Your lens is not soft

[Jonathan]

Laurence Kim talks a lot of sense.  Here he's talking sense about "soft" lenses.

http://laurencekim.com/2011/06/06/your-lens-is-plenty-sharp-wide-open/

[Carlj]

That's a mare with recomposing. If I'm shooting on a tripod, I'll use manual focus liveview confirmation, zooming into the required subject.

Now, if I recall, a long time ago, in a forum far, far away, someone named Jonathan mentioned about the sliver of focus requiring critical focussing when using a F1.4 lens.... 

[anglefire]

I almost never recompose when focusing - and never when shooting with a fast lens wide open.

So, yeah, I'd agree.

[Hinfrance]

He's right about the lenses being sharp enough wide open, in the middle. So for all practical purposes this is sound advice.

He's wrong about the sharpness being the same across the whole lens. Lower cost lenses can have significant softness issues on the edges, not to mention CA - and this is because of the laws of physics, not because of photographers recomposing shots.

The wafer thin depth of field issue is only apparent when photographing close objects, the further away the subject is, the greater the depth of field. At 7 meters the depth of field of a 50mm at f1.4 is greater than a 200mm at f5.6 (less than 15cm in the case of the latter).

Upshot, to avoid CA try not use any lens wide open in contre jour situations, but otherwise just make sure you focus properly.

[Jonathan]

He's right about the lenses being sharp enough wide open, in the middle. So for all practical purposes this is sound advice.

He's wrong about the sharpness being the same across the whole lens. Lower cost lenses can have significant softness issues on the edges, not to mention CA - and this is because of the laws of physics, not because of photographers recomposing shots.

That's true (though to be fair he doesn't say it's the same across the lens) and it's easy enough to compose pictures to deliberately show this.  But like you say, for real world portraits most lenses are sharp enough

Couple of weeks ago I was running a lighting course.  During it I set some lights for a beauty shot of jewellery (that I was, err, shooting for another client.... ).  The delegates also snatched some frames using exactly the same setup.  I've seen one posted on a website where the poor guy got a kicking because it was a little soft.  There was then a spirited debate saying how ridiculous it was ever to shoot at f22 since everybody knew that would always make your images soft due to diffraction.  There's a reason I no longer get involved in discussions like that.....

Here's a 100% from one of my images.  You can see how that nasty nasty diffraction is ruining my image.



[Hmm, cropping in Easycrop has oversharpened that a little but you probably get the point]

[Hinfrance]

Just so Jonathan, time to stop worrying about technical minutiae and just get on with it

[hevans]

for me the sharpness of the lens is more than adequate after camera shake* is added to the equation.

Actually, (looking at that lovely eye and the noticeable pixelation in the lashes), I always find the "softness" tends to provide an element of mitigation of pixelation and provide a more natural image - a pseudo anti-aliasing if you will.

V. interesting article.

Ta.
H.

* usually from a small boy bouncing off me or climbing on my back.

[Jonathan]

Just so Jonathan, time to stop worrying about technical minutiae and just get on with it

Or rather don't believe armchair tech jockies - go and find out.  Occasionally they will be right.

for me the sharpness of the lens is more than adequate after camera shake* is added to the equation.

Actually, (looking at that lovely eye and the noticeable pixelation in the lashes), I always find the "softness" tends to provide an element of mitigation of pixelation and provide a more natural image - a pseudo anti-aliasing if you will.

Yeah plus serious lenses can be a little unforgiving on real skin

To be fair most if not all of that pixellation was added by Easycrop when I took a crop of the pic as a screen grab.  It's exactly where you'd expect to see jpeg artifacting.  Like it matters

[anglefire]

And you can still see the bits of makeup that "splashed" onto the skin