Welcome to our community

Be a part of something great, join today!

Log in
  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Slow-motion artifacts

Jonas Nyström

Jonas Nyström

Well-known member
Joined
Apr 16, 2007
Messages
614
Reaction score
0
Points
0
Age
61
The Slowmos are really quite stunning most of the time, but sometimes something which looks like artifacts similar to computer generated slow-motion appear (like in Color). Have anyone of you had the same experience and do you know any fix? Or is it just to shoot a lot so you have much cut-aways or/and do a lot of playback on the set.

I have enclosed one example (JPG); have a look at the fluttering top of the hat.
 
Could it be rolling shutter artefacts? What's the exposure time?

Regards,

Uli
 
It could be that your shutter speed is to slow. Try using something like 1/250 or higher.
 
Maybe, but I think 1/250 will give stuttering slow-mo instead of the beautiful RED flow ;-) (or?). But of course it depends...
 
Actually I think BlackMatteLine is right. It does not look like an artifact to me really, but more just a blur because of a slow shutter. Make it faster and it should be crystal clear footage - and not stuttering, but silky smooth because you have all the frames there. You're not shooting 25fps here, but 100fps or so. Give it a try and let us know how it worked out.
 
If it is the shutter, the smear should be equivalent all over the hat, and therefore I should not consider it would be any artifact (even if I don't know if it is!). I'm more on to the rolling shutter road...
 
Before anyone points to the "rapid read-reset" (highly modified rolling shutter) for some problem, please read past posts on this topic. That is not the cause here.

Jim
 
OK. Here is the clip, I really would like to hear your opinion about what you think it is - and if it's any way for me not to replicate it again (if it's the shutter speed or anything... )!

http://www.vimeo.com/1107255

Password:LOVEISRED
 
Hm. That really is weird. It's definitely not motion blur.

Also, it doesn't seem like a rolling shutter artefact, unless the camera vibrated right at that point of capture. Even then, I couldn't perceive anything strange going on in the background.
 
Graeme will have a look, let us see what he thinks! I think the hat would like to be part of the castle, IOW wrong hat for the job.
 
It's absolutely 100% not a rolling shutter issue.

It has more to do with being used to seeing motion blur via log response vs a linear one. Neither one is wrong or right. Just different.
 
Sorry Deanan, but what is "log response"?

And is it possible to avoid this motion blur with a faster shutter?
 
Pretty strange! You are right, at first view it looks like those side effects of flow motion calculations…

I can only say that I've not seen anything like it on our Red until now. BTW, we did some testing regarding rolling shutter, and the Red is far better than Sony's EX-1!

We'll soon be doing some tests of 3D-tracking of Red footage, that's where any RS is really causing problems with other cameras.

Regards,

Uli
 
Definitely strange.
Why only on that small part of the hat? There is a lot of other motion in the frame...
Look again, everyone. It's right where the hat passes the muntin of the castle window, very high-contrast and bright, two different shapes right on top of each other, one bright, one dark, both in motion.
Looks like some sort of compression artifact to me.
Cheers,
Harry
 
Can't really tell. Looks like a 5-minute repaint job to me. Not a big problem. Assuming you are finishing at a sane resolution... (eg 1080p / 2K). Well, you are since it's slow-mo, right?

Sorry, would like to take a closer look and step through the frames but Vimeo is just a pain in the ass.

Jonas, post us a good H.264 Quicktime - at least 720p - and we'll take a look... If you can afford a Red, you can afford a decent web server account.

Bruce Allen
www.boacinema.com
 
Ha ha ha - I'm not so fast as you are in Shake then.

Send your mail address in a PM, I have a small cropped clip I can provide.

But you can download the whole clip from Vimeo as well.
 
It looks to me like some kind of weird diffraction / interaction with the light and dark patterns in the windows interacting with the motion blur of the hat. I don't see any skew or wobble or other artifacts in the rest of the image, so I'd be highly surprised if they managed to localize themselves in a hat. I'm bemused....

Graeme
 
It is something with that crazy hat. But I think we better leave it for now, until it appear in another hat (if it ever does). If so, refer to Nystroms Hat Artifact. Thanks for taking your time and all of your input.
 
You must log in or register to reply here.
Back
Top