crawdiddy
qu'est-ce que c'est?
Hello Brian, I need some advice. And probably a ball bearing.
I have a "user" Canon 50mm 1.4 lens. The aperture ring originally turned freely-- it moved the aperture blades, but little resistance, and no click stops.
I removed the locking ring from the back, and that's all it took to reveal the aperture mechanism. There was a piece of brass or steel band bent into a U-shape, and attached with 2 screws. It appeared to me that it was attached backwards. The "bow" of the metal flexed away from the aperture ring. I could see that if it was reattached the opposite way, it would press against the aperture ring like a spring, thus providing resistance when changing apertures. I did that, and it's definitely an improvement.
Now, I need click stops. It appears there's a small hole directly in the middle of the brass or steel spring that presses against the aperture ring. And on the aperture ring there's a small indentation to match up with each designated f-stop. So, there must have been a ball bearing that fit into the hole of the brass or steel spring, that also clicked into place on each f-stop detente.
The question is-- how big should the ball bearing be?
I removed a bearing from a ball-point pen, and it appears to be about .75 mm in diameter. It's too small (it passes through the hole in the spring). Do you have any idea how large it should be? And is the exact size critical, or do I have some latitude?
I looked on the 'bay for bearings, and found some 1mm, 2mm, 3mm, etc. I hate to buy 100 of the wrong size. Also, does the composition matter? Is steel/chrome OK? Or should I get brass balls? (always wanted some of those)
Any advice from Brian, or any other lens gear-head would be appreciated.
I have a "user" Canon 50mm 1.4 lens. The aperture ring originally turned freely-- it moved the aperture blades, but little resistance, and no click stops.
I removed the locking ring from the back, and that's all it took to reveal the aperture mechanism. There was a piece of brass or steel band bent into a U-shape, and attached with 2 screws. It appeared to me that it was attached backwards. The "bow" of the metal flexed away from the aperture ring. I could see that if it was reattached the opposite way, it would press against the aperture ring like a spring, thus providing resistance when changing apertures. I did that, and it's definitely an improvement.
Now, I need click stops. It appears there's a small hole directly in the middle of the brass or steel spring that presses against the aperture ring. And on the aperture ring there's a small indentation to match up with each designated f-stop. So, there must have been a ball bearing that fit into the hole of the brass or steel spring, that also clicked into place on each f-stop detente.
The question is-- how big should the ball bearing be?
I removed a bearing from a ball-point pen, and it appears to be about .75 mm in diameter. It's too small (it passes through the hole in the spring). Do you have any idea how large it should be? And is the exact size critical, or do I have some latitude?
I looked on the 'bay for bearings, and found some 1mm, 2mm, 3mm, etc. I hate to buy 100 of the wrong size. Also, does the composition matter? Is steel/chrome OK? Or should I get brass balls? (always wanted some of those)
Any advice from Brian, or any other lens gear-head would be appreciated.
