M7 meter displays wrong shutter speed

[lincoln_m]

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Hi,

Every now and then my M7 meter gives very wrong readings, it says 24 or 40 when the shutter speed should be 250 or 400 etc. This was when using Provia 400 recently. When I bought the camera (used) about 2 years ago I thought the batteries in it were old because of this occasional issue so I replaced them. I've only shot about 5-6 films with these batteries in warm conditions so the batteries should be OK and I do remember to switch off.

 

The camera is one of the newer ones with the MP Rangefinder coatings, very nice.

 

Are there issue with the M7 meter can it start to play up even though there is no sign of battery low. I used to get a flashing lower dot until I moved the exposure compensation away from zero and back again when the flashing would stop but the camera was in the same no compensation setting.

 

Is it a DX reader issue? It always says the correct DX when I turn it on (after cocking the shutter). Luckly I realised the meter was wrong or I'd be taking very overexposed shots.

 

if I set the shutter speed manually say 250 as it was a second ago before the jittering display, would the M7 generate the correct shutter speed or is that likely to be wrong along with the meter?

 

How many films should you get out of an M7 on 1 set of batteries? I guess the shutter takes some power out of the batteries although the shutter always fires even if I disagree with the meters shutter speed setting.

 

This may mean I'll stick with the MP for expensive trips where I can rely on a single body. A non working M7 could ruin a Safari etc if it messed up but an MP (all mechanical) should be more reliable as you have all mechanical shutter speeds even if the batteries fail.

 

Regards, Lincoln

[budrichard]

I'm having trouble following your description of what you think is wrong.

Is the M7 in AUTO when you think the reading is wrong or is the shutter knob turned to 250 when it reads something different?

My experience with my M7's is that when the batteries for whatever reason cannot supply sufficient voltage, the shutter will NOT actuate but the meter stills works.

The battery lifetime is not dependant on rolls of film used, it is dependant upon how long the metering/shutter system is actuated so it depends on how you use your M7.

If its simply a matter of when your M7 is in AUTO, that you disagree with the shutter speed the M7 determines, that is not the camera but how the camera measures the exposure and must be interpreted as with any exposure meter. I usually meter an appropriate part of the scene and use the shutter lock feature: example bright blue sky and scenic, if you let the M7 expose for your actual scene, most likely you will have some underexposure, if you meter the landscape, lock the reading and then frame and shoot, a good exposure.-Dick

[menos I M6]

Lincoln, does the M7 show the same flaky behavior, when you set the ISO speed manually and not on DX?

 

I never had such a problem, but it sounds possible, that a not properly working DX reader reads out different ISO speeds, leading to the strange exposure values, the camera calculates.

 

I have read in a M7 camera test (can't remember where), that when the "old" tactile DX reader is defective, the camera might show the correct ISO speed, when switching on, but changing to a wrong ISO speed without warning or user control during operation, leading of course to wrong exposures.

 

It is always good, to check exposure times back with logical understanding and experience, if they show questionable values.

[bill]

 

I have read in a M7 camera test (can't remember where), that when the "old" tactile DX reader is defective, the camera might show the correct ISO speed, when switching on, but changing to a wrong ISO speed without warning or user control during operation, leading of course to wrong exposures.

 

That's exactly what mine started doing. Send it to Solms - the upgrade to the optical reader is free and you get a wash and brush up into the bargain. My M7 came back like new.

 

Regards,

 

Bill

[lincoln_m]

Bill,

 

Optical DX reader? Mine is the one with metal bumps. I've never seen or heard of the optical reader. Do you have any pics , obviously when there is no film in your M7.

 

My M7 gives this changable reading when in AUTO. Switching on the camera shows the correct 400 ISO but the meter shows changing readings between 500 and 40 when pointing at the same subject, not the expected readings of 180 , 250 when moving around a subjects light and dark areas. I could imagine if the contacts keep disconnecting it could think the ISO is different and so report a different meter reading. It does not happen all the time but I'll look out in case it does and try and clean the contacts next time I change film. If it gets worse then I'll have to send it back to Solmns.

 

Regards, Lincoln

[bill]

Lincoln, that's it exactly. The metal bumps don't wear well and you end up with exactly the symptoms you describe. I put up with it for months, then realised it was irritating me to the point of not using the camera. It is a known problem, and hence fixed FOC. While your camera is in Solms it will get a general spruce-up - mine honestly came back like a new camera. Don't hesitate, do it today.

 

Regards,

 

Bill

[alun]

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As Bill said -- it's almost certainly the DX reader misreading (or not reading at all) from the film canister. My M7 has had the problem too. But a word of warning -- when you send it back say you want other circuit boards checked too. The first time mine came back with the DX reader swapped but the problem persisting and in fact worse. It turned out that in addition to the DX reader there was a malfunctioning circuit board which the first repair failed to identify. Two fixes later and it's fine.

[lincoln_m]

Guys,

OK so it looks like the M7 will need to return to base soon but while I still have a film in perhaps I can set the iso to 400 (Provia 400) and then the exposure might be correct as the DX reader circuit won't be used? But someone mentioned asking about checking the other numerous circuit boards. I'll see if I still have the problem when I've fixed the ISO. Thinking about it the DX reader is sort of an unnecessary extra, although there were a couple of occasions using the MP that I changed from Velvia 50 to 100 and forgot to change the ISO setting causing very bleached over exposed slides.

 

I saw this M7 cut away at the Westlicht auction page and was a little surprised at the number of circuits. But then again the Ms are small cameras with very little spare space.

https://www.westlicht-auction.com/index.php?id=185055&acat=185055&offset=6&_ssl=off

 

If you can't rely on the AE meter giving the correct exposure then that really messes up the point of the M7. I've had fast battery drain on an M6TTL when in cold weather but never thought I'd have the wrong exposure, MP meter just works until the battery dies many films later or when it gets really cold for a long time. At least with the mechanical Ms you know you can fire the shutter anytime. (Yes M7 has 60, 125th mechanical)

 

I thought the M7 would be an OK camera on Safari because the warm weather would not kill the batteries but if the metering is wrong and I'm using slide film then that is too risky to chance on a very expensive holiday. It will be back to the MP with Provia 400 and possibly the M2 with TMAX400 as a spare.

 

I really like the way the black chrome wears on the M7, much more than the Black Paint brassing to my eye, it feels like the camera has had some real use.

See it on the M7 thread.

http://www.l-camera-forum.com/leica-forum/film-forum/36000-love-m7-6.html#post1431501

 

Regards, Lincoln

[andybarton]

Guys,

OK so it looks like the M7 will need to return to base soon but while I still have a film in perhaps I can set the iso to 400 (Provia 400) and then the exposure might be correct as the DX reader circuit won't be used?

 

Even though I have had my DX reader replaced by Leica, I always use the manual ASA setting on the back (I generally rate my film differently from the speed on the box)

 

Manually setting the speed over-rides the reader, but the AE still works perfectly. In my experience, the AE on the M7 is first class.

[alun]

Guys,

OK so it looks like the M7 will need to return to base soon but while I still have a film in perhaps I can set the iso to 400 (Provia 400) and then the exposure might be correct as the DX reader circuit won't be used? But someone mentioned asking about checking the other numerous circuit boards.

 

Lincoln, Yes, I suggested getting Leica to OK the other circuit boards -- but your own suggestion of checking the metering with the ISO set manually is also helpful. In my case, the same mis-reading/false metering happened *even* with the ISO set manually -- this is what alerted me to the fact that there had to be a further problem in addition to the DX reader.