topic Re: Canon C70 jittering in Professional Video

Canon C70 jittering

utisz — Wed, 23 Nov 2022 23:50:22 GMT

Hello,

do you have any idea what is causing that teribble jitter of antialising in my footage that I recorded with my C70?
Is the digital stabilization which is messing up my clip or something else?

Thanks very much for sharing your expertise on this.

https://drive.google.com/file/d/1T9DeIdrt7t61vzGiP5h1h8HA0jZ1aPuY/view?usp=share_link

Re: Canon C70 jittering

shadowsports — Thu, 24 Nov 2022 00:44:23 GMT

Greetings,

I can view the video, but I'm not seeing jitter. I see some noise, but that's about it.

Re: Canon C70 jittering

utisz — Thu, 24 Nov 2022 00:50:33 GMT

Hello Rick,

thank you. I can't really see any noise as this footage is almost noise free, but there is a severe jittering and antialising. Please look at the left side of the painting's frame and you will notice what I am talking about.

Thanks.

Márton

Re: Canon C70 jittering

rs-eos — Thu, 24 Nov 2022 02:38:28 GMT

It almost looks like focus was struggling? But it transitioned almost too rapidly for that to be the case? I notice by looking at some frames of the placard, that some motion blur was introduced, but vertically. Perhaps it was the Digital IS struggling?

Anyhow, what lens were you using?

Re: Canon C70 jittering

shadowsports — Thu, 24 Nov 2022 04:15:29 GMT

Ok, Now I see what you are talking about. Vertical part of the frame in upper left corner. What I see most now is flickering. It looks like lighting was impacting focus. If you weren't using a tripod, then there was also some shake as Ricky mentioned. Its a dimly lit room. You also have a subject standing approx 5 ft away from the painting. Lots of challenges.

Re: Canon C70 jittering

utisz — Thu, 24 Nov 2022 15:25:53 GMT

Hello Everyone,

I don't think that the issue is related to autofocus as I am always using manual focus. I just uploaded a differerent clip recorded in a perfectly lit environment. As you can see here, the jittering effect caused by probably the Digital IS is also present. The bootom line is that C70 is not capable to record in Digital IS mode due to line skipping and pretty bad antialising?
Here is what I am talking about: https://drive.google.com/file/d/1gkgttwMgsfLmfmTg9nLpQpxhDhaD2X2G/view?usp=sharing

Thanks.

Marton

Re: Canon C70 jittering

rs-eos — Thu, 24 Nov 2022 16:18:26 GMT

I'll ask again though for what lens you are using.

Re: Canon C70 jittering

utisz — Thu, 24 Nov 2022 16:21:07 GMT

Hi Ricky,

thanks very much for your note. I am using an EF 50mm f/1.2L for my EOS C70 via EF-EOS R 0.71x.

Best,

Marton

Re: Canon C70 jittering

rs-eos — Thu, 24 Nov 2022 16:38:11 GMT

That could be it. While a recent C70 firmware update added full support for the 50mm f/1.2L with the 0.71x adapter, I do wonder if the Digital IS was just struggling. Also (I can no longer find any references to this), I though that depending upon the codec, that Digital IS may not be avail? Was that for RAW?

Anyhow, if you have an RF lens, especially one with IS, that should work much better. Or, for fairly static scenes such as this one, try using a tripod along with disabling any IS.

Re: Canon C70 jittering

utisz — Thu, 24 Nov 2022 16:56:38 GMT

Thanks, Ricky. I'll try to do some experiments with my RF 35 f/1.8 too!
Actually, I was using a Sigma 135mm f/1.8 for the first clip that I did upload. The second one was recorded with the 50mm prime.
I was wondering however what is the purpose of Digital IS on C70 as the IS version of the RF lenses doesn't necessaraly require any additonal Digital IS.
I am still convinced that the problem is not lens related, but it is due to the line skipping algorithm of the 4K sensor in Digital IS mode.

Re: Canon C70 jittering

utisz — Sat, 26 Nov 2022 01:38:39 GMT

Okay, today I visited my local Canon service and I did some experiments with a few other C70 cameras. Turned out that it was not my camera which is faulty, but the Digital IS function deteriorates the picture regardless of which lens are you using. I think that it is nonsense that a camera with this hefty price is unable to record decent footage when the Digital IS is turned on. Incredible!

Re: Canon C70 jittering

utisz — Mon, 05 Dec 2022 23:56:34 GMT

As a matter of fact, I was using a non-IS lens. Most of the time I grab the 50mm EF 1.2L and this particular footage was also recorded with that lens.

The other thing that I noticed is that C70 exhibits more moiré artifacts than R7 or R5 cameras, even when Digital IS is turned off. This sound absurd as C70 is using a 4K native resolution and not a line skipping or downscaling method like the above-mentioned cameras. (Yes, I am always using my C70 in its native resolution.)

Only my copy is affected, or this is a common phenomenon with the C70?

Thanks.

Re: Canon C70 jittering

rs-eos — Tue, 06 Dec 2022 14:53:02 GMT

This is most likely due to the R5 doing 4K oversampling. This was also true for HD. In order to get very crisp HD footage, you really need to oversample it. So with 4K worth of sensor sites, you can get very crisp HD. With only HD worth of sensor sites, you get much more aliasing and other artifacts.

Similarly, 8K worth of sensor sites would lead to very crisp 4K. Having said that, I personally find that video is crisp enough at 4K, even with 4K worth of sensor sites. Unless you pixel peep, this is going to look stellar on most every display out there due to typical viewing distances.

Re: Canon C70 jittering

cwilson — Fri, 09 Dec 2022 18:46:31 GMT

What recording mode are you using? I would tend to agree that it might be from the algorithm or codec being used. I've shot with the c70 extensively in 4k long gop and don't recall having seen this, but I'll go back and look at some footage to see.

If you are using Digital IS, I would turn that off. It can be useful occasionally, but because it's essentially line skipping around on the sensor to try and remove small shakes, it tends to look unnatural (at least to me). True IBIS works much better, but we don't have that on these cameras.

Re: Canon C70 jittering

cwilson — Fri, 09 Dec 2022 18:56:51 GMT

Digital IS is, in my opinion, a gimmick, and shouldn't be used on this camera.