which lens for video? 16-35mm f4 IS or 35mm f2 IS ?

I'm planning to buy a 35mm lens to be used for my single-handed gimbal setup. But I still haven't decided which lens should I buy.

Either a zoom lens EF 16-35mm f4 IS or a prime lens EF 35mm f2 IS.
Both have IS which I think it's very beneficial for shooting video.

With the zoom lens, I could go wider if I need to without changing the lens. At extreme wide angle I could use it to make a nice panoramic hyperlapse. But the lens would be pretty big & heavy for my gimbal setup & at f4 it won't have nice creamy bokeh.

On the other hand, the prime lens would be very light weight & suitable for the gimbal setup. Large aperture would also produce very nice bokeh wide open. But obviously the focal length would be limited & seem to be more specialised lens.

Anyone care to share some input here?

If video is a priority, consider a better body first. You can't focus while filming with either of the lenses listed, because your cameras don't do that. 1DX2, 5D4, 6D2, and 80D, all (I think) have DPAF which allows smooth focusing while recording video. If you buy STM or nano-USM lenses, you can take full advantage of your new camera's video capabilities.

I love my 18-135 n-USM on the 80D for video. I have the 24-105 STM for my 6D, but the camera can't do continuous focus while recording.

I'll be a pedant and note that bokeh refers to the subjective quality of the blur, not the amount. I.e you could have a fast lens (lots of blur) with poor bokeh (unpleasant blur characteristics).

You will indeed get less background blur with the f/4 lens, but for video a very shallow depth of field will give you more problems when trying to keep a subject in focus.

Of course, if you're mostly doing static shots then that won't matter.

For architecture and landscape I'd choose the 16-35, for portraiture the 35 prime.

Bassat wrote in post #18656190
If video is a priority, consider a better body first. You can't focus while filming with either of the lenses listed, because your cameras don't do that. 1DX2, 5D4, 6D2, and 80D, all (I think) have DPAF which allows smooth focusing while recording video. If you buy STM or nano-USM lenses, you can take full advantage of your new camera's video capabilities.

I love my 18-135 n-USM on the 80D for video. I have the 24-105 STM for my 6D, but the camera can't do continuous focus while recording.

Jesus I forgot to update my gear list for years.
I've changed my bodies to just one 1DX2 now with Zhiyun Crane 2 gimbal for my video setup.

sploo wrote in post #18656315
I'll be a pedant and note that bokeh refers to the subjective quality of the blur, not the amount. I.e you could have a fast lens (lots of blur) with poor bokeh (unpleasant blur characteristics).

You will indeed get less background blur with the f/4 lens, but for video a very shallow depth of field will give you more problems when trying to keep a subject in focus.

Of course, if you're mostly doing static shots then that won't matter.

For architecture and landscape I'd choose the 16-35, for portraiture the 35 prime.

Thanks for the input.

I forgot to mention that I may use these one of new lens for concert shooting. Maybe 16-35 is better for this situation?

virsago_mk2 wrote in post #18656415
Jesus I forgot to update my gear list for years.
I've changed my bodies to just one 1DX2 now with Zhiyun Crane 2 gimbal for my video setup.

In that case, ignore my uninformed comments, please.

Based on the few things you’ve said (gimbal, concerts) the 35 IS is the way to go.

But if you use the 1DX’s 4K then the crop factor turns the 35 into a 45.5mm lens. The 16-35 then becomes a more versatile 20.8 - 45.5mm Lens.

If I were spending my money and shooting things my way, I’d go 16-35 in a heartbeat. 16mm + 4 stop IS + warp stabilizer = tripod-stable shots that were captured handheld. That’s tough to beat.

virsago_mk2 wrote in post #18656415
I forgot to mention that I may use these one of new lens for concert shooting. Maybe 16-35 is better for this situation?

Good question. If you're desperate for light then the 35 prime would be a better choice; but the 1Dx2 is a superb high-ISO weapon.

The zoom would be more versatile though.

Cinematographers who do gimbal work will side with a wide angle so they don't have to focus while while spending their attention with the gimbal (especially if that gimbal is a Steadicam type): having a greater DOF they don't have to rely on an auto focus (or have a big production where someone else can do the focusing). Having the option of 16mm-24mm is better for gimbal work, especially with the super-35mm crop (4K mode) of the 1DX2.