Tag Archives: star trail

Darken Mode Stack Tip Using AdvancedStacker PLUS 15

Published: March 15, 2018

The new Advanced Stacker PLUS 15 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 15 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 15 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).

Exploring Night Photography Lesson 5: Photo Processing

Published:  May 4, 2016
Last Update: May 10, 2016

Homework assignment: Star Trails. This was created using StarStax with 150 exposures of ISO 800, f/4, 15 seconds.

Homework assignment: Star Trails. This was created using StarStax with 270 exposures of ISO 800, f/4, 15 seconds. What are those things where the arrows are pointing, and what is the circled constellation?

Last week in lesson 4 the subject was star trails. We continue that theme this week and fill in with some material that you may have learned the hard way.

What settings?

Last week’s assignment was:

  • Weather Permitting, get at least 20 minutes worth of star trails. First determine what the best starting exposure is, then take 20 minutes worth.

I chose to take about 270, 15-second exposures at f/4, ISO 800 for my star trails using an intervalometer trick that I demonstrated in class. That nets over an hours worth of exposures. But how did I come up with those settings?  It was a little bit experience, and a little bit application of the principle taught in the very first homework: namely try and see!  But how did I decide what evening I would try to get star trails?  The weather needed to be right, so the germaine question is:

When will the weather be right for star trails?

Well, we strongly recommend weather.gov. See our article about how to use the information. Indeed, we like it so much, we even created a page with forecasts for places we often find ourselves going.

Weather, check. Settings, check. Now what?

Wait, what about the moon? We need to know when it rises and sets. A full moon washes out a lot of the night sky and makes for unpleasant star trails.  There are many places to determine what the moon situation is like, but I like to use The Photographer’s Ephemeris (either the App, or the online version).

Next we need to review the Stacker’s Checklist both to be sure we have all the gear and that we know what we are doing. Best is to run through it at home. Is it surprising that there are SO MANY steps? Sorry, but they are there to prevent you from making all the mistakes we’ve made.

In class we reviewed our homework (star trails) from the last assignment and discussed hits and misses.  Finally we got to the meat:

Photo Processing

It would be foolish to attempt to describe everything we did in class… especially since we have so many articles here describing how to photo process your shots (and webinars and recordings, too – oh my!)

But we demonstrated three things:

  1. Super simple Panorama creation using “Image Composite Editor” from Microsoft. Yep. You have to have a Windows machine to use it… but it’s free and SUPER simple and more effective than anything we’ve managed to get out of Photoshop or Lightroom.
  2. What Lightroom is good for… cataloging your images. And what it’s NOT good for: complex multi-image editing – for example star trails and image combinations.
  3. The three most powerful and useful elements of Photoshop:
    1.  Layers – This is the real meat of Photoshop together with blend modes which mathematically combine layers.
    2.  Masks – Masks allow you to change the way layers and adjustments get combined by “masking” out some of the changes.
    3.  Adjustments:  Curves – Curves are the best tool to learn since nearly everything you can do with the other tools can be done with curves… and if you get the hang of it, curves are actually easier to understand.

We also demonstrated Adobe Bridge which is a “lighter weight” version of Lightroom – one that doesn’t require any importing. And we spilled the beans that “Adobe Camera Raw” is the guts of Lightroom. And that Lightroom adjustments are really just like what you can do in Photoshop… with some of the magic, and much of the versatility – and also much of the complexity removed.

We also explained why RAW is the way to go, and why RAW is ugly (short reason: the camera does not see the way we do it just records heaps of numbers).

We did not do this in class, but we covered much of the ground:

12 Minute Star Trail using Advanced Stacker PLUS version14D from Steven Christenson on Vimeo.

 

Top Six Questions We Answered About Lightroom

  1.  If I use Lightroom to catalog and organize my images (keywords, etc) am I forever wedded to Lightroom?
    Practically, yes. We used to use Picasa and did our organizing and cataloging there…. unfortunately Picasa was discontinued and Lightroom had no way to import the data. If you stop paying for your Lightroom Cloud edition, you may be stuck as we do not know of a tool that can digest your Lightroom catalog.  SOLUTION: BUY Lightroom, don’t just subscribe. This is not so true about Photoshop, by the way, many tools can import Photoshop files.
  2. Is there anything particularly painful about Lightroom I should beware of?
    Yes. Lots! When your image library gets large, managing images is unwieldy, especially if you want to use multiple computers and multiple storage devices to hold those images.
  3. Is Lightroom good for Night Photography images?  Not particularly. Most of the power of manipulating night images is found in Photoshop (averaging, stacking, compositing). Lightroom can not composite images, for example.
  4. Is Lightroom hard to use? Yes. No. Maybe. We think it is powerful and much easier to use than Photoshop. But there is still lots of learning and ample room to do the wrong thing.
  5. Should I import everything I shoot?
    Yes… and No. The smaller the image library the easier it is to keep organized. Of course if you delete the very images you later want you will have paid a price for your anti-hoarding behavior.  We do believe it is reasonable to throw away .JPGs if you are keeping the RAW files. And those fringe images that you are likely to never use – well you are likely to never need them.
  6. Can I do everything in Photoshop that I can in Lightroom?  Yes, mostly. Photoshop has no image organization tools, but yes, you can make all the adjustments in Photoshop that you can do in Lightroom… only it will be harder to do and may be harder to apply to multiple images at once.

Oh, by the way, the official name of Lightroom is “Adobe Photoshop Lightroom” just to confuse everyone.

What Are the Top 4 Things to Know About Photoshop?

  1.  Photoshop is the lingua franca of photo editors. Nearly every other tool does not come close in the level of acceptance and use. Widespread use does not mean Photoshop is the best tool. Remember how VHS beat Beta? These days video tape is hardly even used! Photoshop has been around a long time and has a LOT of baggage. Photoshop is built to do a lot of things way beyond photo editing (scientific analysis, animation, typography to name a few). Because Photoshop has been around so long, the tooling is unnatural .  We started with Paint Shop Pro and found it much, much less confusing.
  2.  Is there an alternative to Photoshop?
    Yes, there is the free Gimp, and many others. Unfortunately as we have noted above, those tools are not as widely used so getting help with them is harder.
  3.  Do you have any suggestions on what I should learn first?
    Why yes, thanks for asking. We have a series of articles on that:  We call the series “The Most Used Image Editing Techniques” and it comes in three parts: Part 1, Part 2, and Part 3.  The one we used the most is the “Simple Astrophotography” Trick to reduce noise.  We also like this trick to select a foreground (it’s used in the video above) and use it a lot.

Homework Assignment

  •  Fire up Photoshop and try to duplicate this image:
Final image with replaced foreground

Final image with replaced foreground

Super big hint… all the files you need and the process to accomplish the task is described in this article: Foreground-o-Matic.

  • Use the same technique on your own image(s) to pick a more interesting foreground image from a “stack” (sequence) of images.

Feel free to comment below if you know the answers to the questions we asked in the first image above. We will reveal the answers in the next article.

Expanse of Waters – Night Vertorama

An example of using a panorama technique at night at Red Rock Canyon State Park, California. Coming soon a lot more information about night panoramas!

I created a Vertorama (vertical panorama) of the very last few shots before twilight began to overwhelm the stars. This is 3 separate images with about 4/5 overlap between each, but only the top image contains the star trail. You can see almost 3 hours worth of star trail taken here in this image.

I like the Vertorama technique here because it allows me to get the sky and the foreground in better context.

People often assume that the foreground was shot during the daylight, in fact the shortest exposure was 30 seconds and that was still at ISO 500! The very nearest components (the rocks and scrub) were taken during nautical twilight.

There was a tiny bit of moon (slender crescent) as well.