# Why so much noise?



## mikebmw (Jan 20, 2012)

Why do I  get so much noise in my hdr pictures? The originals are clean, but when I do the "hdr" alot of noise show up.


----------



## Bossy (Jan 20, 2012)

Google tells me its grain, not noise, and its from Photomatrix processing.
Improve Photography | Portrait and Landscape Photography Tips | Improve Photography
That might help?


----------



## Majeed Badizadegan (Jan 20, 2012)

Try moving your micro-smoothing slider to the right. 

Also try smoothing highlights/shadows as sometimes this helps.


----------



## molested_cow (Jan 20, 2012)

What ISO were the photos shot in? Also, when the range that is captured is not wide enough the capture what's needed, it will turn out to be grainy too. This happens sometimes when I tone map a single exposure.


----------



## Rephargotohp (Jan 20, 2012)

When you use too much Light Adjustment in Photomatix (Medium/ Surreal/ Surreal +) or the wrong amount of Strength, You are making all your Shadows mid-Tone. So basically when you do that you are raising the exposure of the shadows 2 stops. Do that with *any* image and the noise shows up. Either do a more natural HDR or use a Good Noise reduction program to remoce the noise you have


----------



## vipgraphx (Jan 21, 2012)

Realistic HDR = Less Noise if any

Painterly HDR = A little more noise - needs noise reduction software to remove it

Grungie HDR = Lots of Noise - why take it out if thats what you like.

HDR = Noise it just depends as they all said the sliders you use to help keep it down.


----------



## janok (Jan 21, 2012)

What kind of HDR-software do you use? In Photomatix you can use "Exposure Fusion" as an alternative to Tonemapping. This process will not give you the Painterly or Gungie look, but the end result tend to be less noisy.


----------



## ann (Jan 21, 2012)

Bossy said:


> Google tells me its grain, not noise, and its from Photomatrix processing.
> Improve Photography | Portrait and Landscape Photography Tips | Improve Photography
> That might help?



google has mislead you, grain is about film, it's counter point in the digital world is noise. I took a look at this site, and i don't know who this Jim fellow is but his description about noise being "stray light" goes against the scientific answer to the way a sensor reacts to a boost in electricity; which is how higher ISO options are created 

If you use high ISO 's you going to increase the opportunity for more noise. Then of course the software can increase that as well.


----------



## GooniesNeverSayDie11 (Jan 21, 2012)

ann said:


> Bossy said:
> 
> 
> > Google tells me its grain, not noise, and its from Photomatrix processing.
> ...


 While I agree that the word "Grain" was a poor choice of words, he does not say noise is stray light. He says its the sensor confusing stray electronic signals (Noise, not visually, but electronically) which I think is an OK way of describing it.  Increasing the ISO increases the Signal to noise ratio (SNR). The ISO is digital "Gain" just like their is "Gain" on most audio preamps.


----------



## ann (Jan 21, 2012)

If  you want to agree , fine, I don't which is also fine.

I will have to check signal to noise ratio to see if it means confusing stray electronic signals.


----------



## unpopular (Jan 21, 2012)

I keep saying it...

Tone mapping is going to make local adjustments to contrast by pushing shadows, like Rephart said. So often people will just do this goofy ±2 exposure routine and hope that the whole dynamic range is in there. The tone mapping will then try to compensate by pushing the shadows and pulling the highlights rather than using information in the set.

*use your meter, people*


----------



## unpopular (Jan 21, 2012)

GooniesNeverSayDie11 said:


> ann said:
> 
> 
> > Bossy said:
> ...



The noise is always present, it's just that the signal has a larger amplitude that the noise. In any image where signal has a lower amplitude than noise, then you'll get noisy results. This exists in every single image, but it doesn't matter much because those areas are dark anyway. It becomes a problem when those dark areas are being adjusted such that they are no longer dark, then, along with any useful detail being amplified, so is the noise.

This is what is happening in a poor HDR. They need to be over processed in order to account for a lacking of signal.


----------

