This is the 69th in a series of posts on the Nikon D850. You should be able to find all the posts about that camera in the Category List on the right sidebar, below the Articles widget. There’s a drop-down menu there that you can use to get to all the posts in this series; just look for “D850”.
Yesterday, I showed graphs relating to the Nikon D850’s noise and how that relates to the ISO setting in the camera. In my first post today, I posted visual takes on the noise differences from ISO 64 through 320. In the previous post, I did the same thing for ISO’s 400 through 3200. Now I’m going to add one more stop to the ISO range, making it from 400 to 6400.
I made a series of images of my standard subject for this test all with the same shutter speed, using an Otus 55/1.4 set to f/4, at ISOs 400 through 6400 in one stop increments. The exposure I chose was ETTR at ISO 6400, and thus quite a bit underexposed at ISO 400. I processed them all in Lightroom with default settings except for a custom white balance that assured that the WB wouldn’t change from image to image. Here are the full-frame images from the beginning and end of the series.
Then I boosted Lightroom’s Exposure control by an amount that compensated for the underexposure. Since each click on the far right of the Exposure widget in the Library window is a whole stop, this was easy to do. I looked at the noise in each image. Here are some crops, magnified to about 200%.
Pretty darned ISOless, huh?