Noise: digital or analogue?
 

Hello all,

Could an expert here tell me origin of
the color noice on the referred photo?

http://img31.imageshack.us/img31/2010/grain.png

It's a fragment of a scanned photo (slide film), and
I'd like to know whether it is scanner noice or film
grain. The noice I am taking about is best seen on the
women's T-Shirt.

Thank you in advance,
Anton

Noise: digital or analogue?
 

Anton Shepelev wrote:
Hello all,

Could an expert here tell me origin of
the color noice on the referred photo?

http://img31.imageshack.us/img31/2010/grain.png

It's a fragment of a scanned photo (slide film), and
I'd like to know whether it is scanner noice or film
grain. The noice I am taking about is best seen on the
women's T-Shirt.

Thank you in advance,
Anton

looks like dirt in the emulsion.

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Noise: digital or analogue?
 

On 3/13/2010 1:05 PM Jean-David Beyer spake thus:

Anton Shepelev wrote:

Could an expert here tell me origin of
the color noice on the referred photo?

http://img31.imageshack.us/img31/2010/grain.png

It's a fragment of a scanned photo (slide film), and
I'd like to know whether it is scanner noice or film
grain. The noice I am taking about is best seen on the
women's T-Shirt.

looks like dirt in the emulsion.

Ackshooly, the woman's T-shirt looks OK to me: there's what looks like
dirt everywhere else that's lighter. Is this the "noise" you're
referring to? In that case, I think it's just dirt, not noise.

You may need to clean the slide before rescanning it.


--
You were wrong, and I'm man enough to admit it.

- a Usenet "apology"

Noise: digital or analogue?
 

Anton Shepelev wrote:

Could an expert here tell me origin of
the color noice on the referred photo?

http://img31.imageshack.us/img31/2010/grain.png

It's a fragment of a scanned photo (slide film), and
I'd like to know whether it is scanner noice or film
grain. The noice I am taking about is best seen on the
women's T-Shirt.

There are a few things going on here, and I suspect the other replies were
about the wrong one. The most obvious is the specks of dirt all over the
place; I assume you're not asking about that because the cause is obvious.

Then there's the "texture" you get, most prominently in the T-shirt; that's
the film grain and looks fine to me. Finally, there is what looks an awful
lot like digital chroma noise, and I suspect that's what you're actually
asking about. I believe that is also simply film grain, and it's normal
(in my experience, and I'm not a Top Expert) for color film scans.

I determined to my satisfaction that it wasn't digital noise (in my own
scans) by cranking up the scanner to 16x multi-sampling, which should
eliminate any trace of digital noise, and that pattern didn't change at
all. That's just the way it looks.

Having said that, setting Color Noise Reduction to 10 in Lightroom (or
Camera Raw) will eliminate it. (Yes, you can do that on a TIFF from a
scanner.)

--
Jeremy Nixon | http://www.defocus.net
Email address in header is valid

Noise: digital or analogue?
 

Jeremy Nixon:

There are a few things going on here, and I suspect the other replies were
about the wrong one. The most obvious is the specks of dirt all over the
place; I assume you're not asking about that because the cause is obvious.

Then there's the "texture" you get, most prominently in the T-shirt; that's
the film grain and looks fine to me. Finally, there is what looks an awful
lot like digital chroma noise, and I suspect that's what you're actually
asking about. I believe that is also simply film grain, and it's normal
(in my experience, and I'm not a Top Expert) for color film scans.

I determined to my satisfaction that it wasn't digital noise (in my own
scans) by cranking up the scanner to 16x multi-sampling, which should
eliminate any trace of digital noise, and that pattern didn't change at
all. That's just the way it looks.

Having said that, setting Color Noise Reduction to 10 in Lightroom (or
Camera Raw) will eliminate it. (Yes, you can do that on a TIFF from a
scanner.)

Thanks to everybody for their replies. I got another proof of Jeremy's
suggestion: setting a wrong focus on the scanner blurrs away the image
together with the 'noise', which turns to be how grain looks to the scanner.

Now another question:
On optical prints, even at big scales (like 1 x 1 m from 60 x 60 mm film)
there's no such noise visible. Does is mean they are printed with sifted
focus, or is it the natural blurring in the enlarger? One way to check it
would be to get my grainy scan printed in a fotolab without preprocessing.

I am not even sure this grain noise needs to be cleaned up before printing...

Anton

Noise: digital or analogue?
 

Anton Shepelev wrote:

Thanks to everybody for their replies. I got another proof of Jeremy's
suggestion: setting a wrong focus on the scanner blurrs away the image
together with the 'noise', which turns to be how grain looks to the scanner.

Good thought, I didn't even think of that. :)

Now another question:
On optical prints, even at big scales (like 1 x 1 m from 60 x 60 mm film)
there's no such noise visible. Does is mean they are printed with sifted
focus, or is it the natural blurring in the enlarger? One way to check it
would be to get my grainy scan printed in a fotolab without preprocessing.

Scanning seems to accentuate grain. I gather it has to do with the light
source being harder.

It's worth noting that almost all labs now do prints by scanning the
negatives.

I am not even sure this grain noise needs to be cleaned up before printing...

Are you printing optically or from the scan? If you're printing from the
scan, the "noise" is really quite small. But like I said, you can eliminate
it with one slider in Lightroom. If you're ultimately printing optically
then it's probably irrelevant.

--
Jeremy Nixon | http://www.defocus.net
Email address in header is valid