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08-24-2017, 03:46 AM   #1
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From where does this noise come?

Hello, friends,

I started to shoot street photography with my k-x, but I found that the raw files seem either kind of OOF or soft and noisy. And I can not correct it in LR. Well I use the kit 18-55 lens in AF-C for speed. I shoot in Aperture priority f/8 with ISO 200-800, with shake reduction on. And when I focus with central point or 5 points sometimes it seems ok (it shows the subject is on focus). But then when I review the raw file on the lcd and later in LR i find problems in focus and in sharpness. Why is this happening? What do I miss?
Here are some of the shots after some editing (whites, blacks, exposure, sharpening)
IMGP9339.jpg - Google Drive
IMGP9323.jpg - Google Drive
IMGP9337.jpg - Google Drive
IMGP9336.jpg - Google Drive

08-24-2017, 04:13 AM - 1 Like   #2
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Well, the K-x has some noise at ISO 800. The new generation cameras are better at that.
Shutter speed is another reason for blur. Especially in the photos 9337 and 9336, it seems there is shake blur due to slow shutter speed.
Final possibility is LR. If you shoot raw, you have to adjust NR settings. And if you used a Black and white preset, some of those actually add film grain. It is an option near the bottom of the right hand tabs, effects. In Post processing, doing things like adding contrast and brightness will also make noise more visible. A well-lit photo at ISO 800 might not have much noise, but once you add brightness and contrast, the noise will appear. Black and white will mask the colour noise a bit, but it can make the regular noise quite obvious because there is less "stuff" in the photo. A photo of a luscious jungle with a lot of trees and branches and leaves will appear to have less noise, because the noise gets swallowed by the detail.
Noise has a lot to do with perception

Regarding slow shutter - make sure you are using SR correctly. SR needs a moment to activate. There is a little icon in the viewfinder that lights up when SR is active. Half press the shutter, wait for the AF to finish and the SR icon to light up, then push the rest of the way. Make sure you press the button slowly. With slow shutter, just pushing the shutter button can cause blur. It may sound silly, but I got much better results once I learned how to push the button with minimal shake.

Finally, getting a better lens and camera will give you better results in these fields. Lens with faster aperture will let you use faster shutter or lower ISO, and most lenses are sharper than the kit lens so its a win all around. Modern camera like K-70 or KP will give you more MP, more detail, more dynamic range, less noise, faster AF, live view with focus peaking, newer SR system.
I think just buying used DA 35mm f2.4 and DA 50mm f1.8 will already give you better results. Most of the sample photos you posted seem to be around those focal lengths
08-24-2017, 06:28 AM - 1 Like   #3
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Regarding noise... as Na Horuk says, you'll get some noise at ISO 800 on the K-x. Even later models will start to show a bit of noise at this sensitivity if you look for it, or pixel-peep.

Assuming you're not using a preset or other plug-in for the black & white conversion, and you're just selecting "Black & White" under the Basic section of the Develop module, I would recommend setting your noise reduction as follows:

Luminance 25 (or less, to your personal taste), Detail 50, Contrast 0

Color 25, Detail 50, Smoothness 50


More noise reduction than this will likely soften detail. The luminance figure should be set at the minimum value you're happy with for the intended reproduction size. You're not looking for all noise to be removed at 100% (i.e. pixel level) viewing, but for an acceptable amount at the required viewing size. Some noise is absolutely fine - after all, you'd see that with film too. You're only looking to manage it so that it's not too prevalent.

Sharpening can easily accentuate the noise, so don't over-sharpen and always use the masking slider to minimise sharpening on everything except edge detail. I'd recommend starting with the following settings:

Amount 25 to 50 (to your preference), Radius 0.7, Detail 25, Masking 80

Hope this helps
08-24-2017, 01:02 PM   #4
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Thanks for the help! I will share the results! (( :

08-24-2017, 01:50 PM - 1 Like   #5
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QuoteOriginally posted by kmladeno Quote
Thanks for the help! I will share the results! (( :
Good luck

One last tip...

Any sharpening you do on your RAW file is effectively a pre-sharpening exercise on the full-size image. If you want to achieve greater sharpening for your resized JPEG output, do not use the sharpening feature in the export dialogue. It sharpens the entire image, including any noise. Instead, export to a TIFF at the required size, sharpen the TIFF using the same masking technique I mentioned previously (just don't over-do it ), then export that to JPEG without any additional sharpening...
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