Quote:
Originally Posted by Brian W
Next time I will use a shutter speed of 5 s. for better stars.
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Ok I'm assuming you're shooting on camera tripod (not tracking) and found the "500 rule" somewhere. But at least you didnt whine about it like others I've seen and realised its a close starting point.
Yes, go outside and take photos at 5sec exposure, 4sec, 3.5sec down to about 2sec. Basically one or two test shots of the sky at every shutter speed from 6sec down that your camera can be set to. Try pointing the camera due east or west in the sky so the star rotation will be most apparent. Now inside on your computer look closely at the stars in the shots, ignore the difference in brightness completely. You can view the EXIF information of each photo to read the exposure settings, what you want to do is find where the stars are as round as you deem ok, before they football then streak. This value becomes your shutter speed limit and you should note it and never exceed it. Once the stars start footballing they can be difficult for software to align and stack. Round stars are good and it is a factor of your camera, its pixel size and the exposure time (shutter speed), so ignore number anyone tells you. Take the above test shots and see for yourself.
Note this gives you the limit for that camera body and focal length. So if you change lenses or zoom it will be different. But always 500 divided by the focal length gives you a good ballpark exposure time to try your first exposure test at, then drop it down by increments on the camera to find the exposure limit, it'll be close. How round the stars are is up to you to decide what looks best for your needs, but trailing will effect software being able to align shots to stack.
Then because the shots will be underexposed grab DSS and take a dozen or more shots using not exceeding the shutter limit and some darks as suggested and get DSS to stack them for you and learn to use the sliders to bring up the milky way in the shot etc. Its all learning