Archive for September 29th, 2018

Shooting a movie? You only need TWO lenses

In a previous article I mentioned that the best cheap cinema camera you can get today is the Canon EOS M, that can be found for $150 on eBay. In that same article, I listed the hardware you’d need to pull off a believable spectacle. The lens I suggested was the 7Artisans 25mm f/1.8 ($70). You can shoot a whole movie with that lens. But sometimes, you just need something wider. That’s where the Opteka 12mm f/2.8 comes into play ($199).

I own five cinema-worthy cameras, but the ones that are most in my heart because of their ratio of features vs price, are the EOS M, and the BMPCC. The M has a more manageable codec at 45mbps, some basic autofocus, and support for picture profiles to expand its rather limited dynamic range (I’d suggest either Miller’s CLog3 ($25), Technicolor Cinestyle (free), or if you don’t like color grading much, the VisionColor CineTech ($20)).

The BMPCC on the other hand, while more of a pain to operate, particularly because of its poor battery life, it delivers the most pleasing film-like image, since it has a lot of dynamic range. I’d suggest you shoot at ProRES LT with it (84mbps), since RAW takes too much space, and its other ProRES variants don’t have much difference between them. The first feature-length (and serious) movie shot with the BMPCC, the sci-fi drama “Cosmos”, was shot just in ProRES LT and it looks amazing.

Now, regarding the lenses. You’d need one long/portrait, and one wide lens. Whole movies have been shot with just such a two-tier selection. The 7Artisans 25mm f/1.8 and the Opteka 12mm f/2.8 lenses can fit that bill nicely. If you do have an extra $150, go for the 12mm f/2.0 Rokinon “cine” lens instead of the Opteka, however, it’s not necessary. I suggest the Opteka 12mm f/2.8 ($199) instead of the very similar 7Artisans 12mm f/2.8 ($188), because of a slightly better design, and because of a smaller filter thread on the front of the lens — which is important for the reason that I’ll mention below.

Now, one thing you have to consider when choosing lenses is the crop factor. The EOS M is an APS-C sensor, which has a crop factor of 1.6 compared to full frame 35mm. It’s basically a smaller sensor than 35mm. The BMPCC is tiny, being a super16mm sensor, having a crop factor of 2.88. What this means is when we speak of a 12mm lens, and we may think that nobody needs such a crazy wide lens, you’ll have to take into account the crop factor. So on the EOS M, the 12mm becomes a 19mm in 35mm full frame equivalency (12 x 1.6 = 19). As for the BMPPC, the 12mm lens becomes nearly 35mm! Not so wide now, is it? You can barely see the head of your actor from a close distance!

7Artisans 25mm -> 40mm (35mm equivalent)
Opteka 12mm -> 19mm (35mm equivalent)

7Artisans 25mm -> 72mm (35mm equivalent)
Opteka 12mm -> 35mm (35mm equivalent)

For the EOS M, these two lenses would be all you need. They’re wide enough to do the job. For the BMPCC though, you’ll need extra help. You can buy a “Speedbooster” accessory, that widens the field of view of your lens, but at $750, it’s a ridiculous purchase. Instead, a cheap $50 wide angle adapter (0.43x, with a 67mm thread) will help you fix the problem. These cheap wide angle adapters are quite fuzzy on the edges (low quality optics), however, since the BMPCC can’t see the edges of the lens (because of its massive crop factor), the quality that comes out of them is acceptable. In fact, the guys who shot ‘Cosmos’ also used such a cheap wide angle adapter without visual problems.

You will also need a 46mm to 67mm step up ring (to mount it to the 25mm lens), a 67mm to 72mm step up ring to mount it to the Opteka, and you will need to have a 72mm variable ND filter and an IR CUT filter when shooting outdoors (to mount it in front of the lens or the adapter when needed). You will also need a 46mm to 72mm step-up ring, in order to mount these filters in front of the bare 25mm lens.

Basically, with the wide angle adapter, it’s “like” you have four lenses instead of two, depending on the shot you need:

7Artisans 25mm -> 72mm (35mm equivalent, bare lens)
7Artisans 25mm -> 60mm (35mm equivalent with wide angle adapter)

Opteka 12mm -> 35mm (35mm equivalent, bare lens)
Opteka 12mm -> 29mm (35mm equivalent with wide angle adapter)

To put it in perspective, the guys who shot Cosmos, after using both a speedbooster, and a wide angle adapter, their widest lens they used (28mm) was only about 40mm in 35mm equivalency. If they can do a whole movie with a 40mm lens, why can’t we do the same with more readily available and more flexible options? Let’s get to work!