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02-07-2010, 08:53 PM   #1
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Rexatar 200mm f3.3 M42 prime

Hello,

Thanks to a fellow forum member, I got this lens in need pretty much for free. If you have never heard of this brand before, Rexatar, it seems it was some sort of generic "brand name" japanese lens manufacturer in the 60's. I'd be interested in getting any additional information on this company. I've seen reference to a few other lenses in their line.

Rexatar 200mm f3.3 Prime. M42 mount

There was considerable internal dust and the diaphragm blades were oily and sticky








The auto diaphragm pin is broken and not worth saving, so it is disabled. The lens is now manually stop down only.


Took it apart very carefully and everything was cleaned. The blades were also carefully cleaned.


After a few hours in the operating room, everything went back together....


...and it looks promising! Focus is very smooth and the aperture now works reliably.


...ready to rock and roll!


I'll post results with it later.....

Thanks,


Last edited by ismaelg; 07-21-2011 at 07:51 PM.
02-07-2010, 08:59 PM   #2
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02-07-2010, 09:30 PM   #3
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I had a Rexatar 50/1.7 in the early 1970s. It came attached to a Ricoh Singlex TLS as part of a bait and switch from Bass Camera. Instead of a Rikenon, they sent a Rexatar. The lens and camera left my hands about 25 years ago, but my recollection is that it was an Ok lens. Be sure and share your photos on the "Off-brand Club" thread.

Steve
02-07-2010, 09:58 PM   #4
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I have a Makinon badged lens that appears to be identical except for the Makinon name engraved on the pull out lens hood. It's alright, but has heavy purple/green fringing on high contrast scenes. I've essentially replaced it with a Vivitar 70-210 f/3.5 that is about twice the size.

02-08-2010, 05:43 AM   #5
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It looks like new now! You've grown some skills that can turn dust into gold I am about to begin a similar operation--my first--on a M 28mm 3.5. Did you follow any online advice? (I've discovered a couple of very helpful sites, and I don't intend to disassemble the lens completely--I understand blades of a prime can be fairly easily cleaned if I remove the back element.) Anything you could share? Thanks.
02-08-2010, 10:07 AM   #6
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Thanks for the comments!
causey, The best advise I can give you is work slowly and take your time. Make sure you have enough time to do as much as possible in one shot. If you leave it in the middle to come back later, you may loose track of what goes where. I keep a space and I place the parts in the exact same order and orientation (up or down) as I take them out. If possible, take pictures of the process or even a video. I've never done a video but it may help. Another suggestion is to disassemble only the minimum needed. In this case the focusing mechanism was working fine, so I didn't touch it.
I use lens cleaner solution with a microfiber towel to clean the elements. T try to make sure they are streak and dust free (or as close as you can get).
The best resource I've found is right here in this forum. Everytime I have a question somebody here has helped. I am by no means an expert but I'll be glad to help as much as I can.

Thanks,
02-08-2010, 11:50 AM   #7
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QuoteOriginally posted by causey Quote
It looks like new now! You've grown some skills that can turn dust into gold I am about to begin a similar operation--my first--on a M 28mm 3.5. Did you follow any online advice? (I've discovered a couple of very helpful sites, and I don't intend to disassemble the lens completely--I understand blades of a prime can be fairly easily cleaned if I remove the back element.) Anything you could share? Thanks.
I had a couple of M 28mm lenses with slow blades that were really problems with the other parts of the mechanism. On one, I cleaned the blades in place several times before realizing there were other issues. Finally when I decided to take everything apart, I discovered another part was loose. It was the post that connects the blades to the aperture lever, held on by just one screw. On another lens, the aperture lever itself was not moving right. I used some graphite lube on it after taking it off the lens, and carefully removed any excess before reinstalling. If it is oil on the blades and you end up cleaning individual blades and reasssembling, at least there are only 5.
02-08-2010, 05:34 PM   #8
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ismaelg

did you ever figure out a way to stop the aperture from collapsing from the hexagon to a triangle.

Look at your shotr of the lens stopped down, ultimately it will become a triangle as 3 of the 6 blades are stopping down faster than the others.

I have 2 rikenon lenses exhibiting the same problem. a 50mm F2 and A 135 f2,8.

I am not sure whether it is build quality or erar in the mechanism.

02-08-2010, 06:02 PM   #9
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Lowell,

The blades were oily. After cleaning them very carefully with lighter fluid on a swab, it closes properly. However I took another look now and at the smallest aperture (f22) the hexagon is not exactly perfect. Still a hexagon, but not perfect.
So it may be a lubrication/friction issue.

Thanks,
02-08-2010, 07:18 PM   #10
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Here are some shots of this lens, while mounted on the Sightseer camera. (Pentax SV)

Chistopher Columbus ships at the Lighthouse Park











At sunset from across the parking lot


My favorite of this series so far.....even with the thick haze


I think it passes the test. What do you think?

Thanks,
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