Shooting Star Trails
Shooting Star Trails:
Star trails is the topmost in my list of the "things to do before I ____ ". I had tried it couple of times and have got satisfactory results so far. Here I will share the technique for the same. I am in fond of the long exposure night shots now.
Along with the camera you will need shutter release cable (or any other mechanism to lock the shutter button of the camera) and tripod. Few people know my running around for the cable release :-))
Preparation:
Fully charged batteries, google around to locate the polaris star if you want the circulat trails. Study your camera manual well.
Time:
Off course night time, when the moon light is minimum i.e. less than 15% moon phase.
Place:
Sneak out the city chaos and find out the place with the minimum amount of the light pollution. Also please make sure that tripods are allowed at the place. I found real difficulties in using the tripod during my shoot at Raigad.
Frame composition:
Compose the frame in mind. Circular or diagonal trails. The foreground object in the star trails adds another dimension to the image. Consider the strong foreground object. But at the same time be sure that it doesn't overlap with the actual trails you get. Also placing this object in the frame plays important role. For the circular trails, I consider keeping the centre at the third and a foreground object at the centre of the trails.
Actual Shoot:
There are two ways to shoot the star trails. One is the to use the BULB mode of the camera. Place your camera on “bulb” mode and expose for a long enough period of time so that the stars streak through the sky as the Earth rotates. Probably this was the best technique for the films. But exposing the digiSLR sensors for such a long period heatens up the sensor, which is the heart of the camera. Also if there is even slightly illuminated object or a stray light in the frame, there are more chances of the overexposure in the final image. Also if the in-camera noise reduction mechanism is turned on, camera will take the time of equal amount of the exposure time to process the image within itself. And consider the case if in the middle of the exposure time your battery is drained out. Probably this would be the most frustrating case. Most modern digital SLRs have built in long exposure noise reduction by silently taking second “dark frame” for the same length of the first, thus removing the dark current. One of the major problems with the built in noise reduction is that in order to be effective, the camera has to noise reduce under the same ambient temperature as the original exposure(meaning the photographer has to stay on location for twice the amount of time), the other problem is battery life limitations.
The other solution is the one which I followed and almost turned out to be perfect for me, and that too at a maximum ease.So instead of shooting a single long exposure, we can take a large number of short exposures equaling the length of time that our single long exposure would have been and “stack” them together. In this case we turn of the in-camera noise reduction and shoot multiple images. The noise reduction will be done by processing with few black frames manually. Here are the actual steps:
1) Set your quality to .jpg-fine (I know, you want to shoot raw, but trust me, this will save you a lot of batch processing in the future).
2) Turn off any kind of long-exposure noise reduction that is built in to your camera.
3) On a tripod, compose your shot and set your shutter speed to the slowest speed your camera will shoot continuously, most digital SLRs will shoot as slow as 30 seconds, don’t use bulb. Shoot few test shots for the sky, just to check the camera settings for the sky and stars. Within couple of shots you will get the fair idea about the settings.
4) Hold on. You need to shoot a manual dark frame for noise reduction. Keep the camera on the final settings decided. Put your lens cap on, make sure the viewfinder doesn’t have any light shining into it and expose for 30 seconds. In practical around 10 balck frame are enough.
5) Once balck frames are done, remove the lens cap.
6) Shoot a brighter foreground frame for the detail in the foreground. Put your camera on bulb, and make an exposure long enough to get good detail in the foreground, don’t worry about overexposing the sky. Use the same aperture and ISO setting as the 30 second exposures for noise consistency.
7) Now actual go for star trails. Don’t worry about getting too much foreground detail in your exposure right now, just focus on the stars.
8) Set your camera to continuous drive mode.
9) Lock your cable release/remote so that the camera is stuck firing continuously. Now the camera will shoot one 30 second exposure after another until you stop it.
8) Stop after an hour (or however long your predetermined exposure is). The longer you let the camera shoot, the more the earth will rotate and the longer the star streaks. Also, keep an eye on the camera as some cameras do not have the buffer to handle so many shots in a row. You can even continue till your battery is exhausted.
Post Proccessing:
Method-1:
1) Download StarTrails from HERE. We will also be using Adobe Photoshop CS3 (although you can probably use CS2 or even Elements 6).
2) Prerequisite for the startrails application is .NET framework.
Open StarTrails and go to File –> “Open Images” and select all of the frames except for the dark frame and foreground frame.
3) Go to File —> “Open Dark Frames” and select your darkframe
4) Click Build —> Star Trails and give it a few minutes. You can watch as the star streaks grow.
5) Save as a .tiff file and open the .tiff in Photoshop
6) Also open the foreground exposure jpeg and paste it as a new layer on top of your stacked .tiff file in photoshop
7) Create a black mask on the foreground layer and paint in the foreground carefully.
8) Apply curves, noise reduction and other editing adjustments and your done!
Method-2: (I haven't tried this, poor at PS and This is time consuming and tedious).
File —> Scripts —> “Load Files into Stack.” Open all of your exposures except the foreground frame. Change each layer’s blending type to “lighten” and the dark frame’s to “difference.”
Cheers.
Do post the results. And yess, a gala treat due after you get the trails...!!!
Star trails is the topmost in my list of the "things to do before I ____ ". I had tried it couple of times and have got satisfactory results so far. Here I will share the technique for the same. I am in fond of the long exposure night shots now.
Along with the camera you will need shutter release cable (or any other mechanism to lock the shutter button of the camera) and tripod. Few people know my running around for the cable release :-))
Preparation:
Fully charged batteries, google around to locate the polaris star if you want the circulat trails. Study your camera manual well.
Time:
Off course night time, when the moon light is minimum i.e. less than 15% moon phase.
Place:
Sneak out the city chaos and find out the place with the minimum amount of the light pollution. Also please make sure that tripods are allowed at the place. I found real difficulties in using the tripod during my shoot at Raigad.
Frame composition:
Compose the frame in mind. Circular or diagonal trails. The foreground object in the star trails adds another dimension to the image. Consider the strong foreground object. But at the same time be sure that it doesn't overlap with the actual trails you get. Also placing this object in the frame plays important role. For the circular trails, I consider keeping the centre at the third and a foreground object at the centre of the trails.
Actual Shoot:
There are two ways to shoot the star trails. One is the to use the BULB mode of the camera. Place your camera on “bulb” mode and expose for a long enough period of time so that the stars streak through the sky as the Earth rotates. Probably this was the best technique for the films. But exposing the digiSLR sensors for such a long period heatens up the sensor, which is the heart of the camera. Also if there is even slightly illuminated object or a stray light in the frame, there are more chances of the overexposure in the final image. Also if the in-camera noise reduction mechanism is turned on, camera will take the time of equal amount of the exposure time to process the image within itself. And consider the case if in the middle of the exposure time your battery is drained out. Probably this would be the most frustrating case. Most modern digital SLRs have built in long exposure noise reduction by silently taking second “dark frame” for the same length of the first, thus removing the dark current. One of the major problems with the built in noise reduction is that in order to be effective, the camera has to noise reduce under the same ambient temperature as the original exposure(meaning the photographer has to stay on location for twice the amount of time), the other problem is battery life limitations.
The other solution is the one which I followed and almost turned out to be perfect for me, and that too at a maximum ease.So instead of shooting a single long exposure, we can take a large number of short exposures equaling the length of time that our single long exposure would have been and “stack” them together. In this case we turn of the in-camera noise reduction and shoot multiple images. The noise reduction will be done by processing with few black frames manually. Here are the actual steps:
1) Set your quality to .jpg-fine (I know, you want to shoot raw, but trust me, this will save you a lot of batch processing in the future).
2) Turn off any kind of long-exposure noise reduction that is built in to your camera.
3) On a tripod, compose your shot and set your shutter speed to the slowest speed your camera will shoot continuously, most digital SLRs will shoot as slow as 30 seconds, don’t use bulb. Shoot few test shots for the sky, just to check the camera settings for the sky and stars. Within couple of shots you will get the fair idea about the settings.
4) Hold on. You need to shoot a manual dark frame for noise reduction. Keep the camera on the final settings decided. Put your lens cap on, make sure the viewfinder doesn’t have any light shining into it and expose for 30 seconds. In practical around 10 balck frame are enough.
5) Once balck frames are done, remove the lens cap.
6) Shoot a brighter foreground frame for the detail in the foreground. Put your camera on bulb, and make an exposure long enough to get good detail in the foreground, don’t worry about overexposing the sky. Use the same aperture and ISO setting as the 30 second exposures for noise consistency.
7) Now actual go for star trails. Don’t worry about getting too much foreground detail in your exposure right now, just focus on the stars.
8) Set your camera to continuous drive mode.
9) Lock your cable release/remote so that the camera is stuck firing continuously. Now the camera will shoot one 30 second exposure after another until you stop it.
8) Stop after an hour (or however long your predetermined exposure is). The longer you let the camera shoot, the more the earth will rotate and the longer the star streaks. Also, keep an eye on the camera as some cameras do not have the buffer to handle so many shots in a row. You can even continue till your battery is exhausted.
Post Proccessing:
Method-1:
1) Download StarTrails from HERE. We will also be using Adobe Photoshop CS3 (although you can probably use CS2 or even Elements 6).
2) Prerequisite for the startrails application is .NET framework.
Open StarTrails and go to File –> “Open Images” and select all of the frames except for the dark frame and foreground frame.
3) Go to File —> “Open Dark Frames” and select your darkframe
4) Click Build —> Star Trails and give it a few minutes. You can watch as the star streaks grow.
5) Save as a .tiff file and open the .tiff in Photoshop
6) Also open the foreground exposure jpeg and paste it as a new layer on top of your stacked .tiff file in photoshop
7) Create a black mask on the foreground layer and paint in the foreground carefully.
8) Apply curves, noise reduction and other editing adjustments and your done!
Method-2: (I haven't tried this, poor at PS and This is time consuming and tedious).
File —> Scripts —> “Load Files into Stack.” Open all of your exposures except the foreground frame. Change each layer’s blending type to “lighten” and the dark frame’s to “difference.”
Cheers.
Do post the results. And yess, a gala treat due after you get the trails...!!!
hmm .. still if someone shows it in person .. ud give a great experience
ReplyDeleteawesome post. This post inspired me to try some on my own. Just have one tiny query though! There's dew condensation on the lens in cold climates. How I can avoid that?
ReplyDelete