Astronomy Calculations

Pixel Scale

With this tool you can do a pixel scale calculation.

If you have your telescope's or lens' focal length and the camera sensor's pixel pitch (size) you can calculate the pixel scale. The seeing when it's at its best are about 2" (2 arc seconds), compare with that. If you want the most out of it you optimize the optical for half of that, i.e. pixel scale=1" in this case. That take a telescope of at least 100 mm diameter, if not, the theoretical resolution will limit the system resolution. But in most cases the seeing is much worse, I have a seeing from 3" to 6" at my place.

• More to read about pixels:
  Pixel, Wiki

Type in your data

It start to calculate as soon you change or write new figures in the white or dark red boxes. Do not exceed the maximum number of characters, delete characters if necessary.

Note:
You use the information on your own risk! There can always be a mistake in my equations behind the calculations, check that the result is correct. Let me know if you find something wrong and I try to correct it. Some calculations are very simple done and not correct in the small details.

Note:
For a one sensor color camera (DSLR) the pitch is twice for the red and blue pixels, the green ones has a pitch of square rot (2) * pitch at diagonal distance.

*
Pitch and size are not always the same, pitch is the distance between two pixels center to center, size of a pixel is smaller because a pixel doesn't fill up the space to 100% (fill factor), it has a border. But nowadays very common they set the size of a pixel to the same as the pitch.

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