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Jackson
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 16, 2004 - 10:08 pm: | 
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Just thought I'd post the progress I'm making on this beast. Maybe there's something to be learned from my mistakes. A description of the problems and work I've done up to this point are posted below in other conversations.
To summarize, I've separated the lens plate from the body, cleaned the shutter and aperture blades, and replaced the entire meter block and rangefinder assembly with components from a donor (junker). After reassembling the camera two days ago, I checked focus using ground glass (actually a piece of plexiglass with "magic" tape on the film plane side). It turned out the lens was focussing short. Subjects at rougly 4 ft. were sharp when the focus ring read approximately 7 ft., and the lens wouldn't reach infinity. I didn't see an easy way to adjust this, nor did I think anything had broken or been misadjusted at the factory so severely as to create this problem. So, rather than go further into the innards, I decided to double-check my work. Assuming Murphy was the culprit, I removed the rear lens element from the rear lens assembly and flipped it over. (I had previously removed it for cleaning.) Following reassembly, the focus problem was no more (sigh).
While going through all this, I also discovered that the camera will focus very slightly past infinity at the stop. However, I've adjusted the rangefinder so that it agrees with the lens. As long as distant focus is performed using the rangefinder, not the stop, everything will be fine. I should add that infinity focus was checked using the second camera technique illustrated HERE. Wow, that really works! No way could I do as well with the ground glass, even using a 10X loupe. I wonder how the infinity alignment of the test camera (SLR with telephoto lens) affects the result. Does anyone know?
Today, I reinstalled the front lens element (previously removed for safety) and replaced all the rear light seals. I haven't checked/adjusted the meter yet, but it seems to be reasonably close in my initial, non-comparative observations. Regardless, I'll probably shoot a few frames using Sunny 16 tomorrow. I suspect those will be the first photos this camera has taken in at least twenty years. There's something very satisfying about that.
Incidentally, lens barrel removal wasn't without incident. As I feared, the pristine original leatherette tore during removal, so I will have to replace it with something more modern. Cameraleather.com doesn't stock this style precut, so I'll have to trim it by hand.
If all goes well, the meter adjustment and leatherette replacement are the last two tasks to restoring this camera to fully functional condition. I couldn't have gotten nearly this far without all the terrific contributors here. Many thanks again!
My Mamiya Sekor f/1.5 Rangefinder |
Will
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, September 17, 2004 - 03:18 pm: |
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Hi Jackson,
I've enjoyed following your progress on the "beast". That's quite a beautiful camera. I tip my hat to you for a job well done!
Will |
Jackson
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, September 18, 2004 - 06:36 pm: |
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Thanks, Will! I checked the metering circuit yesterday. Ironically, it's a little off with a mercury cell installed, but with an alkaline, it agrees exactly with my Gossen meter and a known good Nikon. I checked medium and low light conditions indoors during these tests, thinking those are usually the most critical and prone to mistracking. In any event, the accuracy is really just an accident; during my work I had to separate all the rings (i.e. carbon tracks), and it's simply luck that I set the adjustment to a good position during reassembly. Also, none of this means exposure will be correct. It only means that the metering circuit "thinks" it is. The shutter times could be off and/or aperture markings might be inaccurate. Luckily, I almost never shoot slides, so I can afford a wider window for error.
Today was a bright, sunny day, so I decided to shoot a test roll of ASA 400 color neg film. I shot several frames indoors using apertures ranging from about f/4 to wide open, then moved outdoors. Once I was outside, I removed the camera from its case and took advantage of the bright day to expose all sides to sun and check for leaks. I also checked the metering (with the alkaline cell) and discovered that it agrees with Sunny 16 rules - 1/500 secs and f/16. I shot a few frames outside to check exposure and stopped-down sharpness, then went inside for a couple followup shots to check focus accuracy.
I picked up the prints this afternoon, and they're remarkable. There's not one "failed" shot. They're accurately focussed and well exposed. Color rendition is also very good, so much so that it makes me wonder why we're all using MC lenses. I'm not exaggerating when I say the color is as good as any camera/lens I've ever used, and much better than many. Another thing I didn't expect is that the negs are all extremely sharp. In fact, I suspect this rivals my now-sold Koni-Omega and my best Nikon 50mm prime in terms of resolution. It's really very good, and I'm much more impressed by the results than by anything else I've shot recently. The only imperfection I can see is a very slight falloff at the extreme corners in frames I shot wide open. I consider this absolutely unimportant.
So, it's a success! Many thanks again to everyone who contributes here! |
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