91 replies to this topic

[CharlieB]

Here's my 1956 NK 50mm.  It is in excellent condition and has almost all of the optional accessories.  I'm only missing the 12.5mm Huygen eyepiece, but I do have the 5mm, 7mm and 9mm orthos as well as the 18 and 25mm Huygens.  There is also the 40mm terrestrial eyepiece.  It even had the original NK silica gel packets.

 

As you would expect, the build quality and optical performance are superb.  It's the heaviest 50mm scope I've ever had.

 

 

 

 

Charlie

[James700]

As you would expect, the build quality and optical performance are superb.  It's the heaviest 50mm scope I've ever had.

 

beautiful set of NK 5cm Regarding the weight, I surprisingly found the prism diagonal on my NK 5cm is made of brass, not sure about other part of the OTA, presumably cast iron.

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[PawPaw]

Here's my 1956 NK 50mm.  It is in excellent condition and has almost all of the optional accessories.  I'm only missing the 12.5mm Huygen eyepiece, but I do have the 5mm, 7mm and 9mm orthos as well as the 18 and 25mm Huygens.  There is also the 40mm terrestrial eyepiece.  It even had the original NK silica gel packets.

 

As you would expect, the build quality and optical performance are superb.  It's the heaviest 50mm scope I've ever had.

 

 

 

Charlie

Charlie.....thanks for posting your beautiful Nippon 50mm.  

 

I posted the following on my observing session a couple of nights ago but on second thought it deserves to be in this thread.  To avoid double posting here is the link to what these small Nikons can accomplish.  https://www.cloudyni...l-orionnot-yet/

 

Clear skies

 

Don

[CharlieB]

beautiful set of NK 5cm Regarding the weight, I surprisingly found the prism diagonal on my NK 5cm is made of brass, not sure about other part of the OTA, presumably cast iron.

Yes, it's brass, as is the objective cell, dew shield and some smaller parts - possibly the focuser, too.  I'm not sure about the OTA, but I think it's some type of aluminum.

 

Charlie

[strdst]

Here's my 1956 NK 50mm.  It is in excellent condition and has almost all of the optional accessories.  I'm only missing the 12.5mm Huygen eyepiece, but I do have the 5mm, 7mm and 9mm orthos as well as the 18 and 25mm Huygens.  There is also the 40mm terrestrial eyepiece.  It even had the original NK silica gel packets.

 

As you would expect, the build quality and optical performance are superb.  It's the heaviest 50mm scope I've ever had.

 

1956 NK 50mm.jpg

 

DSC_0895.jpg

 

DSC_0060-1.JPG

 

Charlie

Charlie,

 

Looking at your 5 CM case photo, (well the felt in your case and presumably your mount cradle too), I'm curious about the different colors Nippon Kogaku used during a relatively short period of time. My 5 CM is all felted up in yellow. I have one 6.5 that is also softened in yellow felt. Then there's a 6.5 CM, in dull green, another in bright green, and another was in brown. What is the serial number on your badge? My 5CM is 2431.   

[strdst]

Yes, it's brass, as is the objective cell, dew shield and some smaller parts - possibly the focuser, too.  I'm not sure about the OTA, but I think it's some type of aluminum.

 

Charlie

So a funny, (not so), thing happened on the, (my), way to the, (this), forum. Or sometimes brass is a PITA!

 

Last week I set up three Nippon Kogaku examples in the garden for a photo shoot in the daylight. Afterword I carried them out the garden gate and in the waning light adjusted their finder scopes, sighting on a cell tower 3 miles distant. I had a passing thought that how cool it was that I had all the caps for finders and objectives, (you don't always get all the bits and bobs when buying used). After night fell I caught a few minutes observing with all 3 scopes just ahead of a storm front moving in. I packed everybody into the house and in the morning I found one finder cap on the kitchen counter. Just one.

 

I spent the morning going through my pants pockets, shirt pocket, sweatshirt pocket (pouch?), all of the flat spots in the house where I might have set the missing caps. The telescope cases, pockets in clothes I know I wasn't even wearing the night before. Checking not once but multiple times!

 

When the daylight got stronger I started scanning the lawn, (which was long enough that my footsteps left a trail). After a while I saw cap 2! I had already tested the cap that I had found in the house with a very large magnet and of course nothing ferrous there. Brass is a PITA). I spent the next few hours raking the lawn with my fingers, massaging the grass and clover over about 600 square feet. I took off my shoes and walked all over hoping to feel cap 3 barefoot...nothing.  I traced my path to the wood shed, out to the mailbox, anywhere it might have wiggled out of a pocket. This added quite a few thousand square feet to the search zone. More nothing.

 

So a few options ran through my mind... It was only 600 square feet. 

 

Spray the most likely area with Roundup herbicide and wait 3 weeks for it to turn orange and wilt down, Voila! Nah.

 

Better idea use my propane weed flamer to reduce the lawn to ash. Probably wouldn't melt aluminum or brass? 

 

Better yet, rent a metal detector! Two roundtrips to town to rent and return = 80 miles. Rental $22 for 4 hours. Sure why not. Greta forgive me, I'm suffering from Nikon-its!

 

Long story/short, (I know too late for that now), I did find it finally. I got a strong signal but when I massaged the grass I couldn't feel anything. I was about to return the detector when I returned to that spot again. To eliminate the assumption that I was just picking up the scent of a lost garden fence staple below ground I dug a shallow plug of sod and soil and ran the detector over the hole and the plug. The plug beeped the hole didn't. I massaged the veg on the plug and still nothing, turned it upside down, gave it a hard shake and success!

 

We look for things. We are nothing if not persistent. Gotta love DS9!

 

Photo of no longer missing cap and habitat it was found in.

 

Photo of Goto finder cap with mitten, (dummy?), string.   

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[CharlieB]

Charlie,

 

Looking at your 5 CM case photo, (well the felt in your case and presumably your mount cradle too), I'm curious about the different colors Nippon Kogaku used during a relatively short period of time. My 5 CM is all felted up in yellow. I have one 6.5 that is also softened in yellow felt. Then there's a 6.5 CM, in dull green, another in bright green, and another was in brown. What is the serial number on your badge? My 5CM is 2431.   

Mine is 2600 with green felt.

 

 

 

 

Charlie

[starman876]

not sure this thread has been created or not, only found on the binocular forum, why not here as well

 

I'll start with a homework that I owe to Johann (starman876) who a year ago passed me a special Nikon (Nippon Kogaku) refractor that was customized for NASA likely in the 60s. Please find the earlier discussion on this thread. As soon as I received it, I sent it off to Mr. Yoshikawa for full restoration. For those unfamiliar with his work, you may find some information from his website. Mr. Yoshikawa is a legendary figure in Japan, once had his own brand of premium telescopes, then served in the unique telescope museum for a decade as the tech advisor of the restoration division before retiring. Today he continues to offer maintenance / restoration service for amateurs. 

 

This NASA Nikon 100 f/12 is made of brass, weighing around 16kg, a factor of 2.5x heavier than the commercial Nikon 100ED f/12. The objective is not using ED glass. According to Mr. Yoshikawa, while we don't know the exact glass types made by Nikon, the crown appears to be similar to BK7 or S-BSL 7, and the flint is similar to F2 or S-TIM 2. Mr. Yoshikawa told me that these kinds of glasses are more resistant to sudden temperature changes and shocks than ED glass or fluorite. This seems to be consistent with the brass construction though NASA's exact purpose for this scope remains unknown.

 

The restoration results were absolutely stunning, both inside and outside. The original black paint couldn't be completely removed, so Mr. Yoshikawa applied a golden paint closely matching the brass color. Not only does it look fantastic, but the performance is equally impressive. I had it out for one night only so far (shame), the optics didn't get broken at 500x. I plan to do a side-by-side comparison with the 100ED at another night soon... I couldn’t be happier with this scope—it’s definitely never going on my parting list! Huge thanks to Johann for entrusting me with this incredible piece of history.

 

Here are a couple of pictures to finish my homework...

 

James

Beautiful scope.  Very happy you are enjoying the scope.

[James700]

Beautiful scope.  Very happy you are enjoying the scope.

many thanks for taking good care of this scope for many years Johann I'm sure it will be enjoyed with starlight as long as I can still carry it to my mount. 

[James700]

Long story/short, (I know too late for that now), I did find it finally. I got a strong signal but when I massaged the grass I couldn't feel anything. I was about to return the detector when I returned to that spot again. To eliminate the assumption that I was just picking up the scent of a lost garden fence staple below ground I dug a shallow plug of sod and soil and ran the detector over the hole and the plug. The plug beeped the hole didn't. I massaged the veg on the plug and still nothing, turned it upside down, gave it a hard shake and success!

such story never gets too long for Nikon-itist 

[Steve Allison]

After reading about these wonderful Nippon Kogaku refractors, I am feeling the urge to acquire one for myself. What would I be looking at price wise for one of these beauties in either 50mm or 65mm aperture?

Edited by Steve Allison, 14 April 2025 - 05:48 AM.

[starman876]

After reading about these wonderful Nippon Kogaku refractors, I am feeling the urge to acquire one for myself. What would I be looking at price wise for one of these beauties in either 50mm or 65mm aperture?

Hard to say considering they are priceless     

[Bomber Bob]

After reading about these wonderful Nippon Kogaku refractors, I am feeling the urge to acquire one for myself. What would I be looking at price wise for one of these beauties in either 50mm or 65mm aperture?

There's a newer version (1980s) Nikon 65mm EQ Kit on ZEN - has been listed for over a year.  BIN price is about $1800.  Sure is pretty, though!

[James700]

Just had a brief session with the Nikon 100ED and Takahashi FC-100DZ set up "side-by-side", working around Boötes. I compared the Airy disk around Arcturus, checked out M3, and visited a few double stars, stopping at Izar just before the clouds rolled in. Seeing wasn’t great, so I topped out around 200x, using a Nikon O-9, Pentax SMC Ortho 6mm, and XP 3.8mm, which gave me about 133x and 200x in both scopes. To my eye, the optical performance is quite close, though the Nikon 100ED has a slight edge — stars appear just a bit tighter, with diffraction rings showing more clearly. Izar, at 2.9”, was still a too-easy split in both scopes. I had planned to swing over to Struve 1864 (1.9”), but didn’t get the chance. That’ll have to wait for a steadier night.

 

Performance aside, it was also striking to feel how much portability has evolved over 40 years. Mounting the 100DZ feels like setting up a guide scope — infinitely easier. That said, it’s of course even more impressive that the Nikon, despite its age and bulk, still keeps up — and maybe even pulls ahead — optically. 

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[PawPaw]

What a beautiful setup.  Looks like  you have a few light blocking tarps to help out but two of those tower lights hurt my eyes.   

 

How does the Nikon mount handle both scopes.........It takes 3 counterweights?

[Scott99]

Sounds like Nikon took no prisoners while developing this f/12 ED apo That slight wandering of the DZ's G-line must be tightened up in the big Nikon.  It sounds like a match for the TSA102. 

Edited by Scott99, 18 April 2025 - 02:56 PM.

[James700]

What a beautiful setup.  Looks like  you have a few light blocking tarps to help out but two of those tower lights hurt my eyes.   

 

How does the Nikon mount handle both scopes.........It takes 3 counterweights?

My home is only 50km out of Tokyo, what can I do the worst is that there is a bright street light right in front of my house… I requested my city hall to convert it sound control on/off, no success the tarp is mainly to block neighbors’s security camera which does have sound control flash light…

 

The Nikon mount has 18kg payload which is conservative. No sign of sweating for these two 4-inch, neither when it is riding Tak TOA-130S or AP-155EDF f/7. It had 400x go-to speed, not fast, good enough for enjoying Nikon!