Photos by Matt Cashore, University of Notre Dame
A macro lens is always a great go-to for lab photos.  Nothing says "research" like a nice tight closeup of a pipet tip, right?  Many zoom lenses do what I call "mild macro" and I have a couple manual focus Nikkor macros with extension tubes for when I get really serious.
I knew reversing rings could turn normal lenses into macro lenses but since I had the macro world covered with my existing arsenal I didn't give much thought to the idea.  
One day I stumbled on a photo blog post about reversing wide angle lenses.  According to the author, wide angle lenses reversed turned into magnifying lenses.  Made intuitive sense and sparked my curiosity in trying it for myself.  I called my local camera store and sure enough, they had a reversing ring in stock.  52mm filter thread-to-Nikon mount.  Well...  Just so happens I have a few old manual focus Nikkor lenses sitting around from my film days which all have 52mm filter threads.  $15 later...time to experiment!
The first lens I tried was a 24mm f2.8 AIS.  I learned a few things immediately:
  1. Focus was going to happen entirely by moving the camera. Focus ring is more or less irrelevant at this point.
  2. It was a PITA to use the traditional viewfinder.  Live view was going to be my friend in this effort.
I first turned my camera on a tiny grape hyacinth in my yard.  "Click." "Whoa!"
The combo of extreme closeup and extremely shallow depth of field gave the image a look and feel I hadn't expected.  

I was hooked.  I was coming off of an especially brutal stretch of consecutive days worked but suddenly I wanted to do photography just for the fun of it.  Spring flowers gave me plenty of opportunities:

Walking with my 4-year-old daughter picking dandelions made me wonder...what would that look like under studio light?  


Strawberries became not just a snack, but a photo op:

Time to totally nerd out.  I wanted to see what the differences were between this new technique and my traditional understanding of macro photography.  For this experiment I put a quarter in an 'A' clamp and photographed it with a 55mm macro & 105mm macro with and without extension tubes, and then with the reversed 24mm lens. 





Just recently I had an opportunity to use it in a lab for a campus job.  

So what have I learned?

  1. Depth-of-field is razor-thin
  2. Exposure is completely manual--live view is your friend!
  3. Works best with the camera on a tripod
  4. I noticed something odd with exposure.  When reversing the 24mm lens I lost roughly 4 stops of exposure.  An image at f5.6, 400ISO normally required f4 3200ISO reversed under the same light.  Hadn't expected that.  
A $15 gadget got me re-energized at a time when I desperately needed it!  Pretty cost-effective.  I look forward to further experiments with it!