How To Choose The Best Exposure Settings For Astrophotography

This is an exercise.

1. Set apperture as low as it can go and leave it there.
2. Row 1: Set the ISO to 12,800 and capture images with shutters speeds of 20, 10, and 5 seconds.
3. Row 2: Decrease ISO to 6400 and capture images with shutter speeds of 20, 10, and 5 seconds.
4. Row 3: Decrease ISO to 3200 and capture shutter speeds of 20, 10, and 5 seconds.
5. Row 4: Decrease ISO to 1600 and capture shutter speeds of 20, 10, and 5 seconds.
6. Study the images closely and decide which images you prefer. Then answer this question: What were the highest ISO and longest shutter speeds you found acceptable?

Tip: Repeat this excercise with the same lens and different apertures, different lenses, or locations with different sky brightness. This will provide a solid basis for educated decisions on “best” exposure settings for each lens in different situations.

NOTE: This seems to be overkill with the Sony. The exposure is almost always way overexposed due to the increased sensitivity of the sensor to light at lower ISO. It’s truly an amazing night shooting beast of a camera.