Measuring rolling shutter: put a number on this issue!

Sorry, I hadn't watched the video. If it's not on a tripod, it's useless. A tiny roll of the camera throws away the measurement by A LOT.
Anyways... Make an effort, I am all curious and following up too : ) Can you do it in the name of our old fellowship? ;-)

I also find kinda interesting to focus on the solution, rather than issues & their sisters & cousins! :-D
 
There are only a few solutions, and we recently discussed them. You need to do one or more of the following:

1 clock the data out faster for a faster scan time
2 use a global shutter (complete frame transfer)
3 use a mechanical shutter and clock the data out during the dark period

Tricks to get #1 are things like crop the sensor so you clock a smaller number of pixels (smaller area), and bin/skip the pixels/lines so you can clock them out faster. Otherwise you need to throw more buffer, more processing, more clock speed at the problem and hope you can deal with the heat produced.
 
Anyways... Make an effort, I am all curious and following up too : ) Can you do it in the name of our old fellowship? ;-)

I also find kinda interesting to focus on the solution, rather than issues & their sisters & cousins! :-D


Haha, sorry, mate, it makes no sense. I'm also interested in whether a fix-it-in-post solution would work, but I just can't get numbers from handheld footage. In any case, in terms of skew it looks pretty good, it makes more sense to ask yourself whether the resulting motion looks pleasing to you (it looks good on my TV, but on my computer screen it looks kind of weird; well, actually, as if it had lots of post motion work on it).
 
Haha, sorry, mate, it makes no sense. I'm also interested in whether a fix-it-in-post solution would work, but I just can't get numbers from handheld footage. In any case, in terms of skew it looks pretty good, it makes more sense to ask yourself whether the resulting motion looks pleasing to you (it looks good on my TV, but on my computer screen it looks kind of weird; well, actually, as if it had lots of post motion work on it).
Your clinic eye... LOL As film editor in my academic background as primary choice/route : ) I have nothing against post, on the contrary, it is a required part of the process. Native acquisition as anything pure and immaculated is BS, as same as finding the perfect camera. Post is just the afternoon part of the day. You well know it, your video work is the finest example of it ;-)
 
I agree with all of that (and in particular the fact that post is a very important part of the process and it shouldn't be played down) except for last bit: you're too kind, my work is not the finest example of anything I'm afraid. I'm still just learning how to make good videos. I'm a good with the technical details, but most of the people in these boards shoot much better stuff than I do!!
 
Canon 5Dsr - https://vimeo.com/136505417
Note you need to Download the video to get the 1080p version.
Shot at 23.976 fps and 1/50th second - wouldn't 1/1000 have been easier to spot the edges?

I did this after finding the moire/aliasing is out-of-the-park better than my GH3 or GH4 when shooting at 1080p, so thought the overall video performance was worth investigating. (Although note the GH4 at 4k is just plain excellent.)

Here's my favourite moire/aliasing test (the GH3 one is just a random video I uploaded late one night when Andrew Reid asked me for one, I have 70+ from both GH3 and GH4 with about every possible combination of settings and they are all rubbish)...
GH3 (GH4 is the same): https://vimeo.com/136023791
5Dsr (Neutral Picture Style): https://vimeo.com/136118235
Thread: http://www.eoshd.com/comments/topic...r-moire-and-lack-of-uncompressed-hdmi/?page=5
 
^ that's 8.3ms, which sounds reasonably good

Anyway, I was on the other side of the world for three weeks, with very limited internet access... Let's look at that 5Dsr test...
 
The full-res download will have timed-out, I'll send it more directly... Hope you had fun!

(Update) You should have an e-mail (to the address in the first post) with a download link (47MB).
 
Thanks!!

I measured that 5Dsr sample at 27.7ms (27.5-27.9-27.6), which means it's just slightly worse than the 5D2.
 
Thanks! It would have been cool if it was a little faster, but I suspect there's a trade-off against the aliasing/moire.
I'm not sure how much actual video I'll shoot with it, as I have a GH4 for that, but the 1080p is so much cleaner than the GH4 I may use it a bit. (The GH4 in 4k is great though.)

Oh and the C300 II White Paper is here:
http://www.usa.canon.com/CUSA/asset...mageperformanceenhancements-eosc300markii.pdf
On page 2:
"In the original C300 image sensor there were two fast readout modes – one, at 1/60 sec progressive and another at 1/120 sec interlace. The new image sensor in the C300 Mark II has a single readout capability of up to 1/120 sec progressive – further reducing rolling shutter skew effects."
 
Last edited:
I added the RX100-IV. It's pretty good in 1080p, and quite bad in 4K.

RX100 IV 1080p -- 15.4 ms(15.2-15.6)
RX100 IV 4K ----- 34.2 ms (34.0-34.4)

In both cases, add approximately 1ms if you use steadyshot standard (which for me means basically always).
 
The NX1 in 1080 is winner by a wide margin. Are there any other cameras in that speed range at 1080?
Too bad 4K performance is so shoddy on the NX1...
 
Well, having both the fastest RS and a very bad RS with great image otherwise isn't so bad at all: if you're shooting something with lots of camera shake, or a fast pan, etc, then switching to 1080p just for that shot shouldn't matter at all: it will be blurred anyway.
 
Well, having both the fastest RS and a very bad RS with great image otherwise isn't so bad at all: if you're shooting something with lots of camera shake, or a fast pan, etc, then switching to 1080p just for that shot shouldn't matter at all: it will be blurred anyway.

Any chance you can add the G7 to the mix? Been looking at one for a gimbal cam since they're so cheap and 4k looks good to 6400. Here's a tripod test that should be measurable.

http://www.videomaker.com/video/watch/reviews/18454-panasonic-lumix-dmc-g7-hands-on-review
 
I'll have a look at that but it's not YouTube so I'm not sure I'll be able to download the video and look at consecutive frames.

Edit: I looked at it, I don't think I can use that video to get the numbers, sorry.
 
Last edited:
I just added the a6300 and a couple more measurements for the a7r II, and revised slightly the RX100 IV numbers (I had made a mistake in the file: I treated it as 25p but it was 24p; also, with stabilization on it's slightly slower)
 
Back
Top