Remote Astronomy and Colour Imaging During these sessions you will learn how to make images from your own remote telescope observation just like this one by Daniel Duggan

Using observation data to create a colour image of your target

Once you have imported your files they have to be turned into ‘tile’s by selecting Window > Images > Tile You now get thumbnail images of your files in Photoshop

The images at this point are grayscale images so they need to altered to colour images For each image select Image > Mode > RGB Colour to alter each image so they can be coloured

Each image needs to be coloured to match the filter used on the telescope to obtain that image. For each image select - Enhance > Adjust colour > Adjust hue/saturation For the blue image use Hue 240, Sat 100, Light -50 For red use Hue 0, Sat 100, light -50 For green use Hue 120, Sat 100, light -50 Tick the colourise box to allow the addition of colours to your images

Once the images are coloured you need to combine them into one masterpiece! You need to set the red image as the background by locking it into place. Next select the blue image then – Select all > Copy > Paste to place it onto the red image and rename the layer blue Next select the green image then – Select all > Copy > Paste to place it onto the red image and rename the layer green

Now your images are combined you need to set them up so they can all be seen at the same time. For each of the non-background images select Screen from the Layers menu so that they can be overlaid on the background image.

If the layers of your image don’t line up you will have to align them by zooming in on a distinct area – showing an object that is quite isolated Now make one layer invisible and move the second layer until the images are well lined up Then repeat with the second layer

Now you can create your final (unpolished) image!! DO NOT do this until you are happy with the colour and alignment. Select Layer and Flatten image to turn the three layers into one image

Optional Adjustment 1 You can adjust your image further by adjusting the colour and brightness – Enhance > Adjust lighting > levels Using channel you can choose to adjust the whole image (select RGB) or each colour individually. Then by sliding the bars on the histogram you can alter the image

Optional Adjustment 2 Sometimes images have ‘noise’ caused by electronic or thermal variations at the telescope. This can be minimised without losing detail by applying a filter. Filter > Noise > Reduce noise By altering the values and using the preview function you can try to sharpen the image further by removing some of the noise.