DIY DX coding for bulk loaded rolls

[FrankS]

So I've got a couple or 3 good P+S type cameras that auto sense DX coding with no way of setting the ISO manually. I bulk roll 400 speed film and need to tell the camera so. Since I consistently use 400 speed film, I'm thinking that it would be easier to mask the camera's DX contacts rather than each film canister. Any one done this? Here is a site that specifies the DX positions: http://www.bythom.com/dxcodes.htm

 

[wolfpeterson]

I would think that doing that to a camera's contacts is a bad idea, I mean, there is a chance that you're one day in a foreign land, run out of film and the shop doesn't have 400. Hypothetically of course 😀

You can buy canisters that are already coded at 400, or you can use metallic tape and a sharpie. I think that this is more advisable, especially if you make the change to your camera permanent by mistake.

 

[Bob Michaels]

Frank, is there a chance that your camera(s) default to iso 200 when there is no reading? I remember seeing somewhere that is a standard. If so, overexposing iso 400 film by one stop might be just the ticket you need.

 

[ChrisN]

Frank, is there a chance that your camera(s) default to iso 200 when there is no reading? I remember seeing somewhere that is a standard. If so, overexposing iso 400 film by one stop might be just the ticket you need.

I've got a few Pentax P&S that default to 100, and the Oly Mju does too.

I think you might be on to something Frank - try it and let us know!

 

[john_s]

As far as I know the DX works by electrical conduction rather than optically. Personally I would just try some very fine wires to join some contacts together, and insulate the whole lot of them from any metal canisters.

 

[Paolo Bonello]

I was thinking about something similar to try to push 400film to 1600 in my P&S which uses DX coding. Is there not a conductive sticker with the correct DX coding printed on available that we can simply stick on a factory loaded film canister?

 

[DNG]

Try this... 35mm Film DX ISO CODES
The lower half of the cartridge coding is the Film Speed, the upper half is other stuff...

The lower left is the code for films, you just put the film speed you want in the 1st drop down field, and look at the LOWER 1/2 for coding...

 

[Phil_F_NM]

Just get a few DX coded canisters and copy the code to a template. After that, cut out a pattern in some adhesive copper tape:

http://www.tedpella.com/SEMmisc_html/SEMadhes.htm#anchor1183976
(no connection to seller, I just pulled his business link off google)

It's quite adhesive and permanent. I have a roll here at home and I find I use it for all sorts of stuff.

The DX coding is indeed conductive, not optical. The canisters are coated with a non-conductive plastic in the corresponding reverse pattern to make them appear correctly coded.

Phil Forrest

 

[yukio]

Ditto the idea of using conductive tape. It's really not that difficult. My local hardware store sells copper tape as a slug/snail barrier for about $10.00. I didn't use a template (the "bits" measure 0.5x0.7cm), but it does help to have a real cartridge next to your diy cartridge to register the distance from the film opening.

One thing that's helpful to know is that if your camera has only one row of contacts then you really only have to worry about the row closest to the film opening. The second row codes for number of exposures and is often not used. The benefit of this is that you can use a solid second row to hold the first row together, making application easier.

Even though they look very different, both are both recognized as ISO 800.

Is there not a conductive sticker with the correct DX coding printed on available that we can simply stick on a factory loaded film canister?

There are pre-made dx recoding labels out there, but the only place I found online that had any real selection of speeds was Firstcall Photographic in the UK. Unfortunately, the minimum charge for anything shipped to the US is roughly 120USD.

.

 

[Paolo Bonello]

Thanks Yukio. I emailed them and seems they'll do an email or fax order for lesser qty and minimal shipping by regular airmail no probs. seeing that it will probably fit in an envelope the shipping was just £2

 

[Iain W]

I bought some new re usable DX coded 400asa cassettes on ebay a couple of months ago. From memory they came from the UK.