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Unknown Nikon F Focus Screen


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#1
mhall2

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I just received a box of equipment today that I purchased online from an estate. In the bottom of the box was this focus screen marked Nikon F, type K. I know that all Nikon type K screens have a split image micro prism focusing aid in their center. However, this screen does not. It is just a ground glass much more similar to a type D screen. It is the same construction as a screen for the F or F2, but it is only about 2/3 as thick. It is too thin to fit into an F or F2 body and just rattles around, not making the appropriate contact with the two pins that should hold it in place. It also does not have the tab on the rear side like an F3 screen, so I know it is not for that camera. I just have never seen a screen this thin and have no idea what camera body it should fit into. I have placed an F screen next to it in the first photo to illustrate the difference (unknown screen is on the left, the F screen is on the right). I'm really stumped on this one. Has anyone out there ever seen this screen before and what camera is it used in?  Thanks.

Attached Thumbnails

  • IMG_0086.JPG
  • IMG_0087.JPG
  • IMG_0090.JPG


#2
Ron

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"Type K is a matte Fresnel field with 3mm split-image rangefinder spot surrounded by 1mm wide micro-prism doughnut."

 

At least that's what KEH says... yours, however, doesn't look like it has the micro-prism doughnut, although 1mm is pretty small. Beyond that... I donno!

 

--Ron



#3
tonyzoc

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I just received a box of equipment today that I purchased online from an estate. In the bottom of the box was this focus screen marked Nikon F, type K. I know that all Nikon type K screens have a split image micro prism focusing aid in their center. However, this screen does not. It is just a ground glass much more similar to a type D screen. It is the same construction as a screen for the F or F2, but it is only about 2/3 as thick. It is too thin to fit into an F or F2 body and just rattles around, not making the appropriate contact with the two pins that should hold it in place. It also does not have the tab on the rear side like an F3 screen, so I know it is not for that camera. I just have never seen a screen this thin and have no idea what camera body it should fit into. I have placed an F screen next to it in the first photo to illustrate the difference (unknown screen is on the left, the F screen is on the right). I'm really stumped on this one. Has anyone out there ever seen this screen before and what camera is it used in? Thanks.

I'm thinking this is an early Nikon F screen. I'm not an expert on this, but I know (think?) that early F bodies had a smaller area where the prism seated. I know that I have a Nikon F that I can't put the FTN photomic finder on. I heard they had a modification and some F bodies that allowed for photomic finders to fit, and these bodies have a red dot made near the serial number (again...I think). My early Nikon F has a prism finder with the square window and my FTN finder from my Apollo F body will not fit it. I'm not sure if all my "facts" are correct but I think my premise is correct.

From this page...

https://www.cameraqu...com/nfinder.HTC

The "RED DOT" before the serial number on the late F 65 bodies starting about 6585000 and continuing to about 6603500 indicate these bodies can mount the Photomic T. A small ridge which extended about 3/32" above the top plate on either side of the eyepiece canal had to be removed to allow the mounting of the new Photomic finder The could be done by Nikon, or by independents. Poorly done conversions just filed these edges flat, decreasing the value of the camera. Modified F's initially had a RED DOT in front of the serial number, starting about 6585000. F production continued with the RED DOT, but was stopped at about 6603500. Production resumed starting at 6700000 -- WITHOUT the RED DOT. After F # 6700000, all F's left the factory modified to take the Photomic. Unmodified bodies are worth slightly more to collectors, and slightly less to users, since they can't mount the more modern Photomics. So, if you have an early body and you can't mount a Photomic finder on it, the odds are you have an unmodified F body. On the other hand, maybe you're just a klutz.
Sent from my Pixel 3a XL using Tapatalk

#4
mhall2

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I'm thinking this is an early Nikon F screen. I'm not an expert on this, but I know (think?) that early F bodies had a smaller area where the prism seated. I know that I have a Nikon F that I can't put the FTN photomic finder on. I heard they had a modification and some F bodies that allowed for photomic finders to fit, and these bodies have a red dot made near the serial number (again...I think). My early Nikon F has a prism finder with the square window and my FTN finder from my Apollo F body will not fit it. I'm not sure if all my "facts" are correct but I think my premise is correct.

From this page...

https://www.cameraqu...com/nfinder.HTC

The "RED DOT" before the serial number on the late F 65 bodies starting about 6585000 and continuing to about 6603500 indicate these bodies can mount the Photomic T. A small ridge which extended about 3/32" above the top plate on either side of the eyepiece canal had to be removed to allow the mounting of the new Photomic finder The could be done by Nikon, or by independents. Poorly done conversions just filed these edges flat, decreasing the value of the camera. Modified F's initially had a RED DOT in front of the serial number, starting about 6585000. F production continued with the RED DOT, but was stopped at about 6603500. Production resumed starting at 6700000 -- WITHOUT the RED DOT. After F # 6700000, all F's left the factory modified to take the Photomic. Unmodified bodies are worth slightly more to collectors, and slightly less to users, since they can't mount the more modern Photomics. So, if you have an early body and you can't mount a Photomic finder on it, the odds are you have an unmodified F body. On the other hand, maybe you're just a klutz.
Sent from my Pixel 3a XL using Tapatalk

 

You are correct regarding the difference in finders between the early F series and the later Photomic versions. I have an early F body (s/n 6567296) that took the standard eye level finder (no meter). I also have a later F Photomic body (s/n 7293161) with the larger finder (with a meter). The larger photomic finder will not fit the earlier F version due to the collar mentioned above. The offending pieces are located on either side of where the eyepiece sits in the camera body -- the rest of the collar is OK. I have included a photo of each of these cameras illustrating this difference. You can see that this portion of the collar is missing in the later version. HOWEVER, that is the only difference in the two models. The dimensions of the mirror box are the same and they use the exact same size focus screen. The last photo shows the two screens from both cameras side by side and they are identical. I even went so far as to switch them between cameras and they fit fine. So, this early version of the F body is not the source for this reduced height screen. By the way, the width and depth of the smaller screen is the same as they larger one. The only difference is in the height -- and the four screws in the frame. These are smaller and do not have any clips holding the glass screen in place. The frame has been squeezed around the glass similarly to the way some lens elements are permanently mounted into the objective housing.

 

P.S.- I emailed the Nikon legacy website today and included the same photos shown here. Perhaps they can clear up this mystery.

 

 

Attached Thumbnails

  • sn 6567296.JPG
  • Comparison.JPG
  • sn 7293161.JPG


#5
Brian

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The screens are the same across all Nikon F and F2 cameras, my earliest Nikon F of just over 6410xxx to the Latest Nikon F  745xxxx use the same screens. The frame was enlarged for the TTL finders- "red dot" on the 65xxxxx block SN or above 67xxxxx is safe. 66xxxxxx is rare, Nikon realized that block overlapped the S4.

 

The mystery screen Looks Like it is for the  for the Nikon Finder Test device, a Rail held screens to be examined before purchase- I found the reference in my 100th anniversary of Nikon book. The frame for the individual screen looks like yours..

 

All the following use the same screen.

 

Nikon-F-Bullseye.jpg

 

The Photomic "Bullseye" fit the early 64 and 65 block Nikons, no modifications required.

 

Nikon-F-Meter.jpg

 

This meter is on a 6420xxx body that I bought 40 years ago- meter still works.

 

Same as the F2 screens.

 

000000.jpg



#6
mhall2

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Thanks for the information Brian. Was this "Nikon Finder Test Device" something used at the factory prior to being shipped out for sale? I don't recall ever seeing a test device at a retail outlet being used. And if it was at the factory, what is doing in somebody's personel camera bag? To further help my understanding, did this test device test the screens or the camera bodies? I guess I'm a bit confused on exectly what this device was and what it was used for.. Thanks so much.



#7
Brian

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Quick pic from my book.

 

RIMG0108.jpg

 

These were used by Nikon dealers to let buyers examine and select screens and eyepieces. I do not own one, and have not handled one in person.

 

Often- devices like this get given to employees when they outlived their usefulness.