Pictures of England Pictures of England

Exploring the most Picturesque & Historic parts of England

Over 150,000 photos of England
22,000+ members
Click here to join the community

Unsharp mask for contrast

 
Paul HiltonPremier Member - Click for more info
Paul Hilton
Posts: 2601
Joined: 21st Nov 2004
Location: UK
quotePosted at 01:36 on 6th April 2008

For Photoshop users ( and possibly others? ) I've found a more sublte way to alter image contrast is to use the Unsharpmask filter.  After-- Filter>Sharpen>Unsharpmask  set the Amount to around 15% ( not critical); Threshold to 0, then use the Radius slider ( pixels) to now adjust the contrast, say 100 Pixels to kick off with, then alter to suit your image.  Seems to be a finer controlled way of altering the Contrast than the usual Contrast adjustment provided.

My favourite: Pictures  |  Towns  |  Attractions
Alan Marron
Alan Marron
Posts: 726
Joined: 14th Jul 2008
Location: UK
quotePosted at 16:55 on 27th August 2008
Nice tip Paul.  Thanks a lot.  I'd never even thought of doing it that way.
My favourite: Pictures  |  Towns  |  Attractions
Pete Rowley
Pete Rowley
Posts: 16
Joined: 14th Apr 2008
Location: UK
quotePosted at 15:20 on 26th October 2008
Great advice. I think for people who are a bit unsure about using photo software, they should just give it a go and in no time at all you'll getting much improved pictures - go on, give it go.
My favourite: Pictures  |  Towns  |  Attractions
lurkalot
lurkalot
Posts: 24
Joined: 29th Dec 2008
Location: UK
quotePosted at 17:00 on 10th April 2010

There's a tutorial here for LCE (Local Contrast Enhancement) ;)

http://www.luminous-landscape.com/tutorials/contrast-enhancement.shtml 

 

My favourite: Pictures  |  Towns  |  Attractions
Edward Lever
Edward Lever
Posts: 676
Joined: 22nd Dec 2005
Location: UK
quotePosted at 09:18 on 30th July 2013

I agree that the unsharp mask can improve apparent contrast, and is particularly useful for enhancing contrast in architectural details, but needs to be used sparingly. I do not have Photoshop, but use Canon Digital Photo Professional, which also has an unsharp mask control. I assume the following comments will apply to any software with an unsharp mask tool.

As I understand it, the threshold slider controls the digital level differences from pixel to pixel at which the mask effect kicks in. Setting the threshold to zero therefore applies the effect at all digital level differences from zero upwards.  

Having looked at a few shots I have taken, I can see that setting the threshold to zero causes unpleasant artefacts on smoother textures such as foliage and skin. Therefore I generally set the threshold to about half way, unless the shot is so poor it needs savage sharpening.



Edited by: Edward Lever at:30th July 2013 09:30
My favourite: Pictures  |  Towns  |  Attractions
 Please login to post to this thread...