blue dots all over my footage

[Martin Ubilluz]

there are blue dots all over my images in the first image that i croped its hard to tell with out motion but if you look close they are there and in the second image i made it brighter so you could see the blue dots whats going on

shot 2k 2:1 - redcode 38 - 120fps
build: 30.4
redcine x 158

 

[Jannard]

there are blue dots all over my images in the first image that i croped its hard to tell with out motion but if you look close they are there and in the second image i made it brighter so you could see the blue dots whats going on

shot 2k 2:1 - redcode 38 - 120fps
build: 30.4
redcine x 158

Not exactly sure what you are referring to... but:

It doesn't look like you did a White Balance before export (one of the Cardinal rules)

The footage looks under-exposed (which will be noisy, especially with an M sensor)

Jim

 

[Martin Ubilluz]

yes it was underexposed and i made the footage look a little more blue than the actual white balance but i have some other underexposed footage that does not have the dots if you look at his face or the black areas or by his wrist you can see the dots. Im crushing the blacks but no matter how much I crush the dots get brighter her is another image. I shot allot at night last week and had a couple of the same problems with underexposure at 120fps but I did not get the blue dots, and I still get them in this footage when I white balanced with my grey card

 

[Dan Hudgins]

Blue and yellow dots.

Blue and yellow dots.

yes it was underexposed and i made the footage look a little more blue than the actual white balance but i have some other underexposed footage that does not have the dots if you look at his face or the black areas or by his wrist you can see the dots. Im crushing the blacks but no matter how much I crush the dots get brighter her is another image. I shot allot at night last week and had a couple of the same problems with underexposure at 120fps but I did not get the blue dots, and I still get them in this footage when I white balanced with my grey card

Those blue and yellow dots look typical for some kinds of Digital Camera.

You don't see the yellow dots as much because your eye does not focus yellow well.

One thing you can do to try to save it is to make chroma - luma separations then use "de-speckle" on the chroma, then blur the chroma down to about 100 lines per frame height, then re-combine the luma and chroma.

I'm working on code like that now, and blue noise is part of the issues with shooting at low light, when you matrix the colors to counter the Bayer filter bias the blue gets more gain than the green, because it is clipped lower, so the noise going into the chroma matrix makes colored spots.

Gimp may be useful to process the frames, but I am not an expert in its use, its a free program,

http://www.gimp.org/windows/

You can also pull RGB seperations and de-speckle and blur the blue sep, but that may not be as good as doing it chroma and luma.

One problem with the noise peaks is that if you low pass them at the wrong point they become bigger blobs, so some work may be involved.

As a last resort, you can pull the luma and keep that, the roto the chroma by hand and re-combine, using a paint program to wash out the speckle in the chroma field.

==

To avoid this in the future expose like you would day for night, you do NOT underexpose but change the angle and lighting ratio, then alter the gamma in post to make mid tones and shadows darker. That way rather than pull up the noise you push it down.

==

I inverted your sample image so you can see the yellow spots as blue spots now.

You need to put CTB filters on your lights or shoot through 80 series filters if you are going to underexpose that much because there is a lack of balance between the red noise and the blue noise, red noise should show up as red/cyan dots and I don't see that, blue/yellow noise comes from the blue being out of balance with green and red, so if you make the exposure more equal the compression will not see blue data as being lower than red data etc.

 

[Deanan]

yes it was underexposed and i made the footage look a little more blue than the actual white balance but i have some other underexposed footage that does not have the dots if you look at his face or the black areas or by his wrist you can see the dots. Im crushing the blacks but no matter how much I crush the dots get brighter her is another image. I shot allot at night last week and had a couple of the same problems with underexposure at 120fps but I did not get the blue dots, and I still get them in this footage when I white balanced with my grey card

It looks to me like it's too aggressive of a white balance towards blue as Jim mentioned.

I'd also do a black shading just in case.

 

[Martin Ubilluz]

Thanks Dan, Deanan, Jim

Ill try doing a black shading and I went back in to redcine x and changed the white balance the dots were not as bad but still there

 

[Blaire Johnson]

What ISO is the 2nd pic set too? Is this an M or MX sensor?

White balance has nothing to do with this problem. Those are uncalibrated pixels, the fix is to Black Shade your camera. Make sure the camera has been warmed up, or else if you black shade it will cause more uncalibrated pixels. If you magnify the image you'll probably see some green and red pixels lit up as well.

I've experienced this, equally as bad on an MX sensor. I wouldn't be surprised if it's Build 30 that's to blame for the sensor's black levels getting so out of whack. Hopefully, you'll only see this at higher than 1600ISO. It is smart to Black Shade your camera ATLEAST once a week to prevent this from happening in the future.

Also if you have 30min. in the morning before you start shooting, warm up the camera by putting the fan on Silent and recording for 10min. Black Shade the camera. Check your Flange. Until Red's manufacturing and quality control methods improve this is the best way you can assure lens mount stability and footage consistency on the Red1.

 

[Dan Hudgins]

Bad pixels.

Bad pixels.

White balance has nothing to do with this problem. Those are uncalibrated pixels,

They seem much larger than single pixels.

If the balck level for the Blue is off, more signal would force the compression to use more bandwidth and should make the noise less of the signal after white balance making the blue spots darker and smaller.

 

[Martin Ubilluz]

it was m sensor shot at 500 iso but i put it back down to 320 in redcine and increased the flut instead. When i updated my camera was not warmed up I simply upgraded and then black shaded. So your thinking I should have the camera on for a while then do the black shade?

 

[Blaire Johnson]

Yes because the heat of a sensor affects how it "see's" black for any given pixel(s). If you record for about 5-10min. then Black Shade everything will be perfect again.

This is a simple uncalibrated sensor issue; not a complicated fix-it-with-all-sorts of-crazy-cool-post-software-and-techniques-issue, sorry Dan try again next time.

 

[Blaire Johnson]

The D21 actually does a Black Balance between every frame in order to prevent this kind of thing from ever happening. That's one of those key differences between a $200k+ camera and an sub $18k one.

 

[Mike Gross]

The D21 actually does a Black Balance between every frame in order to prevent this kind of thing from ever happening. That's one of those key differences between a $200k+ camera and an sub $18k one.

FYI, You also have to black balance:
Phantom
F23
F35
F900
F950
Varicam
Genesis
SI2k

Every sensor has pixels that get stuck on or off. That's why there's black shading. It's a bit disingenuous to suggest that it's because of the price or quality control as you can see even the most expensive cameras have the same things to deal with.

D21 can do it because it has a spinning shutter but that also means it can't do high frame rates or wider shutter angles. I've also heard that light leakage can also mess up black balance if there's leaking back through the eyepiece.

 

[jimhare]

And 2k makes the pixels HUGE.

Seems like a combination of all the dangerous things - 2K, underexposed, heavy blue.

 

[Blaire Johnson]

Mitch I didn't say other cameras don't need to be black balanced. I was just pointing out one method that one particular camera does to try to maintain image consistency. Also none of the cameras you listed take 7min. to black balance. They do it in 1/48th sec. to 7sec. Which again is one of the differences between higher end cameras and the Red1.

But you're taking us off topic. I want to know more about Martin's problem and if he was able to fix it.

 

[Häakon]

I have often experienced this issue when shooting footage in tungsten light at low light levels. Even though the subject is well-lit/properly exposed, dark areas around the footage will tend to show as concentrated blue noise. I've just chalked it up to the characteristics of the first-gen sensor. While resolution is great and performance is better than most cameras, it does have its limits.

I just received my MX-upgraded camera this weekend so I'm very curious to see how it performs differently than the Mysterium chips. The samples in the original post are clearly underexposed - and while that will definitely exacerbate the problem, it's not the sole cause. This phenomenon is yet another reason why oversampling is your best ally.

 

[Mike Gross]

Mitch I didn't say other cameras don't need to be black balanced. I was just pointing out one method that one particular camera does to try to maintain image consistency. Also none of the cameras you listed take 7min. to black balance. They do it in 1/48th sec. to 7sec. Which again is one of the differences between higher end cameras and the Red1.

But you're taking us off topic. I want to know more about Martin's problem and if he was able to fix it.

With the MX upgrade, a $23k camera beats the f35 except black balance time. so?

 

[Martin Ubilluz]

got home late from a shoot I will re black balance and see if it fixes the problem. But I have never had this problem before ive been shooting with red ones for a while now.

 

[Blaire Johnson]

But I have never had this problem before ive been shooting with red ones for a while now.

I haven't seen it like this until B30, which is why I'm leaning towards that as the culprit.

With the MX upgrade, a $23k camera beats the f35 except black balance time. so?

Except for BB time, lens mount stability, stable onboard battery plate, onboard uncompressed recording, not overheating, no crazy glitches that basically freeze the camera, 5sec. boot up time, EVF that works all the time, Global Shutter, is the ISO it says it's set to, can create a LUT in post and apply it to the monitoring system using an SD card, fulling controllable frame rate ramping capability. Just to name a few other key differences.

 

[Álex Montoya]

The RED ONE MX has more latitude than the F35, right?

 

[Mike Gross]

I haven't seen it like this until B30, which is why I'm leaning towards that as the culprit.



Except for BB time, lens mount stability, stable onboard battery plate, onboard uncompressed recording, not overheating, no crazy glitches that basically freeze the camera, 5sec. boot up time, EVF that works all the time, Global Shutter, is the ISO it says it's set to, can create a LUT in post and apply it to the monitoring system using an SD card, fulling controllable frame rate ramping capability. Just to name a few other key differences.

I can make an similar list for the expensive cameras too... like vertical streaking on highlights, overly heavy, crappy EVFs, dust problems, etc.

You sound like a bitter and angry guy.