#000;color:#fff;" | F || style="background:#fff;color:#000;" | T
| style="background:#fff;color:#000;" | T || style="background:#000;color:#fff;" | F

! 1000/31°
| style="background:#7f7;" | G
| style="background:#fff;color:#000;" | T || style="background:#000;color:#fff;" | F || style="background:#fff;color:#000;" | T
| style="background:#000;color:#fff;" | F || style="background:#fff;color:#000;" | T

! 1250/32°
| style="background:#7f7;" | G
| style="background:#fff;color:#000;" | T || style="background:#000;color:#fff;" | F || style="background:#fff;color:#000;" | T
| style="background:#fff;color:#000;" | T || style="background:#fff;color:#000;" | T

|-
! 1600/33°
| style="background:#7f7;" | G
| style="background:#000;color:#fff;" | F || style="background:#fff;color:#000;" | T || style="background:#fff;color:#000;" | T
| style="background:#fff;color:#000;" | T || style="background:#000;color:#fff;" | F

! 2000/34°
| style="background:#7f7;" | G
| style="background:#000;color:#fff;" | F || style="background:#fff;color:#000;" | T || style="background:#fff;color:#000;" | T
| style="background:#000;color:#fff;" | F || style="background:#fff;color:#000;" | T

! 2500/35°
| style="background:#7f7;" | G
| style="background:#000;color:#fff;" | F || style="background:#fff;color:#000;" | T || style="background:#fff;color:#000;" | T
| style="background:#fff;color:#000;" | T || style="background:#fff;color:#000;" | T

|-
! 3200/36°
| style="background:#7f7;" | G
| style="background:#fff;color:#000;" | T || style="background:#fff;color:#000;" | T || style="background:#fff;color:#000;" | T
| style="background:#fff;color:#000;" | T || style="background:#000;color:#fff;" | F

! 4000/37°
| style="background:#7f7;" | G
| style="background:#fff;color:#000;" | T || style="background:#fff;color:#000;" | T || style="background:#fff;color:#000;" | T
| style="background:#000;color:#fff;" | F || style="background:#fff;color:#000;" | T

! 5000/38°
| style="background:#7f7;" | G
| style="background:#fff;color:#000;" | T || style="background:#fff;color:#000;" | T || style="background:#fff;color:#000;" | T
| style="background:#fff;color:#000;" | T || style="background:#fff;color:#000;" | T
|}
</div>
<div style=display:inline-grid>
{| class="wikitable" style="text-align:center;font-size:90%;"
|+Custom film speed encoding
! rowspan=2 | ISO speed
! colspan=6 | 1st row DX contacts
|-
| style="background-color:#7fff7f;" | G
| style="background-color:#ff7f7f;" | S1
| style="background-color:#ff7f7f;" | S2
| style="background-color:#ff7f7f;" | S3
| style="background-color:#ff7f7f;" | S4
| style="background-color:#ff7f7f;" | S5
|-
! ''custom 1''
| style="background-color:#7fff7f;" | G
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#000000; color:#ffffff;" | F
|-
! ''custom 2''
| style="background-color:#7fff7f;" | G
| style="background-color:#ffffff; color:#000000;" | T
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#000000; color:#ffffff;" | F
|-
! ''custom 3''
| style="background-color:#7fff7f;" | G
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#ffffff; color:#000000;" | T
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#000000; color:#ffffff;" | F
|-
! ''custom 4''
| style="background-color:#7fff7f;" | G
| style="background-color:#ffffff; color:#000000;" | T
| style="background-color:#ffffff; color:#000000;" | T
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#000000; color:#ffffff;" | F
|-
! ''custom 5''
| style="background-color:#7fff7f;" | G
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#ffffff; color:#000000;" | T
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#000000; color:#ffffff;" | F
|-
! ''custom 6''
| style="background-color:#7fff7f;" | G
| style="background-color:#ffffff; color:#000000;" | T
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#ffffff; color:#000000;" | T
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#000000; color:#ffffff;" | F
|-
! ''custom 7''
| style="background-color:#7fff7f;" | G
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#ffffff; color:#000000;" | T
| style="background-color:#ffffff; color:#000000;" | T
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#000000; color:#ffffff;" | F
|-
! ''custom 8''
| style="background-color:#7fff7f;" | G
| style="background-color:#ffffff; color:#000000;" | T
| style="background-color:#ffffff; color:#000000;" | T
| style="background-color:#ffffff; color:#000000;" | T
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#000000; color:#ffffff;" | F
|}
</div>
<div style=display:inline-grid>
{| class="wikitable" style="text-align:center;font-size:90%;"
|+'''Film length'''
! rowspan=2 | Exposures
! colspan=6 | 2nd row DX contacts
|-
| style="background-color:#7fff7f;" | G
| style="background-color:#ffff7f;" | L1
| style="background-color:#ffff7f;" | L2
| style="background-color:#ffff7f;" | L3
| style="background-color:#7fffff;" | T1
| style="background-color:#7fffff;" | T2
|-
! ''other''
| style="background-color:#7fff7f;" | G
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#7f7f7f;" | &nbsp;&nbsp;
| style="background-color:#7f7f7f;" | &nbsp;&nbsp;
|-
! 12
| style="background-color:#7fff7f;" | G
| style="background-color:#ffffff; color:#000000;" | T
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#7f7f7f;" | &nbsp;&nbsp;
| style="background-color:#7f7f7f;" | &nbsp;&nbsp;
|-
! 20
| style="background-color:#7fff7f;" | G
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#ffffff; color:#000000;" | T
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#7f7f7f;" | &nbsp;&nbsp;
| style="background-color:#7f7f7f;" | &nbsp;&nbsp;
|-
! 24
| style="background-color:#7fff7f;" | G
| style="background-color:#ffffff; color:#000000;" | T
| style="background-color:#ffffff; color:#000000;" | T
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#7f7f7f;" | &nbsp;&nbsp;
| style="background-color:#7f7f7f;" | &nbsp;&nbsp;
|-
! 36
| style="background-color:#7fff7f;" | G
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#ffffff; color:#000000;" | T
| style="background-color:#7f7f7f;" | &nbsp;&nbsp;
| style="background-color:#7f7f7f;" | &nbsp;&nbsp;
|-
! 48
| style="background-color:#7fff7f;" | G
| style="background-color:#ffffff; color:#000000;" | T
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#ffffff; color:#000000;" | T
| style="background-color:#7f7f7f;" | &nbsp;&nbsp;
| style="background-color:#7f7f7f;" | &nbsp;&nbsp;
|-
! 60
| style="background-color:#7fff7f;" | G
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#ffffff; color:#000000;" | T
| style="background-color:#ffffff; color:#000000;" | T
| style="background-color:#7f7f7f;" | &nbsp;&nbsp;
| style="background-color:#7f7f7f;" | &nbsp;&nbsp;
|-
! 72
| style="background-color:#7fff7f;" | G
| style="background-color:#ffffff; color:#000000;" | T
| style="background-color:#ffffff; color:#000000;" | T
| style="background-color:#ffffff; color:#000000;" | T
| style="background-color:#7f7f7f;" | &nbsp;&nbsp;
| style="background-color:#7f7f7f;" | &nbsp;&nbsp;
|}
</div>
<div style=display:inline-grid>
{| class="wikitable" style="text-align:center;font-size:90%;"
|+'''Exposure tolerance'''
|-
! rowspan=2 | Exposure tolerance<br/>(in [[f-stop]]s)
! colspan=6 | 2nd row DX contacts
|-
| style="background-color:#7fff7f;" | G
| style="background-color:#ffff7f;" | L1
| style="background-color:#ffff7f;" | L2
| style="background-color:#ffff7f;" | L3
| style="background-color:#7fffff;" | T1
| style="background-color:#7fffff;" | T2
|-
! ±½
| style="background-color:#7fff7f;" | G
| style="background-color:#7f7f7f;" | &nbsp;&nbsp;
| style="background-color:#7f7f7f;" | &nbsp;&nbsp;
| style="background-color:#7f7f7f;" | &nbsp;&nbsp;
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#000000; color:#ffffff;" | F
|-
! ±1
| style="background-color:#7fff7f;" | G
| style="background-color:#7f7f7f;" | &nbsp;&nbsp;
| style="background-color:#7f7f7f;" | &nbsp;&nbsp;
| style="background-color:#7f7f7f;" | &nbsp;&nbsp;
| style="background-color:#ffffff; color:#000000;" | T
| style="background-color:#000000; color:#ffffff;" | F
|-
! +2 −1
| style="background-color:#7fff7f;" | G
| style="background-color:#7f7f7f;" | &nbsp;&nbsp;
| style="background-color:#7f7f7f;" | &nbsp;&nbsp;
| style="background-color:#7f7f7f;" | &nbsp;&nbsp;
| style="background-color:#000000; color:#ffffff;" | F
| style="background-color:#ffffff; color:#000000;" | T
|-
! +3 −1
| style="background-color:#7fff7f;" | G
| style="background-color:#7f7f7f;" | &nbsp;&nbsp;
| style="background-color:#7f7f7f;" | &nbsp;&nbsp;
| style="background-color:#7f7f7f;" | &nbsp;&nbsp;
| style="background-color:#ffffff; color:#000000;" | T
| style="background-color:#ffffff; color:#000000;" | T
|}<ref name="Paul_2005_DX-CAS"/>
</div>
{{Clear}}

==See also==
* [[DX number]]
* [[Preferred number]]

==References==
{{reflist|refs=
<ref name="Kodak_1983_Press1">[[Kodak]] press announcement 1-83-1425, 1983</ref>
<ref name="Kodak_1983_Press2">[[Kodak]] press announcement 1-83-1427, 1983</ref>
<ref name="Pentax_PC35AF-M">{{cite web |title=History of Innovations |url=http://old.pentaximaging.com/world_of_pentax/history_of_innovations/1980-1989/ |publisher=[[Pentax]] |access-date=2011-07-21 |quote=1984: Pentax introduces its second leaf-shutter sport model, the Super Sport 35 (PC 35AF-M). The new addition offers all of the features of the Sport 35, plus a built-in auto winder, fully automatic loading and automatic film speed setting using the Kodak-pioneered DX coding system. The Super Sport 35 is the world's first non SLR camera to incorporate the DX film sensing system. |url-status=dead |archive-url=https://web.archive.org/web/20120328024322/http://old.pentaximaging.com/world_of_pentax/history_of_innovations/1980-1989/ |archive-date=2012-03-28}}</ref>
<ref name="Pentax_A3000">{{cite web |title=History of Innovations |url=http://old.pentaximaging.com/world_of_pentax/history_of_innovations/1980-1989/ |publisher=[[Pentax]] |access-date=2011-07-21 |quote=1985: The Pentax A3000, a fully automatic SLR, is introduced. Its automated features include: exposure, film loading and winding, and film speed setting with DX-coded film. The A3000 was the world's first 35mm SLR camera to utilize the DX film sensing system. This new SLR also allows for creative flexibility with features such as: aperture-priority, backlight compensation and a 12-second self-timer. The camera's Pentax KA bayonet lens mount makes it compatible with more than 50 Pentax lenses. |archive-date=2012-03-28  |archive-url=https://web.archive.org/web/20120328024322/http://old.pentaximaging.com/world_of_pentax/history_of_innovations/1980-1989/ |url-status=dead }}</ref>
<ref name="Minolta_AF-E">{{cite web |publisher=[[Konica Minolta]] |location=Japan |url=http://ca.konicaminolta.jp/oldnew/minolta/1980/1984.html |archive-url=https://web.archive.org/web/20080323040027/http://ca.konicaminolta.jp/oldnew/minolta/1980/1984.html |title=Introduction of the Minolta AF-E / Freedom II in July 1984 |work=Minolta camera history |archive-date=2008-03-23}}</ref>
<ref name="Minolta_7000AF">{{cite web |publisher=[[Konica Minolta]] |location=Japan |url=http://ca.konicaminolta.jp/oldnew/minolta/1980/1985.html |archive-url=https://web.archive.org/web/20080323040256/http://ca.konicaminolta.jp/oldnew/minolta/1980/1985.html |title=Introduction of the Minolta 7000 AF in February 1985 |work=Minolta camera history |archive-date=2008-03-23}}</ref>
<ref name="Fuji_Patent_4024557">{{cite patent |country=US |status=Patent |number=4024557A |assign=[[Fuji (company)|Fuji]] |title=Film magazine having film speed indicating means |pridate=August 1, 1975 |pubdate=May 17, 1977 |invent1=Keiichi Aoyama |invent2=Keeji Kaneko |invent3=Katsuji Muramatsu |invent4=Ikuo Fuutagawa}}</ref>
<ref name="AP_1977_Fuji">{{cite journal |journal=[[Amateur Photographer]] |title=Fuji's Latest Auto-System |date=1977-02-16 |page=61 |url=http://www.zenitcamera.com/qa/images/fuji-cassette-ap-1977-02.jpg |access-date=2011-07-21 |url-status=live |archive-url=https://web.archive.org/web/20180122141109/http://www.zenitcamera.com/qa/images/fuji-cassette-ap-1977-02.jpg |archive-date=2018-01-22}} [http://www.zenitcamera.com/qa/images/fuji-cassette-ap-1977-02.tif<!-- https://web.archive.org/web/20180122141126/http://www.zenitcamera.com/qa/images/fuji-cassette-ap-1977-02.tif -->]</ref>
<ref name="Paul_2005_DX-CAS">{{cite web |title=Ausführliche Informationen zum DX/CAS-Code |language=de |trans-title=Comprehensive information regarding DX/CAS code |author-first=Matthias R. |author-last=Paul |date=2005-10-22 |work=Minolta-Forum |url=http://www.mi-fo.de/forum/index.php?showtopic=10279&view=findpost&p=120737 |access-date=2011-07-21 |url-status=dead |archive-url=https://web.archive.org/web/20160326152153/http://www.mi-fo.de/forum/index.php?showtopic=10279&st=0&p=120737&#entry120737 |archive-date=2016-03-26}} [https://archive.today/20190609120650/http://www.so-fo.de/t10279f164-Filmrueckspulung-Minolta-Dynax-1.html%23msg120737<!-- Cached thread in another forum: http://www.so-fo.de/t10279f164-Filmrueckspulung-Minolta-Dynax-1.html#msg120737 -->]</ref>
<ref name="Paul_2008_Fuji-Barcode">{{cite web |title=Infos zu Mittelformatrollfilmen mit Barcodekennung - Barcodes auf Fujifilm Brownies |language=de |trans-title=Information on medium format rollfilms with barcodes suitable for detection through camera - Barcodes on Fujifilm brownies |author-first=Matthias R. |author-last=Paul |date=2008-08-24 |work=Minolta-Forum |url=http://www.mi-fo.de/forum/index.php?showtopic=21332 |access-date=2011-07-21 |archive-url=https://web.archive.org/web/20160804010215/http://www.mi-fo.de/forum/index.php?showtopic=21332 |archive-date=2016-08-04}} [https://archive.today/20190609115151/http://www.so-fo.de/t21332f36-Infos-zu-Mittelformatrollfilmen-mit-Barcodekennung.html<!-- a cache of the thread in another forum: http://www.so-fo.de/t21332f36-Infos-zu-Mittelformatrollfilmen-mit-Barcodekennung.html -->]</ref>
<ref name="Fujifilm_5845869">{{cite web |url=http://www.google.com/patents?id=WQsEAAAAEBAJ&dq=5845869 |title=US-Patent #6026250 "Camera, bar code reader for camera and method of detecting bar code reading |id=US6026250A |date=2000-02-15 |orig-year=1996-12-12, 1997-12-09 |author-first1=Shigenori |author-last1=Goto |author-first2=Hisashi |author-last2=Hamada |author-first3=Shiro |author-last3=Hashimoto |author-first4=Nobuhiro |author-last4=Aoki |author-first5=Tokuji |author-last5=Sato |publisher=[[Fuji Photo Film Co., Ltd.]], [[Fuji Photo Optical Co., Ltd.]] |access-date=2018-01-22 |archive-url=https://web.archive.org/web/20180122190129/https://www.google.com/patents/US6026250?hl=de&dq=5845869 |archive-date=2018-01-22}}</ref>
<ref name="Fujifilm_6050489">{{cite web |url=http://www.google.com/patents?id=DYJ7AAAAEBAJ&dq=6050489 |title=US-Patent #6050489: Bar code system for brownie film and bar code reader of camera |id=US6050489A |date=2000-04-18 |orig-year=1997-04-08, 1998-04-08 |author-first1=Shigenori |author-last1=Goto |author-first2=Teruyoshi |author-last2=Makino |author-first3=Hisashi |author-last3=Hamada |author-first4=Tokuji |author-last4=Sato |publisher=[[Fuji Photo Film Co., Ltd.]], [[Fuji Photo Optical Co., Ltd.]] |access-date=2018-01-22 |archive-url=https://web.archive.org/web/20180122190140/https://www.google.com/patents/US6050489?hl=de&dq=6050489 |archive-date=2018-01-22}}</ref>
<ref name="Fujifilm_6208812">{{cite web |url=http://www.google.com/patents?id=z6AGAAAAEBAJ&dq=5845869 |title=US-Patent #6208812: Camera with bar code reader |id=US6208812A |date=2001-03-27 |orig-year=1997-05-21, 1998-05-21 |author-first1=Tokuji |author-last1=Sato |author-first2=Hisashi |author-last2=Hamada |author-first3=Shiro |author-last3=Hashimoto |author-first4=Shigenori |author-last4=Goto |author-first5=Tatsuo |author-last5=Saito |author-first6=Hiroyuki |author-last6=Arai |author-first7=Akio |author-last7=Omiya |author-first8=Makoto |author-last8=Akiba |publisher=[[Fuji Photo Film Co., Ltd.]], [[Fuji Photo Optical Co., Ltd.]] |access-date=2018-01-22 |archive-url=https://web.archive.org/web/20180122190155/https://www.google.com/patents/US6208812?hl=de&dq=5845869 |archive-date=2018-01-22}}</ref>
<ref name="Fujifilm_6052538">{{cite web |url=http://www.google.com/patents?id=JS18AAAAEBAJ&dq=5845869 |title=US-Patent #6052538: Camera and exposure control method |id=US6052538A |date=2000-04-18 |orig-year=1996-12-12, 1997-12-09 |author-first1=Shigenori |author-last1=Goto |author-first2=Hisashi |author-last2=Hamada |publisher=[[Fuji Photo Film Co., Ltd.]], [[Fuji Photo Optical Co., Ltd.]] |access-date=2018-01-22 |archive-url=https://web.archive.org/web/20180122190206/https://www.google.com/patents/US6052538?hl=de&dq=5845869 |archive-date=2018-01-22}}</ref>
}}

==External links==
* {{webarchive |url=https://web.archive.org/web/20160304234839/http://www.imageaircraft.portfairy.town/DXsim/ |date=2016-03-04 |title=A Java applet for generating and interpreting DX codes}}
{{Eastman Kodak}}

[[Category:Photographic film markings]]
[[Category:Kodak]]
[[Category:Audiovisual introductions in 1983]]