Join for FREE
It only takes a minute!
Magnifying the passion for nature. Zeiss Victory Harpia 95. New!

Welcome to BirdForum.
BirdForum is the net's largest birding community, dedicated to wild birds and birding, and is absolutely FREE! You are most welcome to register for an account, which allows you to take part in lively discussions in the forum, post your pictures in the gallery and more.

Thread Tools Rate Thread
Old Wednesday 8th February 2012, 20:10   #1
Registered User

Join Date: Dec 2011
Location: Kent
Posts: 81
Mottled background

I have been working on a photograph recently in Photoshop but noticed I have ended up with a mottled looking background instead of it being an even blue sky.
The background appears to be blue but has purple(ish) mottling.
I'm sure I have seen this before but cannot recall what its called or what causes it.
I would therefore appreciate any comments or advice on what I'm doing wrong and what the remedy is.
I have tried to include a much enlarged image showing the problem which I have lightened to show it to better effect.

Your help appreciated - Pete
Attached Thumbnails
Click image for larger version

Name:	background.jpg
Views:	153
Size:	86.7 KB
ID:	368612  
Pete007 is offline  
Reply With Quote
Old Thursday 9th February 2012, 12:01   #2
Registered User
Shaggy2070's Avatar

Join Date: Sep 2006
Location: East Durham
Posts: 492
I'm no expert but it looks like camera noise to me.
Others will tell you better.
Shaggy2070 is offline  
Reply With Quote
Old Thursday 9th February 2012, 13:49   #3
Mono's Avatar

Join Date: Dec 2005
Location: Lake District,UK
Posts: 1,833
Agree with above, definatly chromatic camera nosie.
Mono is online now  
Reply With Quote
Old Thursday 9th February 2012, 16:47   #4
Registered User

Join Date: Oct 2009
Location: West Sussex - England
Posts: 366
As someone still trying to learn, can I ask if Chromatic camera noise is somehow different to other or general noise and is the mottling effect characteristic of 'Chromatic camera noise'. ( I can see Noise in other photos but it doesn't have this blue/purple mottling effect as in this case).
Is this something I have done wrong in my workflow and if so can I either eliminate or minimise it ?
I have downloaded the trial or basic version of Neat Image but am not 100% sure I am using this in the most efficient manner.
Any advice is much appreciated.

Originally Posted by Mono View Post
Agree with above, definatly chromatic camera nosie.
Eos9 is offline  
Reply With Quote
Old Thursday 9th February 2012, 17:35   #5
Mono's Avatar

Join Date: Dec 2005
Location: Lake District,UK
Posts: 1,833
Noise comes in two forms chromatic meaning it affects the colour values and luminance which means it affects the brightness. Broadly speaking smaller sensors and high ISOs lead to more noise, the camera is amplifying the signal from the sensor elements and amplifying the noise as well. It is there in the initial image it is not created in the post processing, although if you boost the levels of shadows it can bring it out.

Noise reduction filtering will help but it is important to just use it on the areas where you can see the noise as it has a general softening effect. Use a masked duplicate layer to apply the noise correction to the areas needed. It is also important not to get hung up on noise you can see if you zoom right in to 100%, particularly if you are going to put the image on the web at a fraction of its original pixel size. Open a second window for your image {Window > Arrange > New Window} and size the window to the target size for the image and zoom it so you can see the whole image. Then do all your edits in the original window at what ever zoom is best but you can see at a glance what the full size image looks like. Often the tweaks you do at 100% have little impact on the totality of the image at the size people are going to look at it.
Mono is online now  
Reply With Quote

Thread Tools
Rate This Thread
Rate This Thread:

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

vB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Blurring the background BackGardenMoths Photoshop, Paintshop and Printing 1 Sunday 15th May 2011 10:20
blurred background sandman jim Panasonic 3 Thursday 20th January 2011 09:09
SOme background history woodhornbirder Spotting Scopes & tripod/heads 2 Friday 13th August 2010 06:28
improve background,please Reini Photo Critique 8 Sunday 10th April 2005 15:27
bird in background? Krispo Bird Identification Q&A 15 Wednesday 8th December 2004 12:02

Opticron - Imagic BGA VHD 8x42 – 2018 BBR Award Winner

Fatbirder's Top 1000 Birding Websites

Help support BirdForum

Page generated in 0.13531995 seconds with 18 queries
All times are GMT. The time now is 22:41.