Horizons PollCanon EF L IS USM 500 f/4...Horizons ENTRIES 27/07...What annoyed you today?STREET-ENTRIES-Weekly Com...STREET-CHAT-Weekly Comp 1...POLL for TIME OUTTIME OUT. Chat thread wee...TIME OUT. Entry thread w...Horizons CHAT thread 2...POLL -NUMBERS and / or LE...NUMBERS and / or LETTERS ...POLL Happiness is.......Nice houseHappiness is.... Entry Th...Happiness is.... Chat Thr...

Author Topic: Your lens is not soft  (Read 1807 times)

Offline Jonathan

  • Hero Member
  • *****
  • Posts: 1273
    • PeopleByRyan
Your lens is not soft
« on: June 08, 2011, 05:50:29 PM »
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/


It's Guest's round

Offline Carlj

  • Global Moderator
  • Sr. Member
  • *****
  • Posts: 400
  • Happy to shoot
Re: Your lens is not soft
« Reply #1 on: June 08, 2011, 10:45:10 PM »
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....  :beer:

Offline anglefire

  • Canon Biggamist. Three bodies and some lenses. :) - Sold my 1DMk3
  • Hero Member
  • *****
  • Posts: 1470
  • Canon Owner and Proud of it :)
    • Mark Colston Photography
Re: Your lens is not soft
« Reply #2 on: June 09, 2011, 10:13:19 PM »
I almost never recompose when focusing - and never when shooting with a fast lens wide open.

So, yeah, I'd agree. :tup:
----------------------------------
Mark
* A HISTORY OF THE UNIVERSE - THE SHORT STORY* 'Hydrogen is a light, odourless gas, which, given enough time, turns into people.'

CPS Gold Member
My Website

Offline Hinfrance

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 5151
  • Cake is good
    • Hinfrance
Re: Your lens is not soft
« Reply #3 on: June 10, 2011, 07:11:59 AM »
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.
Howard  My CC Gallery
My Flickr
The theory seems to be that as long as a man is a failure he is one of God's children, but that as soon as he succeeds he is taken over by the Devil. H.L Mencken.

Offline Jonathan

  • Hero Member
  • *****
  • Posts: 1273
    • PeopleByRyan
Re: Your lens is not soft
« Reply #4 on: June 10, 2011, 08:18:52 AM »
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..... :D

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]
It's Guest's round

Offline Hinfrance

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 5151
  • Cake is good
    • Hinfrance
Re: Your lens is not soft
« Reply #5 on: June 10, 2011, 09:21:57 AM »
Just so Jonathan, time to stop worrying about technical minutiae and just get on with it :)
Howard  My CC Gallery
My Flickr
The theory seems to be that as long as a man is a failure he is one of God's children, but that as soon as he succeeds he is taken over by the Devil. H.L Mencken.

Offline hevans

  • Sr. Member
  • ****
  • Posts: 435
  • Sigh....why me again??
Re: Your lens is not soft
« Reply #6 on: June 10, 2011, 10:19:08 AM »
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.
« Last Edit: June 10, 2011, 10:22:18 AM by hevans »

Offline Jonathan

  • Hero Member
  • *****
  • Posts: 1273
    • PeopleByRyan
Re: Your lens is not soft
« Reply #7 on: June 10, 2011, 03:36:45 PM »
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 ;)
It's Guest's round

Offline anglefire

  • Canon Biggamist. Three bodies and some lenses. :) - Sold my 1DMk3
  • Hero Member
  • *****
  • Posts: 1470
  • Canon Owner and Proud of it :)
    • Mark Colston Photography
Re: Your lens is not soft
« Reply #8 on: June 10, 2011, 07:07:40 PM »
And you can still see the bits of makeup that "splashed" onto the skin  :o
----------------------------------
Mark
* A HISTORY OF THE UNIVERSE - THE SHORT STORY* 'Hydrogen is a light, odourless gas, which, given enough time, turns into people.'

CPS Gold Member
My Website

 

latest Posts

Subject Board Views/Replies Member Date & Time
xx Horizons Poll International Weekly Comp Entries 135/1 Oldboy Last post August 08, 2020, 11:48:53 AM
xx Canon EF L IS USM 500 f/4 for sale Lenses 230/6 anglefire Last post August 05, 2020, 07:48:42 AM
xx Horizons ENTRIES 27/07 - 02/08/20 International Weekly Comp Entries 249/5 Oldboy Last post August 03, 2020, 10:25:12 PM
xx What annoyed you today? General Discussion 636540/3972 Jediboy Last post August 03, 2020, 02:13:31 PM
question STREET-ENTRIES-Weekly Comp 1/8-9/8/2020 International Weekly Comp Entries 62/0 Hinfrance Last post August 01, 2020, 04:09:00 PM
smiley STREET-CHAT-Weekly Comp 1/8-9/8/2020 International Weekly Comp Entries 44/0 Hinfrance Last post August 01, 2020, 04:05:33 PM
xx POLL for TIME OUT International Weekly Comp Entries 207/3 Hinfrance Last post August 01, 2020, 01:04:50 PM
xx TIME OUT. Chat thread weekly comp. International Weekly Comp Entries 242/4 Jediboy Last post July 27, 2020, 11:31:15 PM