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09-16-2011, 05:22 AM   #16
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QuoteOriginally posted by Just1MoreDave Quote
I just realized that getting to the other side of the pin mechanism is easier than my original instructions. Those would apply to something like a 50/1.4. For this lens, you remove the trim ring with the lens name on it, unscrewing it with a friction tool via the filter threads. Then you'll see something like this:

Remove the three screws that aren't in little cutouts, and the filter ring comes off. Then remove the other three screws. (Note that these have washers with them.) Then the whole optical assembly can be removed from the lens: front group, rear group and aperture. It's impressively heavy. Set that aside in a safe place and you're left with this:

That's enough access to the mechanism to see what's not moving right and fix it. When you reinstall the optics, the aperture pin on the optic assembly slides into that fork on the right. Put in the three screws with washers but don't tighten them yet. Now you can rotate the assembly to make sure that the blades disappear whjen the aperture ring is at f1.9, and close fully at f16. When that's adjusted, tighten the screws, put the filter ring back on and screw the trim ring back on.
The 50/1.4 comes apart in exactly the same way. You only need to remove the focus ring if you want to fix the DoF scale.

09-16-2011, 08:28 AM   #17
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QuoteOriginally posted by boriscleto Quote
...I am going on the assumption that lenses intended for export to the US had slotted screws while lenses intended for the home market had JIS.

All of the M-series lenses I've looked at have JIS screws.
That's a valid theory. We got all the parts labeled Honeywell, why not different screws? I haven't seen any slotted screws on M series lenses either.

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