Problems with Pentax K1000 light sensor

[PentaxGuy]

I'm fairly new to film photography, so I was hoping someone could help me with my inquiry.

My boyfriend recently gave me a Pentax K1000 camera that he hasn't used for about 15 years. It still had the original battery in it from 30 years ago, and the funny thing is that the battery actually worked! But two days ago, the light sensor stopped working. I bought a new battery because I was sure that was the problem, but after installing the new battery the light sensor still didn't work. The weirdest thing is, if I set the shutter speed to faster (EDIT: actually, slower) than 1 second, the light sensor works just fine. I've tried fiddling with the aperture, the focus, the shutter speed; I've even tried using three different lenses. The only thing I haven't tried is winding the film back up and trying a different roll, though I can't imagine how that would make a difference. I'm really hoping I don't have to buy an external light meter; I'm on a fixed income and I can barely afford to be getting my rolls of film developed.

Thanks in advance for your advice!

 

[Derrel]

I think the film counter might have tio be at frame 1 or higher for the light meter system to work--many modern 35mm cameras with built-in light metering have that requirement. The camera's exposure controls,the film ASA setting, the f/stop on the lens, and the shutter speed on the body all need to be within the range of the metering system as well--so for example if the ASA is set to 25 and the lens is set to f/16 and the shutter speed is at 1/1000 and you are indoors, you could be well below the light meter's working range. As I recall, the meter's on/off switch is the lens cap: with the lens cap removed, the meter is ON all the time, as I recall. Take these as general guidelines,not gospel; it has been years since I held a K1000 in my hands, but I do remember the camera very well from the early 1980's,and I have used several of them.

 

[PentaxGuy]

I think the film counter might have tio be at frame 1 or higher for the light meter system to work--many modern 35mm cameras with built-in light metering have that requirement.

I had 200 ISO film loaded, and it was on exposure 17 or 18... I unloaded it and put in some 100 ISO film, tried advancing it to frame 1, and it's still not working.

The camera's exposure controls,the film ASA setting, the f/stop on the lens, and the shutter speed on the body all need to be within the range of the metering system as well--so for example if the ASA is set to 25 and the lens is set to f/16 and the shutter speed is at 1/1000 and you are indoors, you could be well below the light meter's working range.

The ASA was set to 200 (I think, if I'm understanding the meaning of ASA correctly), the lens was set to anywhere from f/2.8-22, and the shutter speed was at 1000 and I was outside in brilliant sunlight. This doesn't sound promising.

Thank you very much for your advice!

 

[usayit]

First of all, the camera does not read the ISO from the film canister like modern cameras. The camera is completely mechanical. The battery and the ASA/ISO dial are only for the metering.

What you are describing is normal.. (as I understand your description).

If you temporarily set your ASA to 100, the shutter to B, lens cap off, pointed at something with light on it, your meter should read all the way up/+ (lens cap off). That will tell you if the meter is operational and battery is good. In this setting, it will always be at full up/+ under all lighting conditions.

If you go beyond the range of the meter (way over expose), the meter will read all the way down/- which might lead you to believe that the meter is non-functioning. If it is way underexposed reading it will show the same thing.

 

[usayit]

Also,

store the camera with lens cap on and not in "B" to avoid draining the battery. If long term storage, take the battery out. One of the camera's weaknesses is the lack of an off switch for the meter.

 

[PentaxGuy]

^Thanks for the great information. Forgive my ignorance, but is there any way that you know of to fix it? I've cleaned the battery contacts and it's still reading the same thing; way overexposed at B and 1 second no matter what the exposure settings are, and every other shutter speed, ASA and aperture reads right in the centre.

EDIT: I just realised that I may have caused some confusion with my OP; I meant to say that if I set the shutter speed to SLOWER than one second (meaning 1' and B) then the light meter works, but if I set it to >2' then it sits square in the centre.

 

[compur]

It's not broken.

Read the manual and learn how to use the meter.

There's a manual here:
Pentax K 1000 instruction manual, user manual, PDF manual, free manuals

 

[PentaxGuy]

It's not broken.

Read the manual and learn how to use the meter.

There's a manual here:
Pentax K 1000 instruction manual, user manual, PDF manual, free manuals

Thank you, but I'm not seeing anything in the manual that specifically describes my problem.

 

[compur]

Page 24 might help you understand that your camera isn't broken.

The meter needle only moves when your exposure settings are
close to being correct. If they are too far off then the needle
rests at either the very top or bottom. As you approach the
correct settings the needle will begin to move.

If you set shutter speed at B the needle will never move no
matter what else you do because B is not a fixed shutter
speed so exposure can't be calculated in advance.

If you set it at 1 second the needle will only begin to move
if the lighting is dim enough that a 1 second exposure will
be close to being correct and so on.

 

[PentaxGuy]

^Okay, that makes sense, but that's not really the issue I'm having. I'm sorry for being unclear. The light meter rests at the top if I put it on B or 1 second, but if I put it to anything faster than 2 seconds it rests at the centre and doesn't move no matter what shutter speed or aperture I set the camera to. I just tried a wide variety of shutter speeds and apertures from 1/60s up to 1/1000s and f/2.8-22, and nothing made the light meter move.

 

[compur]

^ OK, then if the needle hangs in the center position and won't move then
there is a problem.

All you can do is clean the battery chamber and try a fresh battery. Beyond
that, it needs repair service.

 

[PentaxGuy]

^Thank you, compur.

Something I should add: for the few days after I received it, the light meter worked just fine; last Thursday, though, it completely stopped working aside from when I put the shutter on B and the ASA dial on 200ISO (and even then it only worked when I had the shutter on B or 1'). Any other ISO or shutter speed, the light meter bar sits square in the centre.

 

[Pgeobc]

Silicon photo diodes only live about 15 years or so, someone told me. Indeed, I had an old Weston Master V light meter for which I had to replace the silicon diode.

There is an outfit near Los Angeles, CA or Hollywood that I sent my meter to and they did a spectacular job of putting in parts and calibrating it. Best you should find a good repair house and see what they can do for you.

There is also another little matter: many of these old cameras used mercury batteries to run the light meter. It was a good deal then, because the mercury battery had a quite level voltage output and the meters could be made without voltage-regulating circuitry and were, therefore, cheaper. Modern alkaline batteries and others often do not work nearly as well.

 

[ecenur]

I'm fairly new to film photography, so I was hoping someone could help me with my inquiry.

My boyfriend recently gave me a Pentax K1000 camera that he hasn't used for about 15 years. It still had the original battery in it from 30 years ago, and the funny thing is that the battery actually worked! But two days ago, the light sensor stopped working. I bought a new battery because I was sure that was the problem, but after installing the new battery the light sensor still didn't work. The weirdest thing is, if I set the shutter speed to faster (EDIT: actually, slower) than 1 second, the light sensor works just fine. I've tried fiddling with the aperture, the focus, the shutter speed; I've even tried using three different lenses. The only thing I haven't tried is winding the film back up and trying a different roll, though I can't imagine how that would make a difference. I'm really hoping I don't have to buy an external light meter; I'm on a fixed income and I can barely afford to be getting my rolls of film developed.

Thanks in advance for your advice!

I think your boyfriend bought you a great gift, i think you should take the camera somewhere to see what the problem is before you end up buying something else.

 

[John Mc]

I agree,get it serviced,if its been sitting about doing nothing for 15 years its bound to need a service,i know from experience you can no longer ger the battrys for it,they have a rubber ring around them preventing them moving in the camera body.which might be the issue. the K1000 is a brilliant camera,were using them in my course,and despite having my own flim camera with me,ive allways borowed one as a back up