neurorx said:
I wanted to ask the group their thoughts on sharpness with Canon 5DIII. I notice it most strongly with my 24-70mm 2.8 II in low light and at 70 mm. Some with other lenses with low light or contrast. I've tried live view focus that helps some. ISOs aren't maxed out generally above 1000-5600. Lower F stops for the lenses.
Is this just a gear limitation issue or should I be concerned?
Thank you.
Generally, as you increase the ISO, noise also increases. Noise destroys the detail in a image, so eventually, if you keep cranking up the ISO there is little detail left. You could call it loss of sharpness, its really just noise that creeps in.
The 5D MK III is pretty good at ISO 3200, at 6400, noise creeps in, and at 25,600 its pretty objectionable.
This is the case for all cameras. Larger sensors can use higher ISO's before noise looks bad. If possible to over expose a little, you can alleviate part of the issue when you process the raw image.
You can get a bad sensor, so you are correct to ask. Post a link to a full sized raw photo so some experts can actually see if there seems to be a issue.
I just finished some low light photos, noise in the colored lights is pretty noticeable even at ISO 3200, detail is lost. Its mostly due to my exposure settings. I probably got a stop of extra noise in there, and DR at high ISO's is very small. Most of my images were at ISO 2000 and above with a lot above 12800. At ordinary printed size, even those 25600 photos will look good, but at 1:1 they look ugly.