Exposing to the right means exposure in which the lightest parts of the image where you want to have information are as near as possible to over exposure. The exposed image looks too bright, but it will be corrected later in raw converter. The advantages in this method are less noise and more details. The disadvantage is longer exposure time which can lead to blurry photos. This method works well only with raw images.
I made a test with two cameras in order to see the effect of ETTR. The results surprised me positively.
Sony DSC R1
I bought this Sony in the year 2006. It served me well 6 years and is still in excellent condition. The only annoying thing is that I didn’t know then about ETTR. The old Sony DSC R1 was amazingly good at higher ISO values in the test.
This is the whole image and the white frame shows the area in the example images.
I took photos with both cameras without and with ETTR correction using different ISO values.
Sony Cyber-shot DSC R1
The only way to estimate the amount of exposure in Sony DSC R1 is the histogram and the zebra effect. They are based on the jpg image made by the camera and that’s why they show over exposure at least 1 EV too early. I used +2 EV correction in this test and it seemed to be OK.
Sony R1 viewfinder
R1, ISO 160
R1, ISO 400
R1, ISO 1600
R1, ISO 3200. (maximum ISO)
Whole image ISO 3200. Click the image to see it 1000 pixels wide.
Olympus OM-D E-M5
The other camera in the test was Olympus OM-D E-M5. I bought it in the year 2012 and it is now the main tool for me. This camera and all other Olympus interchangeable lens cameras have indicators in the viewfinder which show the place and beginning of under and over exposure straight from image sensor. That makes it very easy to expose to the right accurately.
Olympus OM-D viewfinder
In the left viewfinder image (1.) ETTR correction is +1.7EV, and there is no sign of over exposure. In the right image (2.) the correction is +2EV and the red waning color shows two over exposed areas.
OM-D, ISO 200
OM-D, ISO 400
OM-D, ISO 800
OM-D, ISO 1600
OM-D, ISO 3200
OM-D, ISO 6400
OM-D, ISO 12800
OM-D, ISO 25600
Whole image ISO 25600. Click the image to see it 1000 pixels wide.
ETTR makes both cameras to produce better images than without exposing to the right. The results of this test were so convincing that I have used ETTR ever since.