Have you ever wondered why increasing and mixing up the Curves and Levels in Photoshop bring out a lot more details in your photograph than you can normally see? Did you ever notice those invisible colors that pop out once you adjust those levels? It is with great awe, that people wonder, how do astrophotographers actually process images that yield out godly images of the celestial background. The mystery unravels here, dear friends, here is how it actually works.
A beautiful image of the Andromeda Galaxy, with its satellite galaxy M32 and the distant M33 visible as brightly as if the picture was taken from nearby
First off, the images you see on paper and on digital media are actually nothing compared to how they look in real life. Do you know what the Sun looks like if you were to view it from outer space? Yes, it would look white. There is no color in outer space that you can distinguish unless you were close to that object. If you were to look at the Andromeda Galaxy through a telescope, this is what it would look like:
We’re being far too kind here, there would be far less detail visible through a telescope than through a processed image. So how do we make this image suddenly appear detailed and full of vibrant colors? Well, simple. Photoshop! Ladies and gentlemen, we give Photoshop far less credit than it’s actually worth. It is a powerful image-processing tool that is capable of bringing out colors that we thought weren’t even there.
We begin the processing by selecting Curves from Image>Adjust>Curves. If you adjust the line that comes out, you can actually control the level of brightness from 14 different regions. You can adjust the shadows without changing the highlights. The X-axis represents the input level and the Y-Axis represents the output level. Click on the line and adjust to your heart’s content until you’re satisfied with the image.
A simple adjustment. Just drag the line upwards a little and you should see an instant increase in brightness in your image
The image should look something like this now:
Stunned? There’s more to follow. You can already see some of the details beginning to pop into existence that you thought weren’t even there. Photoshop can detect every detailed pixel count that is present in this image and if a bright spot is there but just isn’t bright enough for you to see it, it will bring you up to date with a little processing!
If you fine-tune the curve to represent an S slightly, it should come out like this:
Already you can see the colors coming out. This is just the beginning. We hit the final nail in the coffin by visiting the Color Balance section. Here, we tinker with the various colors a little until it looks like a proper color photo to the naked eye. This is where you get creative, because you need to pay attention to details with regards to the color you’re matching tinkering with:
The final processed image should look like this:
There are more advanced image-processing items that are available on Photoshop, including using Levels to adjust the level of detail that is visible in a photograph, as well as making sure noise is reduced on an image. However, with these fairly simple instructions, you could get to process your own photos, and make tiny little details come out that you thought were invisible all along.