MLUnsold Digital Imaging

A set of 24 x 10 minute H-alpha light frames of NGC 7293 were collected using a 12.5" CDK PlaneWave and QSI 583ws camera. After calibration the light frames were normalized, aligned, and stacked with excluded min max average. The stacked image of NGC 7293 is very dark.

The goal is to brighten the image of NGC 7293 and adjust its background to a dark gray uisng digital development.

Initial very dark stacked H-alpha image of NGC 7293.

Step 1

Color | Digital Development is used to increase brightness and contrast by moving the break-point slider to the left to a value of 1004.

The digital development break-point slider is generally used first to increase the brightness and contrast.

Step 2

The break-point sensitivity range is set to 0-1000 since the image is still dark at a break-point of 1004. The finer 0-1000 sensitivity range allows great control of the brightness increase for break-point values between 0 and 1000.
The break-point is set to a value of 241 to increase the brightness of NGC 7293.

Break-point slider sensitivity is set to 0-1000 to allow fine brightness adjust around the value of 241.

Step 3

The background of the image is too dark so the background weight slider is moved towards the left to a value of 0.900 to increase background brightness.

Background brightness is increased to a dark gray by setting the background weight slider to a value of 0.900.

Step 4

The outer area of NGC 7293 is increased in brightness by moving the range slider towards the right to a value of 1.190. value.

Additional brightness increase in the outer area of NGC 7293 using the range slider.

Step 5

Background contrast is increased by moving the background weight slider towards the right from 0.90 to 0.923.
The background weight slider sensitivity range was set to 0.90 to allow fine adjustment.

Final background adjustment using the background weight slider. The coarse background can be smoothed as shown by the feathered background smoothing example.

Initial very dark stacked H-alpha image of NGC 7293.

The digital development break-point slider is generally used first to increase the brightness and contrast.

Break-point slider sensitivity is set to 0-1000 to allow fine brightness adjust around the value of 241.

Background brightness is increased to a dark gray by setting the background weight slider to a value of 0.900.

Additional brightness increase in the outer area of NGC 7293 using the range slider.

Final background adjustment using the background weight slider. The coarse background can be smoothed as shown by the feathered background smoothing example.