Limited DX Coding Range in Compact Cameras.

I have never had a camera that used DX Coding. All of mine have been manually set film speeds. So I have never had this problem before.

At the moment I'm looking at a Samsung AF Slim Zoom going for a reasonable price. It has DX coding and apparently no manual ISO setting.



Now for the interesting bit.

After testing for my personal film speeds and developing times, some of my speeds fall between the standard box speeds given by the film manufacturers.

I thought of using self adhesive DX Code labels to set the camera to my true ISO speeds. But, apparently most, if not all of these DX Coded point and shoot cameras are programmed with only about four or five standard box speed settings available from a theoretical range of twenty four.

I have looked through quite a few instruction manuals at Butkus for different cameras, but they say things like "Automatic setting with DX Coded films ISO 50 - 3200" or whatever the range is for that particular camera. No mention of the actual available steps built into the camera.

Apart from makers instruction manuals that do not touch on this subject, is there any source that reveals the limited range of DX Codes available on the various cameras?

Thanks in advance for any advice.

I don't know of such a listing, but you might be able to spot clues based on how many electrical contacts the camera has. A Canon EOS that I checked as a single row of 6 contacts, so it can detect ISO but not film length via DX coding. But it nevertheless detects film length by unspooling the entire roll, then advancing film backwards.

On the other hand, my Zenit 412 (not 412LS) has just three contacts, and IIRC, it detects ISO up to 400.

More regarding DX code are here:
https://en.wikipedia.org/wiki/DX_encoding

I have the same problem. my E.I for the films and developers I use do not match box speed, when I use a point and shoot I process black and white as a push.

I use tape and scratch to make my own DX codes.

To be honest I don't think dialing in the exact ISO does anything for these point and shoots. I'm convinced they take a more sledgehammer approach to exposure. Overexpose when in doubt kind of thing.

BobUK said:

After testing for my personal film speeds and developing times, some of my speeds fall between the standard box speeds given by the film manufacturers.

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But since these P&S cameras generally have rather crude metering systems anyway, I wouldn't worry about it and just round down (assuming negative film) to the nearest 'whole' ISO rating.

Even if the metering system in these cameras wasn't technologically crude, it certainly doesn't make use of a carefully positioned spot function - in fact, it is usually difficult to pin down what it is pointed at. So I agree with the advice above.

I have a few later model point and shoots that do have a dedicated spot meter setting but I'm still not convinced that it does anything. The camera does what it wants, focus and exposure be darned.

I won't dispute what has already been said, but what I'd look for, as mentioned, is the number of pins in the film chamber. If there are six, then the camera could handle film from 25 to 5000 ISO. The maker of the camera would not add extra pins if they didn't do something.

My point and shoot. Available used for under 300 usd

mshchem said:

View attachment 413572My point and shoot. Available used for under 300 usd

View attachment 413571

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Very good in terms of making your point and I can smile wryly about it as it is not my problem but it hardly aids the OP in terms of his question, does it?


pentaxuser

I assume that cameras that use DX coding AND have manual setting of film speed will state it loud and clear.

The Minolta Maxxum 5 manual states:

FILM SPEED SETTING
AUTOMATIC: 25 to 5000 for DX coded film
MANUAL: 6 to 6400 in 1/3 EV increments

AUTO DX setting means no incremental settings. It's just what the film speed is -- for example ISO 400, nothing else. I know that sounds ludicrous to anyone that normally doesn't use the stated ISO. One option is to use a +/- EV setting if the camera has it -- but that's awkward.

I doubt you will find a list of cameras that offer DX and MANUAL ISO settings, but it's not going to be the lower priced models for sure -- which probably eliminates >90% of the P&S crowd. Lots of them are just 100 or 400 with a switch!

So what KIND of camera are you looking for. You can get a Maxxum 5 for very little $$$, for example.

pentaxuser said:

Very good in terms of making your point and I can smile wryly about it as it is not my problem but it hardly aids the OP in terms of his question, does it?


pentaxuser

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What are the available options on DX codes? Here ya go. I think you can fool the camera easily, top six pins are either conducting or not conducting. A little sandpaper will remove paint a little electrical tape, or nail polish stops current. ISO 25 TO 5000 available. It's not rocket science.

Still think any decent, cheap autofocus camera can be made to work.

BobUK said:

After testing for my personal film speeds and developing times, some of my speeds fall between the standard box speeds given by the film manufacturers.

Click to expand...

You need to adjust your process or buy a fully adjustable camera

If you use a lot of different speed films, camera surgery is not much help.

mshchem said:

You need to adjust your process or buy a fully adjustable camera

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I've never seen a list of "manually adjustable DX-coded cameras".

mshchem said:

You need to adjust your process or buy a fully adjustable camera

Click to expand...

You adjust the film cassettes not the camera

DX is binary. 6 pins, Da or Nyet. Ain't no personal film speeds.

I'm sorry but 1/3 of a stop is pretty darn close. Shutters aren't going to do what the computer brain of a point and shoot expects either.

I'm done here for now. Peace

I have a Minolta Weathermatic 35, simple but waterproof point & shoot for some fun in summer, and I think it knows only iso 100 and 400, everything else gets set to the nearest of those. I think in this case the manual mentioned it...