For those of us not fortunate enough to have a considerable budget for our next film project, using regular photo lenses, such as Sony E-Mount primes or Canon EF zooms still seem to be the most obvious choice and a real viable option for the job. The main reason behind this decision is not only the affordability aspect (more options for different price ranges) but also because these lenses are really capable of putting out some great images. While this may be the case most of the time, there are a few drawbacks associated with still lenses that just don’t work for video, such as struggling to achieve the best and most precise focus, chromatic aberration issues, distortion artifacts, lens breathing, just to name a few.
These shortcomings are addressed through the broad adoption of cinema lenses, designed to work even in the most demanding shooting scenarios and situations. In fact, the use of cinema lenses has grown in popularity in the recent years especially since the majority of them have been made compatible with non-cinema cameras such as mirrorless cameras and DSLRs.
Regardless of the price tag that is over quadruple the price of a regular still lens, it’s reasonable to ask yourself is it really worth investing in a cinema lens these days and what can a cinema lens do that a still lens can’t?
According to Caleb Wojcik and camera rental company LensProToGo, there are several reasons as to why you might want to buy or even rent a cinema lens for your next production. One advantage includes the ability to adjust the aperture in a more precise manner.
With traditional still lenses, you typically control the aperture electronically within the camera, which means you can only adjust the setting in particular increments. Since cinema lenses have a dedicated ring for the aperture, you’re able to fine-tune your settings and make adjustments in a smooth manner.
Another advantage to using cinema lenses over still lenses is the use of T-stops vs. f-stops. Traditional still lenses rely on what is called an f-stop, the ratio between the diameter of the lens and the focal length of the lens. This means that when you change lenses, the amount of light actually hitting the sensor will change, even if you keep the same f-stop and camera settings.
Cinema lenses, on the other hand, rely on T-stop, which measures the amount of light transmitted to the sensor. With this, you’re able to change lenses and maintain the same amount of light in your shot, granted that you keep the same camera and T-stop settings.
When you try shooting video on a still lens, you may notice how your subject may be out of focus as you zoom in. With cinema lenses, you don’t need to worry about that issue since these lenses are considered to be parfocal, meaning that as you zoom in, your subject remains in focus.
In addition to the features listed above, cinema lenses have much more upsides to them including consistent filter thread size, longer focus throw for precise focusing, reduced chromatic aberration, increased consistency in terms of edge-to-edge picture sharpness, and reduced breathing effect in the edges of the frame when racking focus.
While cinema lenses undoubtedly have a significant list of advantages over still lenses, these are not the ultimate replacement since they have their own quirks as well. For instance, cinema lenses do not have any autofocus or optical image stabilization, making it hard to operate in run-and-gun situations, or even when shooting fast moving objects.
And most importantly, cinema lenses can get crazy expensive. According to Wojcik, be prepared to spend over four times as much for a cinema lens than you do for a still lens. If you want to be able to use a cinema lens but can’t afford to purchase your own set, renting out the lens of your choice still would be an excellent alternative.