Recommended Processing Sequence - Orion 52084 Instruction Manual

Deep space color imaging camera

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Table Of Contents

Table of Contents

There are three elements which must be set: the Permanent Stretch Type,

the Input Range, and the Output Range. You can use the Preview Image to

see how changing these parameters will affect the resultant image (or click the

Full Screen button to see the changes applied to your actual image). You can

also open the Screen Stretch Window to see how changing these param-

eters change the histogram.

For the Permanent Stretch Type, the Linear Only mode is useful for adjust-

ing the range of pixels to match a particular file format. The Log mode is useful

for compressing the dynamic range of the image, but can be rather harsh. The

Gamma mode allows you to selectively emphasize bright or dim parts of the

image by entering a suitable Gamma Value. A Gamma of 1 has no effect, less

than 1 will emphasize faint details, while a value greater than 1 will emphasize

bright details.

The Input Range can be set to Screen Stretch, which in Linear Mode pro-

duces an output matching the current screen appearance. This is useful in

producing final images for output to 8-bit image formats which have limited

range. Note that the minimum and maximum values are always taken from the

screen stretch settings for the original image. These can be adjusted dynami-

cally using, for example, Quick Stretch. The Max Pixel selection sets the

input range from 0 to the brightest pixel in the image. This prevents any image

pixels from being saturated in the final result, but may produce images with

low contrast. You can also manually set values with Manual Settings in a

similar fashion to the Screen Stretch Window.

The Output Range is used when preparing a file to be saved in a format that

has limited range. The Output Range maps minimum input to zero, and maxi-

mum input to 255, 4095, or 65535 depending on the settings. Any values that

exceed the limits are clipped. The Unlimited setting disables all limiting and is

recommended when performing Gamma and Log stretches; it is appropriate

when the image will be saved in floating point format.