Spotmatic F - Sticking mirror

[Steve Smith]

I've had a Spotmatic F for about a year now, and my research and experience is that the meter is turned on and off by removing and replacing the lens cap. The switch is for use with older Takumar and other screwmount lenses that need to be stopped down to engage the meter.

You could be right but the part in the manual about checking the battery suggests otherwise:

How to check it

1. Set the shutter speed dial to B (bulb) position.

2. Turn the ASA dial to ASA 100.

3. Push the meter switch to "on" position.

Look at the meters needle through the viewfinder. If the needle rapidly drops, the meter battery has sufficient capacity; if it does not, replace the mercury battery.

Just stopping down the lens would not have this effect.

EDIT: I just found this which also suggests a switch: http://forum.mflenses.com/userpix/27...chematic_1.jpg


Steve.

[drkhalsa]

You're correct Steve, what I mean to say is that for lenses other than the SMC Takumars (which work automatically), the switch needs to be pushed up to engage the meter. The switch in effect stops down the aperture and turns on the meter.

I have 2 Yashinon lenses which require the switch in the up position to activate the meter.

I focus with the switch off and meter with the switch on.

[Toffle]

You're correct Steve, what I mean to say is that for lenses other than the SMC Takumars (which work automatically), the switch needs to be pushed up to engage the meter. The switch in effect stops down the aperture and turns on the meter.

I have 2 Yashinon lenses which require the switch in the up position to activate the meter.

I focus with the switch off and meter with the switch on.

I wonder how many times a photographer has said, "the manual wasn't very clear on that..."?

I still don't get it... so if I have a SMC Takumar mounted, the meter is activated by some ??? mechanism that knows that I've lost the lenscap. (never had it, but in my case, it just saves me time) Will the meter run until the battery runs out or until I stick it inside a sock and block the light from the lens? How about the 28mm Opticam Auto, which has a lenscap, or the 35-80 Tamron Macro Zoom, which doesn't have a cap, but a skylight and a rubber hood?

Oh, I'm so confused. Ok, simple but probably stupid question, will any old lenscap work?

I need a nap.

[MattKing]

Tom:

It's the light itself that turns the meter "on".

So by making it dark, a lens cap turns it off.

[Toffle]

Tom:

It's the light itself that turns the meter "on".

So by making it dark, a lens cap turns it off.

Thanks Matt, I hoped it was something that easy.

[Toffle]

Tom:

It's the light itself that turns the meter "on".

So by making it dark, a lens cap turns it off.

This, from Camerapedia,"The light meter is constantly switched on but there is an automatic cut-off when the light is at EV2 or less, so it is important to keep the lens cap on when the camera is not in use, in order to conserve the battery."

[Steve Smith]

,"The light meter is constantly switched on but there is an automatic cut-off when the light is at EV2 or less, so it is important to keep the lens cap on when the camera is not in use, in order to conserve the battery."

I don't think this is correct. I tried out my father's Spotmatic this afternoon (because mine doesn't have a battery in it). The manual says that to test the battery, put the shutter speed to B and ASA to 100 and turn on the meter. The needle should move down if the battery is o.k.

I did this and noticed that the initial movement of the switch closed down the aperture (it's not an F) then after a bit more movement, the meter needle moved so there is definitely a switch there.

I have heard about keeping the lens cap on some Pentax cameras such as the K1000 and the KM as they don't have meter switches but this thread is the first time I have heard it referred to for a Spotmatic. It also seems silly to me that someone would design a camera with a switch/lever which you had to move to meter, call it a meter switch in the manual but not actually have a switch there.

Someone here must have taken one apart and could give us a definitive answer.

If the information in the Camerapedia link is correct then I think it must only apply to the F model.


Steve.