Stacking for Star Trails

Ever wonder how images like the above were made? There are two main ways: 1)one VERY long exposure, or 2) stacking several long exposures.  In this tutorial post, I'll go through the planing, strategy, and technique of the second option - stacking. 

First up is planning (see my post on that here). After you determine the location, the right night, ascertain whether or not you have do-able weather, and select where to place your camera, then comes the fun part - guessing the exposure length, aperture, and ISO, and subsequently figuring out how many you need to take. Looking at your sensor size + lens combo should give you a good idea of how many frames of a particular length you need to make if your goal is a star circle (facing N to Polaris). I have a  whole separate post on this here. In this post, I want to focus on the post-processing portion of making an image like the above. 

So you have your frames, and (hopefully) your "plate" exposure that you shot for the foreground. Now what?

Step 1: get organized by placing all frames in  your stack in a unique Lightroom Collection. 

Step2: Synchronize ALL develop settings across EACH star trail frame so they are exactly the same.

Step3: Separately develop your "plate" frame to taste. 

Step 4: Select all frames in your stack in Lightroom's filmstrip along the bottom of the screen. Right-click on one of the photos, and choose "Edit In / Open as Layers in Photoshop"

Step 5: In Photoshop, drag the plate layer to the bottom of your layers, if it's not there already. 

Step 6: In the layers panel, select ALL star trails layers, and change the Layer Blending Mode to either "Lighten" or "Screen." Choose one based on which looks better - if shot on a moonless night with dark sky and bring star trails, I find "Lighten" to work better. This should allow all the trails to add up and create your finished blend OF THE SKY ONLY. 

Step 7: Merge all the star trail layers together via the "Merge Layers" command

Step 8: Add a layer mask to the merged star rails layer. Use regular mask-painting techniques with different brushes, hardnesses, opacity, etc. to cover over the foreground of the star trails layer with black paint (remember: white reveals, black conceals). The black paint on the mask will "conceal" or cover up the part of that layer, allowing the part of the next-lowest layer (in this case your foreground plate) to come through to the top in your photograph. Take care to make the blend look realistic. 

If you find gaps in your trails, they will need to be dealt with. Stephen Christensen of the Star Cricle Academy has an excellent post on how to manage this scenario - here

That's it in a nutshell! Any questions, feel free to leave a comment or shoot me an email. 


How to Post Timelapses on Instagram


I love Instagram. It's a great platform for both sharing your photos and also seeing what some of your favorite photographers are up to.

Although it was built for photography, IG can also handle 15 seconds of video in the Quicktime format with H.264 compression. If I already lost you, hang in there, I promise it won't get too complicated.

There are a few basic steps you have to take to get your timelapse clips on IG:

Step 1 - Create your timelapse

I will assume you already have a timelapse prepared, either as a standalone file (I render all of mine as AVIs with the CineForm Codec). If not, you can use your image sequence in PP or AE. If you're looking for directions in Final Cut, you're gonna have to look elsewhere because I'm the last photographer on Earth that uses s PC.

Step 2 - Create a Comp / Sequence in After Effects or Premiere (Respectively)

I use AE for this, since it's simpler**. Start by creating a 1:1 composition with a size of 640x640, and a frame rate of 24 fps (or whatever frame rate your intermediate file is in). Then, import the timelapse files you want to upload to IG into your project. Drag them, one at a time, to the Comp, and scale accordingly. You can keyframe position and scale to taste if you would like to move or zoom through your footage.

Ensure your clip has less than 15 seconds worth of data on the timeline.

Add music if you want, but remember, make sure you have the rights to use it because professionals deserve to be paid for the use of their work!

Step 3 - Render out the Video

Add your composition to the render queue, and then open up the settings dialog. I have found that setting the Quicktime format with the H.264 codec to 100% quality and using a high bitrate of 24 MB/sec produces a smooth video that IG will handle no problem.

after effects settings


 Step 4 - Upload to Dropbox / Download to your Phone

Copy your rendered TL clip to a folder you have prepared on Drobox, and then wait for it to upload. Once it has, open the Dropbox app on your phone, and then view the clip. Hit the "share" button, and save it to your phone's local storage.

Lastly, open IG and browse to the clip, and upload it. Add filters if you want, and then post away as you normally would with a photo. As far as I know, IG uploading apps such as the excellent Latergram do not allow for video uploads, so get those thumbs warmed up and start typing on your phone.

And that's it. You can view my work on my Instagram feed here.

*Step 6 Above is entirely optional and up to you to achieve this milestone

** No one in the history of the world has ever said that about Adobe After Effects before

Landscape Astrophotography Planning Apps and Websites


Students (and sometimes colleagues) often ask about the tools I use to plan for night sky shooting, so I thought  I'd collate a few of my favorites in a blog post.

 NOAA Weather Pages

The first step in landscape photography is understanding what the weather is likely to be doing wherever you may be venturing off to.

The US National Oceanic and Atmospheric Administration offers a wealth of weather date through numerous web pages. I like to use the graphical forecast page, like this example for Truckee:

NWS hourly

(link here--->) Truckee CA Hourly Weather Page. The NWS hourly page is a wealth of information,. including wind, precip potential, and sky cover %. You can generate this for any point in the United States.

And of course, the NWS radar is a great way to see what may or may not be coming over the horizon.

NWS radar

 Clear Sky Chart

The Clear Dark Sky website uses publicly available meteorological data to create a visualization of the aspects of weather that factor into what astronomers call "seeing." Seeing refers to the quality of potential observations at a given time. Good seeing conditions are thus clear, dark skies.

Check out their website for locations near you.

The Photographer's Ephemeris

photog ephemeris

I love this app, and it's essential for forward planning of many different types of photography. Even better, it's a free software download for your desktop. Only the smartphone app costs $.

You can use the Photographer's Ephemeris for many different things, it's really a one-stop shop for planning out astrophotography. TPE will tell you where the sun/moon will be in the sky over time (azimuth and elevation), as well as the times for sunrise/sunset, moonrise/moonset, and astronomical twilight. It provides this info in a graphical format as a line laid over Google Maps. This is a fantastically powerful tool for lining up celestial and manmade objects - say for example you wanted to shoot the moon setting between the towers of the Golden Gate Bridge and wanted to know what time of year this is possible and where you could stand in SF to accomplish the shot.

You can download the program for your desktop computer free of charge at their website, or visit the iTunes store or Andoird Play store to install on your smartphone.


Deluxe Moon

deluxe moon

Sometimes, you need an at-a-glance view of the moon's phase in a monthly calendar format. This app is great for that. it has many other features as well that I rarely use, but I keep it on the front page of my phone so I can easily and quickly tell what influence the moon will have on my night photos on any given day in the future.



Timelapse How to - After Effects Workflow


I'm a huge proponent of using the right tool to do any job, whether the task is remodeling my kitchen cabinets, or processing timelapses. In the case of timelapses, however, things get complicated as there are literally tens of different workflows that a photographer can use to create timelapse videos. How do you know which one is the right one, or which one is the best practice?

The answer to that question is one that my students hate to hear - and one that I hate to give - which is "it depends." Processing timelapses can be heavily taxing on your camera gear, your computer hardware, and your storage solutions. In developing a workflow, each TL shooter must look carefully at what computer power they have available to them, how much time they have available, and most importantly what their objectives / needs are.

No matter what post-processing workflow you choose to use to generate your timelapse clips and edit your showreels and finished movies,  I will assume you are shooting in RAW and starting with either Canon CR2 or Nikon NEF files. If you're not, you should be.

It's also worth noting that I work on a PC that I bought from Dell. I can't afford a Mac with equivalent components. At the end of the day you can argue valid points about which one is better than the other, but you're using the same software so....I'm not convinced that there's a real difference. At any rate, here are the specs of my system, which cost about $1,700 to build:

  • 24 GB RAM
  • Intel Core i7 3.4 GHz Processor
  • RAID-0 Striped dual 128 GB SSDs for scratch drive for rendering/editing
  • Drobo 5D for archiving and storage
  • nVidia GeForce GE645 Video card

Past Workflow - Lightroom / JPEGs 

Before I had this decently fast machine, I was using a much slower desktop with only 12 GB of RAM, thus I created timelapse by the following workflow:

  1. Shoot in RAW
  2. Ingest into Adobe Lightroom
  3. Develop to taste (crop to 16:9)
  4. Export JPEGs
  5. 1920x1080 / 72 dpi for shots with camera movements
  6. Full-frame for static shots if I want to do any Ken Burns-ish pans in the NLE
  7. Import JPEGs as image sequence into Adobe Premiere
  8. Export from Premire as M2V files for intermediates, or use JPEG sequences in timeline for showreels/movies

Current Workflow - LR / LRTimelapse / RAW 

Now that I have  a reasonably decent video workstation, I utilize the following workflow:

  1. Shoot in RAW
  2. Ingest into Lightroom
  3. Develop to taste (do not crop to 16:9)
  4. Keyframe developing parameters with LR Timelapse (see separate blog post about this amazing, game-changing software)
  5. Import sequence of CR2 RAW files into After Effects
  6. In After Effects - make sure Project is in Adobe RGB color space
  7. make sure "import" setting in Preferences matches your frame rate
  8. Make sure sequence has the appropriate frame rate
  9. Add sequence to render queue (if you want to generate an intermediate)

How here comes our first fork in the road. From AE, you can go in many different directions. You can save your sequences, and load them directly into Premiere through Dynamic Link Server, and use these in your editing timeline (but you have to pre-render).

Or, you can make intermediates. I chose this method because I like to have finished movie files for each clip available for viewing and archiving

Now comes the un-fun part of video. What type of intermediate file should you use? Again, the answer is "it depends." On what you might ask? You have to take into consideration things like storage space available, archive disk read/write speed, and color needs for your post-production environment. Here's what I do.

Intermediates - AVI Files / CineForm 4:4:4 Film Scan 2

The knowledgeable Tom Lowe of Timescapes fame recommended the CineForm codec in AVI container as an archival intermediate file format for his 4K timelapse work. According to Tom, the color fidelity was great, stood up to subsequent coloration work in DaVinci Resolve, and also AVI/Cineform Film Scan 2 also was editable in Premiere. Now, you have to understand that Tom is using a custom-built $20,000 monster PC (256 GB of RAM and dual nVidia GeForce 780 Titan cards!).

Nevertheless, on my meager machine I am able to render a 240 frame timelapse from CR2 files in this CineForm AVI compression format in about 10 minutes. File sizes are around 1.6 GB. I can't play these files back from my Drobo without dropping frames, but I can from my RAID-0 SSDs. Here's my workflow:

  1. Add sequence to Render queue in AE
  2. CineForm AVI format, FilmScan 2 quality 4:4:4 color
  3. Drink coffee/beer
  4. Place copy of files on SSD RAID drive array for editing
  5. In Premiere, render previews to smooth editing.

That's it in a nutshell. Feel free to hit me with any questions via email or in the comments. As I said, there are many different ways to post-process timelapse. This is just the way I do it, and it works for me.