How to Photograph and Process Star Trails

well good evening and welcome to my short tutorial on star trail photography now we've got a beautifully clear night in store great for recording images that will show the motion of the sky over an hour or more now I might allowed it to 250 degrees north and it's just a week before summer solstice so it's never going to get very dark tonight but that's ok contrary to what some tutorials might tell you you don't need super dark skies to do star trail photography some of the best shots come on moonlit nights or from sites with some light pollution but here at dinosaur Provincial Park in southern Alberta we've got some great guys to work with so the goal tonight is to shoot lots of frames to stack them together into one image showing the motion of the sky so let's get started first the set up now the great thing about star trail photography is that you can get impressive results with basic equipment and the simplest of techniques now aim a camera to the celestial Pole to the north in the northern hemisphere and you get the stars turning in concentric circles as the sky rotates aim a camera to the east to the south or to the west and you get the stars moving in long arcs that's pretty neat and all with the simplest of gear so here's what you need any good DSLR camera or one of the mirrorless cameras that are now popular I'm using a Canon DSLR tonight whatever you shoot with it has to be on a solid tripod this tripe oh I can't move a smidgen four hours of shooting perhaps and you need a wide-angle lens tonight I'm using the 14 millimeter Rokinon lens to take in a wide swath of the northern sky before you start shooting a decision you have to make is what method you're going to use to shoot start rails there are two methods one is to shoot a single or perhaps several but very long exposures I use this method now and then what I know I just want to create a single image start rail the advantage is that you can shoot it quite a low ISO perhaps ISO 100 on a moon at night and get very smooth noiseless results but the method I'm going to use tonight and the method most people use the shoot star trails is to shoot short and fast we shoot lots of short exposures perhaps 30 to 45 seconds each and at a high ISO speed now each frame has to be well exposed stacking later on doesn't make up for poor exposure we end up with dozens if not hundreds of images we then stack in processing to create the visual equivalent of a single long exposure lasting many hours the advantage to this method is that the folder of hundreds of images we might get can not only be stacked together vertically in space to create a single star trail image they can also be strung together in time to create a time-lapse movie so that's the plan tonight absolutely key to shooting any star trail or time-lapse sequence is the intervalometer it's a hardware item that fires the shutter automatically for you for as long as you want and for whatever exposure time you want be sure to buy one that fits the type of connector your camera uses now we've set in the intervalometer long is where you set the exposure time put the camera on bulb and set the exposure time here int is the interval from most star trails the time between exposures should be no more than one two three seconds any longer and you'll see gaps in the trails but this is where it can get tricky with a Canon if I want an interval of one second that's what I dial in but with many other intervalometer x' if you wanted interval of one second you have to dial in a number equal to your exposure time plus one second so if you want to shoot 30 second long exposures with one second between frames you set the interval not to one second but to 31 seconds the last setting is number set this to zero to have the camera keep shooting until you tell it to stop now some cameras have intervalometer x' built right into their menus for example that's true of many nikons you set the exposure on the camera up to a maximum of 30 seconds in most cases then in the intervalometer menu you set the interval to a value equal to one second or more longer than the exposure time and you set the number frame to shoot then press Start as an alternative there are low-cost hardware units available program buy apps on your mobile device the micron and the trigger trap or two popular choices either way there are a couple of other camera settings to check before you commit to a shoot so what else you need to set on the camera well for things image quality noise reduction focus and course exposures under image quality shoot RAW you're throwing away half your image quality by shooting JPEGs don't waste your time shoot RAW now turn long exposure noise reduction off for single shots I recommend using long exposure noise reduction but for star trails turning on le NR will introduce huge gaps in the star trails so turn it off to help reduce noise what you can do is take your own dark frames at the end of a shoot simply cover the lens and take eight or more frames at the same exposure time in same ISO setting these dark frames record just the noise and we can subtract them and their noise later in processing now focusing is critical you don't want to take hundreds of frames and have them all out of focus to focus use the cameras Live View function to manually focus the lens on a bright star or light in the far distance you cannot use autofocus at night take the time to focus carefully zoom in and make that star as sharp as possible the last step is the set exposure what exposure to use depends on how dark or bright the night is a moonlit night will need exposures much shorter than a dark moonless night give the image enough exposure to shift the camera's histogram display to the right do not under expose typically you'll need exposures of 10 to 40 seconds at F 2.8 and at ISO 800 to 3200 now once the sky is fairly dark take test shots to determine the best exposure for the rest of the sequence okay we're focused and we have exposure sorted out we've set the intervalometer the camera is happily firing away while the sky turns around the celestial pole enjoy the night tomorrow we'll process all the images we took to create our star trail masterpiece well that was a great evening out at dinosaur Provincial Park in the badlands here in southern Alberta except for the mosquitoes they are one of the hazards of nightscape shooting well I shot 285 frames for a start rail sequence each was a 15 second exposure at ISO 1600 and each was with this 14 millimeter Rokinon lens a manual lens at F 2.8 so I'll show you the steps of stacking them vertically into a single star trail image but the beautiful thing about shooting lots of short exposures you can also string together in time horizontally to make a time-lapse movie and I'll show you both processing steps so let's get started with our processing of star trail images well I've imported the images onto my hard drives and here they are in Adobe bridge 285 images or so now out in the field I advise you to shoot RAW the results are better but it also makes it very easy to process a whole batch of images like this now as with my other tutorials my workflow is going to go from bridge into Adobe Camera Raw for development and then we'll go into Photoshop for at least one method of stacking images now anything I do in bridge in Adobe Camera Raw you could do in Lightroom as well if you prefer but once we get to the sacking stage that's where you at least have to use Photoshop or another specialized program for stacking images Lightroom and Camera Raw cannot stack images so that's a little later though first of all we have to develop the images now the processor develop 280 RAW files we don't have to open up every one of them and process each image we just have to in in this particular case in bridge just go through the sequence and pick one image in maybe in the middle of the sequence I've given it a red color label just so it stands out double-click on it it opens up in Adobe Camera Raw and I've already gone to town with the development sliders here in the basic tab broad exposure up highlights down clarity up to give this result but that's what came out of the camera rather dark and gloomy of actually underexposed that probably should have shot at ISO 3200 not 1600 or for a 30 second exposure instead of 15 however had I shot 30 second exposures it would have taken twice as long to capture in this case 280 frames now for a single image start rail often all you need is a hundred or 150 frames but a time-lapse movie well for a movie to last long enough 8 or 10 seconds to be worthwhile you often need 250 to 300 frames so just keep that in mind when you're balancing how many frames you might like in the end versus the time needed to capture them well we'll live with that that's what we shot I brought up the exposure to f stops here to really brighten it brought the highlights down here to preserve some of the highlights in the in the horizon where there's some noctilucent clouds in fact brought the shadows up here to begin to bring out some details in the dark foreground brought the clarity up to snap up the contrast and brought the vibrance up just a bit little deeper blues in the twilight sky this was near solstice time so that's the basic panel again before after really helped recover that rather underexposed picture well the basics panel is where you can do most of the work in making an image look great but over here in the detail panel there's sharpening and noise reduction I brought up the luminance noise reduction quite a bit this was a bit of a noisy image if they in here and toggle the noise reduction off you can see that's what it came out of the camera like and then applying in this case 60 of luminance noise reduction and the default of 25 in color and and just the default in sharpening really snapped up the image and improve the image quite a bit so that's noise reduction now the other thing that you often need to do and should do really is over here in the lens correction panel right here and normally I would go to the profile enable lens profile Corrections and then it automatically corrects for the lens but in this case nothing happens because it's got the 14 millimeter manual Rokinon lens on it that's what I use to take the pictures there's no connection between the lens and the camera the camera and the software doesn't know what lens was attached to it so in that case to do lens correction got to go to the manual tab and dial up manually amount of lens being getting in this case I went up to 58 turning it off just tugging it off that's what came out of the camera that's the natural vignette Elend and wide-angle lenses often have quite a bit of vignetting like this but I've brightened up the corners quite a bit by dialing up a manual lens vignetting of 58 so that was just one image and again pretty quick too to develop that one image now to develop all the images all we have to do is take the one that we did in a bridge in this case right-click develop settings copy settings and command or control a to select all the images now right-click anywhere else develop paste settings and the box comes up to say which settings do you want to paste we probably done a little too all of these settings here hit OK and it's now going to transfer the settings from the one image we did process to all the other images in the folder so in just moments we'll have 280 identically processed images now that's developing the raw files to begin with the next step is to start to stack them together into a start rail image there's there's several ways of doing that in some respects the easiest way is just to go into photoshop so let's take a look at that next so to stack images directly into Photoshop let me go back to bridge here in this case for the demo I'm just going to select 15 images here then in bridge tools Photoshop load files into Photoshop layers and Adobe Photoshop opens up and it begins the process of taking each of those 15 images and bringing it into one file but 15 layers in this particular case this takes a little while so let's wait for it to do it we'll come back and take a look at how you then stack those into a star trail well that took a minute or two for Photoshop to load files into layers and here we are back in Photoshop and there's our layers in fact our 15 images I'll select the top one and then shift-click to select all of them except for the very bottom one and now here's the trick to creating the star trail go under the blending mode right here blending mode normal is the default change it to lighten like magic you've got a star trail there we are there's our star trail if i zoom in on it here you can see it a little bit better however these are only 15 quite short exposures only 15 seconds long so it's not a particularly long star trail and I've only chosen 15 images because the dude stacked 2 or 300 this file is going to get really really big as it is it says it's one point six seven gigabytes right down there if I were to save this off now so this method of stacking and blending the images in lighten mode in Photoshop does work it's very simple and quick to do if you've got just a small number of images and I'll use this method if I have several several minute exposures instead of hundreds of very short exposures so it's an option but really for creating a star trail out of hundreds of frames you have to turn to some july's software one of them is a program called star stacks now of course what you could have done back in Photoshop is taken all those layers and flatten them that would reduce the file size but even so working with several hundred images like that in Photoshop is a little awkward that's why we turn to a program like this this is star stacks it's available free for Mac or Windows and it is specifically for stacking images and we'll hit that button there goes two open images and we'll go to our folder of RAW files here and nothing star Stax doesn't want to work with RAW files it cannot work with RAW files let alone any processing you've done to the raw files instead what you have to send it is a folder what's called intermediates JPEGs or Tiff's that's what it likes that's what it will stack so we have to produce that intermediate folder first now to create that required folder of intermediate JPEGs in bridge we can go to tools Photoshop image processor now if you're in a Lightroom you prefer to use Lightroom to develop the RAW files you just simply use its export function to do exactly what I'm going to do here in tools Photoshop image processor that opens up Adobe Photoshop and opens up it's it's utility called image processor and a dialog box opens up saying we've selected 285 images we'll select where we're going to save those images save the folder called JPEGs and save as JPEG we can convert to this more limited s RGB color space we don't have to and we don't really want to resize the image we might ever doing a time-lapse movie in this case we'll keep all the JPEGs the original size that they were as they came out of the camera and then simply press run and now Photoshop with the ADA Bridge will now open up each of those files one by one and convert those RAW files into a set of JPEG images and it's that set that will we do the stacking with so here is in fact our folder of exported JPEG images here there's star stacks we can command or control a and select them all and simply drag them over here the star stacks and it's put all the images in there there they are ready to stack however you remember out in the field I showed you that you could take dark frames by covering the lens and then take a bunch of exposures of just really nothing except it's the noise and and here's where you can subtract those dark frames up here in there's an open dark frames command hit that and now we'll drill to our folder of dark frames there they are and again these have to be exported JPEGs or tips can't be raw files I've got I think eight or ten of them there are twelve Tiff's open those up and now there's dark frames down here as well and then you would hit subtract dark images and now it will subtract the noise from each of those images as it begins the stack press go up over here start processing and away you go except you pick a mode here lighten will do exactly the same thing as we did in Photoshop a little earlier on but here's a neat effect you could not do in Photoshop not very easily anyway is comet mode and will turn up and dial up long trails this produces a special kind of special effect star trail with the trails are tapering so we've selected lightened common mode long trails dark frame dark images here all our images are loaded the dark images the light frames now you simply press start processing goes to the dark frames and now it starts to go through all those two hundred eighty odd frames and begins to stack them and you can begin to actually see the star trail sequence building up so this again takes a minute or two to work through all the images well the result will be a pretty neat star trail picture so after a few minutes of star stacks doing its stacking here's the the final result here I switch to photoshop there's the image now in Photoshop rotted in it's looking pretty good at least as far as the stars in the sky goes but the foreground we need to do a little bit of work and probably composite in a foreground from some images earlier in the sequence when the foreground in the sky was a little bit brighter and to save the image you go up here in star stack save as that suggests the name for you here and you have to manually type in a dot TIFF or a dot jpg to save it as an image in that formats a little crude but after all star stacks is free so that's star stacks you need to create that intermediate set well there is a way of doing it in Photoshop doesn't need an intermediate set of images so let's take a look at that next now the stacking method I prefer does use Photoshop but uses it in conjunction with a special set of actions called the advanced stacker actions from Steven Kristensen at Star Circle Academy comm they install in Photoshop as a set of actions in your actions palette but to run them you actually run them out of bridge tools Photoshop not load files into layers not image processor where we've gone before but batch and this batch dialog box comes up and it's from this box that you actually fire up the actions now to begin the process of stacking you start with this batch dialog box and we select the action that we want to use we go down to the advanced stacker + selection of actions here there's an installation action you can run that's you do that first when you first install it make sure everything's running okay but to do an actual stacking you do this first you do this action here first we select where we're going to save the image then hit okay little helpful dialog box comes up here it continued and then it takes the first image in our sequence of images that we want to stack and it'll come up with another box to say some useful information which after a while you ignore you just press stop as it says press stop and then you press stop again and it's created this file over here where there's really nothing really stacked yet this is just a basic template file into which it will now stack actions but one of the layers it's created is a dark frame it says dark frame here and you can copy and paste one of those dark frames that we did earlier on into that layer and as it's continuing to stack it will kind of like Starks axe did subtract that dark frame from every layer as it starts to stack the rest of the images so now that we've got our kind of a basic template layer now to begin the actual process of stacking once again go back to the batch command here instead of do this first you've you've got a series of effects that you can apply at just a basic lighten mode is your basic stacking it's kind of what we did in Photoshop at the beginning then there's streaks of various lengths elastic stars is kind of a neat effect as well but just like the comet mode of star stacks these are streaks of various lengths and I'll pick ultra streaks they're already picked a location where it's going to save and then hit OK and it will now start to go through in a batch mode using bridge and this is Photoshop opening up each of those process RAW files one by one layering it into that template image flattening as it goes and again this will take a few minutes to do but what it does leave us is an image with lots of other useful layers so let's let it continue and then we'll show you what we end up with with this in this case the ultra streaks with the advanced stacker actions so after several minutes work in fact you might go for dinner it does take a little while to work through that many frames this is our end result and it's similar to what we got with star stacks maybe looking a little bit better except we're still in Photoshop and we've got I'm just breaking off the layers panel we've got an image that isn't just one flattened stacked image we've got all kinds of useful layers that we can use now that's the actual sort of main stacked image right there stack result but there's a watermark it gives us I kind of turned that off I don't usually use that this layer foreground mask has a black mask on it's not doing anything for you but it's the first image in the sequence if you put a mask on it to reveal just the ground you then have the foreground from the first image in the sequence where the sky and the ground might have been a little bit brighter again here's a dark frame where you could put a dark frame or do that earlier on when you first started stacking these layers here are the last eight frames in the sequence and they are averaged together they are blended together with the blend mode up here opacity of 13 the next one is 14 the next one is 17 the next one is 20 the bottom one is a hundred percent these are blended together so that if you brought those images as a group up to the top of the stack they would actually give you a foreground that's smooth and averaged out where a lot of the noise gets averaged out that's what those blending opacities are doing so that's very helpful as well for giving you a less noisy foreground the first and last frames are just that you can use those to put special effects on stars people like to put diffraction spikes on stars at the beginning and end of a trail or something and those allow you to do some special effects perhaps so the advance attacker actions did produce a result very similar to star stacks but you you certainly always need to do a little more work with a star trail image to kind of process the ground separately from the sky it's something I showed in the the moonlit landscape tutorial what here's the final result I did with a little more work the ground is separate from the sky the ground comes from a blend of several layers several ground images from the beginning of the sequence so the sky is masked out of those so again there's just the sky and the sky comes from the stack of several hundred images but both the sky and the ground have adjustment layers added to them brightness and contrast selective color just to improve the color and the brightness of both components earth and sky as well so with a little more work you get a shot using all the original frames you've taken that looks really great as a still image however that's a single still image both star stacks and the stacker actions can also take those same frames and turn them into frames that you can use to make a time-lapse movie so let's look at that process well to create frames for a time last movie using star Stax go back to the program here and it's as it was we got our light frames loaded in and our dark frames loaded in chosen light mode comet mode long trails here subtract dark images but here's the trick save after each step now it allows you to name the file what kind of file it is number the file they have to be in sequential number and then where you're going to save what is in fact another intermediate set that is what will actually assemble into the movie press start processing go in a way it goes works the dark frames and then works through each of the light frames and start stacking them together but not into one image into in fact 280 other images now you can also do the same thing with the advanced stacker actions so to do with the stacker actions the trick is once you've created that basic template with the do this first you instead come down here and pick one of these actions the same set but now it's with intermediates so now we'll pick ultra streaks with intermediates save where it's going to save the images to and it will now create another folder of 280 odd images and kind of like star sex you've got to number them in sequential order so three digit serial number that will create a new set of images all labeled like that one two three four whatever and we've already selected all the images out of bridge then hit OK and once again it starts to work through the sequence the folder of images one by one opening up each one stacking it in but then saving it off as an intermediate frame so not producing one file but producing in this case I've told it through the customization actions to save a bunch downsize JPEGs for the purpose of turning into a movie so very powerful and again this will give us another folder of intermediates that will turn into a movie now with either program what you end up with is this a folder of hundreds of JPEGs here which you can then assemble into a time-lapse movie there's many programs for assembling time-lapse frames in the Aurora tutorial I showed you how you can use Photoshop to do it I often like to use a program for the Mac I'm on a Mac called sequence there it is there and I can just drag that intermediate set of frames and in just moments its then assemble that into a movie of the stars drawing is trail drawing their trails across the sky so it's just rendering that movie out here and then if I just press play there's the result the star is turning around the celestial pole and drawing those ultra streak trails as they turn around and that again was created out of the advanced actor actions ultra streaks with intermediates so that's the movie we created with the advanced actor actions using its ultra streaks with intermediates actions but star stacks will do something very similar so using either program you create the intermediate frames which you then assemble into a time-lapse movie all from the original frames that we also stacked into a still image back at the beginning so that's pretty neat very powerful way to do star trails stills or time-lapse movies all of the time I had I couldn't go through every option that there is the stacker actions in particular has all kinds of customization options that you can set as well but I hope that gives you an idea of the basic steps for shooting and then processing not only single image star trails but also star trail time lapses to learn a lot more about shooting and processing all kinds of night escapes and time lapses I invite you to check out my 400 page ebook available exclusively on the Apple iBooks store it contains dozens of embedded HD videos and step-by-step tutorials in an interactive and multimedia format the link is in the information below the video here so do check it out but I hope you've enjoyed this quick introduction to star trail tips and techniques I'll leave you with a short montage of start real time lapse movies thank you for watching and I wish you clear skies and happy star trails you

Channel: AmazingSky

Views: 54,109

Keywords: Tutorial (Media Genre), star trails, tutorial, how to, nightscape, time-lapse, time lapse, Alberta, Dinosaur Provincial Park, Alan Dyer, amazingsky, Adobe Photoshop, DSLR, night, landscape, stars, astrophotography, long exposure, Adobe Camera Raw, Lightroom, Star Trail

Id: -fMsYd_6jk0

Length: 35min 13sec (2113 seconds)

Published: Thu Nov 19 2015