Results of a reversed 50mm lens on a 105mm micro lens

[Wampatom]

I got around to testing the effectiveness of mounting a reversed 50mm lens on the front end of a 105mm micro lens. It is very good at getting sharp images. However, the farthest it will focus is 4cm from the end of the lens, which puts it out of range for most things in the aquarium. The picture below shows the setup. I used a Nikon D100 digital camera. 35mm film is 1.5 times larger than the digital sensor. A Nikkor 105mm f2.8 micro auto focus lens has a Nikkor 50mm f1.4 auto focus mounted in the reverse position. The focus of the 50mm lens was set to infinity. I purchased an 52mm adaptor which is threaded on both sides. I wedged a piece of cardboard in the aperture lever to keep it open to f 1.4.

105 + 50 closest 2cm – covers about 9mm (long dimension of image)
farthest 4cm – covers about 12 mm
105 closest 13cm – covers 25mm
farthest infinity

 

[Wampatom]

These photos were taken of the back of a 1 dollar bill. The 105 was used alone. The first picture was downsized from the full image which was 3008x2000 pixels. The second picture was cropped from the center and show the actual pixels from the camera 640x438. You can see the lens is good enough to use the full resolution of the camera.

 

[Wampatom]

The next set of photos were taken with the 105 (closest focus) with the 50 (focus infinity). As before the first was downsized from the full image and the second picture was cropped from the center and show the actual pixels from the camera. This is quite sharp too. It is better than my first impression, which is why I did these tests. It is slightly fuzzy and probably does not use the full resolution of the camera. Still, it takes a fine picture.

 

[Wampatom]

Now the test is repeated through aquarium glass. I photographed a Fiji yellow leather. It was one of the few subjects (except flat worms of course) close enough to the glass to test both setups. This set used the 105 alone. The first was downsized from the full image, the second picture was cropped from the center and show the actual pixels from the camera.

 

[Wampatom]

The next set of photos were taken with the 105 (closest focus) with the 50 (focus infinity). The first was downsized from the full image and the second picture was cropped from the center and show the actual pixels from the camera. While not using the full resolution of the camera, it is quite sharp.

Before you try this setup take a look at this article by Mark Plonsky. http://www.mplonsky.com/photo/article.htm
A recent photo techniques magazine article also covers using reversed lenses.

 

[Anonymous]

That is really really awesome. Thassit, I'm heading up to Roberts' camera to get an adapter ring. ;-)

 

[mkirda]

A recent photo techniques magazine article also covers using reversed lenses.

This is what I've been using for a while now, and the results you are getting look quite similar to what I've gotten with a reversed 20mm. Problem with it is lack of autofocus and the fact you have to manually stop down the lens, which can shift focus if you are not careful. Having a macro rail helps focusing a great deal... Have also used the 28-105mm reversed many times for 1:1 or 2:1 images. I still have the same problem with lack of focal distance... You cannot focus very far from the lens, which limits it's usefulness somewhat. Reversing at 105mm, you can get about 12" into the tank only. At 20mm, only an inch or two. Still, for close to glass subjects, you can get some great full-frame polyp shots.

If you get some time some weekend, Tom, I should swing by with my gear and see how this setup works on film.

Regards.
Mike Kirda