[johnha]

Hi All, I've recently obtained a 75mm shift lens for my P67 - but the camera won't meter with it. All my other lenses are fine in open aperture & stop-down metering with the same body & prism. As the lens has no aperture simulator & stop-down lever - I can't work out why it wouldn't work.

Any ideas or suggestions?

John.

[Silent Street]

Doesn't that lens have a two-stage operation whereby aperture is set also at the front once shift mode is engaged?
Or might it be the case that the lens has been modified?

With shift or tilt+shift lenses (e.g. Canon's TS-E lenses and Nikon's own versions), and also the P67, metering errors are introduced whenever the lens is shifted or tilted from the perpendicular, because the light coming through the lens is being skewed away from the centreline of the metering cell(s). The trick to correct metering is to assess movement(s), then zero them. Meter the scene, and lock the reading in, then apply shift and/or tilt+shift.

Shift alone is a limited and not particularly useful function to have in cameras with no back-tilt to compensate.

[johnha]

Doesn't that lens have a two-stage operation whereby aperture is set also at the front once shift mode is engaged?
Or might it be the case that the lens has been modified?

Yes, the aperture is preset at the front - which I understand - but it won't meter with the aperture set 'wide-open' at f/4.5 with zero shift set. The mount doesn't have the aperture simulator or the stop-down lever (as I'd expect with a non-open-aperture lens) and also doesn't have the AUTO/MAN stop-down switch (again as I'd expect). I don't known how the Auto/Man switch changes the interface with the camera* for those lenses that have them (I believe it does more than just stop the aperture down as one of my bodies/prism will only meter with it in the MAN position).

* Further inspection shows that my other lenses extend a pin at the 3 o'clock position when set to MAN - which retracts when set to AUTO - the 75mm shift lens (with no AUTO/MAN switch) has a different arrangement with a machined notch where this pin mechanism is present on other lenses. It doesn't look like it's been modified.

John.

[abruzzi]

I've never used the lens, but I was under the impression that stop-down metering should work. The aperture selection is transmitted to the TTL finder through the metering chain (on the 6x7 and 67). Because of the shift there is no mechanical way to pass that back to the camera, so It should only meter on actual light. So you would set the aperture and shutter speed to get the meter to give you a good reading. If you close down the aperture during this process the viewfinder will become dark and unusable, so once exposure is set, open the aperture up, focus, stop it back down and take the picture. The preset ring is used so you can easily stop back to your metered aperture without having to look at the lens. Is this what you're doing and its not working?

[johnha]

I've never used the lens, but I was under the impression that stop-down metering should work. The aperture selection is transmitted to the TTL finder through the metering chain (on the 6x7 and 67). Because of the shift there is no mechanical way to pass that back to the camera, so It should only meter on actual light. So you would set the aperture and shutter speed to get the meter to give you a good reading. If you close down the aperture during this process the viewfinder will become dark and unusable, so once exposure is set, open the aperture up, focus, stop it back down and take the picture. The preset ring is used so you can easily stop back to your metered aperture without having to look at the lens. Is this what you're doing and its not working?

The preset & aperture rings are working as described - the lens does not have the aperture simulator mechanism (which connects to the meter chain on other lenses). The lens mount is similar to the Auto Extension Tubes (but without the stop-down lever as I'd expect). As I understand it, stop-down-metering is activated by switching the lens AUTO/MAN switch to MAN - this changes something to do with the pin at 3 o'clock on the lens mount. This lens does not have the AUTO/MAN switch (which makes sense), so it should always be in stop-down mode - except there's no movement from the meter. The lens itself has no moving parts to the mount (as I'd expect), so it's not like anything is missing or broken, the machined notch where the 3 o'clock pin connects looks fine and similar to those on my Auto-Extension-Tubes.

It may be a body/prism issue - I have two body/prism pairs. One pair meters in both open & stop-down modes, the other only in stop-down mode - swapping bodies & prisms leaves neither metering in any mode (I've given up trying to reason why!). Neither pair will meter with the Auto-Extension-Tubes in any mode - which sounds very similar to the problem I'm having with the 75mm Shift lens.

[abruzzi]

strange. So if you open the aperture wide (f4.5), and set the shutter speed to something that puts the needle in the middle (indicating correct exposure) then you shut down the aperture to f32, the needle stays where it is? And to confirm if you do that when you're looking in the viewfinder, it darkens, and if looking at the front of the lens, you see the aperture
stop down?

[johnha]

strange. So if you open the aperture wide (f4.5), and set the shutter speed to something that puts the needle in the middle (indicating correct exposure)

This is the problem, I'm not getting a meter reading at this point, the needle sits right at the bottom of the scale, even though the shutter speed, film speed and ambient light is more than enough for over-exposure. All my other lenses (which do have AUTO/MAN switches) are fine at this point.

then you shut down the aperture to f32, the needle stays where it is? And to confirm if you do that when you're looking in the viewfinder, it darkens, and if looking at the front of the lens, you see the aperture stop down?

The problem is totally related to metering, everything else works fine - there's nothing to go wrong, either on the back of the lens mount or the two aperture rings at the front.

[abruzzi]

Interesting. I can sort of confirm your observation. I took my lens off, set the shutter speed to 1 second and ISO to 400. I then pulled the lever to activate the meter for 15 seconds and pointed the opening of the camer at the sun and the needle in the meter stayed buried. At the bottom.

Then as a second test, I did all of the above, then on the upper portion of the inside of the mount there is a small lever that reads the aperture setting. The lever can be slid clockwise. This is the lever which the aperture ring uses to communicate the the opening to the TTL finder. Doing the same thing, then sliding the lever, the meter comes on almost instantly. So either both our cameras have the same issue, or the system requires the lens to move the lever enough to turn on the TTL finder.

EDIT: additionally, I removed the meter and reattached a lens. If you look just forward of the focusing screen you can see the slot and the piece in the slot that transmits the aperture to the TTL meter. With the finder off you can swing the from end to end and see that piece move back and forth in the slot. What surprised me is that with no lens attached, that piece is on the far left, with a lens mounted and opened to the largest aperture, it is close (but not completely) to the far right. Additionally with three lenses mounted: a f2.8, f3.5, and f4, when set to their widest aperture the piece seems to be at the exact same spot. This would make sense. That position would be open, and every ~5mm to the left is another stop, or halving of light. That makes me think that to do stop down metering there should be something on the lens mount of the shift lens to move the level to open position.

[johnha]

Interesting. I can sort of confirm your observation. I took my lens off, set the shutter speed to 1 second and ISO to 400. I then pulled the lever to activate the meter for 15 seconds and pointed the opening of the camer at the sun and the needle in the meter stayed buried. At the bottom.

Then as a second test, I did all of the above, then on the upper portion of the inside of the mount there is a small lever that reads the aperture setting. The lever can be slid clockwise. This is the lever which the aperture ring uses to communicate the the opening to the TTL finder. Doing the same thing, then sliding the lever, the meter comes on almost instantly. So either both our cameras have the same issue, or the system requires the lens to move the lever enough to turn on the TTL finder.

I think this is 'normal' operation - I presume the aperture simulator represents a very small aperture it it doesn't move at all.

[

That makes me think that to do stop down metering there should be something on the lens mount of the shift lens to move the level to open position.

That's what I thought at first, but my shift lens mount doesn't look like anything's missing and my Auto-Extension-Tubes have a similar mount (they don't activate the meter either).

[abruzzi]

I think this is 'normal' operation - I presume the aperture simulator represents a very small aperture it it doesn't move at all.

[

That's what I thought at first, but my shift lens mount doesn't look like anything's missing and my Auto-Extension-Tubes have a similar mount (they don't activate the meter either).

the funny thing is might not be all that hard to fake it out. You would simply want a fixed something at the position for wide open. When I tested all my lenses, f32 still kept the thingy pretty far from full left. The funny thing is there are reviews mentioning stop down metering on this lens. The only thing I can think of is that it works on the 67II, because clearly if you don't see a broken off/filed down tab on your lens, then it was never meant to meter on a 6x7 or a 67.

[Silent Street]

I'm noticing the mention of 'no metering' with the lens.
It's an outside shot, and a long one, but try resetting the metering.
Remove the prism.
Remove the lens.
Re-fit the prism, then
Re-mount the lens.

[gofour3]

It may be a body/prism issue - I have two body/prism pairs.

Yep I had a similar issue with my 67 TTL meter, it would only work if the lens lever was in the "MAN" position. (So no issues with you shift lens)

Solution was to ditch the TTL metered prism for good and only use a hand held meter on my 6x7 and 67 bodies.

The only good 6x7 metered prism is the 67ii AE.

Phil.

[desertscape]

There has also been a problem with manual lenses (400, 600 Takumar etc) that had problems activating the TTL. The lens locking pin in the face of the body also activates the meter when a lens is put in place. But if your lens slot that was meant to fit over that pin was not machined correctly, your TTL will not activate. That locking pin on the camera body lens mount face also has an internal pin that moves to activate the TTL. Your locking pin slot may not be the right dimension.

[johnha]

Yep I had a similar issue with my 67 TTL meter, it would only work if the lens lever was in the "MAN" position. (So no issues with you shift lens)

Solution was to ditch the TTL metered prism for good and only use a hand held meter on my 6x7 and 67 bodies.

Thanks Phil, I'm rapidly coming to the conclusion that I might have to do this in some situations (the meter prism is handy and works for most lenses).

There has also been a problem with manual lenses (400, 600 Takumar etc) that had problems activating the TTL. The lens locking pin in the face of the body also activates the meter when a lens is put in place. But if your lens slot that was meant to fit over that pin was not machined correctly, your TTL will not activate. That locking pin on the camera body lens mount face also has an internal pin that moves to activate the TTL. Your locking pin slot may not be the right dimension.

Thanks desertscape - I think it's a problem with the pin at 3 o'clock more than the lens (I see the same thing with extension tubes - I wouldn't expect several mounts to have incorrect slots). Happier with the lens now that it looks less likely it's a lens fault.

[tuco]

Thanks Phil, I'm rapidly coming to the conclusion that I might have to do this in some situations (the meter prism is handy and works for most lenses).

None of the the 4 cameras in my signature have light meters and it hasn't stopped me from taking pictures. I have a light meter app on my phone when I don't want to carry my one-degree spot meter and it does a good job.