3 QUICK TIPS
▲ ▼ Detail of the image following the stacking of individual frames – on the left, the stack as it appears before processing and on the right, following processing with an unsharp mask
Selecting numerous points and stacking multiple times for each region will yield a sharp result across the entire image.
1.
Create a circular marquis the size of the Sun to add a black occulting disc to your image.
2.
Use a light hand with an unsharp mask to reveal detail without adding artefacts.
3.
Experiment with the settings; we find a small pixel radius (1.0 pixels or smaller) will provide a good result, improving sharpness without creating harsh edges and unrealistic contrast.
At this stage you can add a black occulting circle to mask the brilliant disc of the Sun. This will reduce glare and allow the faint extensions of the prominences to be seen clearly. Although you can use the Magic Wand tool, we find it much easier to use the Circular Marquis tool. Create a new layer and fill the circle in black to complete the occulting disc (see screenshot, below, left). Note the size of this circle in pixels: dividing this number by 109 yields the size of the Earth to scale.
An Earth-sized circle added to the final picture can illustrate the size of a massive solar prominence (see the left variation in the bottom set of three images).
On the surface
If the observing session provides a good view of the surface of the Sun, this detail can be recorded and added to the final image. The surface is much brighter and requires different exposure settings than the fainter prominences. We again processed using multiple point alignment and an unsharp mask to reveal a sharply detailed view of the solar chromosphere. The disc detail is cut and pasted into a new layer above the original prominence image. There are many ways to process the layers for the final result (see the set of three examples, below left). Here we have inverted the tonality of the surface, which can add to the perception of depth and dimension in the swirls of the Sun’s chromosphere. Layers for prominence and surface are colourised to enhance the final image.
Do keep an eye on the edge of the Sun. There is always something worthwhile to see and shoot. With practice, we will be in good shape to follow the curve of activity upwards and enjoy the Solar Maximum ahead.