Best Aperture for Video on Sony Cameras
~5 min read
Video aperture answers a different question than photo aperture. Stills shooters trade aperture against shutter speed freely; video shooters have the shutter locked by the frame rate, so aperture ends up carrying exposure and depth of field at once. Here is how to pick it on Sony bodies.
Why video aperture is different
The 180-degree shutter rule fixes your shutter at double the frame rate – 1/50 for 24p – because that is what makes motion look natural to human eyes. With the shutter spoken for, aperture and ISO do all the exposure work, and aperture still has its day job: deciding how much of the frame is in focus. Every video aperture choice is therefore two decisions at once, which is why ND filters exist.
Interviews and talking heads: f/1.8-f/2.8
Static subject, controlled light, camera on a tripod – this is where wide apertures earn their keep. f/1.8 to f/2.8 on a 50mm or 85mm throws the background into softness and keeps attention on the face. Watch the eyes: Sony’s real-time eye AF in video mode is reliable enough to trust at these apertures, but a subject who leans forward between answers can still drift out. If the interview is long, f/2.8 buys insurance you will never see in the edit.
Run-and-gun and documentary: f/4-f/5.6
Moving subjects, no second takes, focus pulling itself – stop down and let depth of field be your focus puller. f/4 to f/5.6 keeps a walking subject in focus across several feet of travel and forgives the moments autofocus hunts. Documentary shooters call this the working range for a reason: the footage that matters is the footage that is in focus, and nobody watching the final cut can tell f/4 from f/2.
Daylight: the ND filter does the stopping down
Outdoors at 1/50 shutter, even f/8 at base ISO is often overexposed – and f/16 brings diffraction softness plus a everything-in-focus look that reads as camcorder footage. The answer is a neutral density filter: keep the aperture where you want the look (f/2 for separation, f/5.6 for doc work) and let the ND hold exposure. A variable ND covering roughly 2 to 8 stops handles a full day of changing light.
Low light: wide open is a tool, not a habit
At night or in dim interiors, open the aperture and let ISO rise before you surrender shutter angle – breaking the 180-degree rule is visible in every moving frame. Modern Sony full-frame sensors stay clean well past ISO 6400, so f/1.8 at ISO 6400 usually beats f/4 at ISO 25600. But wide open in low light is still a choice with a cost: if the subject moves, you will miss focus, and soft footage at low ISO is still soft.
Frequently asked questions
Why can’t I just stop down to f/16 for video like I do for photos?
Because video locks your shutter speed. The 180-degree shutter rule – shutter at roughly double your frame rate, so 1/50 for 24p – is what makes motion look natural, and in daylight that combination with f/16 forces your ISO into noisy territory or overexposes entirely. Photo rules assume you can trade aperture against shutter freely; video takes that trade away, so aperture carries exposure and depth of field at the same time, and ND filters do the job a faster shutter would do in stills.
What shutter speed should I use for video?
Double your frame rate: 1/50 for 24 or 25 fps, 1/60 for 30 fps, 1/120 for 60 fps. That 180-degree shutter gives motion the blur our eyes expect. Faster shutter speeds make movement stuttery and hyper-sharp – useful deliberately for sports analysis or a chaotic action feel, wrong for everything else. Lock the shutter first, then set aperture for depth and ISO for the rest.
Do Sony cameras have built-in ND filters?
Most Alpha mirrorless bodies do not – you need screw-on or variable NDs on the lens. Sony’s cinema line is the exception: bodies like the FX6 and FX3’s bigger siblings carry an electronic variable ND, which is one of the reasons video shooters move up to them. On an A7-series body, a decent variable ND is the single most useful video accessory you can buy.
Keep Learning, Free
Aperture, shutter angle, and exposure for motion – the Shut Your Aperture tutorials library covers the full craft, free.