Photography and movie recording is about capturing light, and it is way easier to cut out excess of light than trying to get more light, for that, you’ll need fast lenses, or wider aperture lenses. Nowadays most full frame lenses get results almost comparable to the ones used by Hollywood, the shallow depth of field achievable is amazing, but many people forget why Hollywood used this kind of lenses, it was because back then film wasn’t as sensible to light than modern CMOS censors.
Low light scenes were dificult to shoot back then, that is why Stanley Kubrick used the legendary Carl Zeiss Planar 50mm f/0.7 to show low light scenes in Barry Lyndon (1975) by using just natural light and candle light, well, special candle light, but such a wide open aperture has his quirks, it had a really really shallow depth of field which made the actors to reherse the blocking to stay always in focus.
The history about his lense is quite interesting, it was designed for military use by German Nazis in 1,941 and it was originaly a 70mm f/1.0 lens, it was then “redesigned” by NASA in 1,966 to be a 50mm f/0.7 lense by adding two extra elements, a 0.7x condenser, which in todays DLSR standards could be also called, a Speed Booster.
As you can see, the double-Gauss-type optical cell on the Leica 50mm lense is almost identical to the one in the Zeiss 50mm f/0.7, but there are two extra elements to the end, you can find more information about it in this great article:
Getting the same results
Now, going back to what make me write this article, the Micro Four Thirds System is great, technology is always shrinking so why not shrink cameras, but keeping the same specs. lets look at the typical full frame lens lineup and notice this lenses have constant aperture:
- 16–35mm ƒ/.2.8
- 24–70 ƒ/2.8
- 70–200 ƒ/2.8
So if you want to have the same results you can get with those constan aperture lenses using the Micro Four Thirds System and considering de x2 crop factor you’ll need:
- 8–17mm ƒ/1.4
- 12–35mm ƒ/1.4
- 35–100 ƒ/1.4
¿There are options with those specs? Well, let’s see on the B&H Store which ƒ/1.4 options we have:
- Panasonic Leica 12mm ƒ/1.4 (24mm ƒ/2.8 on FF)
- Sigma 16mm ƒ/1.4 (32mm ƒ/2.8 on FF)
- Rokinon 21mm ƒ/1.4 (42mm ƒ/2.8 on FF)
- Rokinon 24mm ƒ/1.4 (48mm ƒ/2.8 on FF)
- Panasonic Leica 25mm ƒ/1.4 (50mm ƒ/2.8 on FF)
- Sigma 30mm ƒ/1.4 (60mm ƒ/2.8 on FF)
- Rokinon 35mm ƒ/1.4 (70mm ƒ/2.8 on FF)
- Samyang 85mm ƒ/1.4 (170mm ƒ/2.8 on FF)
- Rokinon 85mm ƒ/1.4 (170mm ƒ/2.8 on FF)
As you can see, only prime lenses, not a single zoom lense with constant aperture, so, Which lenses are available that can fit the same focal length of the 16–35mm, 24-70mm, and 70–200mm? Again, looking through B&H Store:
- Panasonic Leica 8–18mm ƒ/2.8–4 which would look like a 16–36mm ƒ/5.6–8 in a full frame camera, it wouldn’t gather much light.
- Panasonic 12–35mm ƒ/2.8 which would look like a 24–70mm ƒ/5.6 on a full frame camera, again, a narrow aperture value.
- Panasonic 35–100mm ƒ/2.8 which would look like a 70–200mm ƒ/5.6 on a full frame camera, at this point you know it wouldn’t have a great aperture.
The Speed Booster Solution
So, many people say that the perfect solution is to use full frame lenses with a Speed Booster even making reference to the Carl Zeiss Planar 50mm f/0.7 use of a teleconverter, and that sounds great until you think twice, yes, the Metabones Speed Booster XL 0.64x sounds great on paper, but let’s dive a little deeper into the crop factor which not only affects focal length but also the F-stop. The Micro Four Thirds System has a crop factor of 2x and the Metabones Speed Booster has a 0.64x crop factor, which combined produce a 1.28x crop factor, so let’s see what would be the result using full frame lenses:
- 16–35mm ƒ/2.8 = 12.5–27.34 ƒ/2.18
- 24–70mm ƒ/2.8 = 18.75–54.64 ƒ/2.18
- 70–200mm ƒ/2.8 = 54.68–156.25 ƒ/2.18
As you can see, it doesn’t achive the same result, in order to achive the same result the Speed Booster need to have a 0.5x crop factor, and it is quite difficult to achieve that with an adaptor, also, full frame lenses are made for low density CMOS sensors, it would produce smooth images instead of sharp images, so, Which solution could be to achieve the full frame results? Well, lens manufacturers should create faster zoom lenses with constant aperture.
You can mount a 50mm ƒ/1.4 on a full frame and get a really shallow depth of field without any caveat, but in order to have the same results on a Micro Four Thirds you’ll need a 25mm ƒ/0.7, a lens that doesn’t even exists, the faster lens for Micro Four Thirds cameras is the Handevision IBELUX 40mm f/0.85 which would look like a 80mm ƒ/1.7 lens, and it costs $2,079.99, Why expend money on that when you can get a Sigma 85mm ƒ/1.4 for $1,199.00 and achieve better results?
If the idea is to have almost the same results as a full frame camera, I don’t see any advantage on investing on the Micro Four Thirds lens ecosystem, lenses are expensive and slower, I know that isn’t hard to produce faster lenses for the Micro Four Thirds System and even charge the same price for the same results, the only current advantage is small size, but I’m sure low light performance on those lenses isn’t great, so I hope to see faster lenses in the future.