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Message |
    
Jwong
Tinkerer
Username: Jwong
Post Number: 8
Registered: 05-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, October 27, 2012 - 10:31 pm: | 
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Got it from eBay. Look nice. But none of the testing shoots turned out correctly (see pic) and believe the lens focus at about 1 cm in front of the film. Wondering the lenses were put back in the wrong order. The front elements look good. I was able to remove the rear lens but not be able to take out the next one. Any idea?
Thanks in advance. |
Jwong
Tinkerer
Username: Jwong
Post Number: 9
Registered: 05-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, October 27, 2012 - 10:41 pm: |
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It is a 50mm F1.8 Mark II. The one with black body.
Thanks, |
Hollenbj
Tinkerer
Username: Hollenbj
Post Number: 92
Registered: 03-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, October 28, 2012 - 11:39 am: |
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I'm confused. Mark II? Are you talking about a 50mm 1.8 lens with Leica Thread Mount (LTM) for rangefinders?
Perhaps you could post a picture of the lens. Also, which body are you using this on? |
Jwong
Tinkerer
Username: Jwong
Post Number: 10
Registered: 05-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, October 28, 2012 - 08:08 pm: |
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Hollenbj,
Thanks for your reply. Will try to post a picture later. Yes, it is leica thread mount. I was using it on a Canon P. I stuck a piece of ground glass at the film chamber to test the focusing. It cannot focus at infinity.
Best Regards, |
Jwong
Tinkerer
Username: Jwong
Post Number: 11
Registered: 05-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 29, 2012 - 09:16 pm: |
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Here is the lens. |
Br1078lum
Tinkerer
Username: Br1078lum
Post Number: 414
Registered: 11-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, October 31, 2012 - 07:54 am: |
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I tore one of these down to clean the elements, though it was only the back set that needed to come out, so I left well enough alone on the front set. But you can see the photos of the operation at http://flic.kr/s/aHsjwpsne9 There is a very thin ring that goes on the rear set, but I'm not sure if it would affect the focus if it were to be missing. It's been a while since I worked on the lens.
PF |
Jwong
Tinkerer
Username: Jwong
Post Number: 12
Registered: 05-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, October 31, 2012 - 08:34 pm: |
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Dear PF,
Thanks a lot. That's the path I am on at the moment. I suspect the internal group may have been tempered. I was able to get to your step 3 and removed rear glass which seems unnecessary. I have no idea to move to step 4 and 5. There is nothing to grasp on to unscrew the rear set. Any hints?
Thanks,
jackey |
Jwong
Tinkerer
Username: Jwong
Post Number: 13
Registered: 05-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, October 31, 2012 - 11:50 pm: |
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Here is where I am. The rear glass was taken out.
Jackey |
Br1078lum
Tinkerer
Username: Br1078lum
Post Number: 415
Registered: 11-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, November 01, 2012 - 07:59 pm: |
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After looking at my photos, I think the next set of elements just screw out. I may have put a grip on them with a jar opener. A grippy rubber pad (like the kind you put under things to keep them from sliding) would work too. Make sure you note where it seperates from the front set, so that you put it back together on the same thread landing.
PF |
Jwong
Tinkerer
Username: Jwong
Post Number: 14
Registered: 05-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, November 03, 2012 - 01:19 am: |
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Dear PF,
Thanks for your advice. The block came off but it is different from your version! Obviously it was serviced before but cannot tell it was put together in the wrong way.
Best Regards,
   |
Jwong
Tinkerer
Username: Jwong
Post Number: 15
Registered: 05-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, November 03, 2012 - 01:54 am: |
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found a schematic of the canon 50mm serenar 1.8 which is a 6 lenses in 4 group. Not sure it is the same for this version. There are 2 lenses on the rear!
Best Regards,
Jackey |
Dirbel
Tinkerer
Username: Dirbel
Post Number: 85
Registered: 04-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, November 03, 2012 - 05:45 am: |
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Looking at the image in your first post, it seems that the lens does not cover the full frame (see the rounded corners of the negative).
I don't think that this is caused by focus alignment. Either the lens is assembled incorrectly, or an element is missing altogether.
According to this link: http://www.dantestella.com/technical/canoleic.html
the Serenar 50/1,8 and the later 50/1.8 are identical, and indeed have 6 lenses in 4 groups.
Ciao,
Dirk |
Br1078lum
Tinkerer
Username: Br1078lum
Post Number: 417
Registered: 11-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, November 03, 2012 - 07:42 pm: |
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The way the lens is designed, going in from the rear, you should have a single element and then a group of two elements. The same if you are going in from the front. As I recall, after looking at my photos again, I had to use all three spanners in my set to get the rear group out. It looks to me from your photos you have the proper elements, so the only thing I can think of is that the rear element may have been flipped. Also, you need to make sure that the rear group is properly seated before you install the rear element.
One thing I do not see in your photos is the thin ring that goes under the focusing mount. If that is missing, then it could be the cause of your problem.
PF |
Jwong
Tinkerer
Username: Jwong
Post Number: 16
Registered: 05-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, November 03, 2012 - 09:50 pm: |
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Dear PF and Dirk,
Thanks for your reply.
I tried to reverse the rear group in the opposite direction but it makes no different. The attached is the rear group which is convex on both side. The one facing the front is move convex then the other side which is different from the schematic I found on the internet. The one towards the front is concave, instead.
Dirk made a good point that it did not cover the full frame. Compared with the other Industar 61 I got, the image is much bigger.
No. I don't have the thin ring. I will try to shim it to see whether it makes any different.
Best Regards,
 |
Br1078lum
Tinkerer
Username: Br1078lum
Post Number: 418
Registered: 11-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, November 04, 2012 - 08:30 pm: |
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J, as I recall, it was about 0.5mm thick.
PF |
Jwong
Tinkerer
Username: Jwong
Post Number: 17
Registered: 05-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, November 04, 2012 - 11:42 pm: |
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Dear PF,
Thanks again. I believe I found there problem. A lens must be missing, bad. I came across the schematic of canon 50 f1.4 for rangefinder which said to be having the same construction. It is evident that the concave lens is missing, the 4th from the front. This lens is renounced for separation. I believe this is one of them. The previous owner removed the lens so that it looks nice from outside and I got a bad one. Bad ebay seller.
Thanks for all your help so far.
Best Regards,
 |
Br1078lum
Tinkerer
Username: Br1078lum
Post Number: 421
Registered: 11-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, November 05, 2012 - 12:20 pm: |
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Sorry to here that, J. Hope you can get your money back.
PF |
Jwong
Tinkerer
Username: Jwong
Post Number: 18
Registered: 05-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, November 05, 2012 - 07:40 pm: |
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Dear PF,
Thanks, it is too late already. I got an expensive body cap, never mind. An experience and hope others in this forum can be benefit from this.
Best Regards,
Jackey |
