Star Trails

Good afternoon,

Today it is onto star trails which are very different from getting the stars to be static. Similarities are; needing a sturdy tripod, know what you are trying to capture, a foreground interest can make a picture, and planning helps.

Now the differences; a high ISO is not needed, a large aperture is not as important, and a remote release is important. After about 15 seconds or so the stars can be seen as more than a dot. With trails we want that so that is why ISO and a large aperture aren't as big of a deal. 

Here is a stack of 30 second exposures taken back to back from a balcony in Lake Tahoe. Pointed North - Northeast. Around 140 images put together for a total of a 70 minutes exposure, each photo was 30 seconds each, 28mm, f2.8, 200 iso.

So there are 2 ways to go about star trails. Either taking a bunch or photos and stacking them afterward like above. The benefits are; less noise, if frames have something unwanted (planes, satellites, UFOs, etc) they can be left out. The down side it is time consuming in post.

Below is the other way which is to keep the shutter open for a really long time. I have heard of all night exposures. Personally I have gone with a couple of hours at most with good results. The benefits are it has more of a set it and forget it approach, and post processing is just a couple of images (if combining exposures of a separate foreground and background). The bad part is if something goes across the frame it is a pain if even possible to remove it and there could be more noise from the long exposure.

This was taken in Death Valley, I light painted the tree. I was trying to capture some meteors in the shot and failed. This was a 29 minute single exposure. 28mm, f5.6, 1759 seconds, 400 iso.

Experiment and see which you prefer. There are programs that are designed to make the stacking process easier, I just use photoshop because I don't take this type of image often. So find a night sky, grab your tripod, shutter release, camera then go out and shoot.

~Scott

The Stars

Good afternoon,

More or less back on schedule. So I was at Cedar Breaks with the family a bit ago. If you are not familiar with it, Cedar Breaks is a designated an International Dark Sky park. The night skies are amazing there. After posting some of the pictures I was asked "How did you capture this?" and a response was placed by a friend "Read his photo blog." So I knew that I had to write about it.

For shooting the stars there are a few things. 1st know what you are trying to accomplish. If we are trying to have static stars then a wide aperture is important, star trails not so much. 2nd have a sturdy tripod and for best results a timer setting or a shutter release. 3rd Foreground interest sets a scale. The sky is a big place, if there is nothing but sky it doesn't seem as big. 4th planning helps, I use Stellarium (www.stellarium.org), and Google Star Maps. 5th Having an idea of what you want to capture. And 6th Knowing the Moon and Sun rise/set times.

Tripod mounted, a57 3200 iso 1/6 second 210mm f4 with a cable release. Venus is on the bottom and Jupiter is on the top with 3 moons.

Today I will talk about getting the stars static. So a wide aperture lens and a high ISO are goals here. Focal length can vary greatly with what we are trying to capture. When Venus and Jupiter had a conjunction a few years back I used a telephoto zoom and a high ISO. 

For the Cedar breaks pictures I was using an 11-18mm lens. Again I used a high ISO and as wide of an aperture as I could, to collect more light I used a longer shutter. Now with the higher ISO you risk losing some stars with noise reduction or having noise. I am okay with losing some stars especially if I am in a dark location. Below the noise can be seen and in the second image noise reduction has been applied. ISO 3200, 10 seconds, f4.5. With a focal length like this I have found that 10 seconds in about the longest that I can go and not see streaks or the beginning of trails. If you go and look around you might come across a "Rule" called the 500 rule. I feel that it is bogus, it says to divide 500 by the focal length. In this case it would be 500/11 which would equal 45 seconds. While I was taking pictures I decided to see how long I could go before seeing trails. It was 13 seconds which is a far cry from 45.

So to answer the question of how I took static images of the stars and Milky Way it was using a high ISO, a tripod, a wide aperture, less than a 10 second shutter speed, and just playing around with settings. So find a dark sky, grab your largest aperture lens, then go out and shoot.

~Scott

Again I would enjoy seeing readers photography.