How to Recode / Edit the DX barcode on 35mm Film Canisters

By Hamish Gill

The DX barcode on a 35mm roll of film is there, in part, to tell the camera it’s put into what ISO the film is. The majority of cameras from the mid 80’s onwards read this code automatically via either electrical or optical readers. Some cameras allow the user to override this code, but many, especially 35mm compact cameras don’t. If you only ever shoot film at it’s box speed, then this won’t cause you any problems but should you ever wish to push or pull your film shot in a camera without manual ISO override setting, then you might wish to recode the DX barcode.

The two things you will need are a sharp knife and a roll of electrical tape, preferably black, especially if your camera has an optical DX reader.

Recoding a DX barcode

Looking at the side of the film with the leading pointing up, it is the top row of silver/black rectangles that we are changing. The film in question is a roll of 200iso film that I’d like to recode to 400iso. If you look at the chart at the bottom of this article and compare 200 to 400 you will see I need to remove one black rectangle and add two.

Recoding a DX barcode

To remove the rectangle I simply scratch it off with the edge of my knife. Like so:

Recoding a DX barcode

Once removed it should look like this:

Recoding a DX barcode

The next step is to add two more black rectangles. To do this I cut a piece of black electrical tape to size and stick it in place like this:

Recoding a DX barcode

And it’s a simple as that! This film will now be read as 400iso by the camera it is put into.

The following table illustrates all the possible DX codes for coding ISO from 25iso to 5000iso:

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

 

Thanks for reading

Hamish

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About The Author

By Hamish Gill
I started taking photos at the age of 9. Since then I've taken photos for a hobby, sold cameras for a living, and for a little more than decade I've been a professional photographer and, of course, weekly contributor to 35mmc.
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Comments

Bob Janes on How to Recode / Edit the DX barcode on 35mm Film Canisters

Comment posted: 20/04/2021

If you find yourself frustrated at a modern 35mm camera automatically rewinding at 36 exposures rather than maybe squeezing out that extra shot or two, the DX coding also contains the number of shots on the roll - and there is a code for 48 shots (see DX codes on Wikipedia for details). Of course some cameras might decide to wind back at 36 anyhow and leaving rewind until the camera detects resistance may put stress on internal motors...
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Hamish replied:

Comment posted: 20/04/2021

Very interesting, I did not know that!

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Clifford Gwinn on How to Recode / Edit the DX barcode on 35mm Film Canisters

Comment posted: 05/05/2020

Been nice if you oriented the canisters the same way as you went through the steps
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5 frames with Santa Rae 1000 and a Nikon EM - by Charles Higham - 35mmc on How to Recode / Edit the DX barcode on 35mm Film Canisters

Comment posted: 27/01/2020

[…] like 100 ISO which for this film would result in serious overexposure. Referring to Hamish’s instructions on DX recoding, and with a view to maybe using a compact camera with no manual ISO control, I […]
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ฟิล์มหนัง ใช้กับกล้องที่ auto set ISO ได้ไหมครับ ต้องตั้ง ISO ยังไง ? – abstractfilms on How to Recode / Edit the DX barcode on 35mm Film Canisters

Comment posted: 17/10/2019

[…] ภาพจาก https://www.35mmc.com/08/03/2014/recoding-dx-barcode-35mm-canisters/ […]
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Notes on the Yashica Auto Focus Motor: A Review - By Michael Raven - 35mmc on How to Recode / Edit the DX barcode on 35mm Film Canisters

Comment posted: 28/09/2019

[…] I love that I have the option to manually change the ISO on a shot by shot basis (yes, you can hack DX coding, but it’s a bit of a faff). I’d love the scale to go one more stop to 800, but then I suppose […]
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A Ricoh mystery camera - the RZ-105 Zoom Date - By Ivan Palli - 35mmc on How to Recode / Edit the DX barcode on 35mm Film Canisters

Comment posted: 17/03/2019

[…] first run through two rolls of Kentmere 400 with the DX code hacked to 800. This is my standard black and white film/ISO for point-and-shoots. Because I had one, I put […]
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The Nikon 28ti and 35ti - a mini-review - By Ahmed Al Shorouqi - 35mmc on How to Recode / Edit the DX barcode on 35mm Film Canisters

Comment posted: 10/03/2019

[…] however, isn’t an option. And you can only shoot a roll at box speed. To get around that you can hack the DX code on your film canister to push a […]
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Olympus L-10 Panorama Review - Guest Post by EMULSIVE - 35mmc on How to Recode / Edit the DX barcode on 35mm Film Canisters

Comment posted: 25/09/2017

[…] to over expose your film intentionally by however many stops, you cant (unless you re-code your DX barcode) but the camera will likely give you a spot here and […]
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daniel on How to Recode / Edit the DX barcode on 35mm Film Canisters

Comment posted: 11/06/2017

Pretty late question, but i just got myself a Yashica and wanted to know if I do the same with overexposing? I always shoot Portra 400 at 200 so i have to change the DX Code to 200 right?
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Hamish Gill replied:

Comment posted: 11/06/2017

Yes, exactly that!

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Oshi Shikigami replied:

Comment posted: 11/06/2017

Exactly correct.

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Joey Harrison on How to Recode / Edit the DX barcode on 35mm Film Canisters

Comment posted: 12/09/2016

After re-examination, I see that i was mistaken. Sorry to take up your time.
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Hamish Gill replied:

Comment posted: 12/09/2016

No probs, thanks for posting back on here to clarify - good luck with your recodings :)

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Joey Harrison on How to Recode / Edit the DX barcode on 35mm Film Canisters

Comment posted: 11/09/2016

They're on the way now ....
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Joey Harrison on How to Recode / Edit the DX barcode on 35mm Film Canisters

Comment posted: 11/09/2016

I was so glad to find this.
Except that when I got set to hack a roll of Kodak Professional Tmax 100, I discovered that your bar code key for ISO 100 doesn't match the one on the film canister. Then, just out of curiosity, I checked two other rolls. Kodak 400UC (C-41) and Fujicolor Super HQ 200 (C-41). The Fujicolor's bar code matched the one on your chart but the Kodak 400 did not.
So ...
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Hamish Gill replied:

Comment posted: 11/09/2016

Not sure ... Would you take a couple of photos of the cans and email them to me? [email protected]

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Alexander on How to Recode / Edit the DX barcode on 35mm Film Canisters

Comment posted: 01/06/2016

Thank you so much! For the isolation, I use nail polish. My wife is not very happy!
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Hamish Gill replied:

Comment posted: 01/06/2016

Haha, not a bad idea - though the drying time would cause me issues... I'd like the smell though! ;)

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JJ Holdijk on How to Recode / Edit the DX barcode on 35mm Film Canisters

Comment posted: 25/04/2016

Does this work for developing services as well? So that when I turn in my roll of 400 ISO film recoded to 800 at the local pharmacy, it's developed as an 800 film?
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Hamish Gill replied:

Comment posted: 25/04/2016

No, colour process is all the same timings - there aren't many places that push/pull colour now. Shooting 400 colour at 800 is probably ok anyway, a lot of colour films will cope with its that sort of underexposure - not ideal, but should be ok.

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Oshi Shikigami on How to Recode / Edit the DX barcode on 35mm Film Canisters

Comment posted: 12/08/2015

I bulk load film. I use commercial reloading cassettes. These of course, do not have any encoding. I have a camera that is auto DX only. I would love to use the bulk loaded film in it. I keep reading of sticky labels, that confer the code, and attach to the cassette. However, I have yet to actually find someone selling these. Does anyone know of a current supplier of the labels?
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Hamish Gill replied:

Comment posted: 12/08/2015

I don't know myself. Some sticky back tin foil and black tape might be a solution...?

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Pieter Geloen replied:

Comment posted: 12/08/2015

If your canisters are metal, you can make your own DX patch. Scratch away (if there is any) all the paint till you see bare metal where the DX patch should be (check with canister that have DX codes) And then use this method to create your own ISO values. Also you should search the web (I believe the wikipedia page about DX codes has this) about how the second line is read. I think that lets the camera know how many exposures there are on the roll

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Barry replied:

Comment posted: 12/08/2015

Hello Oshi, Did you find a solution? I am also bulk loading some expired film which I like to use in a camera with auto DX (normally I use my Rollei 35) did you find some sort of stickers we can use or print and use??? @hamish, tx for the info

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Simeon on How to Recode / Edit the DX barcode on 35mm Film Canisters

Comment posted: 12/06/2015

This is just so fantastic! I can't wait to give this a whirl! I've been trying to figure out how to push film in my Olympus mju ii and this could be the ticket!
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Hamish Gill replied:

Comment posted: 12/06/2015

Hi Simeon, Just a point of note... Pushing and pulling aren't something done in camera. In camera you shoot the film at an "exposure index" or "ei". If you had a roll of 400iso film, you might choose to shoot it as "box speed" or ei400. Alternatively if you shot that same roll at ei800, you would be underexposing it by 1ev, you then might choose to "push process" that film - or develop it for a longer period of time - in order to counter that underexposure. I'm sure you realise this, just thought it might be helpful in your path, good luck!

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Simeon replied:

Comment posted: 12/06/2015

Yup! Thanks, Hamish! I was just looking for a way to manually input the ISO on the Olymlus, and this could be the ticket!

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Roll 1: Testing an Olympus Infinity Jr/AF-10 Super | 52 rolls on How to Recode / Edit the DX barcode on 35mm Film Canisters

Comment posted: 02/01/2015

[…] as 800. There is no built-in over-ride for the DX reading although Hamish Gill also describes (here) how to recode the DX barcode on a film canister to shoot the entire film at a different ISO than […]
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Barry on How to Recode / Edit the DX barcode on 35mm Film Canisters

Comment posted: 09/12/2014

I can't wait to try this! Thanks Hamish.
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Hamish Gill replied:

Comment posted: 09/12/2014

Link me when you do Barry! (Hope all is well with you and the family!)

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Hamish Gill replied:

Comment posted: 09/12/2014

Funny you commenting Barry, I was thinking of you last night as I made myself a hot whisky ;)

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Canon Sure Shot Sleek {Second Chance at Love} | Shoot With Personality on How to Recode / Edit the DX barcode on 35mm Film Canisters

Comment posted: 03/08/2014

[…] and use that information to expose the film properly for its given ISO (tutorials here and here.)  Most cameras I use require me to set the film speed myself anyway, so I can just tell the […]
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Canon Prima 120 - My current telephoto lens of choice! : 35mmc on How to Recode / Edit the DX barcode on 35mm Film Canisters

Comment posted: 15/03/2014

[…] slow, especially at the long end, but if you are worried you can always shoot faster film, or just recode some slower film like I did for my trip to Paris. There are zoom cameras out there that possibly have better […]
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Rob on How to Recode / Edit the DX barcode on 35mm Film Canisters

Comment posted: 08/03/2014

:-)
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Rob on How to Recode / Edit the DX barcode on 35mm Film Canisters

Comment posted: 08/03/2014

Wow. I had no idea. Thank you, Maestro!
Rob
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Hamish replied:

Comment posted: 08/03/2014

Glad to be of service matey! re. Cinestill, if you peel back the cinestill label you will find a barcode of whatever the film used to be. You should be able to recode that to whatever you want!

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