The Long And Short Of Macro Lenses

Written by: Tim Neumann and Lorie McQuirt

BW-WED-0405201701-I001 - "Just Buzzing Around"
BW-WED-0405201701-I001 – “Just Buzzing Around”

You may have noticed, macro lenses come in a variety of focal lengths, a few of the more popular from Nikon and Canon listed below:

  • ~60mm Focal Lengths
    • Canon EF-S 60mm f/2.8 Macro USM Lens
    • Nikon AF-S Micro-NIKKOR 60mm f/2.8G ED Lens
  • ~100mm Focal Lengths
    • Canon EF 100mm f/2.8L Macro IS USM Lens
    • Nikon AF-S VR Micro-NIKKOR 105mm f/2.8G IF-ED Lens
  • ~200mm Focal Lengths
    • Canon EF 180mm f/3.5L Macro USM Lens
    • Nikon AF Micro-NIKKOR 200mm f/4D IF-ED Lens
BW-WED-0405201701-I002 - "The Green Line"
BW-WED-0405201701-I002 – “The Green Line”

Now you can quickly see, looking at our list above, we are talking about true macro lenses here, i.e. those that feature a 1:1 reproduction ratio (meaning something we are photographing in real life, at the close focus distance of the lens, will render that same size on the sensor / film). While there are many, many macro options available, at various price points, these lenses represent the workhorses of macro photography, for these two major brands (Canon and Nikon) at least.

Someone newer to the ins and outs of macro photography and macro lenses might look at this list and assume, the longer the focal length, the more magnification that that lens has to offer. Surprisingly this is not the case, as all the lenses that you see listed above offer a 1:1 reproduction ratio. If you were to look at the relative prices of these lenses and of course noticed that the longer focal length versions were in fact much more costly than their shorter counterparts, you might ask yourself, why spend the additional money on a macro lens that doesn’t offer me any additional magnification? That would be a valid question and our answer is in the following section.

The focal length of the macro lens, has a direct effect on two things:

    • Close Focus Distance
        • When we are talking about the Close Focus Distance for a lens, we are specifying what is the closest we can get with the lens, to a subject, and still be able to focus the image. If we get closer to the subject, than the close focus distance, we are no longer able to achieve focus with the lens. We must in fact back up, in order to obtain focus on the subject. If we look at our list of lenses again, we now see the close focus distance listed for each lens:
        • ~60mm Focal Lengths
          • 7.87″ – Canon EF-S 60mm f/2.8 Macro USM Lens
          • 7.28″ – Nikon AF-S Micro-NIKKOR 60mm f/2.8G ED Lens
        • ~100mm Focal Lengths
          • 12″ – Canon EF 100mm f/2.8L Macro IS USM Lens
          • 12″ – Nikon AF-S VR Micro-NIKKOR 105mm f/2.8G IF-ED Lens
        • ~200mm Focal Lengths
          • 1.6′ – Canon EF 180mm f/3.5L Macro USM Lens
          • 1.6′ – Nikon AF Micro-NIKKOR 200mm f/4D IF-ED Lens
      BW-WED-0405201701-I003 - "Hover Time"
      BW-WED-0405201701-I003 – “Hover Time”
      • So what does this mean to you the photographer, what are you getting out of these pricier lenses, that their less expensive counterparts don’t offer? The answer is, working distance. You can see, looking at the list above, a 60mm focal length macro lens has you working at ~7.75away from a subject to get 1:1 reproduction ratio, however the 200mm focal length lens puts you at ~18 away to get the same ratio. This may not seem like a big difference, but to a bug, or some other skittish critter it’s a whole other world away from them. That added working distance may (read likely) allow them to be comfortable staying in place while you are trying to get focus and grab an image or two.
BW-WED-0405201701-I004 - A little narrower field of view
BW-WED-0405201701-I004 – A little narrower field of view
  • Field Of View
      • Our next point of differentiation is in field of view. Field of view describes, in measurable terms, the angle of sight, horizontally, that a lens allows you to see. While there is some specific math involved, pretty much every lens has a published field of view specification. Generically speaking wide angle lenses offer wider fields of view and telephoto lenses offer narrower fields of view, with there being a gradual shift from wide to narrow as focal lengths go from shorter to longer. We can now, in our list below, the fields of view, that each of the listed lenses offers:
      • ~60mm Focal Lengths
        • 24 degrees – Canon EF-S 60mm f/2.8 Macro USM Lens
        • 26 degrees – Nikon AF-S Micro-NIKKOR 60mm f/2.8G ED Lens
      • ~100mm Focal Lengths
        • 26 degrees – Canon EF 100mm f/2.8L Macro IS USM Lens
        • 23 degrees – Nikon AF-S VR Micro-NIKKOR 105mm f/2.8G IF-ED Lens
      • ~200mm Focal Lengths
        • 13 degrees – Canon EF 180mm f/3.5L Macro USM Lens
        • 12 degrees – Nikon AF Micro-NIKKOR 200mm f/4D IF-ED Lens
    BW-WED-0405201701-I005 - Just a tad wider field of view here
    BW-WED-0405201701-I005 – Just a tad wider field of view here
    • Well that’s great, the field of view gets narrower as these lenses get longer, but how does that help you? Well what it does for you is, it makes composition a little bit easier, mainly due to the fact that the narrower field of view, cuts out more of the potential distractions from the background of the image. Now we realize in macro imaging that may be a fine line and frankly not much of the background is typically in focus, but it can have the effect of limiting your background area to a smaller region and potentially one blurred color, rather than many. It’s a fine line, but it can make a difference.

Okay, so you have some concrete information to work with here and hopefully it will help make your lens selection process easier. Now I don’t want to leave this article without mentioning one important thing about all these focal lengths. There is one more important factor to consider…the longer the focal length, the harder it is to use. The trick to longer focal lengths is, the longer the focal length, the more movement impacts the image. Movement that is tolerable in a 60mm focal length may be an image killer in a 200mm focal length. The longer lengths require steadier hands to combat the added length and weight, often times the move to a tripod is the answer for some.

We there you have it, a little macro focal length insight.

BW-WED-0405201701-I006 - A more comfortable working distance
BW-WED-0405201701-I006 – A more comfortable working distance

See you next week!

tdneumann

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