RetouchPRO

Go Back   RetouchPRO > Technique > Photo Restoration
Register Blogs FAQ Site Nav Search Today's Posts Mark Forums Read


Photo Restoration Repairing damaged photos

Correcting non uniform light?

Reply
 
Thread Tools
  #1  
Old 10-14-2014, 04:34 AM
bugbear bugbear is offline
Junior Member
 
Join Date: Nov 2002
Location: Engand
Posts: 14
Correcting non uniform light?

I will (shortly) be going to an archive to do family history research.

They allow digital photography, but put tight constraints on what you're allowed to do
(including no flash, no tripods).

As a pre-test, I have made an image at home of a map, and I deliberately lit it badly, using a single lamp to the side.

My question is; how can I post-correct this?

Clearly, there are plenty of reference-white spots on the map, but how do a make a full size "reference white" image, and how do I use it? And how do I use a reference white image to correct blacks.

The attached image is actually a panorama, stitched together from 3 separate images, which is another technique I'll need to use.

http://i48.photobucket.com/albums/f2...ar33/light.jpg

BugBear
Reply With Quote top
  #2  
Old 10-14-2014, 10:13 AM
John Wheeler's Avatar
John Wheeler John Wheeler is offline
Senior Member
 
Join Date: May 2011
Location: Colorado
Posts: 583
Re: Correcting non uniform light?

Hi Bug Bear
Not sure of your post processing tools yet your can use Lightroom or Adobe Camera Raw to fix this.

Use the Graduated Filter tool to change the exposure gradient and use the basic tone sliders to adjust the black and white points.

Just my quite thoughts.
Reply With Quote top
  #3  
Old 10-14-2014, 10:58 AM
Tony W's Avatar
Tony W Tony W is online now
Senior Member
Patron
 
Join Date: Mar 2010
Posts: 1,415
Re: Correcting non uniform light?

As an alternative/addition to John's suggestions a series of masked Curve adjustment layers will also work to even out the lighting. I would also expect that you may have to use a D&B layer to even out paper discolouration etc. and a final curve layer to get a satisfactory overall look
Reply With Quote top
  #4  
Old 10-14-2014, 11:06 AM
bugbear bugbear is offline
Junior Member
 
Join Date: Nov 2002
Location: Engand
Posts: 14
Re: Correcting non uniform light?

I'm on Linux/Open source, so Imagemagick, Gimp, netpbm are my tools.

BugBear
Reply With Quote top
Reply

  RetouchPRO > Technique > Photo Restoration


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Hard light but nice skin konamura Photo Retouching 3 09-02-2013 04:34 AM
Light Leaks in Photoshop DomQuichotte Photo Retouching 2 07-15-2013 11:52 AM
flashlight without light reko Photo Retouching 3 06-14-2013 01:16 AM
how can i separate colors from light ? mantra Photo Retouching 33 08-13-2012 09:52 AM
Photo taken on light background > dark background misterlondon Photo Retouching 3 08-26-2011 12:12 PM


All times are GMT -6. The time now is 03:02 PM.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
SEO by vBSEO ©2011, Crawlability, Inc.
Copyright © 2016 Doug Nelson. All Rights Reserved