Category Archives: Timestacks

Time Stacks

One of the great things about developing a repertoire of tools  and tricks for processing photos is applying those tools in creative ways. While we were furiously working on Advanced Stacker PLUS for creating star trails and processing night sky images, one clever fellow: Matt Molloy gained great acclaim by stacking sunset and sunrise shots of clouds skittering across the sky. Matt Molloy coined the phrase Time Stacks for that type of image.

Phoenix Leaping

Phoenix Leaping – 20 separate frames combined in Lighten Mode plus an extra foreground frame.

Where Steven lives in the Silicon Valley, it is difficult to get good conditions for clouds. Indeed, the San Francisco Bay Area has so many blue sky days that having clouds is a stretch – in the Bay Area the options are either low thick clouds (fog), or zero clouds. However occasionally conditions are right – or Steven travels where conditions are right – for creating these shots. Of note are dry climates with mountains and high winds during seasons with moderate moisture in the air. In March in Palm Springs, California, for example Steven watched as clouds formed due to the uplift of the Mt. San Jacinto mountain range and dissipated quickly as the young cloud wandered eastward away from the peak. Literally you could watch clouds form and dissolve in a matter of minutes. In the image above, you’ll notice that some low clouds moved slowly and didn’t dissipate. Because the denser low clouds were in the shadow of the mountain they grew dark and ominous.  You can see more variations on the same theme by checking out this set of images.

Exit Criteria

Exit Criteria – Alviso, California on one of the few days when clouds were present

What Conditions and Equipment Do I Need?

  1. You need partially cloudy skies and the clouds can not be slow creepers. The clouds should be vigorous sailors. How fast? Fast enough to cross a significant field of view in about 20 to 30 minutes. They need to move into an open area of the sky – clouds moving over other clouds won’t be as interesting.
  2. Like any compelling shot, the frame should include a worthwhile foreground.
  3. And finally, it helps if these conditions all occur near sunset or sunrise so you can get extra color in the shot.


  • You will definitely want to use an Intervalometer (or an on-board Intervalometer if your camera has one). Shooting at regular intervals results in a more pleasing outcome.
  • A sturdy tripod is also a must.

What Settings Should I Use?

  1. Select a moderate aperture (f/8, for example), and a low ISO (200). The goal is to get a shot that is relatively long to get a little cloud blur from the cloud motion.
  2. Since most interesting results occur right at or after sunset, start the exposures at 1 to 2 stops over exposed. Subsequent shots will get darker and finally dark to a point where the images will be too dark  to use (e.g. 2 stops under exposed).
  3. While it may be tempting to adjust the exposure during shooting, we have found that strategy does not work well.  You never really know which shots you will want to combine. Therefore it is best to do large sets (40-50 exposures) all using the same settings.
  4. Change settings (and optionally re-orient your camera), then get another substantial sequence.
  5. Be sure to include an exposure optimized for the foreground in the beginning and/or at the end of each sequence.

The trickiest part is selecting the interval between shots. The speed of the clouds across the frame is the key here – and that can vary dramatically depending on your conditions. One possible method is to shoot once every other second, then cull out the interval that works best (which could be 10 or 20 second intervals), but a less memory and processing intensive approach may be to use 5 or 10 second intervals between shots (or longer if your clouds are sluggish).

Also keep in mind that not all clouds will move at the same speed (or in the same direction!), nor will they be illuminated alike.

How Do I Process the Shots?

This is actually the easy part: use the same tools you would use to create star trails. That is, stack the images in Lighten mode. Understand that if clouds move over clouds the net result is sometimes quite unexpected – the brighter clouds (regardless of color) win.

How Processing Was Completed (Click for larger image)

Above is a snapshot illustrating how this shot (62 frames in the life of clouds) was finished in Photoshop. Two image contrast enhancements were added. The bottom layer is the stacked (lighten mode) image, the next image up is the intentionally over-exposed foreground. Notice that the “Darken bright foreground” is linked to effect ONLY the foreground image. Also note that darkening, and in many cases increasing contrast has the affect of increasing color saturation. No saturation or vibrance enhancements were done here. As with Star Trails, we also recommend that you do not alter any of your shots before you stack them – stack them in their raw form with NO adjustments. The result will look flat until you apply manual corrections and curves, but by not altering your shots before hand, the stack will work better and you are far less likely to introduce strange artifacts.

Variations on Time Stacks

Of course your Time Stacks do not have to be daylight subjects like this solar eclipse which was shot with a solar filter for all the shots except the last which was taken at sunset.

Annular Eclipse Sequence [C_040079+5s]

Time stacks can also include night events like a lunar eclipse

Plan C: San Jose City Hall Eclipse Sequence

Get creative and try other Time Stacks and share with us what you get as a result via comments!

Want to see the technique preferred by Matt Molloy, master time stacker? See his tutorial here.


Publish Date: 29-November-2016

I, Steven, have recently completed one of my bucket list items… capturing stars and astro landscapes aboard a cruise ship. My interest in the idea is based on several observations:

  1. Night photography can be about movement – like star trails, for example – and cruise ships move.
  2. Cruise ships go to and through some of the darkest spots on earth – far away from any land producing artificial light
  3. Being aboard a ship means NOT having to drive anywhere or fly anywhere. Bed, food, drink and entertainment are never farther away than the length of a football field.
  4. I can still spend time with my family rather than alone in the wilderness because… we are all in the same “wilderness” at the same time.


My particular cruise was aboard the Brilliance of the Seas by Royal Carribbean. The ship departed from Tampa, Florida to Key West, then to Cozumel and back to Tampa. The good news is the things I feared most did not happen: I only gained 1.5 pounds and none of my equipment fell into the sea. I also had no motion sickness – though some I traveled with were uncomfortable in what were relatively light seas.

Sunrises, Sunsets and TimeStacks

It does not have to be all about night photography, right?  My travel from the West Coast to the East Coast for the cruise made it a lot easier for me to be awake at sunset and near impossible to greet a sunrise.
Sunset Reversal

Location Is Important

These two trails were taken on different days (one when the ship was cruising south, another two nights later when cruising north). Both were taken from Deck 5 with no moon. The first trail was from near the bow (front of the ship), the other from off the stern (back).

South Bound

South bound star trails from near the bow of the ship** Please read below for how I got here… it is an important detail.

Stern Seas

Looking south from the stern of a north bound cruise – with unfortunate clouds – but look at all the motion!  That bright  streak (and the cloud illuminated above it) are another passing cruise ship.

The ship was steadier when southbound – thus the first star trail looks pretty normal. The second one from the stern of the ship looks like a seismograph! Want to get a feel for the motion from the stern? Watch the video.

Tips and Insights

I did not meet any resistance or complaints from the crew or passengers using my tripod on deck. That is in part because I was mostly using it at night and had already scouted out areas to place it. My first recommendation is to …


First scout your vessel thoroughly… do this before embarking (using deck plans available on the internet), then during the first day, and at night.  I discovered that a passageway open during the day, was gated at night. Unfortunately, that passage led to the darkest part of the ship. More about this in a minute.

Too Little Darkness on Board

Cruise ships are floating cities, and like cities, lights are everywhere and unavoidable. Onboard the Brilliance there were 2 darkish places to go and one dark place where I could not go*. One darkish spot was the top deck toward the bow. There are lights everywhere, but if you shield your eyes and moved deck chairs to cover over some of the bulkhead lights you could make out stars. What I could see, however, was nowhere near the glory that I’ve seen in even moderately rural areas. A darkish spot – mentioned by guest relations, was the starboard (right hand) side of deck 5 near the stern (back of the boat). Again, lots of lights everywhere, but that area was dark enough that with some eye shielding I could easily make out Orion.

See the next photo to see just how much light a ship casts about… the moon illuminated the sky as well – but you wouldn’t be able to see even this many stars by eye in a dark clear sky in any normal area of the ship.

Over the Railing

The light from the ship illuminates the water around it, while the moon illuminates the sky (Cuba is glowing in the distance). Notice how the ship’s pitching and rolling turned stars into squiggles.

Getting Where it Is Really Dark

You may be wondering how I pulled off the photography on the bow given that the passageway was barred at night. It happened innocently. I took advantage of a quirk on the Brilliance of the Seas. In the theater on the ship on the upper level there are what are best described as “box” seats adjacent to the wings of the stage. That area has nearby doors, one marked “Exit” the others are marked crew only. I took the “Exit” and it put me out by the passage to the Helicopter landing pad on the bow of the ship.  There was then another “gate” barring access to the helicopter landing area itself – but it was plenty dark up front. I swung my tripod up on the helopad area and controlled it with my intervalometer being careful to create as little light as possible. That’s how I got images for the first of two star trails above. I then stood at the outer rail of the helipad and took a panorama of the bridge area. Straight up and forward were MUCH darker.

Much of the crew area and the wheel house spanning the entire front of the ship is kept dark with little extra light.

Much of the crew area and the wheel house spanning the entire front of the ship is kept dark with minimal extra light. Note how much light there is on the top deck where you can see silhouettes of passengers through the glass. This is a stitched 4-shot panorama.

Packing for the Cruise

For a 5 day cruise, I took one camera, two smaller lenses batteries and a tripod. I packed almost all of my clothing for the trip inside a single large (carry-on size) bag with some extras in a small carry on “personal item”. That packing arrangement works great for short trips. To accommodate “Formal Night” I stole some space in my wife’s luggage for dress shoes and a suit.

Would You Like To See Celestial Delights On a Cruise?

Knowing that many travelers have never seen a properly dark night sky, I contacted Royal Caribbean and let them know I thought a potentially great ship resource was untapped. If you had a chance to view incredibly dark skies on board your cruise ship, would you relish that opportunity?  Please let us know in a comment below or on our Facebook Page. Perhaps the cruise line will contract SCA to teach night photography in addition to the many other courses on board. I, for one, would love to get on a dark deck and stare up into the Geminid meteor shower – or view the Milky Way at its finest.!

Look What You Did!

First we really appreciate the mastery of Matt Molloy who has been using the Advanced Stacker PLUS to reach creative new heights in “TimeStacks”.  This is one of his images below in which he stacks part of the image with Comet mode, and the rest with lighten mode. Click the image to read more.

Reach for the Clouds by Matt Molloy

Reach for the Clouds by Matt Molloy

We invited users of the Advanced Stacker PLUS to give us feedback on their experiences with our Photoshop Add-in. We asked folks is if they had an image that they made with the software that they’d like us to see. Wow. We are impressed! Take a look for yourself. We used the links provided so none of the images shown are on our server. In other words, if an image does not load properly, there is nothing we at StarCircleAcademy can do to fix the issue.  Where possible, clicking the image will take you to the photographer’s site.

Version 14E is available now, by the way.

If your image appears here and you’d rather it did not, let us know and we’ll remove it.

Exit Criteria

Exit Criteria by Steven Christenson (channeling Matt Molloy)

Rocky Mtns

Rocky Mountains by Bob Gibbon

The Chalice by John Mu

The Chalice by John Mumaw

Church by Bob Edwards

Church by Bob Edwards

Lassen Campfire Pano 1

Lassen Campfire Pano 1

Red River Camping Spot Star Trails by Jeff Stephens

Red River Camping Spot Star Trails by Jeff Stephens

Starflight over Pointy Land

Starflight over Pointy Land by Steven Christenson

Chapel in Starlight by Keith Doucet

Chapel in Starlight by Keith Doucet