View Full Version : 7D sunset light iso 100 noise


Javier Salinas
January 12th, 2010, 08:02 AM
I don't know whether is normal or not but I've noticed too much noise on blacks using ISO 100 especially on this clip.

Sunset time, iso 100, 70-200 2.8, 17-55 2.8. I can't remember speed and aperture (actually, is there any way of getting this data on the preview LCD once the clip has been taken?)

I leave this link so you can tell me what do you think:

MEGAUPLOAD - The leading online storage and file delivery service (http://www.megaupload.com/?d=9ZMZ8EUB)

It has been compressed to h264 (best quality) so it's a little bit "noisier" than the original but I bet you'll see what I mean.

Thanks!

Javier Salinas
January 12th, 2010, 11:44 AM
Did somebody watch it?
Thanks for the feedback!

James Miller
January 12th, 2010, 12:53 PM
Hi Javier,

/// You know that you can upload the original straight from the camera (1920x1080) to Vimeo. Vimeo will re-encode the clip but registered users can download the original uploaded clip.

/// It alway puts me off, waiting for clock to tick down before I can download a file form sites like MEGAUPLOAD.


I downloaded the clip, I see compression noise blocking and aliasing.

What picture style did you use, as preset or custom profiles can alter the gain. Also if the scene is slightly over exposed this could introduce noise.

Khoi Pham
January 12th, 2010, 01:25 PM
Use ISO 160 instead of 100, it is much cleaner, but it looks more like compression artifacts than noise, could be how H.264 is, maybe you should try to exposed to the right more, I've seen complaint on this before so you are not the only one, but I've never seen it on my stuff.

Javier Salinas
January 13th, 2010, 03:23 AM
James I didn't know it. Yes, nobody likes to wait. I'll upload it again on vimeo.
I used standard picture style. It wasn't overexposed.

Khoi, do you mean to overexpose a little bit?
I'll try to upload the original on vimeo because this one shows to much artifacts from the compression.

Thanks guys.

Javier Salinas
January 13th, 2010, 03:37 AM
So do you guys think is something I'm doing wrong better than a camera limitation?
Could the picture styles be so determinant?
I gotta try the 160 iso as well.
I normally tend to underexpose a bit so on post I can push the whites more.

Javier Salinas
January 13th, 2010, 04:59 AM
Is there a way to avoid or reduce the aliasing on the water or is something I have to bear with?

Javier Salinas
January 13th, 2010, 05:07 AM
Here's on Vimeo:

7D low light ISO 100 noise on Vimeo

Sorry for overposting.

Khoi Pham
January 13th, 2010, 09:09 AM
James I didn't know it. Yes, nobody likes to wait. I'll upload it again on vimeo.
I used standard picture style. It wasn't overexposed.

Khoi, do you mean to overexpose a little bit?
I'll try to upload the original on vimeo because this one shows to much artifacts from the compression.

Thanks guys.

Yeah overexpose it a little, and the ISO you want to use is 160,200,320,640,800,1250, do a search and you will see why, aliasing is the way of this camera under this type of shot, camera is best for shalow dof without much thin horizontal lines.

David Chapman
January 13th, 2010, 04:40 PM
Khoi,

All of the ISO values you listed are clipping highlights in the camera. The -1/3 EV stops (160, 320, etc) meter higher and end up clipping highlights. ISO 320 actually meters at 400 but gives a harsh angle to the highlight curve. This is why all those "lens cap" tests of visible noise made it look cleaner—the noise was cut off the top, clipping what could have been subtle details in a bride's dress or veil.

The + EV stops reduce the dynamic range from the shot also, making those ISO values undesirable.

The only "real" metering ISOs of the camera are 100, 200, 400, 800, and 1600. And 100 is more/less a tossup since it meters at 119-120 (not 100).

David Chapman
January 15th, 2010, 07:24 PM
I just check my menu and the Auto Lighting Optimizer was set to standard. I turned this to disable and did some low light tests. I don't see anymore noise in the blacks as I had been previously. Nothing but rich blacks where they should be rich.

I guess this is on by default for some reason and is really only handy for people who print straight from the camera and don't do any curves or levels in post. It was adding noise for me and I would just keep it off all the time now.

Javier Salinas
January 16th, 2010, 03:05 AM
I'll try too to see what happens.