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terry
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, April 05, 2005 - 07:36 pm: | 
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Is there anyone who can help me with the next step ? I have a canon 35-70 mm fd zoom lens with some fungus on the front lenses. I have managed to take the rear of the camera apart, and the ring on the front of the camera. The plate holding the aperture controls is still in the back, and I haven't been able to figure out how to get the front lens ssection out. It has been an interesting project. any ideas? |
Glenn Middleton
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, April 06, 2005 - 08:51 am: |
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Which 35/70 fd is this? On all metal early f4 after removing name plate,remove the metal spider,3/4 screws.Do not loose the rubber pads attached to spider.The front group then unscrews,if I remember correctly.TAKE GREAT CARE when screwing the front group back.If you screw it in to far when you focus and zoom,the rear element of front group will HIT AND MARK the front element of rear group.As the hit is in a circular motion, you will leave a nice ground ring on rear group!Seen this 3 times on otherwise mint lenses.If the lens is the all plastic later version then I have not pulled one apart. They are so cheap to replace,not worth the effort.I would suspect that the front group is held in by a circular plate and +point screws,But I do not have any short zoom fd manuals, so I could be completely wrong.I am a prime lens man myself. |
Terry
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, April 06, 2005 - 09:03 am: |
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Thanks Glenn,
This is the metal version. but I haven't figured out how to get off the ring with the nameplate on it. There are no notches as on the outer ring , and no holes to attach a tool to. I will look more closely tonight |
Glenn Middleton
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, April 06, 2005 - 10:22 am: |
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Terry,I assume you mean the circular front name plate.It is held in by adhesive.You have to lever it out.I made a j shaped lever from a thin 6 inch metal ruler.Ground the bent bit to 3/16 inch wide then heated ,bent and polished then retempered.Using a pad of micro lens cloth to protect glass,insert lever between glass and plastic ring.Gently lever ring up and out.The slotted outer ring hides the grooves the spider rides in.If I remember correctly when you remove name plate before doing anything else you should put datum lines on 1,position of spider re outer barrel 2,position of lens group re outer barrel.This should be done at a known focal length and minimum focus,ie get front group as near to front of barrel as possible.Long time since I did this and did not take notes.When spider is removed the front group will rotate with focus ring and not move in/out of helical.To remove screw it out, having marked a datum and count number of turns also.That hitting rear elements thing. |
terry
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, April 06, 2005 - 06:55 pm: |
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I think I did it. Thanks for the help. Unscrewing the lens holder was a shock as it came completely off after about 1/2 turn. It has a 5 start screw thread on the barrel, and before I even knew what was happening it was loose. I think it's all good noe. It doesnt seem to be hitting anywhere, so I ready to shoot some film and see if it works.
Thanks again
Terry |
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