Lake Eaton star trails

How to make star trails

There are a couple of different ways to photograph the night sky with stars. If you shoot a reasonably short exposure then you get stars that are pin points. The exposures have to be fairly short because of the earth’s rotation. More than 30 seconds or so will start to draw the stars out into ‘trails’. You can get a longer exposure but you will have to mount the camera on some sort of drive that will rotate the camera in sync with the sky’s movement. You can make a mount to do this called the barn door mount out of a couple of boards, a hinge and a screw.

Google “barn door star photo”

and you will find many references and instructions for making one of these.

You can make stunning photos with that technique. Look at this one by John Moran

But our subject for this post is making star trails not avoiding them. To make the shot above I took 6 shots, each with 180 second exposures. And combine them using a technique called stacking.

A comment about that shot. I do not claim it is one of my best shots but it is the only successful star trail shot I have so far, so there it is. The red in the sky was from the urban lights from the City of Ocala about 15 or 20 miles away. The red comes from all the forest fires in the area, from the smoke not the flames which were 7 miles behind me. That area across the lake did catch on fire the next afternoon however, causing us to beat a quick retreat before they closed the highway out. Click on the shot for a larger version.

I could have made a single 18 minute exposure rather than 6–3 minute exposures. But the bane of night shooting is sensor noise and the longer the sensor is run the hotter it gets. By dividing the shot up into shorter intervals you can reduce the heating problem.

Now this shot was taken to the north but not quite far enough, the pole star is just off frame to the right. But getting a shot due north will give you concentric trails like this by Harold Davis. You can tell he has had a lot more practice than I have. Unless you live down near Key West or Brownville Texas in the US you won’t get the same effect by shooting south since the southern axis is below the horizon.

The stuttered dotted effect of the shot above was because I let a minute of so go by in between shots to demonstrate the effect of stacking. If you shoot them closer together you will get a continuous trail.

How I did the Stacking

I have Photoshop CS4 extended which includes stacking modes. Standard CS4 does not, CS3 extended does. The version Adobe sells as the educational/academic version is the extended version. So that being said I suspect that most of you will not be able to follow this method, but there are other ways. So I:

• Shot the images and loaded them into Adobe Bridge.
• In Bridge I compiled them into a stack by selecting them all and right clicking and selecting group as stack.
• You can then open tools–>photoshop–>open in photoshop layers
• Or you can download Russell Brown’s scripts which will add a Dr Brown’s Services menu item under tools and one of those services is Dr Brown’s Stack-o-matic. He seems to be having a problem with the scripts but they will show up on this page. He has CS3 and CS4 versions. He has a lot of good Photoshop material on that page too and the scripts do more than stacking. Select maximum mode from his script.
• Anyway, without Dr Brown’s help, go into CS4(or 3) and select all the layers then go to Edit->Auto blend  layers. You may need to auto align the layers first but do not unless you have to do so.
  
• Then Layers–>smart objects–> convert to smart objects
• Finally the Stack Modes menu item will be visible on the layers menu, select maximum mode there. There are a lot of modes and you can play with them.
• If you have a lot of layers in the stack be prepared for long waits as photoshop does the work.

You don’t have PS Extended.

In that case load the shots into layers in Photoshop as above then try to combine them using blend modes and opacity. Screen or lighten mode are likely to work the best and the opacities should probably be 30  percent or so. But you will have to experiment yourself or hit Google.

Other Stacking Software

There are a lot of non-photoshop ways of doing the stacking:

• Image Stacker (look at Max Lyon’s excellent panoramas when you are there)
• DeepSky Stacker
• Registax
• CombineZ

You are on you’re own with these since I haven’t used them. If you have a favorite let me know and I’ll add it to the list. I don’t know of any other photo editing software that does stacking but some may do so.

I’m probably going to step away from night shots for awhile and do some posts for new camera users.

Lake Eaton at Night-from the camera

A quick look at editing

Let’s take a quick look at editing. I say quick because I haven’t figured out a way to squeeze this into a reasonable length post if I go into great detail and add screen captures to show the steps in Photoshop. If there is any interest in that I’ll give it a try.

Look at the image above, it was taken at Lake Eaton in the Ocala National Forest this last Friday. I took my son there on a scout camp-out. The light on the horizon is the urban area to the west.  You can see some stars in the sky but it is basically black. As is the foreground. The whole image is dull and low contrast.

After ten minutes in CS4 we get this below:

After some work in CS4

This is still no great image and it does look a lot better in larger sizes. But now we can see that there are a lot of stars. The sky is midnight blue. The lake water now pops out in a reflection of the orange sky and clouds. There was a large forest fire to the east of this area and that was imparting the smoky orange tones. There is now a boat visible in the right foreground. Let me note that this shot was a 3 minute exposure but the histogram was mostly to the left since I actually shot 6 of these images and intend to stack them. But that is for another post.

How did I get from the first image to the second image?

Edits

In ACR5

• Increased fill light to +67
• Added contrast and just a little more exposure
• Added clarity and vibrance
• Decreased the color temperature to 3050
• Use 5 adjustment brushes
• Reduced noise

In CS4

• added a layer copy
• used noise ninja on the whole layer

Starting with the ACR (Adobe Camera Raw 5) work. The histogram was pushed to the left (Histogram 1 below), so I pushed the fill light slider far to the right from almost zero to +67. That moved the histogram a little to the right (Histogram 2) and brightened the stars and foreground. This revealed the boat.

Histogram 1

Histogram 2

The only reason I can do this is that this shot was captured as a raw file. That gives you 1.5 to 2 stops of leeway at both ends of the histogram. You can recover both shadow detail, as I did above or recover blown highlights on the right side of the histogram. In a jpeg file this is not possible.

I then add just a little more exposure and some contrast which makes the stars pop out a bit more. I reduced the color temp from 3150 to 3050 to make the sky more blue but this makes everything else bluer too.

Why dod I pick the various adjustments? It is just from my experience working in ACR. I make adjustment until I like the effect. You can always go back on these adjustments if you think you went too far.

All of this can be done in CS3 and ACR4. But in CS4, Adobe added adjustment brushes to ACR5 and you can use these brushes to add local changes in exposure, contrast, clarity and several other adjustments to the image by brushing them in. I used this feature five times to brush in more contrast and less exposure to the sky. More orange and adjusted the exposure on the lake with another brush. And used a third brush to do similar adjustments to the skyline and clouds just over the trees. A last couple of adjustment brushes dimmed the foreground weeds and lightened the boat.

All of this added a lot of noise so I used the noise reduction feature in ACR to reduce this. And then moved to CS4.

All I did in CS4 was do a single run with Noise Ninja to reduce the noise further. And I added a copyright watermark.

Why work in ACR?

Everything I did in ACR could be done a different way in CS4 or CS3 (and probably earlier versions of Photoshop). The adjustment brushes could be duplicated by selecting the area and creating a mask. You could then use dodge/burn, curves and saturation to recreate the effects. But by working in ACR you are working in the raw linear data and changes are easily reversible and do not introduce as much image damage.

You could also duplicate this in other editing software. The ability to use layers and masks would make that easier.

So I wanted to give people a brief look at what I do in editing. I probably could have picked a better sample image to work on. I have no hesitation to do any sort of editing that I think improves the image.I never claim that my work is a representation of the scene as it naturally appeared.  The sky was black, the only star really visible was Venus and the boat was dimly visible to my eyes. But it is a representation of my ‘artistic’ vision of what I want to create.

Color balanced lighting

Urban and Industrial Night Photography

Shooting in Urban and Industrial sites poses it’s own set of problems.

• Safety issues
• Color Balance
• Access

Safety

The safety issues were discussed in the first post of this series for urban areas. If you are shooting in industrial areas, like the one above or abandoned sites, then those have their own sets of problems. Industrial areas will have high temperatures, steam, electrical dangers, fall hazards, moving equipment and traffic problems. You should never be in these areas unless you are familiar with the dangers, have permission to be there or are escorted.

Shooting at abandoned sites is popular but the dangers there can be real. These sites are not maintained and there can be uncovered pits, fall hazards and the possibility of a wall collapsing and falling on you. There can be enraged security guards and maybe guard dogs to deal with too. You don’t want to end your shooting adventure in a hospital or jail. I would be sure to have someone along with you for backup in case there is a problem.

You can also run into urban outdoorsmen living on these sites who may not welcome the intrusion.

Equipment and Exposures

The equipment you’ll need for this type of shooting is less than for dark environment shots.

• Tripod
• Remote release
• Flashlight with gels
• Lens Cloth

The equipment is discussed in this post

Exposure durations will most of the time be less than dark areas with the possible exception of abandoned sites. They can be very dark. Just take a guess and watch your histogram. Adjust exposures up or down based on the histogram peak. Too far to the left, add shutter time and if too far to the right then reduce shutter time. ISO should be low, 100 or 200 and try a mid range f/stop like 5.6 or 6.3 to start.

Color Balance Problems

Take a look at the shot above. This site shows at least 5 different types of industrial lighting. Starting at the tower on the left I see blue, orange, green, yellow and white lights. Probably several different types of sodium lights, HID and mercury lamps are present.

I just don’t worry too much about color balance unless it is obnoxious. There is no way you could ever correct that shot above. But I actually like the effect in that shot.

But sometimes, if one light type predominates on the scene, you can tweak the color temperature or use curves to correct the color in post processing.  And sometimes with yellow or orange lighting you will want to do some correction. I don’t try to guess the color temperature and set it on the camera either. I just use automatic white balance and shoot in raw. I do my adjustments in Photoshop and ACR.

Light Painting

This type of shooting is natural for light painting, you can put a gel over the lens of your flashlight and add light and color to the scene.  The traditional way to get gels is to get a sample kit from one of the manufacturers like Rosco. However the manufacturers are not giving out the sample kits like the once did. You can try to request one but it might take some creative form-filling-out skills to succeed.

You can buy gels from B&H and others but you’ll end up with a huge sheet which will be a 100 year supply of that one color. So there is no great solution. Too bad these people don’t sell the sample kits. It would be worth $20 to get a sample kit.

–update– I have a comment that say that B&H does sell the Rosco sample kits for less than $10. I just spent 10 minutes trying to find the sample kit but could not; but Rosco has thousands of different items on sale at B&H so I may have used the wrong search terms.

Finally

Like other night shoots these images will also require a lot of post production. But you can produce wonderful images. So get out and give it a try.

After Sunset

How I do a night shoot

OK I decide to head out for a night shoot, I gather all the equipment together. But I generally keep it all in my truck. I watch the sky anxiously as sunset approaches. I want a clear to lightly cloudy sky. Too many clouds spoils the photo, but I sometimes head out hoping for the best. I have almost always, pre-scouted the place where I will be shooting but sometimes not, especially on the more distant locations.

The descriptions are for a sunset shoot but of course apply to a sunrise shoot as well. The sequence would be reversed, you need to get out on site an hour before sunrise and the beginning shutter speeds will be long and get shorter as the sun gets near the horizon. Being there an hour before sunrise can mean getting  up at 3 or 4 AM.

Having a Canon DSLR and never having used a different brand my terminology is going to be influenced by what I know. If you use a different camera brand you’ll have to dig into your manual for the equivalent instructions. It should be obvious what I am talking about if you are familiar with your camera, and shame on you if you are not.

When I get to the location I set up the camera on my tripod with a remote attached. I mostly use an ultrawide lens, the one I am using now is a Tokina 11-16mm f/2.8 lens. I used a Sigma 15-30mm before that one. While I am fond of ultrawides there is no reason you can’t use any lens if it is reasonably fast. The perfect location is a site with water between you and the sunset/sunrise. The foreground should be interesting to you. Sometimes I use a grassy plains instead of water. The water works very well since it will pick up colors and reflect them.

For this type of shoot you don’t want much moon in the sky, so either a moonless night or before or after moonrise/moonset at best. A first or last quarter moon is OK since those will not overwhelm the rest of the image. The moon getting close to full will blast so much light into the scene that you won’t be able to capture much of anything else with out some trickery.

I set up a chair and wait for the sun, if the sunset itself is good I’ll shoot some sunset shots while waiting for the sun to slip below the horizon. Once the sun goes under the horizon I get going. If your camera has live view and you can use that for focusing, then you may want to try to use it for critical focusing.

My initial conditions are usually:

• f/5.6 to 6.3
• Aperture Priority mode
• ISO 100 or 200
• shooting in raw
• camera set to long exposure noise reduction

I then start firing off shots and look at the histogram after each of these. I want the histogram off the left edge of the frame and preferably out approaching the center of the frame. This is easier when you are shooting near the sunset but calls for longer and longer exposures later on. If the histogram looks good I’ll just fire off occasional shots every minute or two.

Shutter times will get longer and longer and will eventually reach the 30 second mark. When this happens it is time to change to manual mode(M) and increase the shutter duration to the bulb setting(B). Bulb as I mentioned holds the shutter open as long as the shutter button is activated. Either with a finger (bad idea) or the remote shutter trigger.

I’ll start at 30 seconds and watch the histogram. You will have to guess at increasing shutter speeds, if 30 seconds produces a shot with the histogram peak all the way to the left try 1 minute or 2 minutes. I find that after a certain point the shutter speeds will stabilize often around 5 or 6 minutes. But dark nights will mean longer exposures, I have used up to 15 minute exposures. Watch the battery indicator it will start going down quickly. The small flashlight can be used to check camera settings.

At the 30 second point on Canon DSLR the long exposure noise reduction kicks in. The camera will make the exposure that you set, it will then make another equally long exposure with the shutter shut. It then subtracts the second exposure which recorded shutter noise from the first exposure. This is called dark frame subtraction.

The practical result of this is that exposures have now become twice as long. A five minute exposure is now ten minutes. A 12 minute exposure is now 24 minutes and now you will appreciate the chair rather than sitting on the rock with the snakes. Keep an eye on that battery indicator.

At this point I usually look for interesting foregrounds, trees hanging over the water, docks or whatever you can find. A boat going by can leaving interesting ripples. Move the tripod around to try different spots. You can use the big flash light to try some light painting.

That is basically the process. Like most digital photography it is less than half of what is needed to produce a high quality art photo. The rest of the work will be done in front of your computer running Photoshop or whatever you use. Look at the image at the top of this post. I assure you it did not come out of the camera looking that way. If you believe that a photo is made in the camera then this type of photography is not for you.

Long exposure shots will almost always need serious noise reduction. You will also use curves to adjust the tones and give you a nice dark velvety sky. If you succeed in getting a good histogram with the peak near the center, you will not be happy when you look at the image for the first time. It will need serious post processing to look like a night shot. But the extra data you captured will hold the noise down and produce a much better end result.

I’ll be doing a post on star trails and urban night work in the near future. And one on moonlight photography. And I will do some posts on post processing these images. Keep tuned to this channel.

Update: take a look at this post for more thoughts about long exposure noise:

Amusement park ride

What do you need?

Lets take a look at what gear you need to do night photography in dark environments. I say dark environments because there is actually another type of night photography: urban and industrial night photography where there may be a lot more ambient light. Like the shot above. I’ll talk about that sort of work in another post. This post is about gear for long exposures, at least 10 seconds up to many minutes.

Safety First

John D Moore has pointed out that we need to first think about safety while engaging in any sort of photography but especially night photography in unfamiliar areas. He has an excellent PDF file available on this subject which you should read.

Gary Crabbe recently took a dive off a 40 foot cliff at midnight and woke up four hours later  much worse for the experience. So be like a boy scout–prepared. Try to look around where you plan to shoot during the day to get an idea of the hazards and the lay of the land. Carry a flashlight when moving around and use it.

Equipment

My basic night photography outfit consists of:

• A sturdy Tripod
• A remote release and/or intervalometer
• At least two flashlights one small and one larger more powerful light
• Gels and Strobe(s)/Flashes (if you will be doing light painting)
• A timer, watch(with light) or intervalometer
• Extra Batteries
• Something to sit in–ie a folding canvas chair
• A microfiber lens cloth

Tripods:

Lets look at tripods. You really must have a sturdy tripod, and that means a heavy tripod unless you can pay for one made out of the exotic materials like Carbon Fiber. A lightweight flimsy tripod is worthless and can dump your $1000 camera and $700 lens on the pavement. Carbon Fiber tripods can cost twice as much and don’t seem to me to save that much in weight for the extra cost. But a flimsy tripod will not hold the camera steady for 10 or 20 minute exposures.

A cheaper alternative is Amvona who sells Hong Kong knock offs of Bogen tripods. I got mine from them when they were selling on eBay. It is a copy of the discontinued Bogen 3021 (which was selling for over $200 at the time, I paid $40) and is steady as a rock and very well made. The one problem I had was the feet fell off so I ended up gluing the feet to the legs and have had no trouble since then. You should check eBay to see if they are still selling there.

If you buy an Amvona I would not buy the tripod head from them, especially not the pistol grip looking one. I cannot comment on the newer ones they now have. The quick release failed, on my copy of that, and dropped my 350D and Sigma 15-30mm five feet onto a rock ledge.

Make sure you get a set of legs long enough for your height. legs that only open to 58 inches will not be much use if you are six foot two. The tripod needs to be able to support the weight of the camera and the heaviest lens, I think you want one the supports 9 or 10 pounds minimum.

Most tripods in this class will have leg spikes that can be extended to dig into the ground if you are on soil and not pavement. And some will have a hook at the end of the center post, that you can hang a weight from, to make them even more rigid. The extra weight would mostly be of use in windy conditions or if you had the tripod set up in an unstable position.

Tripod heads:

I’m not going to say much about heads. A good one is better than a cheap one. But they can get very pricey. I have an Acratech head and very much like it but my wife was taken aback when I wanted a $275 tripod head for Christmas. Really Right Stuff also makes excellent heads. I’m sure new users are saying you paid how much for a ballhead!? But a good one will help your photography and will lock the camera in an immovable position thru these long exposures. Manfrotto-Bogen make fairly good heads that cost a lot less. the Acratech and RRS are mid-priced heads not expensive ones, hard tho that may be to believe.

Remote releases, intervalometers and timers

To shoot one of these long exposure shots you need to lock down the shutter for the length of the exposure. You put the camera in Manual mode(M) and select Bulb (B) as the exposure duration. B holds the shutter open as long as the button is held in by your finger or by a locking remote control. You cannot hold the shutter button down for long periods without jarring the camera so some sort of remote control is needed.

You can get a remote release either as a wired version or a wireless radio type that has a receiver that plugs into the camera and a transmitter that you can trigger from a distance. There are infra-red triggers but you need to be in front of the camera to use them and they are reportedly of doubtful reliability. You can buy a remote from your camera manufacturer or use a third party version. Those seem to work well enough and are a fraction of the cost. Be sure to get a locking remote because your finger will get mighty tired holding that button down.

You can even make a remote. That link is for the Canon XXX series (350D, 400D ect.) but you can probably use Google to find a version for your camera body. The eBay remotes are so cheap that it hardy seems to make sense to make one. I’m not going to put up a link for those since it would probably go bad in a short time. One word of warning, Canon XXXD series cameras do not use the same plug on remotes as the XXD (30D, 40D ect). So be sure to get one that works on your model.

If you have a plain remote you will need some way to watch the time; either a watch with a light or some other timer. People are using small kitchen timers with a light. You can pick up one for less than $15.

The best way to do this is to buy an intervalometer, that is a remote that has a built in timer. You can set a single time or even set a series of shots with a duration and interval that you set. Again manufacturer and third party versions are available. Most intervalometers work as remote releases too so you won’t need both.

Flashlights, strobes and gels

I carry a couple of flashlights with me. A small led light for looking at the camera settings. And a bigger three cell led with 150 lumen output that is so bright you cannot look at the light. That is for light painting. The gels are to change the color of the light. We will get to light painting in another post. The big light is also good for picking your path in the dark.

Flashes or strobes can be used for light painting too.

Batteries and chairs

Your camera will eat batteries in very short times when you are doing long exposures. The camera uses power to hold the shutter open and I’d guess that my cameras have 60-90 minutes of shutter time in a fresh battery. That somewhat depends on the camera temperature. But 60 minutes means that 6 10 minute exposures will drain your battery. So carry extras. It is discouraging to have the light change from OK to absolutely wonderful and have your battery die.

The chair is somewhere to plant your body in while you wait for those 10 minutes to creep by (actually 20 minutes). I carry one of those ubiquitous folding canvas chairs that can be had for $12 or so.

Lastly carry a lens cloth and keep an eye on your lens. Night conditions are often damp conditions and your lens can fog up. And it’s no fun to get home and find a lot of photos that look like they were taken thru a shower curtain.

Well I see my word count is up over 1200 and I promised to keep these posts reasonably short so we will talk about actually taking night shots next time.

Glowing wave

What is Night Photography?

Right now I would have to say that night photography is my favorite form of photography.

Just when does night photography happen? Personally I say it is from right before sunrise, maybe up to an hour before. That is when the above shot was taken. The sun is still below the horizon but you can see, with the camera and long exposures, the light and colors from the sun.

Night waves

Or you can do it right after sunset for an hour or so, like the shot above. The sun is just below the horizon and is still lighting the sky and clouds and injecting warm colors into the image. You can see the orange color in the water.

Night Sky

And of course you have the time in between these two periods for more night photography of the dark sky with the stars and moon. As above. The color in this image comes from the city of Gainesville which is about 25 miles away.

Let me point out that the camera is seeing what you cannot see with your eyes. The sky was not glowing yellow and orange when I was out at Watermelon Pond taking the shot above. It was as black as the inside of a sack with the faintest hint of a glow on the horizon. But multi-minute exposures show us sights that are denied to us otherwise.

Resources

Some of the resources available on the web for night shooting are.

• The Nocturnes. I would guess that this is the premier site for night photography. Be sure to look at their galleries and resources
• Gorillasite is a site by Andy Frazier. Andy is one of the Nocturnes, who are centered in Northern California.
• Harold Davis’ site and blog. Harold Davis is the author of several books including at least one on night work. He has a blog too and does more than night shots. He has some videos on the web about night shooting and does seminars. He is also in the Frisco area.

Many of the Nocturnes use a technique called light painting. That use a flash or other light to paint a building or other object while the rest of the shot remains dark. I have tinkered with it, but not to my satisfaction yet. I finally bought a very bright 150 lumen flash light that I’m going to use to play with this more. But right now I’m doing more of the straight type of night shots.

In the next post on this series I will go into just what hardware I use to do night photography and just how I go about setting up a shot.