I have explained the lens reversal technique earlier. It is one of the techniques I like because of the reasons I mentioned before. I have been getting a lot of questions on reverse lens technique ever since I published it. Since it is becoming a favorite technique of photographers, I thought I should write more about it. I wrote the article by showing how to reverse a 50mm lens. But, it only gives you a 1:1 magnification. But, what if you want a magnification higher than that?
So, in this article, I will explain how to take high magnification macro photographs using the lens reversal technique by reversing an 18-55mm kit lens. The tutorial is structured in the following way:
Lens reversal technique for high magnification macro photography — Reversing an 18-55mm kit lens
What is high magnification macro photography?
There are some of confusion about the magnification in macro photography. Most people get confused with the jargons like magnification ratio, life-size magnification, and numbers like 1:1, 1:2, 2:1, 3:1, etc. Or 1X, 3X, etc. But it is pretty simple. You need to know what these ratios mean when you read or do something about macro photography. Some of you might think, “why do I need to know the magnification ratio or all that mathematical stuff? If the subject is big enough in the photograph, then it would be fine” But, trust me, it will help you in framing and, moreover, that would help you improve your macro photography.
It is no rocket science. A 1:1 magnification (life-size magnification) is capturing the true size of a subject. Say, your camera has a 23mm sensor and if you photograph a subject which is 23mm long, it will fill the entire frame. And if you photograph the subject at 1:2 magnification, then the length of the subject would be 11.5mm in the photograph. Thus, a 2:1 magnification means you are capturing the subject twice its original size. And 1:2 magnification means you are capturing the subject half its original size. Some lenses like tamron 70-300mm offer 1:2 magnification where it let you focus a little closer than normal lenses to get that magnification. A dedicated macro lens gives atleast a 1:1 magnification. Similarly, 1X means the magnification is same as that of the real size of the subject, 2X means twice the size of the subject, and so on.
What are the various methods for high magnification macro photography?
I had used reversed 50mm for macro photography before I started using the reversed kit lens. Like I have mentioned before, a reversed 50mm lens will only give a 1:1 magnification. Even though it was good enough, I wanted to try higher magnification. So, I looked up for various methods to take high magnification macro photography and found these:
- Dedicated lens like canon MP-E 65mm.
- Lens reversal technique with a focal length smaller than 50mm (or longer that 50mm, but I wouldn’t recommend that method)
- Using extension tubes along with a dedicated macro lens or a reversed lens.
- Lens coupling.
- A magnifier like Raynox DCR-250/150 along with a dedicated macro lens.
- Using microscopic lens (for very high magnification like 10X or more)
I decided to reverse my 18-55mm lens to take some high magnification macros because of the following reasons:
- I could not afford a dedicated lens.
- Drastic light loss if I use lens coupling or extension tubes.
- I already had a kit lens.
- Kit lens gives me the flexibility to change the magnification (1X -5X).
So, all I had to do was to buy the reverse ring for my 18-55mm kit lens and get started.
How to reverse an 18-55mm kit lens for high magnification macro photography?
I would suggest you to read my earlier posts on reverse lens technique since the steps are pretty much the same.
- A DSLR with a cropped sensor. I haven’t tried reversing an 18-55mm lens on a full-frame DSLR. And I won’t recommend you to use it since at 18mm there will be vignetting (dark corners in the pictures). However, since the effective focal length of 18mm in a 1.6 crop factor DSLR is 34mm, you can reverse a lens with a minimum of 34 mm in a full frame camera. That would give the same magnification as 18mm in a cropped sensor.
- A reverse ring for your 18-55mm lens. The filter thread diameter for 18-55mm lens is 58mm. So you need a reverse ring of that diameter.
- An external light source. You need to use either your pop-up flash or an external flash as a light source to compensate for exposure loss. It is not just that simple to use the flash and get good results. There is so much to talk about lighting and it would make this post insanely lengthy. I will explain in detail about the lighting in high magnification macro photography in another article.
- Some colored objects, flowers or leaves. This is for getting a colored background in the photograph. I will explain more about this when I explain lighting and exposure.
Next, I am going to explain how to use this setup to take high magnification macro photographs and how to get better results with a reversed 18-55mm kit lens.
How to measure the magnification of a reversed lens?
F-number, magnification, and depth of field
How depth of field is related to magnification and f-number?
Changing the magnification while using a reversed 18-55mm kit lens
- Changing the focal length of the lens.
- By an internal focusing mechanism. This technique is used in dedicated macro lenses like 90mm, 100mm, etc. When you focus closer using these lenses, the length of the lens doesn’t change.
- A fundamental idea about depth of field, f-number, and magnification in high magnification macro photography.
- Enough information to set the camera settings (aperture settings at various magnifications).
- An idea about how to change the magnification when the lens is in reverse mount.