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-   -   Curse the noise (https://www.dvinfo.net/forum/canon-xh-series-hdv-camcorders/101192-curse-noise.html)

Mike Banks August 12th, 2007 06:14 PM

Curse the noise
 
I've yet to manage to get a noise free image on my shoots and that's with mostly using a pair of 500w lights. My previous XL1 was great but as much as I like the picture quality overall I'm being driven nuts by this noise.

I'm shooting between 0db and +6db, nothing too mad? I could shoot with a wider f/stop but need to keep all in focus so therefore a tad of gain.

Is there a way to reduce this noise? I have a de-noising plug-in for FC but it reckons to do an hour's footage on my C2D Mac - 3 days!

Any help would be greatly appreciated :-)

Mike

Don Palomaki August 12th, 2007 06:29 PM

What are you shooting, 1000 watts sounds like a lot of light, unless you are shooting a large stage lit from a distance.

What are you using for presets?

That shutter speed? What aperture?

Noel Evans August 14th, 2007 03:25 AM

I never shoot in anything over 0 gain. I usually am on -3. I make sure I expose the area in frame correctly that is the subject of the shot. Zoom right in as close as I can, set exposure, zoom out to the framing I want for the shot. I also have NR2 set on low.

Piotr Wozniacki August 14th, 2007 03:43 AM

Quote:

Originally Posted by Noel Evans (Post 728643)
I never shoot in anything over 0 gain. I usually am on -3. I make sure I expose the area in frame correctly that is the subject of the shot. Zoom right in as close as I can, set exposure, zoom out to the framing I want for the shot. I also have NR2 set on low.

If so, ncje, than your comparing the results with what you get from the V1 is unfair, I'm afraid:)

Mike Banks August 14th, 2007 05:26 AM

I'm shooting at f/2.8 or wider so not extreme, only one stop down tops. Frame rate of 50. Most of the footage is shot wide and I use 25F as the main use is for web use so saves on de-interlacing. I'll try to find some still grabs to post but in many ways the noise is worse by the snow from frame to frame so I'd really need to post a few seconds of full size footage.

I have set up using several presets on here but will be spending the day experimenting. Maybe I need better diffusers on my lights. I am finding that if I set the lights so that hot areas don't burn means that I'm maybe running slightly under-exposed = more noise. While shooting video I also take stills with a Canon 5D etc so maybe I am just expecting more than the cam is able to give.

Don Palomaki August 14th, 2007 07:17 AM

> ...I also take stills... <

As you know, video is not the same as stills. In general, video lacks the latitude of still photography (and flash illumination), but makes up for it with motion and sound, which do have the effect of masking perception of other artifacts that would be glaring defects in stills. If the scene were lit to the same light level you need for a stills without a flash at the same shutter speed and aperture (say 1/60 at f/2.8) you should get a nice clean image.

Try experiment a bit with the NR presets and the black levels.

Mike Banks August 14th, 2007 07:48 AM

Thanks Don.

I never use flash, the stills are mostly taken at between f/1.2 (yes, f/1.2) and 2.8 using the same lighting. I was kind of comparing with f/2.8 and 60th to 125th ISO 200-400.

I'll play with the NR and black levels :)

Cheers

Mike

Jerome Cloninger August 14th, 2007 08:16 AM

Mike, why not post a frame grab or short clip to show us the noise. Its hard to imagine the noise with 500 watt lights.

Mike Banks August 14th, 2007 08:40 AM

crop

http://recordproduction.smugmug.com/...83861913-L.jpg

not right aspect though

Jerome Cloninger August 14th, 2007 12:17 PM

Quote:

Originally Posted by Mike Banks (Post 728749)

There shouldn't be that much noise in it with that amount of light and it looks darker than it should too, but then again, I don't know what that exact location looks like.

Here's a frame grab with similar (probably lower) amount of lighting
http://www.jcdv.com/test/lowlightstill.jpg (Tweaked in post)
http://www.jcdv.com/test/lowlightstill_raw.jpg (Straight out of camera)

I was out of focus some on this shot and can't recall what preset I was using or exact settings, but 60i HD, I was zoomed in about half way I guess, full manual, and I'm going to guess I was on my low light preset I posted a while back.

Mike Banks August 14th, 2007 01:52 PM

Hmm, thanks Jerome. I think that maybe I need to try fiddling with the noise reduction. I know that I tend to fractionally under expose as I have been caught out with blowing highlights before. I would expect to see a bit of extra noise but I have been getting a lot.

As much as I am grumbling, my main iMac 24" is currently rendering a 20 min interview with noise reduction (CVH) filters doing a great job of cleaning it up plus brightness tweaks, colour tweaks etc and to render down for web streaming at 720 x 405 will take about 10 hours - 2 pass H264. The picture quality after these tweaks is excellent, I'd just rather have that fixed in camera so I can be more productive, or maybe I should go get an 8 core 3GHz machine?!

Oh, is there any way to view the presets in a not Excel Spreadsheet way? I don't do office apps!

Cheers!

:)

Mike

Jerome Cloninger August 14th, 2007 02:03 PM

Quote:

Originally Posted by Mike Banks (Post 728872)
Oh, is there any way to view the presets in a not Excel Spreadsheet way? I don't do office apps!

Cheers!

:)

Mike

Try adjusting your knee to low in the preset config screen. That will limit blowouts *some*.

You can download the preset and put onto memory card and open in in your camera and you can go through all the settings and see what they are.

Someone posted a program they made somewhere on here about viewing and editing presets....

Good luck.


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