So you want to shoot super 35mm with b4 lenses? You’ve come to the right place.
What Are B4 Lenses?
First off, b4 lenses are a special kind of lenses that “fit onto” the Arri 1.3x and Super 35mm sized digital cinema cameras such as the Arri Alexa and Red Epic/Scarlet. With these lenses, you no longer have to use PL or Panavision mount cine lenses, but can instead choose from a huge variety of still photography optics.
The first company to offer 1.3x crop factor adapters was Letus35, which is now defunct. Fortunately, optical engineer Bruce Hemming has continued their legacy through his company Hiam and B4 adapter line.
Why fit B4 lenses on 35mm cameras
When shooting on film one would typically shoot with an anamorphic or spherical prime lens set, or with prime lenses in the Panavision, Arri/Zeiss Super Speed, Cooke S4/i, Leica Summilux-C, or Canon CN-E sets. With these lenses, you can get an extremely shallow depth of field and beautiful bokeh.
When shooting on digital one would typically use PL mount cine primes (which are not ideal for other reasons). Now we can instead shoot with a set of amazing zoom and prime lenses from the still world.
Many people say that one should not adapt b4 lenses to work on super 35mm cameras because they were meant for film and therefore must be “unsharp” meaning less than ideal as still. This is simply not true.
Any lens that is designed for an optical format looks the exact same when shot on another format. For example, a 50mm f/1.4 lens will look like a 50mm f/1.4 regardless of if you shoot it on film or digital, on the small sensor or large, etc. A 35mm color head will look like a 35mm color head whether shot on super 16mm, 1″ CCD (Sony F900), b4 (Arri Alexa), or RED DRAGON.
Are B4 lenses cheap?
If we’re talking about truly high-quality lenses then, of course, they aren’t cheap – but that’s true for cine and still lenses too. There are some bargains be had in this market, however, as some lenses were released as still photo optics and are still available for super 35mm cameras.
In fact, there’s a whole host of great Zeiss still lenses that can now be shot on digital cinema camera.
Here are some interesting models that you might like:
What B4 lenses can be used on 35 mm cameras
All work perfectly, with no issues whatsoever. All these lenses look perfect when shooting anamorphic or spherical on a digital cinema camera. There’s nothing “unsharp” about them – they all look like what they’re supposed to look like (a 50mm lens looks like a 50mm regardless of format). Both cine primes (Zeiss Ultra Prime) which cost over 20x more than the highest quality b4 zoom were also tack sharp as well, so this whole “b4s are unsharp” thing is just a myth.
How do they look?
The b4 lenses use the Arri/Zeiss LDS mount and should be compatible with all models of Alexa and other Arri digital cinema cameras (and should also be fine on Red as well). The lens body itself looks like an Arri standard prime or zoom lens, including focus and iris gears and hard stops.
These lenses even have proper Arri PL-style flange focal depth.
These lenses however only cover the actual sensor area – meaning if you shoot anamorphic (with a 2x squeeze) you’ll get black bars around your image; but it’s still sharp within those boundaries – perfectly acceptable for lower quality b4 zooms which are generally slightly less sharp than still lenses.
Also with most of the lenses, you have to set the aperture to ND2 or ND4 (unless you’re using ND or IR filters) as the LDS mount automatically stops down for you to your chosen T-stop, and doesn’t pass any light through otherwise (it’s like an Arri/Zeiss Standard lens in that respect).
The reason is simple: the 1.3x crop means we need a wider FOV lens on this format which would be impossible given today’s technology – so rather than sacrificing image quality by putting a wide-angle fisheye optic on this camera we instead make them stop down and work like normal still photo lenses (you can of course still use them in full open aperture mode if you’re not shooting anamorphic or spherical).
What B4 lenses are there on the market?
There are around 15-20 different b4 zooms and primes, with each lens covering a certain focal range, like the 18-80mm, 30-90mm, etc. They all look great when shot on digital cinema cameras – no issues at all.
You can find the complete list of all zoom and prime lenses here.
The most common zoom is the 32-76mm T3.5 (followed by 24-290s ). The only differences between these lenses are speed (Tstop), size, weight, price, and image stabilization (none, optical or electronic).
Will they work on my camera?
Yes. These lenses are designed to cover full-frame sensors so they’ll work on any super 35mm digital cinema camera – RED, ARRI ALEXA, etc.
What about still cameras?
These lenses are NOT compatible with regular still photography cameras like Nikon or Canon, because you cannot reach the T-stop through the whole aperture range.
They are only optically corrected up to f/5.6 which is completely useless for most photo optics as at that point there’s almost no light transmitted anyway, especially when stopped down by ND filters (T3.5 becomes f/8.3)
We can’t recommend these lenses enough. Use B4 lenses on 35mm cameras, please.
Yes, they’re expensive; yes they don’t cover the whole sensor but that’s not a problem because you’ll be using them for anamorphic or spherical anyway (if it bothers you: shoot stills and use a cheaper fisheye instead).
We would much rather have a sharp 32-70mm T2.8 than a crappy old 3x zoom on this camera any day, especially when you consider how much sharper Zeiss primes are compared to b4 cine zooms (which are also cheaper).
The lenses themselves look great, they work perfectly with digital cinema cameras and there’s nothing wrong with them optically or mechanically.