Today’s guest post is from Fabrizio Belardetti (www.fabriziobelardetti.com) who also reviewed the rare Nikkor 19mm f/2.8 Macro lens last year. He will explain how to turn your Nikon G lens into a telescope (or a microscope) with the help of an old Nikon lens scope converter:
The Nikon lens scope converter is an unusual item (check those eBay listings), quite rare and really well built. Nikon lens scope converter is from the AF D era when Nikon lenses had their mechanical aperture rings.
Here's a view of the inside of Nikon scope converter - as you can see there's no coupling mechanism for the diaphragm, it just contains a prism and a 10mm focal length eyepiece. If you want to use the Nikon lens scope converter with G lenses, you have to modified it a little in order to get the aperture blades fully open.
When the lens is not attached to a camera body, the aperture blades inside the lens are fully closed:
Aperture blades are controlled by a lever connected to a spring which holds the diaphragm closed. There is no lever in the Nikon lens scope converter that would operate this lens lever when you attach it to the lens. To get the aperture blades fully open, you just need to build a small piece of plastic to fill the gap and keep the lever up - as a result the diaphragm will stay open. The work needs to be very precise, so I carefully worked with a knife a piece of plastic. It took several tries, but at the end it just worked. Since there's no coupling, there's no risk of damaging anything inside.
It's important that the plastic piece stays shorter than the mount edge so you can lock the scope converter easily:
For my lens, the plastic piece was about 4mm in length:
The power of the telescope is calculated by the focal length of your lens divided by 10, in my case a 51x telescope. I can assure the image quality is simply amazing! This is because the converter doesn't use the entire image area, just a small portion in the center, which of course is the sweet spot for any lens.
If you mount the Nikon lens scope converter on a Micro lens, it will give you 25X the magnification of the lens that is attached to. I've use it on my AF-S 105mm 2.8D Micro and I end up with a 25X handheld microscope.
VR won't work without a camera body, so you need a sturdy head and tripod to minimize any wobbling when you use this setup.
With this "telescope" you can see things that your eyes can't just imagine and everything is sharp and detailed. A couple of days ago there was a full moon with a clear sky and spent some time looking at the moon and stars... I truly got lost in the sky! Everything appears like...in 3D. Really amazing!
You cannot take any pictures with this setup, you can only look inside and say WOW!