Luminous Landscape Forum

Raw & Post Processing, Printing => Digital Image Processing => Topic started by: Khurram on November 09, 2009, 01:09:40 am

Title: Understanding Noise and sharpening
Post by: Khurram on November 09, 2009, 01:09:40 am
I've been doing all of my RAW processing using Canon's DPP since going digital at the end of 2005. I did purchase CS3 a couple of years back but continued processing all of my RAW files using DPP and then using CS3 strictly for pano stiching, file resizing and watermarking my files.

I finally decided to do my RAW processing out of DPP and purchased Lightroom and will be swiching over to Lightroom to process my RAW files once I learn it. After a lot of procrastination I have downloaded the Michael's Lightroom tutorial videos to learn LR.

However, I don't have a very good understanding of noise reduction or sharpening.

In DPP, I pretty much arbitrairily used the Noise reduction and sharpening settings and eyeballed the outcome without really understanding the reasonings for my settings.  I have started watching the first few videos, but I think I need to get some understanding for sharpening and noise reduction before I think I can get full value out of the videos.

Up to now, for noise reduction, I have used the luminance and chrominance noise sliders in DPP for my noise reduction, but really haven't understood which ones to adjust or how much to adjust them by.

However, I doubt if I can get by with my limited knowledge of noise reduction when I start to use Lightroom and have some shots where I wasn't able to correct the noise reduction in DPP.

I'd appreciate if I can some guidance on how to learn the basics about dealing with noise reduction and how to correct it. I'd also like to get advice on how to deal with noise reduction - should it/can it be dealt with in LR, or should is it better to deal with it outside of LR?

In DPP when there are small colored dots (green/orange, blue), that aren't correcte, i'll often stamp them out, which obviously is not the most effective way of dealing with the issue.

Here is an examples from my recent trip to the southwest.  In this case, I'm not even sure if this is flare or green blotches of noise.  Either way I'd like some advice on how they can be dealt with in LR.  As I've stated, I'm not even sure if it is noise or flare.  But unless it is flare caused by individuals using point and shoot flashes, I don't know how I would get flare from my shooting position.

Similarly with regard to sharpening, I've pretty much used the sliders in DPP to set sharpness and then when I want to resize for the web, I resize the files in PS3 and then simply use the "Sharpen" and "Sharpen Edges" commands in PS3 to sharpen the files - again doing an eyeball test to decide which to use, rather then understanding or trying to learn how to use the unsharp mask.  Now that I have decieded to switch to Lightroom, I'd also like some advice on getting a better understanding sharpening and whether sharpening should be dealt with in Lightroom or another program.

The files i'm posted were quickly processed in DPP, but I'd like to get some advice on how to deal with them in Lightroom.

I've only watched the first two (intro and ingestion) tutorial videos and would appreciate some guidance on what I should learn before I get further in the videos.  I'm laid out with H1N1 right now and am supposed to be in quarentine, so I actually have some time to learn Lightroom during the next week, so, I'd appreciate any advice on how to proceed with learning Lightroom.
Title: Understanding Noise and sharpening
Post by: NikoJorj on November 09, 2009, 11:18:08 am
First it's flare - it may come from an area brightly lit by the sun just over the top of the frame?
It can be decently cured by LR by desaturating and replacing with an appropriate color with the adjustment brush, if the original area doesn't contain important detail (maybe not so easy here).

About noise and sharpening tools in LR, this post about ACR (http://photoshopnews.com/photoshop-cs3-for-photographers/camera-raw-41-update/) is fully relevant, but what to aim for is foremost a matter of taste.
Some general quick'n'dirty principles though :
- better to undersharpen than to oversharpen,
- better to sharpen the right amount than to undersharpen,    
- generally better to use color noise reduction (much) more than luminance noise reduction.
Title: Understanding Noise and sharpening
Post by: Khurram on November 09, 2009, 12:12:33 pm
Quote from: NikoJorj
First it's flare - it may come from an area brightly lit by the sun just over the top of the frame?
It can be decently cured by LR by desaturating and replacing with an appropriate color with the adjustment brush, if the original area doesn't contain important detail (maybe not so easy here).

About noise and sharpening tools in LR, this post about ACR (http://photoshopnews.com/photoshop-cs3-for-photographers/camera-raw-41-update/) is fully relevant, but what to aim for is foremost a matter of taste.
Some general quick'n'dirty principles though :
- better to undersharpen than to oversharpen,
- better to sharpen the right amount than to undersharpen,    
- generally better to use color noise reduction (much) more than luminance noise reduction.
Thanks for the link and the pointers!  

I'll try using your suggestions for correcting the flare in the photo.  You know, I took around 15 shots and the last 3 or 4 shots I shot it wider to include more of the canyon and those are the ones where I experienced the flare issues.  That was also when more individuals came in with their point and shoot.  It could also have been when more light creeped through.  however, while shooting I don't remember there being as much light as is visible in the photos.  I looked through the more tightly cropped photos and there definately isn't this much light in the scene.