Hello to all, and thank you Rick for inviting me back again for a guest blog!
Today I want to share a moment I captured a few days before Christmas 2013. Actually, this moment lasted for a little more than an hour. During this time I captured a total of 120 shots and then merged them together in post processing to create the star trails you see here. I also must thank Rick and Juan Pons for introducing me to this location in 2012. It’s the Very Large Satellite Array in the midst of New Mexico and just happens to be a great place for night time/astro photography, not to mention loads of fun.
On this particular night the temperature was about 18 degrees when I started. The good news is, once you are set up and start this process you can jump in the car and take some cover. I spent about 20 minutes setting up, checking out the area and composing my shot. Then it was off to my Jeep to warm up and kill time on the trusty iPad once my camera was all set.
So what does setting up consist of? It’s a pretty straight forward process. You will need a fast lens, tripod and some sort of intervalometer/time lapse ability within you camera. Of course you can use an external remote to do this part as well and even apps now. The lens I use is fairly fast at f/2.8, but for these shots I actually shoot at f/4 most of the time. Once I have a rough idea of where I am shooting I will take some shots with the ISO cranked up very high, as I am simply getting my composition together at this point. Now that I have my shot framed, I set my ISO back down near 800, which is a good starting point for star trails. I then take a few shots to ensure everything is in order. All that’s left now, is to set my shutter time. You have a few ways to do this:
1. Take a single exposure for the entire duration of your shot. Note you will be in bulb mode at this point controlling the exposure time with a remote, camera feature or even duck tape. (solid star trails, more susceptible to camera shake due to time, harder to eliminate plane streaks, quicker post processing/less post processing power required).
2. Take multiple exposures (usually per 30 seconds) and “stack” them in post processing. (may have gaps in the trails, though they can be fixed, more control in post processing, but you will need a somewhat recent computer with power if using full rez images, and easier to recover from unexpected surprises like headlights)
So to recap - I am shooting at 800 ISO, f/4 aperture and 30 second shots. Both methods have pros and cons as you can see, and I would encourage you to try both methods to see what works best for you. If you have built in time lapse, some settings I found that work good are 30 seconds for the exposure with a 4 second pause until the next shot fires again. This gives the shutter plenty of time to open and close. One thing to note is that I got away with a decent ISO at the VLA because there was a half-moon rising behind me so it lit the scene up nicely. Experiment and see what works for you and your current situation/location.
Now that you have all your shots (assuming your took multiple shots) you can get your final piece by using an automated process, such as Starstax, which is free. This actually works very fast and smooth. You can also take a more hands on approach (but much more time consuming!), and import each shot into Photoshop within the same document. If you have access to Adobe Bridge, you can easily get all the shots into the same document, layered and ready to go. Your number of layers should equal the number of shots you captured. Select every layer except the bottom one and set the blend mode to “Lighten”. Note that on the Photoshop layers it’s now very easy to edit a layer one at a time and remove any plane trails or other movement I mentioned earlier using Photoshop’s masking abilities. For my V.L.A. shot, I had to do a lot of masking because the satellites were actually moving very slowly the entire time. They move so slow it’s hard to notice, but you can hear it the whole time! Check out my time lapse video to see how much the satellites actually moved in an hour.
Feel free to visit me on my Google+ page! It’s a new season for star trails and I will be posting more on Google as the nights go by, including processing tips.
For a final note, I use a lot of the same plugins as Rick to help post process these. My favorite is Color Efx Pro. You can really pull out some nice details with this and get some great colors. I would encourage anyone to at least try the 30 day free trial. If you like it and want to purchase it, check out Rick's Play & Save on Plug-ins page for a discount code.
I leave Rick’s blog with a very recent shot from this last weekend about an hour from home in AZ! Thanks Rick once again for having me! Until next time, follow the stars and capture them in the process!