jaapv
Subscriber Member
It is with some trepidation that I put this on a forum run by Photoshop jockeys
.
But it has worked so well for me that I wanted to share. I also put it in the M9 FAQ on LUF. I hope to learn from the reactions.
.But it has worked so well for me that I wanted to share. I also put it in the M9 FAQ on LUF. I hope to learn from the reactions.
There is a vital difference between the M9 and all other high-end digital cameras. The M9 has virtually no in-camera noise reduction at high ISO, resulting in more detail, but also more visible noise. To avoid this noise, there are two steps to be taken, but first consider the type of photograph:low contrast with diffuse light vs.high contrast with specular highlights. This will make a big difference to the approach you need to take in capture and post-processing.
SHOOTING:
The first trick is to gather as many photons on the sensor as possible to improve Signal to Noise Ratio (SNR) without overexposing. That means: use the histogram. And go manual.
It is easiest with the low contrast image - just bunch the peak up to the right and flatten the lefthand side of the histogram.
The high contrast image will need clipping of the specular highlights. So move them off the righthand side of the histogram, and you will see the signal coming up on all other light levels. There is your optimum SNR which you must try to preserve whilst taking photographs by manually adjusting the exposure to the amount of real light, i.e. disregarding the bright spotlights that are trying to fool you into underexposing.
This presupposes that you are on manual and are spending some time “ shooting the histogram in” before starting to shoot in earnest.
Note that at ISOs below about 1250 you have enough SNR leeway to start trying to preserve highlights - a whole different game than avoiding noise!
POSTPROCESSING
Now we come to the second step: the capture sharpening and noise reduction in Adobe Camera raw 6 and Lightroom 3. I will describe the procedure for ACR 6.0, Lightroom users will be able to translate this easily, as it is basically the same.
First make sure the program is set to Process Version 2010. You will find the setting under the Camera Calibration menu.
If an exclamation mark appears on the lower righthand side of your preview it means you have an image that has been processed in Version 2003. Click the exclamation mark to reset the Process Version.
With the image open (make sure your output parameters are set to Profoto RGB and 16 bits!) adjust the color balance and exposure to taste, and switch to the detail panel and hit alt-option(command)-0 to go to 100% view.
We will use the sliders from top to bottom( more or less), bearing in mind that ACR is non-destructive and, with a subsequent adjustment made it is wise to got back to the previous steps for finetuning. It takes some experience to “ play” all settings to their optimum.
Sharpening slider.
Set for the optimum detail separation (normally between about 10 and 40), never mind that you seem to increase the noise, in conjunction with the next
Radius slider
Use the range of 0.5 to 1.5, never more. 0.5 is for high-frequency detail images like wooded landscapes, 1.5 for low-frequency detail images like glamour portraits.
Once set, bearing in mind that visible halos and artefacts introduced here will get you in trouble later, skip the next
Detail slider
for the time being.
And go to the
Masking Slider.
Then drag it with the alt key held down and you will see an edge mask being created on the fly. This will only be visible with the image at 100% or larger. It shows ( in white) what areas are being sharpened and (in black) which ones are being protected.
So drag it until only the edges you want sharpened are showing. Never mind the small detail. For that you have the
Detail slider.
Alt-drag that one until you have your fine detail back without enhancing too much noise.
Now go to the noise-reduction group.
First go to
Color.
Normally the default setting of 25 will be fine to suppress the color noise completely, but by all means play with the slider to find the optimum setting. If you get some color bleeding on color edges you can move the
Color Detail slider/Luminance detail slider
from its default of 50, but be careful not to go too far left as it will make the image digitally smooth.
Normally you won’t be using those two.
The most important slider of the group is the
Luminance slider
Pull it right to see the noise disappear. When you are happy, go back to the sharpening group and tweak if needed, back to luminance, etc. (*)
And you are done, go back to the adjustments panel. Now if you have a mixed frequency image, you can correct by using the adjustment brush and tweak the sharpening, both to more sharp ( for instance the eyes in a portrait) or softer ( for instance the skin of somebody in a landscape) (**). Then go on and open the image.
Now this is a long instruction manual, but with a bit of practice it gets really quick and easy, and you can of course make a few presets for image types you commonly shoot. You can make the presets camera- and ISO specific too. Just tick the relevant boxes in Preferences
(*)This is a most interesting slider. At a setting between 0 and 10 it will act as an extra sharpening slider for low-noise images, as it seems to add a bit of fine random structure, which enhances the impression of sharpness
(**) Of course, for the more Photoshop-minded the elegant way to do this is to optimize for one frequency, open as a Smart Object, copy and redo for the other frequency, create a layer mask in PS and paint in the effect, but on the whole I find that a bit of overkill for routine use.
