{"id":8512,"date":"2017-07-02T12:02:23","date_gmt":"2017-07-02T11:02:23","guid":{"rendered":"https:\/\/phillipreeve.net\/blog\/?p=8512"},"modified":"2024-04-21T14:26:04","modified_gmt":"2024-04-21T13:26:04","slug":"4-tips-improve-astrophotography","status":"publish","type":"post","link":"https:\/\/phillipreeve.net\/blog\/4-tips-improve-astrophotography\/","title":{"rendered":"4 tips to improve your Astrophotography"},"content":{"rendered":"

Introduction<\/h1>\n
\"astrophotography
Sony A7s | Voigtlander 35mm 1.7 + 5m PCX OptoSigma + NiSi Natural Night filter | panorama from 5 shots<\/figcaption><\/figure>\n

The shot above can be found in higher resolution here<\/a>.<\/p>\n

With the increased High ISO capabilities of even entry level cameras astrophotography has become available to almost anyone. But if you want your files to show low noise and high dynamic range – or you want to print big – it might be worthwhile using some of the techniques I am going to show you in this article.<\/p>\n

<\/p>\n

1. Exposure stacking<\/h1>\n
\"astrophotography
Single frames taken from the same position used for the exposure stacking<\/figcaption><\/figure>\n

With this technique we make use of the light’s wave-particle duality<\/a>. When just taking one shot it is easily possible not all of your 12 to 42 million pixels caught light and those who didn’t lack useful information which will lead to noise and false colors.
\nWhen taking several shots of the same scene without moving your camera you can use Adobe Photoshop to filter out these pixels with “false information”.
\nWhat difference does it make?
\n

<\/div>
\nBefore: single image | After: stacked image (12 images) | 100% crops<\/span><\/p>\n

The difference is quite obvious, especially in the dark foreground which is pretty much unusable in the single exposure. But there are some caveats to this method: aligning the files before stacking isn’t always easy (Ian Norman from lonelyspeck.com<\/a> has some nice videos explaining how to do it here<\/a> and here<\/a>).
\nFurthermore when having something sticking into the sky (as I do here) combining the stacked foreground and background may pose a problem:
\n

<\/div>
\nBefore: stacked “sky” frame | After: final combined image | 100% crops<\/span><\/p>\n

In the stacked “sky” frame the foreground will be blurred and all the spires of the mountain overlap so there are neither stars in these areas between the spires in the stack nor later in the combined image. One would have to use parts of a single “non-stacked” frame as a third layer with more noise to reintroduce these “lost” stars.
\nTo make a long story short: if you want really good results you will be spending quite some time in front of your computer when using this method.<\/p>\n

2. Astrotracker<\/h1>\n
\"astrophotography
Sightron Nanotracker (white box) with camera mounted<\/figcaption><\/figure>\n

The are several portable astrotrackers available today. I was using the Sightron Nanotracker<\/a> (affiliate link) which is to my knowledge the cheapest and smallest.
\nWhat does an astrotracker do? It rotates the camera at the same speed the earth rotates but in the opposite direction. Therefore you can take longer exposures of the sky and may even use a lower ISO or a slower lens.
\n

<\/div>
\nBefore: 2 min exposure without tracker | After: 2 min exposure with tracker | 100% crops<\/span><\/p>\n

In theory this sounds like a great option, but there are a few things to be aware of:<\/p>\n