How To: There are numerous ways to get great results, but for this tutorial I want to focus on one particular technique. First, I must give due props to Alan Walker for telling me about it. I’m calling it the Reverse Lens technique. Basically, you take a second lens and set it up backwards against the lens on your camera (see image below). If you’re really hard core, like Alan, you can tape the two lenses together like this.
If you’re anything like me, then your curiosity has already gotten the better of you =) You will probably save yourself some frustration if you read the rest of this before trying it yourself, so allow me to explain how this works. The lens on your camera is designed to take a wide angle of view and focus it onto a much smaller plane (traditionally, a strip of film). This allows you to capture huge landscapes on a frame of film only 35mm wide. Zoom lenses work by altering the angle of view (see diagram 1). To simplify it a bit more, just remember that a single lens takes the subject from “big to small.”
Now, imagine if you flipped the lens around. (see diagram 2) The subject would go from “small to big.” This is essentially how the lens on a projector is set up; it takes the small image and enlarges it. As I understand, you can get great macro results with a single reversed lens like this, but you need a special “reversing ring” accessory.
Now lets take a look at what happens when you put the two lenses together. The reversed lens takes a really small subject, and magnifies it. The attached lens then takes that magnified image and shrinks it back to fit on the “film.” The result is that the small object now fills the frame of film -exactly what we want!
Still with me? I hope so. It gets a little more complicated, but it makes perfect sense once you think about it. If your second lens is a zoom lens, then you can actually zoom in closer or farther from your subject. In other words, not only can you do shots that are pretty typical for macro, but you can also do shots that are the verge of being classified as microscopic. It’s important to remember that the lens is backwards, so your zoom will be backwards too. If you “zoom in” the reversed lens, it will appear that you are zooming out in the viewfinder. The more the lens is zoomed out (“wide angle” or “short focal length” for you technical buffs) the more extreme the change in scale, but when you zoom in, the scale shrinks. I feel like this is a very difficult concept to describe, so instead let me just show you the diagram below.
If the diagram doesn’t help, then don’t worry about it. Just remember that the lens is backwards so the zoom will be backwards too.
The above diagrams were designed to help describe the techniques outlined here. They were not designed for technical accuracy.
Based on my experience and what I’ve read elsewhere, it’s best to use a fixed 50mm lens as the one attached to the camera. These lenses typically have a very large aperture and the image quality is superb because there is comparatively very little glass for the light to pass through before reaching the film. For my reversed lens I used a 28-80 zoom lens. I also tried the setup with an 18-200 lens attached to the camera, and the same 28-80 lens reversed, and I experienced no problems. That all goes to say that you should be able to pull off this technique with nearly any two standard-range zoom lenses.
When you first put the two lenses together and look through the viewfinder it will probably just look black. This is mainly because the aperture of a lens will shrink to it’s smallest setting when it’s not attached to a camera. In other words, most of the light is being blocked. While it is indeed possible to take pictures like this, it’s not very easy. If you look on the back of your reversed lens, you will see a small lever.
That lever controls the opening of the aperture. If you slide it to the other side it will open it as wide as it can go. Doing that will allow you to have considerably faster shutter speeds even at low ISO values (of course, make sure the aperture of the attached lens is open as wide as it will go too). Since the lever is spring-loaded, you will need something to hold it in place. I cut and folded a piece of card stock (i.e. “thick paper”) and wedged it in place. Be careful not to damage the lens while doing this, and make sure you don’t accidentally drop something down that slit. (Note: this paragraph was written based on my experience with Minolta equipment. It may or may not be applicable for Nikon or Canon.)
Before you get started, there are a few things to keep in mind.
1.) The two lenses have to be literally butting up against each other. Unless you tape the two lenses together you will need to be careful that they are held tightly together so that light doesn’t leak in from the side and wash out the image. On more than a few occasions this caused me to think the Exposure Compensation was all whacked out because the images weren’t consistent.
2.) Set the focus to manual. Autofocus simply won’t be able to help you. You won’t be able to adjust the focus by turning the ring but by moving the entire camera closer to your subject. Note that very small objects probably won’t be in focus until they are less than 1 inch from the end of the lens.
3.) If your second lens is set to a wide angle (remember that this is will appear to be zoomed in, in the viewfinder) you will most likely get a vignette. With the lenses I used, I wasn’t able to avoid it when the focal range of the reversed lens was inside the 28-50 range. You can crop it later if you really don’t like it, but it’s just something to be aware of.
4.) Keep an eye on the exposure; chances are, the camera’s metering system won’t give extremely accurate results since you are shooting through a second lens. I found that I often needed to turn down the Exposure Compensation. Setting the drive mode to Manual (M) is a better alternative if you’re comfortable with that.
5.) Turn off the flash. Unless you have a wireless or external flash your subject will be too close to the lens that the flash will cause a shadow to fall on it. This is called “self-shadowing.”
6.) Make certain that you have a UV filter or lens protector on both lenses. If you scratch the lens itself, there’s virtually nothing you can do to fix it, but if you scratch the $20 UV filter, you can always pick up another one. I always keep a UV filter on all of my lenses, for what it’s worth.
7.) Using a tripod is completely impractical.
8.) A cable release or remote would be ideal since the slightest change in position can throw the whole image out of focus. Pressing the button on the camera often “bumped” the position and caused the focus to shift. Using a remote allows you to trip the shutter without bumping the camera. Likewise, you could use the self-timer, but that requires an extraordinary amount of patience.
Examples: The three pictures below emphasize how powerful this setup can be. The first image was taken with only the 50mm lens; it’s as close to the subject as I could get while keeping it in focus. The second was taken with the reverse lens set to 80mm, and the third was set to 28mm.
Or consider the following example: In the image below you see a very small speck right in the middle of the image. That speck is actually a bug.
I wasn’t able to focus any closer with my 50mm lens, but when I added my reversed lens set to 28mm I was able to get close enough to see the bug’s eyes.
Advanced Techniques: You can purchase accessories like extension tubes, reverse rings, macro flashes and others specifically designed for macro photography, but I’ve never played with any of them. As far as I can tell, none of them really enable you to do anything that you can’t already do with a reversed lens, but rather they are designed to make things easier.