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Krafty5260
Tinkerer Username: Krafty5260
Post Number: 43 Registered: 02-2008
Rating: N/A Votes: 0 (Vote!) | Posted on Monday, January 31, 2011 - 02:55 pm: |
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Greetings all, I haven't been here for a while, but here I am again. I just received a Nihon Seiki Mocronta 35 viewfinder camera. It's cute. That's what attracted me, plus the description read, very good condition (well, except for the dent in the finder housing, and the loose focus ring, but I digress). It has a Yamato look and feel, but it's not a Yamato variant. It's a sibling of the Ranger 35, and Nescon. My question for the day is, aren't apertures supposed to open symetrically, in a concentric pattern? This one opens eccentrically, and when fully open, still blocks some glass in a crescent pattern. I've seen that before and I'm just trying to determine if that's correct, or not. Is that right, or is this another problem with this camera? I'm not completely discouraged, just trying to assess what needs to be done. As usual, any input is appreciated. Thanks again, Michael |
Donnie_strickland
Tinkerer Username: Donnie_strickland
Post Number: 104 Registered: 09-2006
Rating: N/A Votes: 0 (Vote!) | Posted on Monday, January 31, 2011 - 05:13 pm: |
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Rick Oleson has one; maybe you could ask him about it: http://tinyurl.com/4tc6v4z |
Scott
Tinkerer Username: Scott
Post Number: 126 Registered: 07-2006
Rating: N/A Votes: 0 (Vote!) | Posted on Monday, January 31, 2011 - 06:38 pm: |
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I've never seen a crescent shape, but I do have several good-quality Japanese rangefinder cameras (Olympus 35RC, Olympus Trip 35, for example) that have 4 aperture blades that make almost-square diamond-shaped apertures, which even at "wide open" still appear 4-sided. If the shape is not even symetrical, my guess is that the pivots of one or more of the blades is out of place. |
Krafty5260
Tinkerer Username: Krafty5260
Post Number: 44 Registered: 02-2008
Rating: N/A Votes: 0 (Vote!) | Posted on Monday, January 31, 2011 - 08:16 pm: |
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That's what I'm thinking. How can one possibly get a decent photo from a lopsided aperture? Square makes some sense, as long as it's concentric with the lens. This just can't be right. Hmmm. Thanks for brainstorming with me, Scott. |
Rick_oleson
Tinkerer Username: Rick_oleson
Post Number: 1119 Registered: 07-2006
Rating: N/A Votes: 0 (Vote!) | Posted on Monday, January 31, 2011 - 09:18 pm: |
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The aperture has 6 blades, in a uniform hexagon shape. The shutter, however, has 2 blades, each having a crescent shaped edge so that when fully open it clears a circle. If one blade was missing or stuck open, the remaining blade would form a sort of crescent shaped opening when in the closed position. |
Krafty5260
Tinkerer Username: Krafty5260
Post Number: 45 Registered: 02-2008
Rating: N/A Votes: 0 (Vote!) | Posted on Tuesday, February 01, 2011 - 06:27 am: |
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Hey Rick, Thanks, for the input. What I see with the shutter on B is an aperture opening offset at about 7 or 8 o'clock, and, of course, it is larger or smaller depending on the aperture setting, but never concentric or fully open. And, the focus ring is loose from the helical. If I turn the aperture ring all the way in one direction, or another the helical will move, but not with the ring. This camera needs some help. I'll have to put in on the list. Thanks again, Michael |
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