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Ex-1: reputedly-proverbial noise issue

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Marius Sørli Finnstun
Ex-1: reputedly-proverbial noise issue
on Feb 28, 2010 at 8:20:06 pm

Hi

I have been reading this forum on and off for quite some time now. Mostly trying to get my head around noise and/or grain issues I've been experiencing with my ex-1.

There seems to be quite a few posts on the subject, but no overall conclution or solution.

I completely understand that the XDCAM codec is a very compressed one, so I'll go along with it if everyone else is having the same results as I'm having… But the footage I'm getting seems too awful...

I'm starting to think that there is a problem with every ex-1 camera I thouch. We used ex1's at the filmschool I went to, and with our two major projects we allways seemed to have slightly more grain than the other groups - even though we didn't exclusively use one camera.

And I know the obvious conclution is that we mess up the settings on the cam somehow, but I'm convinced that we're not.

This is a 30 second clip I just shot with a diffrent cam than from school. This is one I bought (used) last year.

This is just point and shot - I pointed the camera somewhere in the room with a random lightsource, and is without any PP. Basically standard settings as far as I'm aware.

I've read that one can minimize grain by using PP and stuff, but one should be able to get ok footage just by turning the camera on and pointing it where ever..

Any thoughts or insight are joyfully welcomed :)

Full details:

VBR 1080/25p
F1.9
0dB
SHT:1/50
PP:OFF
W:B 2900K
No steadycam.

Ex-1 -> XDCAM Transfer

Download link (Can be downloaded only 30 times on this link. Give me a shout if I need to reupload it.):

http://www.filemail.com/dl.aspx?id=PKJSTMIKFVNUUTL

Cheers
Marius Sørli Finnstun






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Craig Seeman
Re: Ex-1: reputedly-proverbial noise issue
on Feb 28, 2010 at 8:40:22 pm

[Marius Sørli Finnstun] "I completely understand that the XDCAM codec is a very compressed one, so I'll go along with it if everyone else is having the same results as I'm having… But the footage I'm getting seems too awful... "

Maybe it depends what your point of reference is but given the chips and light sensitivity, the EX has low noise compared to other cameras in its price beyond and often much higher. Maybe if your point of reference is a Sony F23 you might find EX1 noisy but if it's HVX200 or DV, you'd find it low noise.

[Marius Sørli Finnstun] "I've read that one can minimize grain by using PP and stuff, but one should be able to get ok footage just by turning the camera on and pointing it where ever.. "

I don't get this at all. You're assuming the default . . . on any camera, would be ideal for any situation. It couldn't be farther from the truth. It's why most modern professional cameras have Picture Profile type systems.

Certainly some camera are inherently more prone to noise than others but, depending on your point of reference, the EX series is on the low side, competitive with some cameras in a higher price class.

[Marius Sørli Finnstun] "PP:OFF "
Which, if memory serves me, might be STD3 by default (someone feel free to correct me on that but it's pretty easy to tell). It may not be the best profile for your shooting circumstance.





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Marius Sørli Finnstun
Re: Ex-1: reputedly-proverbial noise issue
on Feb 28, 2010 at 8:53:30 pm

"I don't get this at all. You're assuming the default . . . on any camera, would be ideal for any situation. It couldn't be farther from the truth. It's why most modern professional cameras have Picture Profile type systems."

I'm sorry, that not what I wanted to express at all. I only ment that I feel I should be able to turn a camera on (with stanrd settings) and get the "default" amount of grain.

"Certainly some camera are inherently more prone to noise than others but, depending on your point of reference, the EX series is on the low side, competitive with some cameras in a higher price class."

I'm sure this is true. I'm only saying, that I feel the noise I'm getting is way more than I feel everyone else is getting. So I was backing that statement up with the feeling I have with wanting to turn things on and only getting default noise.

"Which, if memory serves me, might be STD3 by default (someone feel free to correct me on that but it's pretty easy to tell). It may not be the best profile for your shooting circumstance."

So your saying that some PP produce more grain than others (in certain lighting conditions??







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Noah Kadner
Re: Ex-1: reputedly-proverbial noise issue
on Mar 1, 2010 at 12:53:59 am

shooting at such a wide open aperture as F1.9 tells me you're not adding enough lighting. Remember just because it's a video camera doesn't mean you don't have to light and light well. Bringing in enough lighting to at least get to a 2.8 or above will buy you a much nicer looking shot and the grain will be reduced.

Even without turning on the gain you can easily get grain in a shot when you're shooting wide open and without realizing it underexposing big parts of the frame. When you set the aperture with the built-in light meter it picks the middle of your exposure- so if it's picking f1.9 that means half your frame is lit to below an f1.9- i.e. way underexposed.

Noah

Check out my book: RED: The Ultimate Guide to Using the Revolutionary Camera!
Unlock the secrets of 24p, HD and Final Cut Studio with Call Box Training. Featuring the Sony EX1 Guidebook, Panasonic HVX200, Canon EOS 5D Mark II and Canon 7D.
Watch Formosa- My indie movie shot with the SDX900 and finished with Final Cut Studio.


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Marius Sørli Finnstun
Re: Ex-1: reputedly-proverbial noise issue
on Mar 1, 2010 at 1:12:16 am

Hi!

Well yeah. This shoot was just a corner with a reading-light being the only source of light - so this ranges from overexposed to complete black. The idea was to get the whole range of values. The shot looks horrible :)

Are you saying the shot would have less grain if the shot was lit so that I wouldn't need to have the camera wide open?





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Noah Kadner
Re: Ex-1: reputedly-proverbial noise issue
on Mar 1, 2010 at 3:58:15 am

[Marius Sørli Finnstun] "Are you saying the shot would have less grain if the shot was lit so that I wouldn't need to have the camera wide open?"

Ha- that's exactly what I said...

I'd get ahold of a basic book on Cinematography. Putting up a shot with a single reading light is not going to give you a nice looking contrasty shot. It's going to give you a grainy looking shot that has far more contrast than the camera can capture. The grain is the extreme underexposure.

Your eye has far more latitude than any existing camera. So to compensate you need to reduce the contrast in a shot with balanced lighting to keep the values from darkest to brightest within a more compressed range than what the naked eye can resolve.

The way to get a proper exposure is to work on your key:fill ratios- you need to add in a certain amount of fill light to balance out your keylight. Otherwise the key light will be much too bright and the fill too dark. Typically no good shot is made with a single light- well not unless you're bouncing it all over the place.

-Noah

Check out my book: RED: The Ultimate Guide to Using the Revolutionary Camera!
Unlock the secrets of 24p, HD and Final Cut Studio with Call Box Training. Featuring the Sony EX1 Guidebook, Panasonic HVX200, Canon EOS 5D Mark II and Canon 7D.
Watch Formosa- My indie movie shot with the SDX900 and finished with Final Cut Studio.


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Marius Sørli Finnstun
Re: Ex-1: reputedly-proverbial noise issue
on Mar 1, 2010 at 4:32:45 am

Hmm. I see.

The footage was something I just shot so I had something to show.

The thing is I also have footage from filmschool, in a studio with more decent lighting - a greenscreen shoot in fact, with same grainyness present.

I wasn't operating the camera, and that was also shot with a Letus Extreme so I didn't want to use that as the best example I had. (I've read that somehow the Letus can put more stress on the codec and enhance grain) and I really didn't want that variable in this discussion. So forget I even mentioned it :)

But I found some other footage shot outside.

I can't rembember all the settings. It was shot a while back - but it was really bright so I'm pretty sure I used both the internal ND as well as a smaller aperture.

http://www.filemail.com/dl.aspx?id=MKTMOSFDVNMEOOT

Its not as grainy as the dark footage, but there is noise in the leaves (for the lack of a better word) and trunk of the tree.







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Mick Haensler
Re: Ex-1: reputedly-proverbial noise issue
on Mar 1, 2010 at 1:43:31 pm

I just did a shoot where I was doing a fireside scene where I didn't want to blow out the fire yet not have noise in the blacks. It all came down to lighting and F stop like everyone is saying. Once I got my F stop at around 4, the grain disappeared. I have found on the EX it is noisier at F1.9 at -3 db gain than at F4 with 6 db of gain. So don't be afraid to use gain with higher F stops, it doesn't necessarily mean noise. The other thing I've found is that if I'm downconverting final product to DVD, even if there is some noise in the blacks, it will more than likely disappear once downconverted and viewed on a standard TV. I have good HD monitors that show EVERYTHING so while it may look like garbage on them, I don't trash footage until I've fully color corrected a short clip, burned a DVD, and looked at it on a standard TV. Now if you're going for HD distribution, that's a different story. Still though, check a short clip on the final viewing medium before you trash it.

Mick Haensler
Higher Ground Media


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Marius Sørli Finnstun
Re: Ex-1: reputedly-proverbial noise issue
on Mar 1, 2010 at 4:29:41 pm

"I just did a shoot where I was doing a fireside scene where I didn't want to blow out the fire yet not have noise in the blacks. It all came down to lighting and F stop like everyone is saying. Once I got my F stop at around 4, the grain disappeared. I have found on the EX it is noisier at F1.9 at -3 db gain than at F4 with 6 db of gain. So don't be afraid to use gain with higher F stops, it doesn't necessarily mean noise

That is incredibly helpful to know! I'll experiment with different lighting setups and stops to see if I can get different results :)

Thank you (and to you Noah!)

If you have a reading light in the shot (a "practical" in production terms) there is no reason not to light things to make it appear that it's the only light while the scene is in fact lit - carefully - to create proper exposure. Post-shooting color correction is a good friend here as well.

Hi! Yes of course. We had some basic lighting courses at school. I hope you don't jugde me only on this unplanned-unlighted-complety-random testfootage ;)

Thank you though!




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Alan Lloyd
Re: Ex-1: reputedly-proverbial noise issue
on Mar 1, 2010 at 10:25:48 pm

No, just trying to be helpful.


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Marius Sørli Finnstun
Re: Ex-1: reputedly-proverbial noise issue
on Mar 1, 2010 at 10:36:19 pm

I appreciate it! :)


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David Burch
Re: Ex-1: reputedly-proverbial noise issue
on Apr 17, 2010 at 2:16:10 am

"I have found on the EX it is noisier at F1.9 at -3 db gain than at F4 with 6 db of gain."

Really? That surprises me. I normally try to keep my iris as open as possible because, in my opinion, the stock lens on the EX-1 and EX-3 looks much better the more open it is. I have found that anything more closed than F8 tends to start looking soft. Also, I typically shoot for as shallow a depth of field as possible.

I have actually been very pleased with how these cameras handle low light, and have not found them to be excessively noisy at all, except for in certain conditions. One thing I have found to be helpful in minimizing noise is to try to shoot in light that has a higher color temperature. Typically, in sub 3000K lighting the camera has to compensate by boosting the blues, which is where a lot of your noise can come from. There are some good PP settings floating around on the web that help minimize this, but if you have control of it try to keep the color temp up if possible.

Gamma settings can play a huge role in noise as well, as they can essentially be applying gain to the image even when the camera is set to 0dB.

If it's true that the camera is noisier at F1.9 in -3 than at F4 in +6, then something strange is going on. The lens aperture should have nothing to do with noise, and if an image is correctly exposed at F1.9, the sensor should have enough light to minimize noise. What matters is how much light is hitting the sensor, not how big the aperture is.

That said, I never use auto iris, and a lot of the scenes that I shoot would probably cause the auto iris to overexpose. (I rarely have any control over lighting, as most of what my company shoots is live events.) Typically. my rule of thumb is to try to keep the iris as open as possible, which usually means my gain is set to either 0 or -3, and so far I have been very happy with the results :)


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Alan Lloyd
Re: Ex-1: reputedly-proverbial noise issue
on Mar 1, 2010 at 4:23:00 pm

If you have a reading light in the shot (a "practical" in production terms) there is no reason not to light things to make it appear that it's the only light while the scene is in fact lit - carefully - to create proper exposure. Post-shooting color correction is a good friend here as well.

As Dick Reizner used to say (and maybe still does) "It doesn't have to be, it just has to look like it is!"


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Alister Chapman
Re: Ex-1: reputedly-proverbial noise issue
on Mar 3, 2010 at 5:46:49 pm

It's important to understand how noise works. The amount of noise and grain in an image remains constant whether the image is fully exposed or not. Say, for arguments sake, the noise in the EX is 14mV, that would represent just 2% of the total video signal (700mV is peak white). Now if your image is very dark and is only reaching a peak of 100mV and you add to that the 14mV of noise it is modulating or varying your picture by 14% which is going to be quite noticeable. However if your image is brighter at say 600mV then adding 14mV of noise to that means the signal is only being modulated by 2.3% which is hardly noticeable. This is why a well exposed image will appear to have less noise than a dark one. So if you can lift the overall brightness of an image you will have less visible noise.

On the EX cameras the Standard Gammas have a little more noisy than the CineGammas. Standard Gamma 1 is much noisier than the others.

Alister Chapman
http://www.xdcam-user.com


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Rafael Amador
Re: Ex-1: reputedly-proverbial noise issue
on Mar 8, 2010 at 3:06:46 am

The post of Alister explain as well why is important don't to crush the Blacks in camera.
Just lowering the Blacks in post would be enough to get rid of the most part of the noise in the dark areas.
rafael

http://www.nagavideo.com


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Robert Clegg
Re: Ex-1: reputedly-proverbial noise issue
on May 20, 2011 at 10:52:08 am

Hi All,

Sorry to hijack this thread and hopefully it actually compliments this - can anyone take a look at the footage we captured yesterday. Shot by pro lighting cameraman on EX1.

http://www.mediabank.co.uk/Sample_H264.mov

There is so much noise in it - and I am befuddled what is causing it. Obviously this is compressed H264 but it looks very similar to the RAW footage when viewed through the viewfinder of our EX3 and through XDCAM Browser. Its in his jacked you can see it most.

Anyone got any idea what has caused this. We shoot on EX3's all the time and have never seen noise like this before. I believe the EX1 is same camera fundamentally so not sure what I am seeing...

Thanks for any help you can offer as I am little concerned about what we have got here

Thanks

Rob



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