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  • 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 :)

Slowmo footage very noisy all of a sudden :/

Asif Limbada said:
doing BS for each frame rate is just plain....pain in the ass.
Click to expand...

Yes, very annoying. I'd rather be annoyed and be able to get a high FPS like this, then not have the feature though.
 
Dom. I'm thinking the 1/1000 is a possible problem. When you shot at sunset, the shutter was much lower? You should be able to shoot daylight without worrying about noise.

What if you had a lower shutter, 1/48 -1/200 and use a ND filter to get you to your exposure.

By now, you should be opening up a ticket with RED.
 
Will Keir said:
Dom. I'm thinking the 1/1000 is a possible problem. When you shot at sunset, the shutter was much lower? You should be able to shoot daylight without worrying about noise.
.
Click to expand...

I'm using a higher shutter speed cause I pull stills from this footage as well...some of this sunset footage was shoot with even a higher shutter speed, some of it 1/4000 of a second and as I said...its clean as. No noise.

The problem with lower shutter speed and ND's is that my rig keeps getting bigger...most of these videos are shot with just my epic, lcd and lens....as soon as I start using my 4x5.6 ND's I need a rail system...mattebox and it all gets big n heavy.

Just opened a ticket with RED.
 
Yup, I see dancing flies. That sucks. Had the same thing happen to me too. RED team are you out there?
 
hey matt

I actually think it might have something to do with the format for some reason, just did a quick test shooting out my window switching from 2K to 2K-WS and the WS footage seems cleaner on the same settings.

I will do a thorough test on saturday with different frame rates and formats.
 
did some couple of tests and the level of noise definitely varies more with the shooting format than the framerate.

at 2K 240fps its definitely the worst and at 96fps at 5K its the cleanest on my camera :/
 
Can you provide an R3D frame
if you already have my bad i missed that post
but if you have not let me see an R3D frame pull and perhaps can give you some kind of idea

all the best
Luis
 
That does not carry the meta data.
The meta data will give me a better idea on what can be done to improve the shot.
It will also allow me to see exposure in various ways.

That link is nice but does not help.
 
Ok So found your problem

You shot in 2K 2to1
You will have much cleaner, less noisy results by shooting 4K with the Scarlet and 5K with the EPIC
Unless you are forcd to go to 2K by shooting high speed in this case you did shoot high speed 240fps
I understand this forced you into 2K
Give 5K 120fps a try and then process your footage threw twixter if you want to slow it down more.
That is a very helpful solution.
Or if you can get away with 4K or even 3K highest resolutions staying out of 2K you might like the results better
Whatever you do give them all a try and see what works best for you.


PS i understand youve seen good images shooting 2k 300fps under your same conditions
try shooting at iso 640 opening up your lens a touch more without over clipping those highlights



Best of luck
 
I noticed the same in 2K 300fps when I did some testing at home. I had my daughter jumping on the trampoline with a lot of trees in the background. I closed the lens down quite a bit as it was just a test for slow-mo. As the trees with all the leaves in the background was still in focus they looked very bad and blocky, I think throwing the background more out of focus would help a great deal. Still, 2K 300fps dosen´t look very good the times that I´ve tried it. I have seen footage in 2K 300fps that involved waves that looks quite good, and it could be that water is easier on the sensor and codec?

So now I usually stick to 4K or some times go down to 3K for slo-mo work
 
Dominik Muench said:
here is an R3D snapshot from the origianl raw file: http://www.blacksun-productions.com/leah.R3D
Click to expand...

Do you have an r3d of your fist jpg with the girl infront of the water. This one is a completly different scenario then the one above that is better lit and with hardly anything moving. Also (I cant really tell from looking at the JPG) but my guess is that the water highlights fooled you into underexpose the girl. So I think the exposure of her black bikini and hair might been overseen and is now a bit to close for comfort to the sensor floor, but that is only possible make a firm judgment for when looking on the actual r3d.

You got a lot going on in the shot.. waves eating data rate, low contrast light, thin shades of black and also the scenery that might fool you to expose for the background...

So my guess is that your blackshading is fine, just the exposure thats a tad off if, if you look at the rocks and the swells there is not really any noise So this one might have been better to shot with HDRx and expose for the black bikini and then have a HDRx pass that could save the background.
 
thanks for that Lu, I will give it a try, shot everything in 96fps 5K yesterday, a lot of it in very low light situations and the footage is really nice and clean. I will definitely give twixtor a go.

hey bjoern i ll try and get one done tomorrow. might give HdrX a try on my next shoot. you have a droidworx rig ?? were flying one here in Australia with my Epic on it....great fun those :)
 
Dominik Muench said:
thanks for that Lu, I will give it a try, shot everything in 96fps 5K yesterday, a lot of it in very low light situations and the footage is really nice and clean. I will definitely give twixtor a go.

hey bjoern i ll try and get one done tomorrow. might give HdrX a try on my next shoot. you have a droidworx rig ?? were flying one here in Australia with my Epic on it....great fun those :)
Click to expand...

Might not need HDRx. but make sure when shooting highspeed / low data rate to expose your shadows... in other words use a spot meter or zoom into the panties of the girl with the darkest bikini and set your exposure there, then zoom out and see where the rest of your scene lands in terms of exposure. As long as your darks are pushed away from the sensor floor you will stay out of noise. Then if the highlights are falling out on the other end then HDRx. But in terms of noise protection you should rather expose the darks than keeping the highlights.

Love the droid, even though we for the moment have software issues... hope it solves soon, we missed a shoot due to it this weekend.
 
Not saying this for cert but it looks like compression to me in the dark areas. I had similar results. Anything that is low in the histogram is prone to this 'dancing'. I haven't read the entire thread but try rating the camera at 320 and opening up the iris instead of shooting 800 and see how you get on (if you haven't already done this) - that will push the signal up on the histogram and you'll get less noise in places like the hair.

I always rate the camera at 320 when doing slo-mo, because anything underexposed could end up looking like mush. Rating at 320 protects the noise floor by a few stops.
 
Hi Karl

I looked at some footage that I shot last week....just catching up with the transcoding now...and this footage I shot at 320 ISO instead of 800....you're right. its definitely cleaner at that ISO range.

this is what came back from the RED Support after I sent them an R3d and camera log file, seems to be a number of factors coming together:

The camera appears to be fine. There are no indications of anything going on sensor or hardware related.
I believe the problem just has to do with the high shutter settings you are using, mixed with the high compression and lowered resolution. This is why the problems you are seeing is showing up primarily in the blacks. I would recommend using your exposure check, as you have a very bright sun, mixed with very dark elements in the shade, especially the black hair.

Your Blackshading methodology sounds accurate- it's exactly what we would recommend using those settings, so you are good on that.

The only other suggestion would be the lens itself- There appears to be some chromatic aberration using that lens- it is possible the focus is slightly off, and I would suggest testing your back focus adjustment. It is possible the back focus settings are slightly off.
 
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