Selective NR (1 Viewer)

Having taken a liking to my 7D which provides many advantages over my old 30D, I now need to enhance my skills at adding selective NR as I find the 7D shows more noise than I need where image exposure is less than optimum, light was "poor" and ISO was raised ISO400 and above.

I shoot in RAW and use LR4 with either PS7 or CS3. I don't have any experiance of using NR plugins with PS although I have used NeatImage (free version) which I like. The masking function in LR4 seems quite good but is only utilised for selective sharpening and not NR.

For lazy posting of images on the web I tend to export to jpg directly from LR, then crop & resize in PS rather than "open as" a tiff copy in CS3 for further refinement.

Whilst I can use layers and masks in PS, the step that seems to let me down is being able to accurately select the area I want to exclude/include for the layer mask.

Would anyone be able to offer suggestions to improve my PP capabilities in general and/or suggest any good tutorials, books or workflows for using tools in PS (or in LR4 come to that) for selection, particularly within nature images.

I recognise there's a lot of factors here but any simple advice would be much appreciated.

Robin Edwards said:

Having taken a liking to my 7D which provides many advantages over my old 30D, I now need to enhance my skills at adding selective NR as I find the 7D shows more noise than I need where image exposure is less than optimum, light was "poor" and ISO was raised ISO400 and above.

I shoot in RAW and use LR4 with either PS7 or CS3. I don't have any experiance of using NR plugins with PS although I have used NeatImage (free version) which I like. The masking function in LR4 seems quite good but is only utilised for selective sharpening and not NR.

For lazy posting of images on the web I tend to export to jpg directly from LR, then crop & resize in PS rather than "open as" a tiff copy in CS3 for further refinement.

Whilst I can use layers and masks in PS, the step that seems to let me down is being able to accurately select the area I want to exclude/include for the layer mask.

Would anyone be able to offer suggestions to improve my PP capabilities in general and/or suggest any good tutorials, books or workflows for using tools in PS (or in LR4 come to that) for selection, particularly within nature images.

I recognise there's a lot of factors here but any simple advice would be much appreciated.

Click to expand...

Easiest way I've found, using PS7, is to make a background layer, apply NR then switch to Quick Mask Mode, select Brush from the toolbox and pick a hard brush from the brushes palette then paint the parts you want to mask. By changing brush size and image zooming you can be very accurate with your coverage. When happy flatten the image and switch to Standard Mode, you now have "marching ants" around your selection and you can sharpen (or do anything else) to your masked area or background separately by selecting Inverse from the menu.

thanks john-henry - a belated reply on my part.......

I occassionally use the method you explain using PS7. Equally, I can replicate more or less the same results in LR without layers but I'm torn as to which is best and quickest in terms of what others tend to practice in their workflow where both LR and PS are deployed. I don't have CS5 or better which also seems to provide for making more accurate selections?

I also tend not to manipulate images by removing offending branches or the like, but do manipulate tone curve, WB, NR and Sharpening. My feeling is that PS is better at enabling selections for masking but the advantages of using LR are that all changes are non-destructive and easily redone.

Are there any LR4 users out there that have clear situations where PS/CS comes into play?

I almost exclusively use LR now for selective NR.
I apply a large NR to the whole image, up to 100%, then use a brush with negative NR to isolate the bird by painting over all of it with a hard brush, then using a brush and/or eraser to do the edges with autofill enabled.
It works a treat and is really quick (5 minutes), convenient and non destructive. It also works using a mouse, no stylus needed.

Probably a dumb observation, but why would one apply noise reduction selectively? I can see the sense in selective sharpening, but not the former. Surely if a picture is "noisy" which most would agree is less than desireable, why not clean the whole frame up and then turn to other adjustments?

Regardless, the season's greetings to one and all.

Adrian

Noise reduction can mean you lose some definition on small details.

A common procedure therefore, is to apply no or low noise reduction to the bird and heavier noise reduction on the background.

You could also target specific parts of the bird for heavier noise reduction - for example, if the underwing is in shadow and shows more noise than the rest of the bird.

selectively using NR can make the bird really stand out when taking noise out of background
Rob.

Also, noise is much more noticeable on a large, smooth, out of focus background than a textured bird with feathers.
Removing noise is not important to me, only removing distracting noise.

Weekend Birder said:

Noise reduction can mean you lose some definition on small details.

A common procedure therefore, is to apply no or low noise reduction to the bird and heavier noise reduction on the background.

You could also target specific parts of the bird for heavier noise reduction - for example, if the underwing is in shadow and shows more noise than the rest of the bird.

Click to expand...

I will second all this :t:
For bird photography I most always run a pass of heavy(ish) NR on the backround if only to give a nicer bokeh. I only apply NR to the bird if it is essential and then it would only be a light pass (if it needed a lot of noise reduction I would bin the shot!).
Giving the right amount of NR on areas like water can make it look superb and smooth but you have to make sure you do not over do it as it could look like a lump of plastic.

All the best for 2013 Roy missing you on the Canon SX40 threads sir, take it you are busy with your astro gear. GEORGE

Mackem George said:

All the best for 2013 Roy missing you on the Canon SX40 threads sir, take it you are busy with your astro gear. GEORGE

Click to expand...

Same to you George - have a good 2013 :t:
It has hardly stopped raining in North Devon for getting on for a month now so so not been out at all lol.

There are a number of ways to select the bird and mask it so only the background is reduced from noise. I have written a tutorial a few years ago now, but you may find it useful if you have photoshop.

Have fun!

http://amatteroflight.com/tutorials_files/Tutorial 01- QM and NR.pdf

I also have some other tutorials, which you may find helpful.

http://amatteroflight.com/tutorials.html

I did my own test a couple years ago where I downloaded 4 different NR tools (which included CS5's NR) on the same image. I wanted to see how these different applications affected both the details and the color fidelity of the image. It took less than an hour to download and install trial versions of the NR applications.

I made 4x4 sections of the same image and used the different apps to make a processed image and then combined them into a single large image with each quadrant labeled as to the app used. Comparing the results on my monitor it was easy to see the relative impact on detail and color fidelity with each app. Some damaged the details more than others and it was also obvious which best preserved the tonality and tonal range of the original image and which had in effect compressed the colors so that color detail was lost.

I found tha CS5 did as good a job as the third party plugins though it took more time to use than the Auto NR of the apps. If I wanted to see the results of different CS5/CS6 NR adjustments I would do the same as before and create sample sections and layer them into one large image so I could see on the screen the best combination of slider settings for a particular type of image.

Before you work on NR in post processing I highly recommend first testing your camera. Find a scene with dark blues and dark reds and shoot at the metered setting (0.0 EV) and then shoot a shot at -1.0 EV and another at +1.0 EV - all in RAW format. Then open each file in ACR and adjust the EV for the best image and then compare the three images. You may find that the "overexposed" image has more color detail and produces a better picture a fair percentage of the time. You will also be able to see the extent to which having to boost the EV in ACR will boost the noise as well.

Best to have enough light and increase the camera's ISO setting as needed or worst case use the camera's own NR capabilities with a high NR setting than to underexpose and try to fix the noise later in post processing. Don't take my word for this but take a few hours and do you own test images and see for yourself first hand how your camera functions and what settings produce the best results to minimize the need to do NR in post.

I can't speak to Canon, but with Nikon it is better to not use the camera noise reduction. It can be a little heavy handed and obscures details you might want to preserve in post processing. Long Exposure Noise reduction is different and generally should be used in the camera.

I also use selective noise reduction. Think of sharpening and noise reduction as opposites. Things that you want at their sharpest, should have little noise reduction. Backgrounds and meaningless areas won't be sharp anyway, so you can use noise reduction more freely.

Post processing workflow can create noise. You might need to apply noise reduction more than once to offset noise created by ingest sharpening, increased contrast, or shadow recovery. In a noisy image, always apply your sharpening after noise reduction. Output sharpening is typically a final step and would be tuned to your output size and format.

If you need to severely crop an image, noise may become more apparent - especially if you are moving to a relatively large print size. When I need to upsize an image - either for a large print or a normal print from a severe crop - I try to upsize early in the workflow before shadow recovery, contrast, saturation and sharpening. It can make a huge difference.