Canon FD-Nikon Extension Tube

It was easier than I thought it would be. With the help of some scrap metal, tin snips and a Radio Shack notching tool, I fashioned a tool to remove the corrective optic from the Fotodiox FD-Nikon Lens Mount Adapter, effectively creating a 13mm extension tube that will mount Canon lenses to Nikon bodies. The added benefit of which is that it also serves as a Canon Macro Hood/Diaphram adapter.

Infinity focus is way, way off, but then so would it be if I used an extension tube with a Nikon Lens.

So now, I can consider that the $39.95 was well-spent, and I can actually recommend this product to anyone who is, like myself, handy and a little on the adventurous side.

But what exactly does this give me?

A compact, fast, high power macro lens based on the Canon FD 24mm f/2.8
This lens, when reverse mounted with a Fotodiox 52mm Reverse Lens Mount and fitted with the FD-Nikon adapter becomes a high-power manual macro lens with full aperture control. This setup has extreme magnification and a short working distance. With the Nikon BR-6 installed on the FD-Nikon adapter, I can attach any 52mm filter of my choice.

A compact, fast, macro lens based on the Canon FD 50mm f/1.4 or f/1.8
This lens, when conventionally mounted to the camera body with the Fotodiox FD-Nikon adapter, becomes a moderate-power closeup lens with full aperture control and a longer working distance. It’s the equivalent of using a 50mm Nikon AI-S lens with a 13mm extension tube. Interestingly, I have slight control over the degree of magnifcation by adjusting the focus and working distance. Reverse-mounting it would give me a speed advantage over the 24mm, but the magnification would not be as great. The wider the lens, the greater the magnification.

A moderately fast, zoom macro lens based on the Canon FD 35-105mm f3.5
This lens, when conventionally mounted to the camera body with the Fotodiox FD-Nikon adapter, becomes a macro lens with a versatile zoom range and variable working distance. This of course comes at the expense of speed, but an added benefit is that this lens has a constant aperture of f/3.5 unlike my Nikon AF-S 16-85mm f3.5-5.6. With the Canon, I can achieve 157.5mm @ f/3.5, whereas with the Nikon I can only get 127.5 @ F/5.6. So the magnification is 24% greater and the aperture is 1-2/3 stops faster. But, we do have to take into consideration the 13mm extension, so the effective magnification is even greater, and the speed a little slower. At 35mm, I have high magnification with a short working distance. At 105mm, I have moderate magnification with close focusing and a longer, very comfortable working distance. At any working distance between these two points, the zoom acts like a focus ring, so it’s extremely easy to find the optimal scale and simply focus to it. Since this lens isn’t wider than the 24mm, there isn’t an advantage to reverse-mounting it, even if I could find a 72mm reverse lens mount adapter.

A moderately fast, zoom macro lens based on the Canon FD 70-210mm f4
This lens, when conventionally mounted to the camera body with the Fotodiox FD-Nikon adapter, has a less useful range than the 35-105mm, but then I can get closer while being further away. Again, the widest angle of view gives the greatest magnification, so I can fill the frame with a flower at about 6" away and achieve about half that magnification at 210mm. At that zoom level, the maximum lens-to-subject distance is about 128", a little over ten feet, so it almost feels like using a normal lens at close range. Again, the continuous aperture is a benefit here, but this setup doesn’t seem to offer as great an advantage over using my Nikon 70-300mm.

I can add extension tubes to any of these setups to increase magnification by reducing the minimum focusing distances. For example, if I add a 36mm extension tube to the 50mm f/1.4 lens, I'll increase the magnification by almost 75% (0.72). To determine this, I divided the extension distance by the focal length of the lens. This amount is then added to the original magnification of the lens.

I could also add my Canon FD 2x-B teleconverter to increase magnification by a factor of two while increasing the maximum focusing distance. However, this comes at the expense of adding two stops of exposure.

Finally, I can simply reinstall the optic and accept its qualities for what they are, using it as…

A Soft-focus Effect Canon FD to Nikon Lens Adapter
Used for the purpose it was originally designed, I was initially disappointed. Now, knowing it has additional purpose hidden within, I can judge it less harshly. I’m not going to achieve the 36mm, f/2.8, reasonably sharp images I originally thought. But the question is, can I achieve an image with a pleasing aesthetic quality? Since the answer is a definite yes, it’s worth pursuing.

Canon FD 24mm f/2.8 + Fotodiox FD-Nikon adapter

The down side to all of this? Now I have to unpack and keep accessible all the Canon FD lenses that I’d squirreled away since I made the transition to Nikon, because I’m going to be using them.

A Lot.