what does it mean

Auzelia

Auzelia

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158
Name
Caroline
Edit My Images
Yes
when someone comments.

"There is alot of noise in your picture!"
 
To me it means there are grainy areas or artefacts that should not be there (I don't like noise in images)

The easiest way to see it is to take a picture with a lot of sky and then sharpen it and look at the sky at 100% - or more . I would post an example but my editing programme is busy at present.

Some people will use a noise reduction programme such as Neat Image, others like me will tend more to blurring the area slightly
 
a noisey picture is a picture that doesn't have adequate lighting. You know when you shoot something and you get all those speckles that shouldn't be there? That's noise.

Nattelie.jpg

That is a terrible picture, noisy and out of focus.
 
Noise is an electronic artifact - basically coloured speckles most visible in dark areas, and at high ISO. It's especially noticeable in pictures from mobile phones because of their tiny sensor size - they just don't gather much light to work with. Smaller the format, the worse the noise - all other things being equal.

Noise is always present but at a very low level. Normally it isn't noticeable because the image signal is so much higher it is effectively suppressed.

But when the light is low or the ISO is high, the signal-to-noise ratio is much lower and when the image data is amplified to get a nice good bright picture, so noise is amplified with it.

There are vaious ways to reduce noise, both in camera and in post processing. Most of them are very effective but all have their (slight) downsides.
 
thanks guys :D

Still trying to learn the terminology that is used in Photography
 
MagicMynx said:
a noisey picture is a picture that doesn't have adequate lighting. You know when you shoot something and you get all those speckles that shouldn't be there? That's noise.
That is a terrible picture, noisy and out of focus.
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No - it's created by use of high ISOs. Higher the ISO, higher the noise. Long exposures suffer from it also..
 
specialman said:
No - it's created by use of high ISOs. Higher the ISO, higher the noise. Long exposures suffer from it also..
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MM was right actually - while higher ISOs do aggravate the nose problem, it's also caused by low light situations and under-exposure even at moderate ISO's and will always be most noticeable in the darker parts of the image.
 
purpleclouds said:
'Grain' would be a more descriptive term :)
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I know what you mean Phil, but it would also be very misleading. Grain is the actual grain size of the emulsion coating showing up in your prints with film photography - the faster the film, the larger the grains of silver halide which make up the light sensitive coating.
 
Auzelia said:
when someone comments.
"There is alot of noise in your picture!"
Click to expand...
a digital term for what could be interpreted as grain...not all that bad..and as commented above slightly differing in origin...the effect can be similar
noise can be taken out slowly by software
noise comes with faster asa settings on your digital camera...similar to the grain on faster films
use slow asa settings..i use 64 and set my digi cam at high quality imagery

i use noiseware community free download to get rid of noise...and in some cases enhance eyes in portraits by apparent sharpness

http://noiseware-community-edition.en.softonic.com/
 
MagicMynx said:
you can get noise by using a low ISO and inaiquate lighting too
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That's more correctly described as underexposure rather than inadequate lighting.

The problem with your pic in post #3 is underexposure and when you try to brighten the image in post processing the noise gets amplified with the signal to the point where it becomes obtrusive.

What is happening in effect is that you are dramatically increasing the ISO in post, hence the noise.
 
Auzelia said:
when someone comments.

"There is alot of noise in your picture!"
Click to expand...

I'm not sure as 'alot' is not a word!

It usually occurs at high ISO as there is less light so the gain needs to be increased.

It's a bit like making a quiet recording on a cassette tape and turning up the volume to compensate. The tape hiss level will rise. Likewise, increasing the gain on a sensor will introduce some random artifacts which will show up in the image.


Steve
 
If you look through a lot of darker pictures you will find noise in some shape and form. In some cases I think it can work well though.
 
Thanks everyone,

and thank you Steve for the english lesson.

Didn't realise that came with the forum!!
 
Auzelia said:
Thanks everyone,

and thank you Steve for the english lesson.

Didn't realise that came with the forum!!
Click to expand...

being a pedant is not a requirement for membersip, but some folk just cant help themselves.
 
Phew, glad we've all got that out of our systems ;) Thought it was gonna turn into a full-on handbag fight!!!

Oh, and I concede that poor lighting does push the sensor beyond its limits at times, but in general, noise most people refer to is related to higher ISO values being used...


....oops, I've kicked it off again! ;)
 
come back kodachrome25...all is forgiven
 
Auzelia said:
:thinking::suspect:
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that was or may be still is a very fine grain transparency film...with good colour integrity for flowers etc

i know grain isnt the same as noise...but i was being a bit ironic that film speeds went up quite a bit from 25..yet you can get 50 on your digital camera..some makes..and probably no noise at all

did you download that noiseware site i posted

i have just used it and it does help some shots
 
I havent downloaded it yet as I am using my laptop atm, once I am back on the PC (Wish I had a Mac though ) then I will :D

Thank you x
 
Auzelia said:
I havent downloaded it yet as I am using my laptop atm, once I am back on the PC (Wish I had a Mac though ) then I will :D

Thank you x
Click to expand...

your online...:thinking:

later perhaps
 
CT said:
Grain is the actual grain size of the emulsion coating showing up in your prints with film photography - the faster the film, the larger the grains of silver halide which make up the light sensitive coating.
Click to expand...

and we all know that grain is better than noise ,:)
 
I have to keep reminding myself that not everyone here has even heard of Kodachrome 25...


or even...film...
 
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