View Full Version : How sharp is sharp?

12-07-2007, 06:41 PM
How sharp or in focus should an image be? When I shoot, mainly outdoors, my camera settings are set correctly, lighting conditions are great, I most of the time get an image that is slightly out of focus. When I zoom into the image on my camera (Canon 5d) everything looks in focus and sharp. When I bring it into Photoshop and zoom in, the eyes are slightly out of focus. To the average person, you couldn't tell whatsoever but I can and it drives me crazy! I know I'm not shaking the camera, sometimes it's on a tripod. Could it be my lens (Canon 70-200mm/f2.8)? I don't have IS on it.


12-08-2007, 05:53 PM
Hi Samirah,

IMO, the eyes should always be TACK sharp when you are focusing on the eyes.

It could easily be your shutter speed. You must keep in mind that when shooting a portrait, EVEN if your camera is on a tripod that humans can normally be shot at 1/60 or faster (1/125, 1/250). A human that stands still wavers slightly so a shutter speed of 1/30 or slower will NOT normally be tack sharp even when on a tripod.

On the other end...the rule of thumb is 1/focal length of the lens as the minimum shutter speed. In your case, if you were using the 200mm end of the zoom, the shutter speed should be AT LEAST 1/250. It has been my personal experience that with digital, you need to go a bit faster by about 1 stop. It sucks but other photographers also seem to suggest the same.

What shutter speed were you using and what were the lighting conditions?

Hope that helps!


PS - studio lighting podcast coming in a day or 2.

12-09-2007, 07:55 PM
Lighting conditions were great, overcast. My shutter speeds were high 1/125 and higher.

Look forward to the studio podcast.


12-09-2007, 11:11 PM
Apparently from a technical standpoint adjustments in camera for sharpness, colour, saturation etc. do not provide as high a quality result as the same adjustments done within PhotoShop.

Adding to this, camera makers know that all professional photographers and most amateur enthusiasts use Photoshop. The result is that for their medium and higher cameras such as the Canon 5D which you are using, they do NO in camera tweaking of sharpness, leaving it to be done by the photographer in Photoshop for better results.

Realize by the way, that all adjustments other than shutterspeed and fstop tend to contribute to either noise or a degradation in resolution. It is a matter of which approach has the lesser negative effect.


12-10-2007, 08:16 AM
Tegan has an EXCELLENT point. I was blown away the first time I started using digital because I noticed sharpness issues. On my camera (Canon 30D) you can adjust sharpness in camera through the menu...but I prefer to do it in Photoshop.

1/125 is normally a good shutter speed for portraits, but if you were using the 200 end of that zoom...then as per my previous post, that as well can contribute to imperfect sharpness....

The best way as always is to do a test. Shoot a regular portrait (focus on the eyes) at 1/125, 1/250, 1/500 - at a longer focal length (say 200mm)
Then just open them on your computer and see if you can see the sharpness differences before using any filters like the unsharp mask filter (which sharpens the image)
.....There is no better learning than trying something for forself and proving it to yourself.