M7: problems with DX code

[Alex Krasotkin]

Guys,

I have recently discovered the following problem: I was shooting with 125 ISO film (Ilford FP4+). In most of the time, when I switch my M7, the correct value of 125 appears on a screen. However sometimes I was seeing a wrong ISO value of 2000. In this case a meter starts to evaluate the light based on 2000 ISO. The problem dissaperes after switching of the camera for a longer time.

I have heard somitimes before that M7 model has occasional problems in reading correct ISO value. I presume that the only way in such a case is to set ISO manually..?

Do you have any advise/remedy, or am I completely stupid?

Thank you

 

[J J Kapsberger]

Didn't you have a problem with trying to lock in auto exposure readings? Did you solve that problem? If not, your M7 might be a lemon. If it doesn't allow you to lock in the exposure (via a partial depression of the shutter button) and can't consistently read DX coding perhaps you should send it in for some passport attention.

Could it be the film itself? Have you tried other films?

 

[Eelco Amsterdam]

If you are in your first 5 years, send it back to Solms.

http://www.rangefinderforum.com/forums/showthread.php?t=43704

 

[sepiareverb]

You must be completely stupid 😀

(you asked for that one!)

I've had some troubles with my M7's and DX also. I never found that there were any problems in exposure though when shooting in Auto- the readout seemed wrong but the exposures were fine. I've never had the exact problem you describe- I sometimes get a shutter speed of '50' appearing in the display lately.

I've started setting my ISO manually and the extra little blips of light are for the most part gone. I'd send it in if you are still in warranty.

 

[tmfabian]

I belive this occurs because the dx code has swiveled slightly off the dx readers. Usually when i see this happen i lightly tap the back of the camera and it's fixed. However as of late i've taken to just simply setting my DX manually which is the permanent fix really.

 

[Alex Krasotkin]

Yes, I've solved the problems with locking the exposure, this function works perfectly well. DX problem was happening 2-3 times so far and only with Ilford FP4+ film. DX readings with the rest of films are ok!

 

[hlockwood]

Yes, I've solved the problems with locking the exposure, this function works perfectly well. DX problem was happening 2-3 times so far and only with Ilford FP4+ film. DX readings with the rest of films are ok!

An added note: I've been told that the VF always shows the DX reading, even if you set the film speed manually. I set XP2 to 320, but when the M7 is first turned on, the LED shows the DX reading of 400. This is confirmed in the manual, see table on p. 77.

 

[rogue_designer]

An added note: I've been told that the VF always shows the DX reading, even if you set the film speed manually. I set XP2 to 320, but when the M7 is first turned on, the LED shows the DX reading of 400. This is confirmed in the manual, see table on p. 77.

That's really really dumb.

really.

 

[Eelco Amsterdam]

When there is no film inside the M7 and turned ON it shows flashes 100 ISO in auto !

I had a lot of problems with my DX reading.
My dealer send it to Solms and they replaced the old DX contact strip for a
new optical strip. No problems any more :<)
I dont need lightly tap the camera on my hand to remove my film.
The film drops out like the old M6 / M6 TTL without DX contact strip.
Much better I think.

Eelco

 

[Eelco Amsterdam]

How more film is used (push in the M7 and pull out again, time and time again) with the "old" DX strip the problem gets bigger and bigger. With the optical reader this problem is solved.

Tap the back of the camera works ! But 3 times in a 36 exp. film ???
Very annoying !
I am very happy with my optical reader.

Eelco

 

[Magus]

Post deleted by posters request

 

[peter_n]

One of my M7s has the sensor that touches the canister, the other has the optical sensor AFAIK. I'm not quite sure why, but so far I don't seem to have suffered from this problem at all. The one with the contact strip was back with Leica for an upgraded VF and I asked them to check on the DX mechanism and the report was that it is OK. So far so good. 🙂

 

[sepiareverb]

Well, in looking at the two cassettes the DX coding on the Ilford is noticably wider than the Plus-X. Measured them and the Ilford bar code is 22mm wide, the Kodak is 20.5mm wide. Lines are the same, just not exactly in the same place. Anyone got some Tri-X and HP5 to compare?

I'm assuming that the placement of these barcodes must determine to some extent the reliability of the 'read'? My M7's have a series of little cones that appear to do the reading- if the barcodes are irregular in size might this have an effect?

 

[Eelco Amsterdam]

snap shots

snap shots

For snap shots like these, the M7 is very nice and quick:

Memphis, Tennessee USA May 2007




Sometimes (my wife) I like flash :angel:
Gatlinburg, Tennessee USA May 2007


Eelco