lens reversal

Reverse lens technique is very easy to set up. It is a cheap solution for macro photography. You normally go for a dedicated macro lens for macro photography, or use the 'macro' mode available in your camera. However, a dedicated macro lens may not be affordable for most people, and using the macro mode may not give you a good magnification. So if you want to do macro photography on a budget, you can try various inexpensive techniques for macro photography like close up filters, macro converters, reverse lens technique, etc. When I started photography, I didn't have money to buy a macro lens; so I came across lens reversal or reverse lens technique for my macro photography. Through a series of articles, I am going to show you what this technique is and how you can implement it to take macro photographs. Read: Introduction to Macro Photography What is reverse lens technique? It is mounting your lens backwards on the camera. A magnification of a reverse mounted lens increases -- and that's what you wanted. This is the idea of reverse lens technique. I am going to show you how to reverse a 50mm prime lens. You can follow the same technique to reverse any type of lens you have. I prefer reversing a prime lens for macro since prime lenses give sharp images and show good color reproduction. Read: Top 8 Reasons Why you should buy a 50mm lens Equipment Required A DSLR/SLR camera. This technique will not work for point and shoot cameras. A lens you want to reverse. A reverse ring for your lens: To mount the lens backwards, you need to use a reverse ring. It has two sides: a filter thread side and mount side. How do you select a reverse ring for your lens? If the filter diameter of your lens is 52mm, then you should buy a reverse ring which has a filter thread diameter of 52mm (the filter diameter of the lens is written on the front element of the lens). So, buy a reverse ring which has the same diameter as that of your lens. How to reverse a lens? NOTE: If you don't have a reverse ring, you can just reverse your lens, hold it in front of your camera and see how it works. Canon 50mm f1.8 lens and a 52mm reverse ring. Step 1: Attach the reverse ring to the front element of your lens via the filter thread. Step 2: Detach the lens and mount it backwards. Now the back side of the lens is exposed outside. Here is the comparison of magnification: What's the trade-off? Since you are reversing the lens, it loses its electronic communication with the camera. So auto focus will not work, and you cannot change the aperture of the lens either. Lens could not focus when you reverse mount it. There will be only one fixed focal plane and you have to physically move yourself to focus the subject. The lens cannot focus at infinity. The depth of field becomes extremely shallow. Frequent lens reversal causes accumulation of dust and particles on the sensor. Reversing a 50mm lens will provide only a 1:1 magnfication. Learn how to take high magnification macro photography using the reverse lens technique: Below are some of the images I had taken using the reverse lens technique: Challenges of using this technique Now, lets see how to overcome those challenges to take better photographs using this technique. But, first, let me tell you, in brief, the challenges of using the reverse lens technique The challenges of reverse lens technique: How to find the right lens for desired magnification and good image quality? How to change the aperture in reverse lens technique? -- The F00 aperture number How do you focus the subject when in reverse lens technique? Control the depth of field to get sharp photos? Customize external lighting for good exposure? Secrets of Macro Photography Using Reverse Lens How to find the right lens? How to find the right lens for desired magnification and good image quality? Using this technique, you can reverse any type of lens you want, provided if you have the right reverse ring. F8, ISO 800, I/160s So how do you select the type of lens for reverse mounting for macro photography? The concept is simple. Wide angle lenses (in normal mount) decreases the magnification of the subject. That means, the image appears on the sensor is small than the real size. And telephoto lenses in normal mount increases the magnification of the subject. So when you reverse these, you will get the opposite outputs: Reverse wide angle lenses for high magnification. When the focal length of the reversed lens is small, the magnification is high. For example, when you reverse a 28mm lens, you get a 3X magnification. And, when you reverse a 50mm lens, the magnification is 1X or 1:1. So, if you reverse a lens with a focal length of more than 50mm, the magnification will be less than 1:1. If you are reversing a wide angle lens, say, an 18-55mm kit lens, you can adjust the magnification by changing the focal length. How cool is that! Magnification at 18mm is higher than the magnification at 55mm. However, there are some drawbacks when you reverse an 18-55mm kit lens: You don’t get sharp images. Image vignetting (dark areas around the corners) when the focal length is at wide angle ranges (below 28mm). I prefer to reverse prime lens like 50mm f1.8 for macro photography. Why? Because there is not much optics present in prime lenses. Thus, they give sharp images. The only drawback is that you cannot change the magnification as you can do with a wide angle lens. That is, if you wish to change the magnification, you need to have several prime lenses of different focal lengths. So, the choice of lens in reverse lens technique based on The magnification you want Image quality How to change the aperture? How to change the aperture in reverse lens technique? -- The F00 aperture number Since reverse mounted lenses don't have any electronic contact with the camera, the F-number will be shown as F00 Ah. You will see this when you reverse a lens. I was panicked when I saw this. I thought my lens or camera was corrupted or something. But it is nothing to be worried about. A lens in reverse mount does not have any electronic contact with the camera. So, you cannot change the aperture of the lens from the camera. Because of this, the camera displays the f-number as f00 (as shown in the picture) Then, how do you change the aperture? Well, it depends on the lens you are using: Some lenses have an aperture ring to change the aperture size. For such lenses, you can use the on lens ring to change the aperture. For those lenses which do not have an aperture ring, the f-number has to be set in advance before reverse mounting it. Here is how it is done in canon cameras: Mount the lens normally Set the desired f-number. Now press the Depth of field preview button (shown in the picture). This closes down the aperture to the f-number you have set. So, while depressing the DOF preview button, detach the lens from the camera. Reverse mount your lens. Press and hold the depth of field (DOF) preview button while detaching the lens from the camera.. How to control the depth of field How to control the depth of field? When the magnification increases, the depth of field will become too shallow. i.e. the area of focus will be small. It results in blurry images. So, the selection of aperture depends on the magnification of the subject. Here’s how you should select the aperture for macro photography: For the same f-number, the depth of field is inversely related to the magnification of the subject. Confused? Okay, let me make it clear to you: At f8, a 3:1 magnification would give a more shallow depth of field than the depth of field at 1:1 magnification OR At 1:1 magnification, the area of focus at f8 is larger than the area of focus at 3:1 magnification. So the bottom line is, to get more area in focus, choose a larger f-number depending on the magnification. I usually go for f8 (or f9, depending on the available light) when I use reversed 50mm – 1:1 magnification. And for a 2:1 magnification, I prefer f11 to get more area in focus. Focus Focus Since the lens loses its electronic contact with the camera in reverse mount, you will not be able to use autofocus function. Also, manual focus will not work because of the lens’ close proximity to the subject. A reverse mount lens has a fixed plane of focus. So the only solution is to physically move yourself, or the subject, into focus. So using a tripod is practically impossible. Lighting Lighting You cannot trust your camera’s inbuilt light meter once you reverse the lens. So you have to do some trial and error to find a good exposure. Another important issue you experience is the loss of light. As I have mentioned before, you have to use a narrow aperture to control the depth of field. So, obviously, there will be some loss of light. The solution is to increase the ISO or decrease the shutter speed to let in more light. But this may result in noisy and blurry images respectively. Another solution is to use a flash. But, since, flash produces harsh light, you have to use a diffuser to create soft light. However, if the light is too soft, you cannot capture the details on the subject. Putting it all together Putting it all together An optimal setting is important for getting good results. The choice of aperture is crucial as it controls the depth of field and light coming into the camera. I.e. if you choose a very small aperture to control depth of field (large f-number), it cuts down the light. And even if you use a flash along with it, you would get a low key image. So select the f-number wisely – make sure you get enough natural light and a proper depth of field. A sugar crystalPhoto Credits: Ashay Gangwar Reality Check A reality check To be frank, macro photography using a reverse mounted lens is not the best technique. It has a lot of limitations – the autofocus will not work, which makes it difficult to photograph moving subjects; loss of natural light as you have to use narrow apertures, and if you are taking macro photographs of insects, getting close to them might scare them away. So you need a lot of patience and practice to get the hang of using this technique. But I can assure you that the end results are rewarding -- it matches images taken from an expensive macro lens. Anyway, it’s a very cheap technique for macro photography. So why not give it a shot. Your turn I have told you my secrets. So, Are you ready to try this technique out? Share your results in our Flickr group: Shutterstoppers Flickr group I have published a new article on how to use reverse lens technique for high magnification macro photography. High magnification macro photography using reverse lens technique