NikonGear'23

Gear Talk => Lens Talk => Topic started by: RonVol on June 24, 2016, 23:09:25

Title: Fisheye-NIKKOR 6mm f/1.4
Post by: RonVol on June 24, 2016, 23:09:25
Here's a lens that, until yesterday, I had no idea existed.
Fisheye-NIKKOR 6mm f/1.4 with serial #901401.

The lens is on display at the National Museum of Nature and Science, Tokyo.
Apparently it was designed for capturing images of auroras and probably cloud patterns too.

I've asked a friend in Tokyo if he could visit the museum to see if more info might be available.

Image is by Itoshiki Ku.
Title: Re: Fisheye-NIKKOR 6mm f/1.4
Post by: Bjørn Rørslett on June 24, 2016, 23:48:58
Now, that is a surprise ... any idea whether it had an F-mount?
Title: Re: Fisheye-NIKKOR 6mm f/1.4
Post by: Akira on June 24, 2016, 23:53:43
Here's the story about the upper atmosphere observation using this very 6mm/f1.4 fisheye.

http://www.nikon.com/about/technology/field/aurora/index.htm
Title: Re: Fisheye-NIKKOR 6mm f/1.4
Post by: RonVol on June 25, 2016, 00:03:33
Here's the story about the upper atmosphere observation using this very 6mm/f1.4 fisheye.

http://www.nikon.com/about/technology/field/aurora/index.htm

Thanks for that link Akira  :)
Title: Re: Fisheye-NIKKOR 6mm f/1.4
Post by: Akira on June 25, 2016, 00:05:38
Thanks for that link Akira  :)

You are welcome.  Hope you enjoy it!  :)
Title: Re: Fisheye-NIKKOR 6mm f/1.4
Post by: RonVol on June 25, 2016, 00:39:14
A little bit of research has yielded this series of images, examples of what the lens/camera combination is used for.
Title: Re: Fisheye-NIKKOR 6mm f/1.4
Post by: RonVol on June 25, 2016, 00:40:10
...................and some tech specs.
Title: Re: Fisheye-NIKKOR 6mm f/1.4
Post by: RonVol on June 25, 2016, 00:43:07
.............and this from the Nikon site that Akira provided the link to.
You can see the plastic dome that the lens is housed in.
Title: Re: Fisheye-NIKKOR 6mm f/1.4
Post by: RonVol on June 25, 2016, 00:45:31
Now, that is a surprise ... any idea whether it had an F-mount?

Based on the images above; it's not an F-mount.
Title: Re: Fisheye-NIKKOR 6mm f/1.4
Post by: Akira on June 25, 2016, 01:13:08
Ron, thanks for the additional info.  512x512 pixel is pretty dense.  :D  I wonder if you need to "cool" the CCD in Antarctica?   ::)
Title: Re: Fisheye-NIKKOR 6mm f/1.4
Post by: RonVol on June 25, 2016, 01:32:30
Here's a shot showing 2 of these lenses being used in a configuration from 2002.
So we now know that at least 2 of these lenses exist and were around as far back as 1996.

The configuration is called the CRL-ASI, here's a description;

As an objective lens, the CRL-ASI has a fish-eye lens with a 6mm focal length and F1.4 made by Nikon Technologies Inc. It is capable of a 180deg all-sky field of view, which enables it to observe a wide area within a radius of several hundreds km range around the observation point. Rays of light pass through the objective lens and then through a collimator lens to become a collimated beam, through an interference filter for spectral separation and is then focused on a CCD device unit. This optic system is based on the all-sky auroral imager developed by the National Institute of Polar Research (NIPR) in 1996 as well as on the airglow-observation-imager developed later at Kyoto University. Interference filters are mounted on the five-channel filter turrets, enabling observation at any of five channel-selected wave-lengths. The telecentric lens has a focus-adjusting mechanism to enable the capture of high-resolution images. The detector unit is a cooled camera with 512 X 512-pixel back illuminated CCD, achieving high-sensitivity and convenient in handling.

Title: Re: Fisheye-NIKKOR 6mm f/1.4
Post by: chris dees on June 25, 2016, 09:06:16
Based on the images above; it's not an F-mount.
Just send it to Erik.  :)
Title: Re: Fisheye-NIKKOR 6mm f/1.4
Post by: Dr Klaus Schmitt on June 26, 2016, 11:55:09
There have been very similar lenses made by other vendors for similat applications (often military), I've seen them sold quite a few times. Image circle is rather small though, although the back focal length is rather long (due to the required filter wheel).

First Nikon I ever saw, thanks for sharing!
Title: Re: Fisheye-NIKKOR 6mm f/1.4
Post by: Bjørn Rørslett on June 26, 2016, 11:59:33
The impressive speed might be easier to achieve when the image circle is small.

The long "tail" of the lens might include a built-in relay system.

A pity these lenses are so elusive, should be fun to experiment with.
Title: Re: Fisheye-NIKKOR 6mm f/1.4
Post by: RonVol on June 27, 2016, 06:35:09
There have been very similar lenses made by other vendors for similat applications (often military), I've seen them sold quite a few times. Image circle is rather small though, although the back focal length is rather long (due to the required filter wheel).

First Nikon I ever saw, thanks for sharing!

Thanks for the info and also thanks for the positive feedback  :)
Title: Re: Fisheye-NIKKOR 6mm f/1.4
Post by: RonVol on June 27, 2016, 06:39:07
The impressive speed might be easier to achieve when the image circle is small.

The lens appears to be around the same physical size as the f/2.8.
I'm wondering if in fact it's the 6mm f/2.8 but , because of the reduced image area, they've gained an increase in speed.
Would this be possible?
Title: Re: Fisheye-NIKKOR 6mm f/1.4
Post by: Bjørn Rørslett on June 27, 2016, 09:13:58
No.

It's the light gathering that counts, not what is delivered at the rear end. The size of the entrance pupil is the important parameter and this is set by the lens design.
Title: Re: Fisheye-NIKKOR 6mm f/1.4
Post by: RonVol on June 27, 2016, 09:29:20
No.

It's the light gathering that counts, not what is delivered at the rear end. The size of the entrance pupil is the important parameter and this is set by the lens design.

Ok, thanks...................I guess that makes sense.
Title: Re: Fisheye-NIKKOR 6mm f/1.4
Post by: Dr Klaus Schmitt on June 27, 2016, 11:04:27
The impressive speed might be easier to achieve when the image circle is small.

The long "tail" of the lens might include a built-in relay system.

A pity these lenses are so elusive, should be fun to experiment with.

IF it doesn't have NIKON written on it, I could help. Let me know.... ;-)
Title: Re: Fisheye-NIKKOR 6mm f/1.4
Post by: Bjørn Rørslett on June 27, 2016, 11:09:19
I'm all ears, Klaus.
Title: Re: Fisheye-NIKKOR 6mm f/1.4
Post by: Dr Klaus Schmitt on June 27, 2016, 18:16:20
I'm all ears, Klaus.

You have PM