# 70D + 16-35 f/4L IS USM - DPAF noise/smoothness?



## Ruined (Mar 21, 2015)

Hi all,
I am wondering if anyone here has compared the 16-35 f/4L IS to the kit 18-135mm f/3.5-5.6 STM.

The latter is fantastic for video with smooth precise and quiet focusing, but the former has better optics even on crop.

Has anyone tried the 16-35 f/4L IS to see how it stacks up for video in terms of:
1) noise
2) focusing smoothness

I am asking as I know the 16-35 f/4L image stabilization is a bit noisy to initialize when taking photos but for videos this may not be the case. Also, not all USM lenses focus as smoothly and accurately as the 18-135mm STM when using the 70D's touchscreen DPAF.

Thanks!


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## wyldeguy (Mar 21, 2015)

So I don't have either of those lenses but I do have the 17-40f4L and the 24f2.8 stm. To answer your question:

1. The noise from the 17-40 focus is minimal, if the IS is anything like the 70-200 the startup can be quite loud but it's for a split second, which wouldn't be picked up because recording hasn't started. The continuous use of IS would be picked up by the camera mic. The stm lens is probably a little more quiet than the 17-40 but just barely and its a higher noise so you could probably filter it out in post.

2. The 17-40 is pretty smooth to focus but in my opinion, and I'm sure most people agree with me, the stm lenses are by far smoother as the stepper motor has finer gears and movement.

Also some other factors I feel I should point out:
1. If you are concerned about noise then it would be better to get an external mic such as a shotgun.
2. If the 18-135 stem is built to the same standard as the 24stm then the image quality won't make a massive jump when going to the 16-35, so don't expect it to dramatically improve your videos. I bought the 17-40 mostly to get wider shots but also to get better image quality and I really didn't see much of an improvement.

So to sum up, don't bother getting the 16-35 unless you feel you might upgrade to full frame in the future. And get a shotgun mic or an off camera stereo mic if you want a non-directional mic option. If you want wider get the 10-18stm, it's probably a third of the price of the 16-35 and because of the crop factor you will actually be getting 16-28mm. When I bought my 24-70 I forgot about crop and didn't realize I couldnt really use it for selfie video, that's why I got the 17-40


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## ajfotofilmagem (Mar 21, 2015)

The STM lenses give best results really doing auto focus in video. The smoothness of the mechanical movement, and the silence during AF are not as good at video with USM lenses.

Below is a comparison between 18-135mm STM, and the new 16-35mm F4, with the two lenses mounted in the same housing and adjusted in the same aperture diaphragm.

http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=809&Camera=736&Sample=0&FLI=0&API=1&LensComp=949&CameraComp=736&SampleComp=0&FLIComp=0&APIComp=0


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## Ruined (Mar 21, 2015)

ajfotofilmagem said:


> The STM lenses give best results really doing auto focus in video. The smoothness of the mechanical movement, and the silence during AF are not as good at video with USM lenses.
> 
> Below is a comparison between 18-135mm STM, and the new 16-35mm F4, with the two lenses mounted in the same housing and adjusted in the same aperture diaphragm.
> 
> http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=809&Camera=736&Sample=0&FLI=0&API=1&LensComp=949&CameraComp=736&SampleComp=0&FLIComp=0&APIComp=0



I know the screw-type STM lenses like the 18-135mm STM are best case scenario for video autofocus w/ DPAF.

I know the micromotor-type STM lenses like the 40mm STM are so-so for video autofocus.

But for RING USM, it seems to vary quite a bit how well the autofocus works depending on lens. That is why I am curious about the 16-35mm f/4L IS since it is a newer USM lens.

Reasons:
1. Though its great on the 70D, EF-S 18-135mm will not work on my 6D
2. The 16-35mm f/4L IS has better IQ than the 18-135mm - much less CA, sharper, less distortion, less falloff
3. 16-35mm f/4L IS has constant aperture

So I am really curious on how the 16-35mm f/4L IS operates on the 70D for things like touch "focus pull." Also curious about the 35mm f/2 IS USM.


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## wyldeguy (Mar 24, 2015)

I didn't know you had the 6D otherwise I wouldn't have recommended the 18-135. I believe there is a 24-105 stm although not constant aperture it is stm so it would have smoother auto focus. Basically the usm lenses are good for video focus but they tend to hunt where the stm don't hunt. Either way you will have a good focus system but it really just depends on what look you're going for. You will get a far more cinematic look with stm especially with your 70D as you can adjust focus speed with movie servo focus.


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