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Mikejd80
Tinkerer
Username: Mikejd80
Post Number: 1
Registered: 10-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, October 07, 2012 - 10:49 pm: | 
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I recently find a mind condition eye level finder, but the inner wall surfaces all show regular white dots, do not look fungus to me, could this be caused by silver coating fallen off? or is it normal. they are not affecting the focus. thanks.  |
M_currie
Tinkerer
Username: M_currie
Post Number: 303
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 08, 2012 - 09:02 am: |
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I've never seen it that bad, but it is, unfortunately, rather common for the silver to fall off, especially where the little rubber pads are used to hold the prism down.
I don't think it should affect focus, because the prism is solid, and the mirror is on the outer surface. On other devices, such as rangefinders, if the coating gets too mad you may end up sighting from the wrong surface of the glass, but I don't know how you could on this prism. |
Edgy01
Tinkerer
Username: Edgy01
Post Number: 2
Registered: 05-2013
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, May 25, 2013 - 12:44 am: |
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The most common issue with the Nikon f eye level prism is with separation along the spine, or very center of these prisms in the Y axis. What you appear to have may very well be the beginning of mildew inside the prism. Carefully peel back the leatherette at all corners of the prism and then gently remove the small steel plates that hide the screws that secure the top cap to the prism. A special black paint coating beneath the prism cap should be undisturbed and protect the silver coating that provides you with the prism's reflectivity. It appears that the assembly was stored improperly and ambient humidity affected the paint. If it has not eaten into the silver layer simply neutralize it and store the finder in dryer surroundings. (If you never fully eradicate mold/mildew In optics it will be harder to prevent in the future.
Dan |
M_currie
Tinkerer
Username: M_currie
Post Number: 300
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, May 28, 2013 - 11:38 am: |
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I have heard of people with deteriorated Photomic prisms getting them out of a different model Photomic finder, since many do not work any more. I have s suspcicion that this could be done with a plain finder too, though I have never compared the prisms up close.
If someone else can confirm, I'd love to know a full answer to this. These days a broken Photomic finder can be found fairly cheaply, and at least a few have intact prisms. IN my experience, the first part to go is the area right under the little clamps that hold the prism down, resulting in a couple of brown spots sort of like sundogs in the viewfinder. It's a nuisance but does not affect the useability.
Still, it would be nice to be able to completely re-prism a plain finder with the innards of a dead Photomic. |
Brcamera
Tinkerer
Username: Brcamera
Post Number: 275
Registered: 08-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, May 28, 2013 - 02:14 pm: |
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Good idea, but unfortunately the form factor of the prism on the metered Photomics is not the same as the plain F finder.
Bill |
Hofmannra
Tinkerer
Username: Hofmannra
Post Number: 1
Registered: 05-2013
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, May 29, 2013 - 11:34 am: |
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Early Nikkormats have the same prism as the F eyelevel-finder
http://www.nicovandijk.net/restore.htm
Rainer |
M_currie
Tinkerer
Username: M_currie
Post Number: 302
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, May 29, 2013 - 08:41 pm: |
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Thanks, BRcamera for the definitive if unwelcome information. Too bad. |
Cooltouch
Tinkerer
Username: Cooltouch
Post Number: 263
Registered: 01-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, May 31, 2013 - 01:58 pm: |
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"Early Nikkormats have the same prism as the F eyelevel-finder
http://www.nicovandijk.net/restore.htm"
Does anyone here know if this applies to the F2 eye level finder as well? My finder has the identical problem the F's finder has, shown in the above link's photo: a fracture at the top of the prism.
Alternatively, if you have a banged up F2 DE-1 that still has a good prism, let me know if you want to sell it. |
Brcamera
Tinkerer
Username: Brcamera
Post Number: 276
Registered: 08-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, May 31, 2013 - 07:18 pm: |
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The prism used in the Nikon F eye level is not quite the same as the one used in the DE-1. The Nikon F eye level prism is a few hundredth of an inch smaller (a bit less wide) than the DE-1. so although you might be able to install it in the DE-1, the viewed image would not show the full frame.
Bill |
Cooltouch
Tinkerer
Username: Cooltouch
Post Number: 266
Registered: 01-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, June 01, 2013 - 09:06 pm: |
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Thanks, Bill. Am I right in assuming that the DE-1's prism is unique to the DE-1, then? I mean, the DP-1's won't interchange, for example? |
Brcamera
Tinkerer
Username: Brcamera
Post Number: 278
Registered: 08-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, June 01, 2013 - 09:25 pm: |
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Yes, the DE-1 prism would be unique in that it is the only non-metered standard prism for the F2. The DP-1 prism is quite different as the metered Nikon heads have two small prisms attached to the main prism to allow the photocells to receive light.
Bill |
Brcamera
Tinkerer
Username: Brcamera
Post Number: 281
Registered: 08-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, June 03, 2013 - 01:55 pm: |
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Some time ago I was searching for a replacement prism for my Nikon F eye level finder. I checked all the older Nikon cameras to see if there would be some compatibility and found none. Before anyone runs out to buy an older Nikkormat as mentioned above to use the prism in their Nikon F eye level finder, keep in mind that the Nikkormat prism is close, but will not fit the Nikon F eye level finder. The original Nikkormat FT prism is a bit too small and the FTN prism does not have the same shape so will not mount in the Nikon F eye level frame.
Bill |
Olympfix
Tinkerer
Username: Olympfix
Post Number: 58
Registered: 05-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, June 03, 2013 - 04:05 pm: |
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Olympus OM-1s also suffer from de-silvering of prisms. OM-10 and 20 prisms are identical, and can be substituted straight in . OM-10s are available as wrecks or even operating quite cheaply. |
Rtucker
Tinkerer
Username: Rtucker
Post Number: 11
Registered: 02-2013
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, June 03, 2013 - 08:56 pm: |
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Would a prism from a Nikkormat El have any luck fitting into the F prism. |
Brcamera
Tinkerer
Username: Brcamera
Post Number: 282
Registered: 08-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, June 03, 2013 - 11:47 pm: |
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I have never tried to fit the EL prism into a standard F eyelevel so I can't say for sure, but I would guess not since the EL was introduced around 13 years after the Nikon F...
Bill |
