Following on from last week and our discussion regarding extension tubes, I thought this week I’d go over my experience with another cheap way to achieve macro shots without the cost of a dedicated macro lens.

One of my favourite lenses is an old, full-frame 50mm 1.8 prime lens. It’s camera mount is M42 thread and it has a 49mm filter thread. It’s crisp at all but the very widest aperture.

To use this lens for macro work I needed to change my micro 4/3 mount to a 49mm male screw thread.

I already have a M4/3 to M42 adapter, so I just bought a M42 to 49mm  step-up ring.

Micro 4/3 to M42 adapter

Micro 4/3 to M42 adapter

   
42mm to 49mm 'Step-Up' ring

42mm to 49mm ‘Step-Up’ ring

 

 

 

 

 

 

 

 

 

 

Then I could mount the micro 4/3 adapter with the step-up ring to the camera body, then reverse the 50mm lens backwards onto the threaded end of the mount.

There are a few technical differences with using a reverse mounted lens, but as long as your happy to use your camera on full manual, you won’t have any problems if you use an lens with manual aperture control.

Because the lens is mounted backwards on the camera, you lose;

  • all of your cameras automatic systems.
  • there is no aperture control from the camera
  • there is no auto focus, etc.

On most cameras, you’ll still have the ability to meter the scene, which will help you get the correct exposure, but you’ll have to make the adjustments manually.

Most old film camera lenses (and some digital lenses) have an manual aperture switch on the lens body. This allows you full aperture control, even when the lens is reversed on the camera body.

If your lens doesn’t have this switch, but has a manual adjustment ring, you’ll have to design some way of holding the release arm shut. Usually a piece of BlueTak will do the job fine.

Lens switched to Auto control

Lens switched to Auto control

   
Lens switched to Manual

Lens switched to Manual

Because the camera always shows you the image through the lens with the aperture fully open, if you don’t shut off this automatic setting, you’ll have no aperture control, which will mean almost no depth of field.

The other issue you’ll come up against if you’re using your cameras kit lens, or any other non-aperture ring lens, is that you’ll lose any control over aperture adjustment when you reverse it on your camera.

This gives an added problem in that for most macro images, to obtain a usable depth of field, you’ll need to use a small aperture (high f number). You can get this by attaching your lens to the camera normally, selecting the required f-number in the menu, or on the dial and then removing the lens.

The lens will stay at the aperture it was last set to. The problem now, is that when you reverse it on your adapter mount, the subject is probably too dark to see it!

You may have to make a creative decision on the level of depth of field that’s acceptable to you, so you’re still able to see as much of the image necessary to focus correctly.

Providing your happy to do that, the results are very similar to the ones you get when using extension tubes.

When comparing the two options there are a few things to consider;

  • Because you’re mounting the lens directly to the camera body, there’s no loss of light like there is with extension tubes.
  • Because you’re not physically moving the lens further away from the sensor, you’re able to get sharp macro shots without the subject needing to be right on top of the lens.
  • You will need to set you’re aperture manually, which if you’re using an automatic lens may be a problem.
  • If your lens has image stabilisation, it doesn’t when you reverse it.
  • When using extension tubes, the front optic is outermost. The opposite is true with a reversed lens. This means that the rear optic is open to get damaged. You can put a filter on the front optic to protect it, the same isn’t true of the rear optic.

It’s also worth remembering that the smaller the focal length of the reversed lens, the greater the magnification. The simple way to remember is that the lens does the reverse of what it normally would….. a wide angle lens acts like a telephoto and the longer a lens becomes, the more wide angle it becomes.

Finally, just a couple of images taken with the Olympus e-PL1 and a reversed 50mm lens. The distance to the subject was 6 inches (15cms).

Click for full size image

Click for full size image

Click for full size image

Click for full size image