Canon Quest

The AT-1.
Using FD lenses.
The newer lens, with the silver push-button release function Fine/Normally.
The older style FD, with the silver ring that turns, operates the aperture blades.
Looking through the view finder, you see the blades opening and closing as you turn the aperture ring. What causes this.?
Thank You

CMoore said:

The AT-1.Using FD lenses.The newer lens, with the silver push-button release function Fine/Normally.The older style FD, with the silver ring that turns, operates the aperture blades.Looking through the view finder, you see the blades opening and closing as you turn the aperture ring. What causes this.?Thank You

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When you are mounting the breach-lock (old style) lenses, make sure that the aperture pin (little pin on the bottom of the lens) is getting lined up with the arm that pushes it. Make sure the camera is not in Depth of Field Preview (botton the left of the lens, when looking through the view finder, the slides in towards the lens). If it is, the arm might be pushed in and the lens might not be mounting right.
The FDn (new style) lenses twist on, so they mount pretty much perfeclty every time, but I have mis-mounted a breeach lock lens on my AT-1 where the pin was on the wrong side of the arm and the aperture didn't work right.
Remember when mounting FD lenses on the AT-1 that they have to have an aperture selected, you can't mount them with the aperture set to "A".

Pretty much what this guy said.

T90 user here.

Hhmmmmm...OK. Definitely do not have the DOF selected, but let me check out a few things.
Thanks

The older breech-lock style lenses also have an "FL-mode" position of the aperture lever on the back of the lens. The big lever, the one that sicks out farther. If, looking from the back of the lens, you push that lever counterclockwise until you feel some resistance, then keep pushing it farther, it will click and stay in the FL-mode position. Then, when you mount the lens, the aperture will move with the ring as you describe. To take it out of this mode, simply push the lever clockwise until it clicks past the midpoint and then you're in fully automatic FD mode again.

A couple of breechlock lenses didn't have room for this mechanism, and so they had a little swinging black lever that would flip over to lock the long aperture lever in place when you wanted it in this mode. But the vast majority of breechlock lenses work as described above.

The later bayonet style lenses had no provision for manual aperture mode, I guess because they thought nobody cared any more, or had any FL cameras that needed new lenses at that point, or something. So Canon actually sold an official little piece of plastic that would jam the lever in the most counterclockwise position! (If you can't find one of those doohickeys for sale, a cut off piece of Q-Tip shaft works pretty well...)

Duncan

That is kind of what I did ^^^^^^^. ...and YES, it as that aperture lever.
I pushed down on the small, silver, button on the inside lens rim, and then pushed that lever to its "down" position.
Now the lens operates "normally" when installed.
Thanks Again