04-15-2016 11:00 PM
5d MKIII with 17-35 f2.8 lens I get this a few times in my pictures where an area of the photos is grainy and the rest is sharp. to the bottom right of this image it has as grainy area and the rest of the picture is clear. I enlarged the area to sh
ow more. Dont know if its the lens thats causing this or the camera. I have had the sensor cleaned a week ago but this has happen for the past couple of months.
04-16-2016 03:02 AM - edited 04-16-2016 03:26 AM
Normal. You have after the exposure tried to brighten an underexposed area. Then you will see the grain.
If you don´t want to get that again you will need to shoot HDR, Dual ISO, or take a longer exposure. But with a longer exposure you will clip the highlights...
Only seeing the picture on a laptop screen, but seems okey for me. Don´t really notice the grain.
04-16-2016 10:05 AM
Peter is correct. You have exceeded the limit of the camera's f-stop range with that type shot. This is called the Dynamic Range, or DR, of the camera. It is usually around 10 stops. The human eye has the ability to see approx, 20+ stops.
04-16-2016 12:53 PM - edited 04-16-2016 12:54 PM
A thing that is good to know is that camera sensors have a hard task to collect light at wide apertures. Sensors with smaller pixels will not be able to collect light as easy as sensors with larger pixels.
For example, a 5D will lose 0,4 Ev of light at f/1,2 and a 450D will loose 1 Ev at f/1,2. Because of this Canon and other manufacturers increase the ISO automatically by around 1/3-1/2 Ev.
So if you use f/4-f/2 and wider than that your camera may bright the picture without you knowing it.