unsharp images

Joined: 15 Apr 2005 Posts: 266 Location: South Australia

Hey all,
Just from some photo's I've taken recently I've noticed that they aren't particularly sharp. I took some shots of a friend skydiving last weekend and again today I took some shots of my dad. All at 70mm. When i zoom in on the eyes of my dad in camera raw. They aren't that sharp. A couple of them were ok though. I was shooting with my flash on a stand off to the side on my tripod and holding the camera. I was shooting at f4 and 1/180th so i thought it would have been plenty fast enough to get a sharp image hand held. Any ideas? Is it because its hand held or could the lens be damaged (it has been dropped by a friend before but repaired (metal ring inside snapped and replaced).

Posted: Sun Jun 10, 2007 9:59 am

At what focal length were you shooting at? If you were shooting a 70-300 at 300mm then your shutter speed of 1/180 was not nearly fast enough.

The general rule for sharp images is 1/focal =shutter speed. So if your shooting at 300mm then your shutter speed needs to be near 1/300 or faster. There is some leeway here but if you try and follow this you will see a marked improvement in sharpness.

Joined: 15 Apr 2005 Posts: 266 Location: South Australia

benen wrote:

All at 70mm.

i only have a 50mm and an 18-70mm :)

Posted: Mon Jun 11, 2007 7:06 am

Sorry I didn't read the thread throughly enough, if your still not getting sharp images then possibly the lens could have been damaged.

Posted: Mon Jun 11, 2007 7:49 am

benen wrote:

Hey all,
Just from some photo's I've taken recently I've noticed that they aren't particularly sharp. I took some shots of a friend skydiving last weekend and again today I took some shots of my dad. All at 70mm. When i zoom in on the eyes of my dad in camera raw. They aren't that sharp. A couple of them were ok though. I was shooting with my flash on a stand off to the side on my tripod and holding the camera. I was shooting at f4 and 1/180th so i thought it would have been plenty fast enough to get a sharp image hand held. Any ideas? Is it because its hand held or could the lens be damaged (it has been dropped by a friend before but repaired (metal ring inside snapped and replaced).

At f/4 the depth of field isn't going to be huge (about 12cm at 2m, 27cm at 3m) so it could be a focussing issue with the lens. You could try using a focus chart to check for any front or back focussing issues with the lens and get it recalibrated if required.

Cheers
Mark

Joined: 15 Apr 2005 Posts: 266 Location: South Australia

I tried taking a bunch more shots at both 1/180 and 1/500 and they all came out perfect :S. Maybe it was a focusing issue because the only difference the first time was that i was firing the flash through a white sheet and camera settings were identical. Oh well, i'll see what happens next time I take some portraits :) thanks guys

Posted: Thu Jun 21, 2007 2:06 pm

If your other images came out nice and sharp, it sounds like it was probably operator error. No one is going to catch it perfect 100% of the time.

Joined: 18 Nov 2006 Posts: 288

Put the focusing thingy right on the eye, hold the shutter release half way and then recompose. They you will be focused where you want.

Posted: Fri Jun 22, 2007 12:06 pm

One more thing to consider, as that when shooting in raw, no sharpening is carried out by the camera software, like it does with jpeg.
That's exactly what RAW is, the RAW data captured by the sensor.
If some look sharper than others before RAW processing then like armyrugby says getting it right every time is pretty tough.