In the early days of digital photography I used Neat Image to reduce noise in my images. Early cameras suffered from noise even at low ISO, despite their low pixel counts, and enlarging for print made the problem even more visible.
Recent full frame DSLR’s have significantly improved however so I rarely need to use a specialist noise reduction (NR) program, instead a small adjustment of the NR sliders in Lightroom is usually sufficient, and while this may reduce sharpness, with 21 MP to start with, it is unlikely to be noticed in print and certainly wont be on screen.
However, I have started shooting more recently with the iPhone (4.54×3.42 mm), the Sony RX100 (1″ Sensor 13.2 x 8.8mm) and a newly acquired – from ebay Sony R1 (APS-C Sensor 21.50×14.40 mm).
The tiny iPhone 4s sensor suffers from a high level of noise and artifacts even at low ISO. The Sony RX100 is surprisingly good – better in fact that the bigger sensor in the “vintage” Sony R1 – which I am finding is surprisingly noisy for a relatively large sensor at 400ISO upwards.
Neat Image works by taking a sample of noise, either from the picture itself, if it can find a large enough – uniform area, or it can use a previously saved noise profile with ideally the same settings for ISO and shutter speed. There is a little skill involved in this as it is possible to do a better job at finding the uniform area than Neat Image can automatically! It is also possible to display a test target on your screen – or print one, and take pictures of it with a range of settings, that can then be processed as a batch by Neat Image to create profiles to be used in future. This works really well when you can alter the settings – but not so well on the iPhone.
The only way to get profiles for the iPhone then is to take lots of pictures in different lighting conditions, and thus different ISOs and shutter speeds and manually “auto profile” each image then, if the score is high enough (over 90% save the profile for future use. Another useful tip is to shoot something uniform whenever you take pictures, under the same lighting as this could give you a useful profile for the images taken on that occasion, and be useful for future use. I should say at this point that I use the “645Pro” Camera app on the iphone which gives me a TIFF output before compression, rather than JPEG.
Several people have uploaded their sample profiles and these can be accessed here
And the iPhone…
Shooting a Calibration Target
Note that it is meant to be blurred! Set your AF to manual and focus on infinity.
Setting up batch Processing
Optimising performance.
Neat Image can carry out a test on your hardware to determine whether it is better to use teh graphics card processor, or the CPU of the computer or a combination of both. Very clever!
Links
Neat Image Website
Neat Image Profiles
Wayne John Grundy's PhotoTech Blog 