EM10 Noise Filter

[Stonge]

The JPEG noise reduction on the EM10 is called the 'Noise Filter'. Noise Reduction on the EM10 refers to long exposure 'hot pixel' noise reduction using Dark Frame Subtraction.

All digital cameras offer noise reduction on their JPEG outputs at higher ISO settings. Noise reduction causes some loss of detail, so it is necessarily a compromise between reducing noise on the one hand and retaining detail on the other. Areas of an image where excessive noise reduction has been applied, typically in the shadows, may look artificially smooth and 'smeared'.

The EM10 (and other OMD models) offers four levels of noise reduction in its Noise Filter setting: Off, Low, Standard, and High. You might expect 'Off' to mean Off, but it doesn't - a small amount of noise reduction is applied even then. On 'Standard' you might expect almost zero NR at base ISO, increasing in intensity as ISO increases.

However, I've found some surprising facts about EM10 noise reduction, bearing in mind that m43 is competing primarily with APSC sensors and that, as far as I'm aware, the EM10 sensor is the best that Olympus has to date. Surprisingly, it is clear that noise filtering is still having a harmful effect even at ISO 200! It seems that even at low ISO Olympus applies significant noise reduction to JPEG outputs.

Ironically, the truth is that up to 1600 ISO noise levels are perfectly acceptable with the Noise Filter set to 'Off' and infinitely preferable to the horrible effects of setting it to 'Standard'.

[CaledoniaMan]

On reading this I went and searched the web on noise and specifically its correlation with sensor size and came up with the following references on a very worthwhile site called Cambridge in Colour http://www.cambridgeincolour.com/ which is great if you want to get in to the technical theory of all things photography.

For anyone who wants to know more about noise have a look at the link http://www.cambridgeincolour.com/tutori ... -noise.htm

And for how it's influenced by sensor size http://www.cambridgeincolour.com/tutori ... r-size.htm about 3/4 of the way down the page.