Canon 50 1.4 newFD

ilguercio · Posted: Mon Jun 04, 2012 1:02 pm Post subject: Canon 50 1.4 newFD

I have one right now and i want to clean its elements and adapt it for EOS.
I already have a spare M42-EOS adapter for the conversion but i can't undertand how the aperture works.
So, does anybody know how to make it work?

ilguercio · Posted: Mon Jun 04, 2012 2:55 pm Post subject:

Ok, the adaption is quite easy as shown here.
I had figured that already, good for me.
Now , i am trying to unscrew the name plate at the front of the lens. It is turning but isn't screwing out Confused

ilguercio · Posted: Mon Jun 04, 2012 10:18 pm Post subject:

The name plate isn't screwed like most of the lenses but it is just fitted by pressure into the threads.
Fit a thin flat screwdriver between the ring and the barrel margin and you're done, just be gentle.
Once i removed thet fron group i saw a good amount of oil around the diaphragm assembly so i cleaned it.
The front group is strange, the furthest element (the nearest to the blades) is like fitted by pressure because it turns but it doesn't scren in or out.
What now?

ilguercio · Posted: Mon Jun 04, 2012 11:22 pm Post subject:

Just tried the lens freehand and it sucks Confused

Orio · Expire: 2012-12-04

Post some image samples, otherwise it's difficult for the people to comment on nothing...

ilguercio · Posted: Tue Jun 05, 2012 12:04 am Post subject:

Ok, i was clumsy enough to smear something on the front element rather than clean it.
Now it is back to normal, i guess.
Sorry for the stupid samples:
The lens itself under surgery

A sample from the lens handheld in front of the M42 adapter at 1.4

Now i need to design a spacer that'll screw on what is left of the mount and prevent the adapter from jamming the aperture ring.
Then i'll fit the adapter onto this spacer-ring and the mount will be complete.
I need to design something to link the aperture lever to the diaphragm fork as well, i just have to think about what's best.

Orio · Expire: 2012-12-04

The image taken by the lens looks ok to me.

ilguercio · Posted: Tue Jun 05, 2012 12:21 am Post subject:

Yes, now it's ok.
I already deleted the bad samples as they were took with a clearly dirty element (oily, i guess) .
Still, i can't understand how to separate the front elements.

ilguercio · Posted: Tue Jun 05, 2012 5:34 pm Post subject:

Ok, i figured out how to disassemble the front group of lenses.
There is a plastic retainer that simply snaps off with the help of a flat screwdriver, just be careful because it might break if you're too harsh.
Then you have the 3 elements just lined up and what you got to do is simply put the front element facing upwards and gently tap the bottom of the group onto a soft towel so the rear element of the front group can be freed.
Then it's the turn of the second lens, same procedure.
The front assembly isn't glued but spaced by air (thanks canon, at least i know that those spots arent the sign of adhesive deterioration) and that's a good thing.
As for the rear group, the last element simply screws off and then you have another lens together with the cemented doublet behind the aperture assembly. It looks like it is held in place by some sort of ring and since most of the dirt was in the front group i won't disassemble it further. I just cleaned the last element and the outer side of the penultimate, that's enough for me.