Another question on sharpness of the Pic.

[gandhi]

Hi Iam trying to get sharp pictures with have canon 5D Mark II and canon 135mm F2 lens. Since the lens does not have IS , I am using shutter speed of a minimum 1/200.My question is , does high shutter speed effect the sharpness of the picture?
Another question I have is higher the ISO, less sharp are the pics, is that true? or is there a sweet spot for ISO as well?

[DavidEccleston]

Shutter speed can affect sharpness in a few ways:

Camera movement - intentional or not. People aren't 100% steady, that's unintentional movement. Some tripods aren't very steady either. On the other hand you might be tracking a moving subject. That's intentional, and you're expecting the background to be blurred, but if your tracking isn't absolutely perfect, you may see softness in the subject with lower shutter speeds.

Subject movement - I need to use 1/2000s or so to ensure I get sharp pictures of my dogs. They're pretty fast. That's probably a mix of panning, and subject movement.

Mirror bounce - When the mirror in your camera moves up to take the picture, it introduces a small shake that can affect sharpness with lower shutter speeds.

At higher ISO there will be more noise, and the noise reduction will soften the image. Since more reduction occurs at higher ISOs, there is more softness. The slight softness you see from high ISO is preferable to the ruined shot from too low a shutter speed, or too short an exposure and attempting to brighten in post.

[jrw]

Only things to add are that 5D2 has very little ISO noise up to around the 800 mark. Most people find the ISO noise becoming objectionable between 1600 and 3200 depending on their own tolerance level and willingness to lose some sharpness cleaning up the noise.

Not sure where yours is at, but you may be able to bump ISO for faster shutter speeds to see if that helps. Those with rock steady hands can use longer shutter speeds than the rest of us.

Long exposure times will also increase noise levels due to the sensor heating up.