Translate

Monday, April 27, 2015

"Echoes" - Star Trails at Cape Leeuwin Lighthouse Tutorial


The Universe - Endless Space...


Hi everybody and welcome to a new blog post from Random Lights! Today I will share with you a few insights about a star trail photo that I took over the past weekend, including some tips on planning, shooting/gear and post processing.

We'll start off with the planning for such a shot.


For this particular shot, several factors needed to be considered for it to be successful: Light pollution, weather, direction of the subject and length of shot/trails.

I went out on Saturday night to get the shot, but my planning began already on Wednesday. I have been keeping a close watch on the weather forecast since then, as you want crisp and cloud-free skies to shoot astro. In fact, the winter months are better suited for astro photography then the summer months as the cold temperatures bind the moisture in the air and thus create clearer skies. I usually use the Weatherzone App(http://apps.weatherzone.com.au/) to check the forecast as it gives me quite reliable results.
The location was already decided upon. It was the Leeuwin Lighthouse near Augusta in Western Australia. The reason why I choose this Lighthouse? A: It is in a remote location which means very little light pollution (apart from the light of the lighthouse itself). B: it's accessible from the North which means I would be able to align the top of the lighthouse with the south pole(earth's southern axis of rotation) in order for the stars to "rotate around the lighthouse" in the final image. C: it's not a popular photography spot for astro so I was relatively sure that nobody would be "destroying" my star trails with their torches.

Another factor that needs to be considered when shooting astro is the moon cycle. Ideal shooting conditions for astro shots are when New Moon is happening. But really, any time at night when the moon is not visible it is a good time for astro. I use two more mobile Apps to help me scout locations and sun/moon cycles: The first one is SkyView Free (http://www.terminaleleven.com/skyview/iphone/) which gives me a rough idea of where the milky way is going to be at a certain time. It also shows the orbit of the stars which helps when lining up your subject. The other App, and I absolutely love this one, is Photopills (http://www.photopills.com/). This App is not free but for a few bucks you get a very comprehensive photography App which covers nearly everything from location planning, sun/moon set/rise times, exposure- depth of field and field of view calculators, augmented reality for day and night shots, time lapse calculators and much much more. It's the best App I have found for photography and is well worth the little price. I am actually using Photopills more often than SkyView simply because it is more comprehensive.
I also use The Photographers Ephemeris [TPE] (http://app.photoephemeris.com/) to double check locations and sun/moon rise and set times. It's browser-based desktop version is free to use and very accurate.


This may be a good time to state that I am not getting paid to share or recommend any of these Apps or products in this article. I use and recommend them because they work for me and give me the results that I want.

So with the location decided upon, the weather forecast looking sha-weet and the moon setting at 11;35pm it was time to prepare the gear. 

120 year old Cape Leeuwin Lighthouse near Augusta, Western Australia under the Milky Way
--------------------------------------------------------------------------------------------------------------------------



Things you will need for a star trail/astro time lapse shoot: 


- A sturdy tripod( I can't stress this enough!) and weight-bag
- Camera (duh!)
- Wide angle lens
- Intervalometer(or Magic Lantern if you shoot Canon)
- Warm Clothes
- Head light(comes in extremely handy!)
- A good book, music or something to keep you entertained while your camera does it's magic
- Food and warm drinks

For the tripod, I use an Induro carbon fibre tripod with an Induro ball head. It is a beast. Relatively large when folded-up, it extends to over 2 meters height which is great if you need that extra reach(or if you're a tall fella with back problems like me). The other advantage is that, because of this kinda height, the legs are nice and thick which makes the tripod more stable and less flimsy. It may not be the ideal travel tripod but it is built to last and will not disappoint(unless you're travelling of course). 

My Camera is the Canon 6D, which is an entry level full frame DSLR camera. This is a great camera for astro photography because of it's splendid low light performance. For star trail shots, though, you can use pretty much any camera that has manual controls and the ability to connect an Intervalometer. I have loaded Magic Lantern (http://www.magiclantern.fm/) onto my camera because it adds a few features I wish Canon had implemented straight from the factory. These features are mainly the possibility of setting shutter speeds of more than 30 seconds without the use of a remote shutter release cable, the option to turn off the GPS when the camera gets turned off (this preserves the battery life of your camera, why didn't Canon add this feature??!!) and the inbuilt Intervalometer - an essential tool for star trails and time lapses.

My go-to lens for pretty much everything is the Canon 16-35mm f/4. This is an exceptional lens with superb sharpness and very little to no coma. It's built in image stabilization works like a charm and allows me to take crisp images at shutter speeds that normally require the use of a tripod(to a certain degree, of course).
As a general rule of thumb you want to use a very fast wide angle lens for astro/nightscape shots. You are going to shoot wide open, which means you want a lens with a maximum aperture of at least f/4, ideally though f/2.8 or f/1.4. The faster your lens(means:the bigger the maximum aperture of your lens) the more light you can capture, the lower the ISO needs to be, which in turn means less noise. Since my budget is limited and I wanted an all-rounder-lens that I can use for landscapes, astro and even some portraiture/lifestyle photography, the Canon 16-35mm f/4 is ideal. This lens is on my camera 90% of the time and I really, really love it!

As mentioned above, I don't use a shutter remote/physical Intervalometer since installing Magic Lantern on my camera. Again, this is only an option for Canon shooters so if you shoot with any other brand, you may have to invest in a remote shutter cable with built in Intervalometer. These can be found cheap on ebay for around $10-15. If you do shoot Canon, I suggest you give magic lantern a go. It's free to download although it needs to be said that it is not endorsed by Canon and Magic Lantern does not take responsibility if your camera get's bricked, though chances are very slim. I used it on 3 different cameras and never had any issues.

Warm clothes are essential as you're going to be spending several hours out in the elements in the middle of the night. For this session, for example, I was wearing two pairs of thick bamboo socks, 3 pairs of pants, 2 T-Shirts, 2 long sleeve shirts and 3 jumpers, fingerless gloves, 2 beanies and a scarf. None of these things were specifically designed for cold and windy temperatures(i.e. technical outdoor gear) so I had to layer myself like an onion and still felt pretty cold. This, though, may have been due to the fact that I contracted a cold earlier in the day and as a result of spending some 6 hours out there with an already weakened immune system, I am now sick like a dog. So please, learn from my mistakes and wear warm clothes ha!

I recently bought a Black Diamond Revolt headlight, after doing several nightscape sessions and not being happy wit my torch as it meant only having one hand left to use and operate your gear while the other hand holds the torch. This headlight is rechargeable by USB, has a spotlight that shines 70 meters, a broad light function that is brilliant for reading or when you're searching for something in your car or backpack, and it sports 2 red LEDs which preserve your night vision but still gives off enough light to see the buttons of your camera so you can change settings without being temporarily blinded by your own light. It's my first ever head lamp so I can't compare it to other brands/models, but it works like a charm and I am very happy with it as it frees up my hands and I can concentrate on the task at hand.

When you're out there for a prolonged amount of time it can get extremely boring. So bring a good book, your pad/laptop and/or some music. I usually bring my ipod and a little speaker and do a little shimmy(I go bonkers sometimes and doa one-man-moshpit, after all you're most likely all alone out there lol). A pleasant side-effect of having a little dance is that it warms up your body and causes your blood to flow into your limbs so don't feel embarrassed  :)

I don't need to mention that food and water/warm drinks are as essential as warm clothing. I always bring a 1,5L thermos and some snacks and make sure I have something to eat before leaving home. You may be driving several hours to get to your location and then spend another several hours shooting, so be prepared and bring plenty of food and drinks.


--------------------------------------------------------------------------------------------------------------------------
Taking the Shot

As I mentioned earlier, according to the Photopills app and TPE the moon was due to set at 11:35pm. I had some dinner, got dressed and left home around 10pm as I had a 45 minute drive ahead of me. When I arrived at the lighthouse the setting moon was blood red and I watched it disappear behind the horizon.
I walked up to the Lighthouse and used Photopills and SkyView to determine the location of the south pole, in regard to the lighthouse. This was a bit tricky. First of all, I had no idea how accurate this process is and I was afraid that in the end the centre of the south pole would be slightly off-centre from the lighthouse. Unfortunately there is no way of telling until the files are processed at home on the computer.
The other challenge was being close enough to the lighthouse so that the light beam of the lighthouse would go over the top of the camera and not shine directly onto the lens and cause lens flare, all the while being far enough from the lighthouse so as to get enough of the scene into the frame and at the same time being able to align the south pole with the top of the lighthouse. Luckily I managed to do all these things by carefully placing the camera/tripod just inside the lighthouses shadow and then aligned the south pole accordingly. I brought along a cotton shopping bag that I filled with rocks and suspended it from the tripod to stabilize it. Then I fired off a few test shots. 

My base settings were pretty clear to me:

- Camera in MANUAL mode
- Shooting in RAW
- White Balance at 3100 Kelvin(close enough for this scene but can be corrected in post processing)
- Exposure time 30 seconds
- Image Stabilization OFF
- Focus Mode MANUAL (switch to live view first, zoom in on a bright star, then let the camera focus on it. Once the camera has focused, switch focus mode to Manual)
- Shooting Mode CONTINUOUS 
- Display brightness on low(not only does this preserve your battery life but also your night vision
- GPS and WIFI disabled, to reduce battery usage


As the exposure time and aperture were set in stone, the brightness of the image would be determined by the ISO value. I tried several settings at ISO 200, 400, 800, 1600, 3200 and 6400 and finally settled for ISO 1600. This gave me enough illumination on the actual lighthouse but didn't overexpose the stars(thus retained the color in the stars) and also didn't introduce too much digital noise. 

I programmed Magic Lantern's Intervalometer so that it would fire off 330 shots at 30 seconds each with a gap of 2 seconds between shots. These 2 seconds give the camera a chance to stop vibrating from when the shutter opens and closes before the next shot is fired, thus reducing camera shake.

Once I was happy to go ahead, I turned off the screen completely, covered the view finder with gaffers tape to avoid accidental light leakage from my head light and started the Intervalometer. I then walked back another 20 or so meters, set up my "camp" and waited. I brought a book that my sister gave to me a few years ago about photography(fully immersed!), a camping chair and some hot tea and began my 3hr marathon. In these three hours I couldn't take shelter from the winds and had to keep warm so eventually I cranked up my ipod and just jumped around(mind you, far enough from my tripod so that I wouldn't shake the camera or even knock it over).

I also had ample time to just lie on the ground and gaze at the stars and the milky way. This is a very humbling experience and I never grow tired of it. Seeing shooting stars in all directions and imagining how smallwe are in comparison to this galaxy is simply amazing. It connects you somewhat a little bit more to this planet.

Once the sequence was shot I recorded another 10 dark frames. These are simply shots with the same settings but with the lens cap on the lens so that the sensor only records the hot pixels. This helps in post processing to remove the noise from the final image.

Since I didn't really feel like going home just yet, I stayed for another 2 hours and just shot away, trying out various different compositions. At 5am then, it was finally time to head home and take a warm shower and get some sleep.


A short time lapse video from Leeuwin Ligthouse created with Startrails.exe

--------------------------------------------------------------------------------------------------------------------------


Post Processing

The next morning I loaded all the images into Lightroom and waited for the previews to be built (this usually takes some time with 400+shots, so go get yourself a coffee and keep occupied until the import process is finished). I then stacked all the shots that were to become the final star trail image, and the dark frames into a separate stack. I selected all images and, with Auto-Sync ON, I base edited the images. Once I was happy with the edit, I exported them as tiffs into a folder on my desktop(you can probably export them as jpegs as well to save time and memory on your hard drive). 

I had done some research before and found two free softwares for star trails. One is called Star Stax (http://www.markus-enzweiler.de/StarStaX/StarStaX.html) and the other is Startrails (www.startrails.de). I downloaded both and put them through their paces. In the end I slightly preferred Star Stax as it gave me a visually better/more pleasing result, but Startrails has the benefit of being able to create a time lapse video of your shots which I always love. And why not, since you have the shots anyway!?!

Once the star trail image was created, I re-loaded it into Lightroom and gave it the final touches. 

What do you think?

330 images combined into this one star trail of Cape Leeuwin Lighthouse

--------------------------------------------------------------------------------------------------------------------------

Duration of the Star Trail

As you can imagine, the amount of pictures you take determine the length of the Star Trails. To give you a visual idea, I have prepared the following images as a rough guide. Please note that for the final image I have opted for the "comet" effect in Star Stax, this makes the trails appear to fade away. For the examples below I did NOT use the effect.

Single Exposure at 30 seconds. 

30 images at 30 seconds, approx 16 minutes shooting time

60 images at 30 seconds, approx 32 minutes shooting time

120 images at 30 seconds, approx 1hr 4minutes shooting time

200 images at 30 seconds, approx 1hr 45 minutes shooting time

 300 images at 30 seconds, approx 3hrs shooting time 

Note that the top right corner sees a denser cluster of stars/trails. this stems from the MilkyWay which was situated just to the top right of the Lighthouse as you can see in the time lapse video above.

--------------------------------------------------------------------------------------------------------------------------

If you found this tutorial helpful, please feel free to subscribe, share the article or leave a comment below. Also if you have anything to add or think I have missed something, please comment and share your tips with us.

All the best and happy shooting to you all!
Hannes

No comments:

Post a Comment