Advanced - Stars' traces around the circumpolar.EDIT: I've created the chatroom #Phototalks (http://chat.deviantart.com/chat/Phototalks) to talk about photography tips, tricks, doubts, and all these things. Also some general talking is allowed. I'll probably be there if you join.Advanced - Stars' traces around the circumpolar. by MarioGuti
Okay so, this complicates a little bit. Because of the Earth's rotation, when we put a long exposure time all the stars appear moving, excepting one: the Polaris (the circumpolar star), and, in the picture, the traces of the rest of the stars will turn around this Polaris star. The objective,then, will be getting results like these: http://marioguti.deviantart.com/art/Looking-for-the-north-322352741?q=gallery%3Amarioguti%2F33821496&qo=74
You'll need a tripod, a DSLR camera and a remote control or delay trigger.
I'll post the different steps I follow when I make these kinds of pictures:
1 - I find the Polaris (okay, I'm not an astronomer, so my mobile phone does so for me, there are Apps for iPhone and Android
Advanced - Catching the stars stood.Well, I've classified this as advanced because it includes some mathematical equation, but it's quite simple. With this you can get results like these: http://marioguti.deviantart.com/art/Exploring-in-the-night-318831781?q=gallery%3Amarioguti%2F33821496&qo=93 http://marioguti.deviantart.com/art/Lights-on-the-other-side-324127837?q=gallery%3Amarioguti%2F33821496&qo=58Advanced - Catching the stars stood. by MarioGuti
You'll need: a DSLR camera, a tripod, and a remote control (well, or you can set delay trigger, the goal of this is not moving the camera when we push the button)
Okay so, you'll need to set the aperture value to the lowest possible, and a long exposure time but...how long? if it's too short you will get the photo underexposed (dark), and if it's too long the stars will not appear stood, but moving (this is because of the Earth's rotation). How do we calculate the maximum exposure time we can set? Easy!
Exposure time = 500/Focal lenght. For example, for a 24mm focal lenght: ET=500/24=20,83 seconds. This is the max. we can