Use high ISO and overexpose or not?

[flyalf]

Hi all,

I want some feedback on M9 on this since I haven't had time yet to do a thorough test myself.

The general idea is to use RAW, set higher ISO, overexpose and the post-correct (in Lightroom ot other). As an example (for a D90) you will get less noise, better tonality and gain +0,7EV by using ISO3200 +1,3EV than ISO800 -1,3EV .

As a general rule is proposed to expose:

• Rainy weather = +1,3EV to +2,0EV
• Clouded = +0,7EV to +1,3EV
• Light clouded = 0EV to +1,3EV
• Sun = -0,7EV to +0,7EV


This is described by Geir Brekke in a very good article (alsa, only in Norwegian):
http://foto.no/cgi-bin/articles/articleView.cgi?articleId=41506

 

[jaapv]

Overexposing is not the answer either - you blow out the highlights. But in general, you have the right idea. Expose to the right solves the noise problem. However, blanket exposure corrections don't work. Go to manual and expose correctly and liberally, and then CHECK YOUR HISTOGRAM! Switch off overexposure warning; it is hopelessly pessimistic.

 

[venchka]

Over at the LUG (Leica Users Group) this suggestion was made as an example:
Set ISO @ 400
Set Exposure compensation @ -1
Correct exposure in post to +1.
The theory is reduced noise compared to ISO 800 and no exposure compensation.
I must agree: Get the exposure as close to right as possible in the camera.

 

[ebino]

I don't speak Norwegian so I have no idea what the article is saying.

As to the question of overexposure at high ISO, it sounds plausible because if you're shooting at high ISO there are no bright lights or sunlight in the frame to risk blowing up highlights. However, over exposure with digital should be done carefully otherwise that bit of extra noise is not worth blowing highlights.

Also if you're shooting for b&w at high ISO, a little overexposure would help with tonality.