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-   -   How many stops under can you get away with? (https://www.dvinfo.net/forum/sony-xdcam-ex-pro-handhelds/117820-how-many-stops-under-can-you-get-away.html)

Michael Maier March 27th, 2008 09:08 AM

Quote:

Originally Posted by Piotr Wozniacki (Post 849249)
My experience is that underexposing you can get away with provided you crush (compress) blacks; otherwise the noise will hit - even without using gain.

That's exactly my experience too and I'm starting to wonder if this is the best the camera can perform with shadows? Either no detail in the shadows or noise.

Bill Ravens March 27th, 2008 09:11 AM

Obviously, this won't work with night scenes.
Interesting comment from Piotr. Really haven't played much with crushing shadows. I don't shoot, much, in very low light and have no experience with it and the EX1.

Randy Strome March 27th, 2008 09:32 AM

Quote:

Originally Posted by Bill Ravens (Post 849331)
Obviously, this won't work with night scenes.
Interesting comment from Piotr. Really haven't played much with crushing shadows. I don't shoot, much, in very low light and have no experience with it and the EX1.

This is it exactly. The curves are all amplifying (stretching) the lower quartile values. The more of the scene that registers there and the darker it is, the more this amplification will show noise, unless the curve is flattened and or compessed. It is all a matter of amplifying darks.

Michael Maier March 27th, 2008 09:36 AM

Quote:

Originally Posted by Randy Strome (Post 849352)
This is it exactly. The curves are all amplifying (stretching) the lower quartile values. The more of the scene that registers there and the darker it is, the more this amplification will show noise, unless the curve is flattened and or compessed. It is all a matter of amplifying darks.

Could you explain it in layman's terms?

Thanks.

Bill Ravens March 27th, 2008 10:00 AM

Randy's not making much sense to me. Seems like any dark scene will have a gradation from crushed black up into grey. Somewhere in there, there's gonna be some real ugly noise. I don't like the low light noise on the EX1. It's almast as bad as my HD110.

Michael Maier March 27th, 2008 10:13 AM

Quote:

Originally Posted by Bill Ravens (Post 849371)
Randy's not making much sense to me. Seems like any dark scene will have a gradation from crushed black up into grey. Somewhere in there, there's gonna be some real ugly noise. I don't like the low light noise on the EX1. It's almast as bad as my HD110.

Well, yes but surely not as bad as the HVX200 or HV20.

Bill Ravens March 27th, 2008 10:27 AM

It's just the nature of the 4:2:0 MPEG2 codec. Not much to do with it.

Michael Maier March 27th, 2008 10:51 AM

Quote:

Originally Posted by Bill Ravens (Post 849391)
It's just the nature of the 4:2:0 MPEG2 codec. Not much to do with it.

Well, the HVX200 is supposedly 4:2:2 but it's worse in noise and low light.

Piotr Wozniacki March 27th, 2008 11:41 AM

2 Attachment(s)
OK, perhaps these are too extreme to illustrate what I mean, but which one do you like better?

And yes - Bill is right that on the gray scale, even with the darkest areas crushed down to the floor along with any noise, the noise will appear elsewhere - but somehow I still prefer the crushed one for its "Nighty" look.

Randy Strome March 27th, 2008 12:54 PM

Quote:

Originally Posted by Piotr Wozniacki (Post 849449)
OK, perhaps these are too extreme to illustrate what I mean, but which one do you like better?

And yes - Bill is right that on the gray scale, even with the darkest areas crushed down to the floor along with any noise, the noise will appear elsewhere - but somehow I still prefer the crushed one for its "Nighty" look.

Hi guys,

What are your settings here? What gain and what gamma (curve)? If the curve is modified by other PP settings, please let me know. I am typically shooting towards the right, but this has me wainting to do some tests.

Also, Piotr, did you have sharpening on in these shots? Pretty heavy halos are present around the couch. Sharpening off is pretty well a must where noise is an issue, as you end up sharpening the noise.

Chris Aaron March 28th, 2008 09:32 AM

Underexposing never produces noise for me. If anything it helps (at least 1 to 1 and 1/2 stops)...its only the overexposing that does it. I'm shooting a really pretentious artsy fartsy black and white short and underexposing by 2/10ths of a stop to really enhance the chiaroscuro lighting by adding contrast and it looks better than a contrast filter added in post:D

Randy Strome March 28th, 2008 01:23 PM

Quote:

Originally Posted by Chris Aaron (Post 850006)
Underexposing never produces noise for me. If anything it helps (at least 1 to 1 and 1/2 stops)...its only the overexposing that does it. I'm shooting a really pretentious artsy fartsy black and white short and underexposing by 2/10ths of a stop to really enhance the chiaroscuro lighting by adding contrast and it looks better than a contrast filter added in post:D

My few early experiments there were the same. Also, helpful to reduce black gamma (which should really be called lower value gamma) and will help to reduce noise which is more apparent in the lower values. I haven't tested below 1.5 stops down, but you will not likely need to go that low to achieve a low key look if you back off the black gamma (which is actually pretty pumped up by default).

Michael Maier May 7th, 2008 02:39 AM

Quote:

Originally Posted by Eric Pascarelli (Post 849187)
If you are using a spot meter, you are probably asking more about latitude that over/under exposure. You can probably go about 4 to 5 stops under mid grey in your spot readings before the metered areas disappear in the noise floor.

Hi guys. I'm revisiting this subject at the moment and was wondering if you all agree with Eric here. 4 to 5 stops under 18% grey is all one should go in order to avoid noise? Or will this also depend on the type of gamma selected (cine, std etc)?
It's interesting to note that the RED ONE also has the same bottom of 5 stops under 18% grey before noise kicks in really bad.

Andy Nickless May 7th, 2008 10:42 AM

Quote:

Originally Posted by Piotr Wozniacki (Post 849449)
OK, perhaps these are too extreme to illustrate what I mean, but which one do you like better?

Thanks for posting those images Piotr.
I'm a little worried about the halos too, but the one on the right looks much nicer than the one on the left.

What I don't understand is why everyone's hellbent on producing the "film look" in camera when there's so much fabulous image and colour control available in post these days.

I prefer to shoot correctly exposed footage whenever possible and crush the blacks or whatever else I want to do in post. That way I keep my options open with the original footage.

Crush your blacks, or blow your highlights in camera, and you're stuck with it forever. Where there's no detail, there's no detail but correctly expose in the first place and you can have fun as long as you retain the originals.

Enlighten me someone!

Craig Seeman May 7th, 2008 11:40 AM

Andy I'm with you on this. My main concern when shooting is not blowing highlights because you can't retrieve those in post.

Getting the widest dynamic range is important to maximum flexibility in post.

Of course there certainly is good reason to paint as much as possible in camera too. Some DPs want to have as much control of the source they hand to the post people. Sometimes they deliberately want to limit their options. Sometimes one might feel in camera processing can avoid issues that might happen when processing in post.

That said, I'd like to have maximum options in post.

It is nice that with the EX1 we have choice though. Tailor to your workflow. That's flexible!


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