Photographing Insects: Is a Macro Lens Worth It?
What are the advantages of using a true macro lens?
I replaced my Canon RF-S 18–150mm kit lens with extension tubes by an expensive macro lens, the RF 100mm 2.8L Macro. Now, after four weeks and 2,000 shots, it is time to ask myself: was it worth it?
An adapted version of this article has appeared in my free book My Journey into Insect Photography that you can download here.
This is a very difficult question to answer. The value of money is something that is hard to quantify. Is a polarizing filter worth more than a nice dinner? Impossible to say. So let me describe what the advantages of the macro lens are and whether these are important for me and for insect photography. They fall in three categories: convenience, magnification, and quality.
Convenience
This is actually the biggest plus. Using a macro lens is way more convenient than using my kit lens with extension tubes. Here are some aspects:
- It is easier to locate the insect. With extension tubes the focus range (distance between smallest and largest focus distance) become rather small. When you are not in that range, the image in the viewfinder becomes very blurry. This makes it hard to find the insect. I lost many shots because I simply failed to locate the insect before it disappeared. With the macro lens you simply focus from a distance and then get closer to the insect with the focus button pressed. Piece of cake. The focus distance delimiter is really useful here. Otherwise the camera regularly tends to focus on the background.
- There is no limit on the focus distance. For example, when I see a butterfly that is slightly further away, I can still take the shot. And when I occasionally see something completely different (like a nice animal) I can photograph it too.
- I can stay further away from the insects. The insect will not scare away. And, in particular, I will not bump into the plant with the camera or the diffuser. That was a serious problem with the kit lens. Once you hit the plant either the insect flies away, or the plant starts moving, making it almost impossible to focus. Also, the flash light now reaches the insect more easily.
- No need to set a focal length. With the kit lens I first had to determine the focal length the get the magnification I wanted. This was an additional parameter to control and I missed some shots by not setting it correctly.
- Both camera and lens are now weather sealed. Not that I shoot in bad circumstances, but it makes you worry less when there is some rain or dust. And I want to go to some covered butterfly garden in the near future that is very humid. There it should avoid condensation inside the camera.
All these aspect do not influence the photographs themselves. It just makes my life easier, and leads to more successful shots.
Magnification
With the kit lens and extension tubes I could theoretically reach a maximal magnification factor of 1.38 (for APS-C sensors) although this meant having to get extremely close to the insect. With the macro lens this become 2.24. That is a considerable difference. I like to shoot small insects, like little flies, beetles, and spiders (not really an insect). This becomes easier now.
On the other hand, I hardly ever use that very large magnification. Keeping the camera steady become so hard and, hence, getting the focus on the correct spot is almost impossible. With wind or a moving insect it just won’t work. Also, the depth of field becomes really shallow. So sometimes it is better to use a slightly smaller magnification and crop the image a bit more. But having the possibility to get closer is a huge plus. It gives me more flexibility.
In the EXIF information in the images, the camera stores the focus distance from the sensor (though not very precise), but not the magnification. To get a better insight in the magnification I created the following table. For each focus distance it shows the magnification for full frame (FF) and the equivalent for my APS-C camera. So, for example, the planthopper image below has a focus distance of 31 cm and, hence, a magnification (on APS-C) of 1.3.
I could use the extension tubes and/or Raynox 250 close-up lens to get an even higher magnification. But I never use them. It removes almost all the conveniences I described above.
Image quality
I do see some improvement in the image quality. The parts that are in focus are clearly sharper and I need to do less post processing. And because I need less digital crop the final image quality also improves.
I now realize that the autofocus of my kit lens was very good and fast. I don’t think the new lens is much better there. Part of that is due to the fact that I now use more magnification, making focusing harder.
Because the lens is heavier I have to hold the camera in a slightly different way to avoid unwanted motion. I am now holding the lens with the left hand, rather than the body. I also noticed that often I moved the camera at the very last moment when pressing the shutter. This is bad for focusing. I now use the tip of my index finger for this, and do not use that finger at all to hold the camera. That helps.
A tip: You can indicate in the menu that the camera shows the focus point when previewing the image. This is very useful to see whether you hold the camera steady and focus on the intended spot.
Some other aspects
The flash and the lens diffuser work fine on the new lens. Because the lens is a bit thicker the diffuser fits better. I bump less into plants and the flash is still strong enough, even though the focus distance is increased.
Image stabilization was already good on the kit lens, but it is slightly better with the macro lens, helping to keep the camera more steady.
The macro lens has a wider maximal aperture. I did not really use that yet, but it might be handy in situation where you cannot use a flash, like when doing handheld focus stacking or when you want to create continuous shots of a flying insect.
The focal length of 100 mm becomes 160 mm on my APS-C camera. That makes the lens pretty useless in other situations than macro. It is not enough for wildlife photography and it is too much for photographing landscapes or people. So except for the occasional shot, this is not the lens to use in those situations.
Conclusion
Is the RF 100mm Macro the ideal macro lens for the Canon R7? I don’t think so. I think that would be a dedicated RF-S macro lens of 65mm. Laowa makes such a lens, but it is fully manual. I don’t think Canon will ever make such a lens, but maybe Sigma will at some moment. So, currently the RF 100mm is clearly the best automatic macro lens you can buy.
But was it worth it? I am very happy with the new lens, and that counts. You can create great insect shots with a kit lens and some extension tubes, so there is no real need to buy a macro lens. Some people even take great macro shots with their mobile phone. But if you decided that insect photography is the thing for you, and you can spare the money, I recommend getting it.
However, remember, it is the photographer that makes the great shots, not the camera.
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Mark Overmars is a dedicated insect photographer that loves to share and regularly publishes about his work and about photography in general. You can visit his website at www.insectphotography.org. Download his free insect photography book at www.insectphotography.org/book.
