13
Replies
When working with noisy images, sharpening has to be done carefully and conservatively, and the Masking slider is particularly important.
It is set to 0 by default, which means that every part of the image is sharpened equally.
Dragging the slider to the right will mask out flat areas (where noise is most visible) and protect them from sharpening.
You can see the effect by pressing the Option key (Alt key on Windows) while dragging the slider. White areas will be sharpened, black areas will be protected.
After applying masking, use Luminance noise reduction if necessary. This also has to be done carefully, too much noise reduction will reduce sharpness.
Always work at 100% when applying sharpening and noise reduction.
Can you upload one of the raws to something like Dropbox so the actual raw data can be examined outside any processing with something like RawDigger?
ISO per se isn't the cause of more noise (in some cases, higher ISO actually reduces noise):
One major factor in the noise here is under-exposure. This is from RawDigger, which provides NO processing like LR or any other raw converter and shows the actual raw data with exposure stats (and in this case, blue overlay for under-exposed data). See the stats outlined in the 3rd screen capture below.
This last image is likely to be a wider dynamic range than the camera can capture! If you add another stop or more to provide much better data in the shadows (and blue areas), you'll blow out the window. In fact, with the exposure just above, you can see, the window is already blow out (red overlay):
Again, this IS the raw data itself being analysed, there is no raw processing edits etc being applied.
This is fundamentally an exposure issue. Less exposure, more noise.
This has nothing to do again with ISO either. ISO does not affect exposure. ISO affects an exposure recommendation. You (can) control exposure if you wish. Setting ISO speed does not change the sensitivity of the sensor to incoming light, like volume control does not change the sensitivity of a radio. In both cases the setting (ISO or volume) controls only the signal processing, while the input stage (sensor, antenna) provides the same input signal and in this case, exposure to the sensor.
That's why when ISO setting is cranked up, automatic exposure results in more noise - automatic exposure in this case decreases the exposure (that is, the combination of aperture and shutter speed is set to allow less light captured by the sensor). Less exposure, less light, more noise. If a camera 'feature' under exposes the raw, that's not good. Optimal exposure, for raw (which differs from a JPEG), a color neg, a transparency is all basic photography 101.
Articles on exposing for specifically and only raw: http://www.onezone.photos http://schewephoto.com/ETTR/ https://luminous-landscape.com/the-optimum-digital-exposure/ http://digitaldog.net/files/ExposeForRaw.pdf https://www.fastrawviewer.com/blog/mystic-exposure-triangle https://www.fastrawviewer.com/blog/red_flowers_photography_to-see-the-real-picture https://www.rawdigger.com/howtouse/exposure-for-raw-or-for-jpegs https://www.rawdigger.com/howtouse/beware-histogram https://www.rawdigger.com/howtouse/calibrate-exposure-meter-to-improve-dynamic-range
AdChoices
