Mirror lockup on Spotmatic SP II

Vonder · Jun 12, 2009

Does the Pentax Spotmatic SP II have a mirror lockup feature? I went to take a pic with mine today and discovered the mirror was up. I had just changed the lens. It came down after I pressed the shutter button.

Never seen this before, but I've had the camera less than a month.

ntenny · Jun 12, 2009

I am given to understand that this is a common age-related behaviour with screwmount Pentaxen. Eventually the mirror gets stuck in the up position and stays there.

I've got an SP500 that's in terrific shape other than a stuck mirror, and I've been trying to figure out how to fix it; no luck so far.

-NT

filmamigo · Jun 12, 2009

I have also seen folks demonstrate an "undocumented" Mirror Lock Up for Pentax bodies -- where light pressure on the shutter release will release the mirror without firing the shutter. Pressing the shutter release fully then completes the cycle.

I had heard about this, but someone actually demonstrated it to me on a Spotmatic body.

Phil · Jun 12, 2009

The SP II does not have a mirror lockup, but I did learn a trick from a Honeywell Pentax salesman back in the early 70's... With a little practice you can get pretty good at it, too.

With the shutter cocked, lightly tap the shutter release - what you are going for is a 'half release' - you want to release the mirror without releasing the shutter. It may take a few taps - a bit harder each time - to get the knack of it. Once the mirror locks up, press the shutter release and the shutter opens and closes, and the mirror returns to the down position.

I'd guess your shutter release got bumped whe you were changing the lens and kicked the mirror up.

Rol_Lei Nut · Jun 12, 2009

I can also do the "flick" mirror lockup trick, but not dependably (also works on the Leicaflex SL & SL2).

Your mirror probably got flicked up by accident as has been mentioned.
Otherwise, I think only really sticky bad foam or "extremely" thickened old grease, or some loose screw or foreign object which got stuck would cause it to stick in the upward position.

Vonder · Jun 12, 2009

Thanks, everyone!

It returned to normal after I clicked the shutter, so it sounds like I must've accidentally hit the button enough to cause the lockup. Scary moment though. I thought for a second it was broken. I did try and wiggle it back down, but stopped when I saw it was mechanically locked. It just came back from CLA and I think it's working as it should.

geauxpez · Jun 12, 2009

A mirror lockup switch was a dealer-installed option for the Spotmatic that not many consumers took advantage of. It would be located on the left side of the lens mount (when facing the lens) and resembles the metering switch. I have only seen a photo of one that came up in a thread on Pentaxforums recently.

John Koehrer · Jun 13, 2009

ntenny said:
I am given to understand that this is a common age-related behaviour with screwmount Pentaxen. Eventually the mirror gets stuck in the up position and stays there.

I've got an SP500 that's in terrific shape other than a stuck mirror, and I've been trying to figure out how to fix it; no luck so far.

-NT

Remove the bottom cover & towards the center of the camera is a lever that has probably slipped past is engagement point. simply pull the lever toward the back of the camera until it latches.
You will see the lever that cocks the mirror as viewed from the edge & going into the deep recesses of the body. The catch is flat with an engagement pawl.

ntenny · Jun 13, 2009

[SP500 with mirror stuck in "up" position]

John Koehrer said:
Remove the bottom cover & towards the center of the camera is a lever that has probably slipped past is engagement point. simply pull the lever toward the back of the camera until it latches.
You will see the lever that cocks the mirror as viewed from the edge & going into the deep recesses of the body. The catch is flat with an engagement pawl.

Thanks! This solves half my problem, in that nudging the lever releases the mirror, but if I cock and fire the shutter again, the problem just recurs.

The root of the problem seems to be that the arm that catches the mirror lever isn't turning clockwise far enough to release it when the shutter fires. Everything else is happening correctly, as far as I can tell, but the mirror lever doesn't quite get enough clearance to return. Research continues, but does anyone know how (or if) I can adjust that L-shaped arm?

Thanks

-NT

ntenny · Jun 13, 2009

Hey, I got it! I decided I stood to lose little by just futzing around with the L-shaped pawl, and managed to find the sweet spot, where it was providing enough tension to catch the mirror lever when the shutter was cocked, but had enough play to release it when the shutter fired. One more working camera!

-NT

Mirror lockup on Spotmatic SP II

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