Category Archives: Star Trails

Landscape Astrophotography

Thanks for attending my Landscape Astrophotography discourse with the San Jose Astronomical Association on Tuesday, June 19, 2018. 7:30 PM to 10:00 PM. Most of the audience are Astrophotographers.

Below is a form you can fill out and we will email you a PDF of the notes from this lecture.  Following are some brief excerpts from the talk.

The Meeting of Earth and Sky

Big Sur, California, has earned a reputation for being The Greatest Meeting of Land & Sea, a phrase attributed to Robinson Jeffers, the “Walt Whitman” of the West Coast. Indeed living here is inspiring. The towering cliffs and mountains, lush forests, crashing, craggy Pacific surf all work together to evoke a sense of beauty and wonder that is astonishingly intimate.  There are certainly other beautiful places in the world – even nearby. But I believe that there is awesome, virtually undiscovered beauty that touches nearly everywhere in the world: the night sky.

Night Sky photography has grown by leaps and bounds in the last decades. Prior to the age of digital photography, there were relatively few painters of the night sky. Not surprisingly, none of those painters painted just stars. All featured stars with landscapes. Perhaps the most well-known painter of the night is Vincent Van Gogh. In Van Gogh’s day, light pollution was far, far less noxious than it is now. Indeed our super abundance of artificial light has rendered our night sky almost unobservable. But the night sky has such depth and mystery that everyone should find a dark sky to sit under for a time. Part of the allure of the night sky is its expansiveness… its immense scale.

Because the scale of the night sky is difficult to grasp I believe it is important to link human-scale to the starry night. Deep-sky photography of nebula and galaxies reveals things completely unseen or unseeable by the naked eye – and the revelation of those objects is  compelling and engaging. But even more compelling are photographs that tie humanly identifiable scale to the mysterious night.

In addition to scale, compelling photographs reveal the unexpected. Photographs can show time, location, relationships, colors, and details that are unobservable by looking. To draw lay people, however, I believe there must be a strong link between what is observable with what is not: a Marriage of Earth and Sky. And for that reason, I’m urging Astrophotographers and astronomers to try Landscape Astrophotography.

As Numerous as the Grains of Sand

This is truly a meeting of Land, Sea and Sky

For more details, please see the accompanying notes.


Landscape Astrophotography Notes
Landscape Astrophotography Notes
71+ Pages of notes covering the following topics:
  1. How to Make Images Memorable
    • Scale / Grandeur
    • Connectedness
    • Interest
    • Revelation
  2. Impact of Photos
  3. How to Create Scale / Grandeur
  4. How to Connect - Interest and Familiarity
  5. Revelatory Photographs
    • Time | Location | Relationships | Familiarity | Seeing Differently | Surprising Colors | Intricate Detail
  6. Inspiration from Painting
  7. A sense of place
  8. An Astrophotography Idea
  9. Conclusion
  10. Resources and References





 

Other articles on this site that you may find relevant include:

Why Aim North?

Reaching for the Sky

Reaching for the Sky: 112 images, each f/4, ISO 800 for 60 seconds including a shot from twilight hour for the foreground Alabama Hills, Lone Pine, California

Want to capture Perseid meteors, the Milky Way, and star trails in an awesome location?

Join us for our>>> Field Event: Meteors, Milk Way in Alabama Hills <<<Sunday, August 12, 2018 (with an optional second night).  SORRY EVENT IS FULL

I live and travel in the Northern Hemisphere. In fact I have yet to travel south of the equator, so my apologies to those of you from the southern half of the planet for my obvious northern bias.  I believe those of you in the bottom half of the planet can just substitute the word South for North everywhere and everything should be correct.  I have added [parenthetical content for those who are in the southern hemisphere where that north/south swap doesn’t work]

The results obtained by shooting a long exposure at night depend quite a lot on which direction the camera is pointed. I favor long star exposures with a northern view for many reasons.

The Advantages of Shooting To the North

  1. Curvature of the star trails is strongest around the north star. Exposures of about 6 hours will appear to be full circles (24 hours of exposures are actually needed to make complete circles and that is not possible in one night except near the North Pole!).
  2. The moon will never intervene into the shot because the moon never passes through the northern sky.  [NOTE: those in the southern hemisphere still have to worry about a moon in their Southern shots]
  3. Cassiopeia and Ursa Major (the Big Dipper) are bright constellations that can always be found in the Northern Sky – so there is always some interesting sweep of stars possible. The region immediately around the North Star, however has dimmer stars which may only be captured through long exposures. [The southern hemisphere suffers for lack of many bright constellations near the southern celestial equator]
  4. With just a smidgen of star hopping skill it is easy to find the north star which, weather permitting, is always visible in the night sky.
  5. The moon sweeps east to west giving long shadows from the right or left of the subject. And when the moon is highest in the sky it can cast strong face light.
  6. The sun also never appears in the northern sky so it is safe to leave a camera running from before sundown to after sun up. Camera damage can result from a long exposure pointed at the sun.  [NOTE: those in the southern hemisphere still have to worry about a sun in their Southern shots]
  7. Since the moon cannot enter into a northern shot a photo can be made regardless of the moon’s phase and for as long as I choose. For shots toward the East, South or West it is important to know the moon phase and location during the hours of shooting to prevent problems from flare or washout. [NOTE: those in the southern hemisphere still have to worry about a moon in their Southern shots].
  8. The stars in the north move the slowest through the field of view which allows them to be brighter and reduces inter-exposure gaps in the trails.
  9. If I know my latitude I know how high to point the camera and be guaranteed to get a circle in the view.
  10. I do not need to know what constellations will be visible in the direction I will shoot.
  11. Two major meteor showers (the Perseids and Quadrantids) and 3 periodic meteor showers (the Giacobinids or Draconids, the Ursids and the Andromedids) are well placed in the northern sky.

The Disadvantages

There are a few detriments to pointing north, however:

  • Not every situation lends itself to a view from the south.
  • It takes a longer exposure to form a pleasing arc.
  • To get a circular arc, I must include at least 10 degrees or so above and below the North Star. The farther north you are, the higher in the sky the center of rotation. Those at more northerly latitudes will be more constrained in their choices.
  • The altitude (degrees above the horizon) of the north celestial pole may constrain the choice of lenses to very wide-angle – and may force you to use portrait mode. Or you can create your exposure by stitching together foreground and sky shots.

Another Northern View

Grand View [C_009613-686br]

Looking North from Grandview Campground, White Mountains, Bishop, California.  Shot at ISO 800, f/3.2 for 6 minutes each. Began at 10:11 PM and ended at 5:35 AM. That is 75 shots x 6 minutes = seven and a half hours. Grandview is at latitude 37 degrees North, so the center of the circular pattern is 37 degrees above the horizon.

What About OTHER Directions?

Southern View

Woosh

Woosh: 19 images. Each image: 6 minutes, ISO 800, f/3.2, Canon 5D Mark II, 16mm; Patriarch Grove, White Mountain, California

Eastern View

Valley of Stars (Remix) *Explored*

Western View

Stars and Stripes [5_065561-626li]
Granite Park - 53 Minutes (edited)

Notes

Contrary to popular belief, Polaris, the North Star, is not the brightest star in the sky. Sirius is the brightest star. The brightest objects in the night sky are the moon, and the planets Venus, Mars, Jupiter and Saturn. Also while Polaris is quite NEAR to the North Celestial Pole, it’s not exactly there so even Polaris will make a trail.

This is a reissue of an article originally written in October 11, 2010; Thoroughly revised and updated.

Darken Mode Stack Tip Using AdvancedStacker PLUS 18

Published: March 15, 2018

The new Advanced Stacker PLUS 18 is our attempt to make processing simpler. One of the things we find we often do is run multiple stacks (Lighten, Darken, Streaks, etc) to determine which effect(s) work the best. Well, we did something for the first time that worked REALLY well, so we will start by sharing that, even though Advanced Stacker PLUS 18 is not yet ready for publication.

In a nutshell, we created this:

Orion, Falling

From this:

Long Streaks Stack Result – no modifications  f/4, ISO 1600, 15 Seconds. Nikon D600, 24mm x 250

There are several obvious differences between these images.

  1. Because there was strong moonlight (and other light), the sky is over-bright and lacks contrast.
  2. The wind together with surrounding lighting (including flashing red lights from a passing fire truck) caused strange artifacts in the palm trees.
  3. Different colored light sources lit the palm trees differently (notice the really cyan colored palm fronds in the second tree from the left).
  4. There was utility wiring intruding into the image.

The Processing

Stacker 18 allows you to simultaneously stack in multiple modes. For example, to create this effort I used Lighten, Long Streaks, Darkest, and Average modes. I ended up NOT using Lighten or Average modes in this case. Is there extra overhead keeping more stacks? Yes, there is. However we’ve paired down the stacks to as few frames as possible to keep the overall footprint low.

Once the stacking had finished, the result of the Long Streaks was a bit unappetizing due to the red and other artifacts in the trees (see second image). However the Darkest mode stack effectively removes all of the stars – and as it happens, all of the strange highlights in the trees.  First we applied a Curves adjustment layer to the Long Streaks and darkened it.

Blending a Clean Foreground with the Star Trails

Darkest Stack results

The next operation was to find a way to blend the darkest mode stack (right) with the Long Streaks stack while preserving the star trails  and getting the cleaner looking foreground.

 

Duplicate the Darkest mode result (it’s a single layer) on to the Long Streaks stack. Then drag the darkest mode stack to the top layer. Set the new layer blend mode to normal, 100%.

Next we need to mask out the sky of the Darkest stack so that the long streaks will show through. The tool for that is to use Select -> Color Range. Holding down the shift key allows you to click multiple areas of the sky to add to the selection. You can vary the fuzziness of the selection to determine how closely the color has to match the sample. The mask will probably need some manual cleanup afterward, but as you can tell from the selection in the image below, just clicking different areas in the sky produced almost exactly what is desired.

Photoshop Color Range Selection

After pressing OK you get a selection. The next step is Layer -> Create Layer Mask from Selection -> Hide Selection Once you have a mask, you can paint on it to clean up any artifacts. Adjust the opacity of the darkest layer to make it “look right”. In this example, the combined image looked best at about 93% opacity.

Correcting “Off” Colors Due to Light Source Issues

The penultimate step was to create a Hue and Saturation adjustment layer. Lock the adjustment to the Darkest layer (hold the Alt/Option key and click on the boundary between the adjustment and the darkest layer). Then click the “Finger selection”  (just below the word Presets). Now there is an eye-dropper which you use to select the color that needs correction. In this case, clicking the dropper on the cyan colored palm frond is the right move. Adjust the saturation slider way down, lightness down, and fiddle with the hue to make the bizarre color more natural.

Aggressively toning down the cyan colored palm fronds

Removing Wires (and other distractions)

Finally we also used the Spot Healing Brush tool to “heal out” the utility wires. Here is a short-cut for healing out a straight line. Click the beginning of the area with the spot healing brush, then hold shift and click the end of the line. Shift causes the brush to be applied in a straight line between the first and second clicked points. The shift-trick works with almost all brushes. Two other tricks with the spot healing brush tool are to:

  • Start where the surrounding area has a predictable substitution (not a busy area) and work outward from there
  • Use as small a brush as you reasonably can

For example you can adjust the spot healing tool brush size to about double the width of the utility line, then click the healing brush tool where the arrows point below. Next work your way outward toward the tree on one side, then the other.

Summary

Here is a summary of the steps taken – not including the palm frond “naturalization” or spot healing described above.One more trick worth noting… the histogram shown on the Curves adjustment will give you a clue what may need adjustment.

Want to know what we consider the top 5 most used photo editing skills? Read here (and part 2 and part 3).

Back In The Saddle

Published: October 30, 2017

It is premature to say we are back in the saddle after a long hiatus, but Steven Christenson did recently join forces with his mentor: Harold Davis for another “Dark of the Moon” Shoot in the Eastern Sierras. We have plans in motion to do more workshops like this beginning in 2018 (planning date is early September).

Harold and Steven at Lathe Arch. Photo by Julian Köpke.

As is our custom, we arrive early and re-scout our planned locations during daylight – as well as checking other potential locations. Not every location is suitable for our participants. Some locations are too dangerous, or too difficult to reach due to vehicle clearance or hiking distances or too small to accommodate participants. One pretty place that fails some of those tests is Steven’s favorite spot he calls Pointy Land.

Pointyland Redux

Three shot panorama of “Pointy Land” in Alabama Hills, California

Give Us A Tip, Will You?

On the optional last night we went to a place that while large in area and easily accessible is not able to accommodate many photographers jockeying for the premium views. Such a place is the Lady Boot Arch below.

It seems appropriate to leave you with a processing tip (thanks for asking). The shot below was created from two exposures. The filename we gave it is LaserBoot_C-5550+75.psd The name serves to identity both the photo AND the two images (C-5550 and C-5575) that we used to create it.

Laser Boot

Layers and Adjustments

Here is what the processing looked like from the “Layer Palette” of the image above.

Alignment Headaches

The tricky part in assembling the images was that the ball head had a problem. The head was not stable and it rotated left and right slightly between shots. We had to figure out how to align the images.  Here are some things that DID NOT work:

  • Using Lightroom Photomerge. (“Sorry at least 40% image overlap must be present”)
  • Using Photoshop Merge to HDR Pro. “Composite mode” balked that the photos could not be merged, while the “Automatic mode” produced an image like the one below.
  • Using Photoshop Align Layers – “Not possible”

Photoshop could not figure out how to align the two nearly identical images. The laser and lit foreground confused it.

So how did I get them to align? Selection, slight rotation and “nudging”.  Since there was a lot of green bleed on the laser image (C-5575), I masked off that bleed – look at the layer mask on the bottom image in the “Photoshop Layers” image above.

Merging Images

To make it simple to merge the laser image with the light painted foreground, I:

  1.  Used the “Quick Selection tool” on the sky of the laser image,
  2.  Deleted the sky. Delete? Yeah, just the delete key. That operation makes the selection go bye-bye and become transparent. The same effect can be done using the Eraser tool, but that is just too much work!
    Note: I should have first duplicated the layer in case I needed to do more work on it.
  3. Set the lighted foreground (C-5550) to Lighten mode. Removing a potentially conflicting sky from the image below results in an accurate sky that did not need much cleanup.

We show one of the adjustments (Sky Color Correction). The actual curve(s) to use depend on the sky you start with. A careful observer will notice a lot of Curves Adjustment Layers. Curves can do almost everything all the other adjustments can do (lighten / darken / contrast / white balance and much more) so I recommend learning how to use Curves. Indeed we use curves so much that the Advanced Stacker Plus has a dedicated hot key: F9 to create a custom contrast enhancement adjustment layer.

Once the masking and adjustments were all just as I wanted, the almost last step is to do Ctl-Alt-Shift-E (Cmd+Alt+Shift+E for Mac people). That finger twister is a little noticed but VERY handy shortcut that does the same thing as “Flatten image” – but it does the flatten to a new layer and leaves everything else alone. If for some reason the finger-twister does nothing, be sure to select a visible document layer – not an adjustment layer. After the magic twister sequence, drag the newly created layer to the top.

I name the final layer: combined/heal. On that layer any distractions can be cleaned up using the spot healing brush. In Laser Boot photo there were a few hot pixels and some distracting marks on the rock that needed attention.  If there is some significant noise reduction to do the heal layer can be cloned again and Noise reduction applied.

A Parting Image

We like this image created the second night of the workshop. This is a conventional star trail, but apparently Flickr-ites loved it. It became Steven’s most popular image ever.

Reaching for the Sky

Not surprisingly, the image was created using the same foreground/background blending technique described earlier.  The background was stacked with Advanced Stacker PLUS. But there was not any movement, so it was easy to combine the two shots.  If you’d like to see another gorgeous view of this landscape from a different perspective, check out Harold Davis’ shot: Forgotten Kingdom (and read about it on his blog)

Steven in Galen’s Arch with composite Milky Way background. Foreground by Julian Köpke.

Wait, looks like we have two more images for you. The image above is a complete cheat: a combination of an iPhone daylight shot by Julian Köpke, and one of the pieces of the Milky Way we shot for the image below. We make no guarantee that the sky can be oriented like that in the arch. We included the above shot because it used the same foreground/background blending technique we just discussed – but with a bit more manual mask painting.

The image below is a Milky Way from horizon to horizon. North East is at the top, South West at the bottom.  We included this image here because … we like it.

Overarching Majesty

One of the reasons we like this image is that the Milky Way is natural – not processed to death.  We could have cloned out the camera, but thought it provided a nice context.