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iPhone Low Light Noise Management

Posted: April 12th, 2014, 10:38 pm
by Darius
Last night, I got some pictures from my antiquated iPhone 4g in a restaurant at night under low light, where I couldn't use the flash. I tried to cope with the situation by using the iPhone's HDR feature (on only some of the photos) with scanty success.

With my limited expertise, I used the PWP brightness curve in HSL mode, in which I simply made sure the sliders on both the low & high ends were right on the transition of where the pixel count would drop off sharply. This did have the positive effect of brightening the photo a little, but at the same time, the camera noise was seemingly amplified. How can I best cope with this?

With what I've given above (feel free to ask any question(s) for more info), can those of you reading this & in the know about the ins & outs of my situation please advise me on what I can do to restore as much as possible these photos? Also, I would greatly appreciate being directed to any other posts on this board (or anywhere) that would give me constructive advise on my problem. Many thanks!

P.S.
Some of the photos are a little on the blurry side, and for that, are there any other posts on here that are about 'focusing' images? Thanks again!

Re: iPhone Low Light Noise Management

Posted: April 13th, 2014, 3:57 pm
by jsachs
You will probably get more help if you can post some images - preferably on a photo sharing web site such as Snapfish or Flickr or some other file sharing site such as Dropbox as this message board only supports posting small size images.

There is a limit to what you can get from a cell phone image taken in low light, but a sample image will suggest some ideas. PWP's Advanced Sharpen transformation can do both noise reduction and sharpening, but any noise reduction technique inevitably discards some image detail.

Re: iPhone Low Light Noise Management

Posted: April 18th, 2014, 6:47 am
by tomczak
Small sensors at high ISO tend to produce ugly, coarse chroma noise (often blue/yellow colour blotches), especially in the shadows. Presently, removing them is not easy, but may preserve more details than trying to remove luminance noise (also to my eye, chroma noise tends to look uglier than luminance noise). The best I know of is this method.

Re: iPhone Low Light Noise Management

Posted: April 20th, 2014, 11:16 am
by den
Sometimes recovery of scenes captured on the margin of optimal camera/lens specifications/settings is possible by embracing the defects:
1) Turn the low light noise into film grain... ...if there is significant chroma (color) noise consider converting to a grained Black/White or Sepia tinted image...
2) Soft focus-ed main subjects sometimes can be made to appear more in focus by blurring background visual elements further. Not too much can be done to embrace un-intended motion blur though...
3) Consider creating a 'glow' ambience image...
4) Be prepared to acknowledge that recovery is not possible...

Post an image... ...I like challenges...

...den...