# Frequently asked questions

## Q: Where should Noise Ninja be used in the workflow?

It is usually best to apply noise reduction as early as is practical in the workflow. Post-processing adjustments like sharpening, contrast stretching, and color balancing can alter pixel values and noise levels in unpredictable ways. Depending on the amount of adjustment, this can make it more difficult for Noise Ninja to estimate noise levels. Sharpening, for instance, is a nonlinear operation that can significantly distort the distribution of noise values.

If your workflow requires that you use Noise Ninja after some other operations, then try to create noise profiles using calibration images that have been put through the same operations.

## Q: Do you have a profile for camera XYZ?

Current profiles are listed at www.picturecode.com/profiles.htm. If your camera is not listed there, it is easy to create your own profiles, and it only takes a few minutes once you understand the process. Click here for instructions. If you create new profiles and would like to share them with other users, feel free to email them to us. You can also email calibration images and we will make profiles from them to include in the distribution files.

Also, realize that even if you find a profile for your camera on our website, you might still want to create your own profiles. Our profiles are usually created for a single set of camera parameters, and those values might be different from the ones that you use. Likewise, raw conversion tools can have many parameters and controls that influence noise characteristics. So, if you shoot RAW, you should consider creating your own profiles in order to get the best results for your particular workflow.

## Q: Do I need 8-bit or 16-bit output?

An 8-bit file represents each pixel using three 8-bit values: one each for red, green, and blue, for a total of 24 bits per pixel. A 16-bit file represents each pixel using three 16-bit values, for a total of 48 bits per pixel. In an 8-bit file, there are only 256 possible brightness levels for each color channel. In a 16-bit file, there are 65536 possible levels.

16-bit files hold up better to subsequent image adjustments like contrast stretching or color balancing. 8-bit images will tend to show obvious posterization artifacts or contouring even after modest adjustments. Dark shadows, for instance, have very few bits of useful information in an 8-bit file, so they exhibit visible steps in color values when they are lightened. Gradient areas of the same color can also show banding or steps after adjustments.

So, if you expect to make substantial adjustments to images after filtering them with Noise Ninja, then 16-bit output is recommended. However, if you only intend to make minor adjustments before printing or displaying the images, then 8-bit output will probably be adequate. Professional workflows typically use 16-bit files because it allows fine control over tonality and color with less risk of introducing objectionable artifacts.

Internally, Noise Ninja processes all images at 16 bits or 32 bits per channel, in both the Home and Pro editions. Conversion to 8 bits only happens when you save the file to disk in 8-bit mode.