REVERSING EL-NIKKOR 50 F/2.8N ENLARGER LENS

Though my first extreme macro lens is not this EL-Nikkor 50 f/2.8N enlarger lens, it is the second one after searching through the internet and various macro related forums. I totally bought the idea that enlarger lenses are designed to project a small negative film onto a larger photo paper with enough resolution and flatness.

Image Stacked With EL-Nikkor 50 f/2.8N

By reversing it, it makes a perfect sense to project a (relatively small) subject on to a flat sensor with enough resolution.

When I received this lens, my first impression was that it is small compared to my Canon EF 50 f/1.4 lens. It feels very plastic but very solid and it impressed me with that industrial look, particularly its coating on front and back elements. Here are some basic facts about it:

50mm focal length
Front filter size is 40.5mm
Lens mount is M39
Six element glasses in 4 groups
8 blades manual aperture
Maximum aperture is f/2.8 and minimum aperture is f/16
Manual aperture with full stop clicks.

Front of EL-Nikkor 50mm f/2.8N

Back View of EL-Nikkor 50 f/2.8

There are two versions of this lens, one designated with additional letter N (for new design?). This N version of the lens is what is described here. I do not have the old lens with original design, but I doubt there is any of that left.

Whenever I reverse a lens (the other reversed lens I did was a Minolta 28-70 f/2.8 manual zoom lens), I tend to convert the front mount to a standard M42 male thread. With this in mind, here are the steps.

The C part of this picture is not part of reversing, but it is used as lens hood described below.

Step 1 — Since the front thread size of this lens is 40.5mm, we need something to convert it to 42mm. So a 40.5mm-to-42mm adapter ring is needed. This adapter ring is the B in above picture.

Step 2 — Because the 40.5mm-to-42mm adapter ring ends up a female thread on the M42 side, we need to convert that to M42 male thread. At the moment of this writing, I do not have a M42 male-to-male ring (it does exists), so I used three rings, namely, M42-to-M49, M49 male-to-male adapter ring, and again M42-to-M49 ring. This is shown as A in above picture. Again, the whole assembly of A can be replaced by a single M42 male-to-male adapter ring which should be available on the market.

Step 3 — Once Step 1 and Step 2 are finished, the lens itself ends up with a male M42 mount. Since we are using M42 as a standard thread size, we need to use this standard for extension tubes. There are a lot of plain dumb extension tubes for either Nikon or Canon camera and these are cheap and widely available. Fortunately, well it is my intention, too, that there are a lot of M42 to either Nikon or Canon mount adapters, such as these below

Nikon and Canon Mount to M42 Adapter

So, it is a simple matter of getting one of these and extension tubes for your camera, that is it, you will end up with something like these:

Camera or Nikon Mount Converted to M42 Mount

One important note is to avoid those “precision” M42 mount adapters like below

Bad Camera Mount to M42 Mount Adapter

Why? They are precision mount adapters right? Well, they are precision ones and fits tightly on camera, but they are shiny and light will bounce back and forth inside the extension tube and create hazy images. Of course, if you have the patience and the right paint, you can paint it black, I personally prefer not having to do this kind of thing.

Step 4 — After assembling and converting both the lens and extension tubes to M42 mount, it is just matter of screwing the two together. That is it.

Very important note here, when reversed, this lens has pretty long working distance, so it is quite reasonable to add a lens hood to prevent glaring and other side effect it could cause. This is the C part of previous image — it is consisted of one M42-to-M39 and a M42 7mm extension segment.