View Full Version : Should footage be this noisey?
Jon Sands October 9th, 2008, 12:00 AM I've been starting to notice noise in the picture, and not gainey noise, it's showing up at 0db. (please don't tell me to shoot at -3db, it limits superwhites to ~90IRE, and obviously drops exposure)
The attached picture is straight from an EX1 sitting on my desk, 1080/24p shutter off 0db gain, f/1.9. The picture profile is Bills TC2, detail off, with blacks at -2. Do you see all that noise in the shadows, specifically the wall? Should that be there?
Also completely unrelated, I've been having trouble in general getting that ridiculously good looking look out of the camera that people seem to effortlessly get. (Yes, including grading) It's like I have something in the picture profile set horribly wrong.
http://fohdeesha.com/data/pictures/other/noise.png
Perrone Ford October 9th, 2008, 12:06 AM Can you set up a shot for F4 and post that? Also on your other issue, are you seeing the same problems on the stock profile settings??
Jon Sands October 9th, 2008, 12:39 AM No problem, thanks for the response. To get any exposure at all at f4 I had to use a 500 watt halogen, so it's obviously going to be hard to judge the difference with there not really being any shadows or "low light". I'm still seeing that odd noise in certain areas though.
http://fohdeesha.com/data/pictures/other/noisef4.png
As for the standard profile, I'm not sure as I've never really shot with it. I guess I should experiment.
Perrone Ford October 9th, 2008, 12:59 AM Jon,
I am about as far from an expert as it gets. I was curious about something which is why I wanted to see the F4 image. Out of curiousity, are you shooting with tungsten light? I am wondering if you'd see a difference with 5600k light. Tungsten light is particularly noisy in dark scenes.
I'd be curious to see if you'd see a difference with the standard profiles, and also with 5600k light if you had it available.
Tom Roper October 9th, 2008, 10:41 AM Noise doesn't jump out at me as much as the severe "stairstepping" on the power cord for the charger in the lower left corner of the picture.
Could the noise (and stairstepping) be in the frame grab itself?
The picture also looks grossly oversharpened to me.
Dave Morrison October 9th, 2008, 11:38 AM ...<snip>...Tungsten light is particularly noisy in dark scenes.
...<snip>
Huhhh!!?? Are you saying........huh????
Perrone Ford October 9th, 2008, 11:40 AM Huhhh!!?? Are you saying........huh????
I am saying that due to the design of most video cameras, the blue channel tends to be the noisiest, and when using tungsten the relative lack of blue in the light tends to make the problem worse than when using daylight balanced light.
Dominik Seibold October 9th, 2008, 11:59 AM the blue channel tends to be the noisiest, and when using tungsten the relative lack of blue in the light tends to make the problem worse than when using daylight balanced light.
Exactly. Whitebalance technically isn't more than per-channel-gain. And a low whitebalance-temperature means a lot of blue-channel-gain.
Try this:
1. Set detail to off.
2. Use cine1 or cine3 instead of std-gammas (because std-gammas have some "built-in-gain" for leaving headroom for their knee-feature).
(3. don't deinterlace progressive footage ;) )
Dave Morrison October 9th, 2008, 12:10 PM Thanks Perrone. I learn something new every day here!! ;-)
Perrone Ford October 9th, 2008, 12:15 PM Beautiful discussion on it here:
Demystifying Digital Camera Specifications Part 7: Single Sensor Cameras Continued (http://media.panavision.com/ScreeningRoom/Screening_Room/Demystifying_Part7_480p.html)
Dave Morrison October 9th, 2008, 01:00 PM Thanks again, Perrone. I just watched the segment you linked to and now I'm going back to the first segment and watching the whole thing. This should be required viewing for all of us.
Jon Sands October 9th, 2008, 02:53 PM Exactly. Whitebalance technically isn't more than per-channel-gain. And a low whitebalance-temperature means a lot of blue-channel-gain.
Try this:
1. Set detail to off.
2. Use cine1 or cine3 instead of std-gammas (because std-gammas have some "built-in-gain" for leaving headroom for their knee-feature).
(3. don't deinterlace progressive footage ;) )
detail was off, I was using cine 1, and oops LOL. Was wondering why the bmp output was all jaggedy
Jon Sands October 9th, 2008, 03:10 PM heres the f4 properly exported without "deinterlace" checked (oops)
http://fohdeesha.com/data/pictures/other/noisef4proper.png
also, why does it look like details on cranked all the way up when it was clearly turned off in the PP menu?
edit: going back into the pp menu, detail was turned on. What in the world? I give up
Paul Cronin October 9th, 2008, 04:27 PM Thanks Perrone great link.
Adam Reuter October 9th, 2008, 05:01 PM heres the f4 properly exported without "deinterlace" checked (oops)
http://fohdeesha.com/data/pictures/other/noisef4proper.png
also, why does it look like details on cranked all the way up when it was clearly turned off in the PP menu?
edit: going back into the pp menu, detail was turned on. What in the world? I give up
Jon,
I'm not really seeing a noise problem with this new screen grab or the other one. Where should I be looking?
As far as appearing "sharpened" f/1.9 (the first post's screengrab) vs. f/4 will get you a lot more depth of field and therefore more objects will be in focus in your video. Between f/2.8 and f/8 is the "sweet spot" of video lenses and you're there.
Jon Sands October 9th, 2008, 05:41 PM As far as appearing "sharpened" f/1.9 (the first post's screengrab) vs. f/4 will get you a lot more depth of field and therefore more objects will be in focus in your video. Between f/2.8 and f/8 is the "sweet spot" of video lenses and you're there.
I'm pretty familiar with depth of field, but the entire image was looking like detail was being applied. When I returned to the pp menu, detail was in fact on, even though i specifically remember turning it off.
The noise does seem to have gone away when I used the halogen, it's like if the overall image is darker then a crapload of noise shows up in the shadows
Paul Curtis October 10th, 2008, 02:39 AM I've been starting to notice noise in the picture, and not gainey noise, it's showing up at 0db. (please don't tell me to shoot at -3db, it limits superwhites to ~90IRE, and obviously drops exposure)
The attached picture is straight from an EX1 sitting on my desk, 1080/24p shutter off 0db gain, f/1.9. The picture profile is Bills TC2, detail off, with blacks at -2. Do you see all that noise in the shadows, specifically the wall? Should that be there?
Also completely unrelated, I've been having trouble in general getting that ridiculously good looking look out of the camera that people seem to effortlessly get. (Yes, including grading) It's like I have something in the picture profile set horribly wrong.
http://fohdeesha.com/data/pictures/other/noise.png
Aside from all the other things people have noted, you'll always get noise in shadows. The lowest range from a sensor is really about at what level is noise unacceptable in the shadows. As is noted too, blue sensitivity is a fundamental characteristic of silicon sensors. So low tungsten light and shadows are the worst combination for this. It's also not just the EX1, everything to a degree is similar. The nice thing about the EX1 is that it is a 3 sensor camera so analogue gain can be just applied to the blue sensor without affecting the others - difficult in a single sensor design.
cheers
paul
Perrone Ford October 10th, 2008, 01:48 PM I'm pretty familiar with depth of field, but the entire image was looking like detail was being applied. When I returned to the pp menu, detail was in fact on, even though i specifically remember turning it off.
The noise does seem to have gone away when I used the halogen, it's like if the overall image is darker then a crapload of noise shows up in the shadows
Jon,
Have a look at this:
Teapot Dark on Vimeo (http://www.vimeo.com/1362321)
Download the original file if you like. I'd be curious to see what you think of it in comparison to your scene.
Jon Sands October 11th, 2008, 02:21 AM That looks excellent Perrone, were you shooting at 0db? I think my original noisey image was due to balancing to yellowish light, detail being on, and perhaps a couple other things. I'm getting better results now that I changed a couple things.
Steven Thomas October 11th, 2008, 09:23 AM Jon,
Have a look at this:
Teapot Dark on Vimeo (http://www.vimeo.com/1362321)
Download the original file if you like. I'd be curious to see what you think of it in comparison to your scene.
Perrone,
What was the color temp for the bulb you chose?
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