If you’re a Star Trek fan, you recognize this blog post title as a reference to the #1 law in the Federation: don’t interfere. Well, this blog post has absolutely nothing to do with the final frontier. Instead it’s about the #1 type of lens many DSLR filmmakers like to shot with: primes.
A prime lens is a single focal length lens, i.e. it doesn’t zoom. For many videographers switching from the world of professional or prosumer camcorders with built-in, zoomable lenses, to shooting with primes may seem like a pain not worth taking. But there are two primary reasons why filmmakers love primes lenses.
- Better glass: Prime lenses tend to have higher quality glass. And more of it. Because there are no moveable parts required (as is the case with zoom lenses), more of the lens can be focused on the glass (pun intended.) You therefore will get better looking imagery with a prime lens vs. a zoom lens.
- They’re usually faster: a lens is said to be “fast” when it can open up to a wide aperture (i.e. the “F” number on the lens is small). So an F1.4 lens is faster than an F2.8 which is faster than an F4.0, etc. Again, because of the glass quality, and because there are fewer elements needed to make the lens, there’s more room to allow for a wider iris opening. Therefore more light can get into the lens, ergo, they’re faster.
Naturally, the downside to shooting with primes is that they require more set-up when filmmaking. As they say in the biz, you have to “zoom with your feet.” So, if you want a tighter shot, you need to either move the camera closer, or get a longer prime lens. If you shooting an event that requires getting larger variety of focal length shots in the least obtrusive way possible, then I strongly suggest using zoom lenses. Especially during sacred ceremonies like weddings, bar/bat mitzvahs, etc. Use something like a 70-200mm so that you can get tight and wide shots without have to disturb guests by picking up your tripod every now and then to move back and forth.
Here’s a short list of popular focal lengths to consider when picking primes for DSLR filmmaking. I primarily use Canon lenses, but I also like Tokina and Tamron lenses as well. Note: if you’re using a camera with a crop factor, divide these numbers by that crop factor to get the equivalent needed lens. For instance, if you want a 50mm look on the Canon 7D which has a 1.6x crop factor, you should use a 30mm or similar focal length lens. I use the Canon 35mm f1.4L when shooting with this camera and I want a 50mm look.
- 14mm f2.8: great for “flying” shots on a Glidecam or Steadicam style device.
- 24mm f1.4: another good lens for flying shots with less distortion around the edges that you may see from a wider lens like the 14mm.
- 35mm f1.4 and 50mm f1.2-f.18: these offer a more natural view (50mm approximates the human eye’s field of view). Great for interviews or medium shots. For many filmmakers, if they could only get one lens, it would be a 50mm (ideally f1.2 to f1.8)
- 85mm f1.2: this is a great lens if you want a beautiful bokeh narrow DoF.
- 100mm f2.8 macro: great lens if you need a super-tight close up of something very small like an insect or eyeball.
- 135mm f2: if you need a long shot that is crisp and clear.
RENT vs. BUY
Lastly, I couldn’t write a blog post about lenses without addressing the issue of cost. These lenses can get pretty pricey, especially if you go for Canon’s L-series (the lenses with the red line). As many of you who follow me know, I don’t advise going into debt to get equipment. So, if you can’t afford these lenses outright, rent them for places like LensProToGo, BorrowLenses.com or LensRentals.com.
What are your favorite lenses to shoot with?