Geometry and The Moon

Please do not run away. We are about to use adult language here. For example we will be using the word trigonometry. Still here? Good.  Here is a very pedestrian looking lunar eclipse photo taken with a 280mm lens*, cropped.

Near and Distant Neighbors

Very Ordinary Photo of the Lunar Eclipse with the planet Uranus in the lower left.

This past lunar eclipse several of us put our heads together to try to come up with a more creative photo than the one above. We had a trigonometry problem, however. On the West Coast the last moment of totality occurred at 4:24 AM PDT. We were brave enough to be out at any time of night – even if it meant extreme sleepiness in our day jobs but our problem was that the lowest the moon would be in the sky at the last bit of totality was 32.6 degrees above the horizon. We determined that angle using Stellarium, by the way. Unfortunately there is pretty much nowhere to go to get a nice large moon near an interesting object when the moon is almost 33 degrees high.

Wait: Why do we want the moon and the object to be similarly sized? Here is why… we want the moon to be noticeable like the Fantasy version below, not merely “present” like the real photo on the right. Even bigger would be better, right!?


Notice above right (Reality) and below how tiny the moon is compared to the building in the foreground?  Indeed, if you see a photo taken from anywhere on the West Coast where the eclipsed moon is significantly lower in the sky or larger than shown against foreground, you know it has been “photoshopped“.

Plan C: San Jose City Hall Eclipse Sequence

In short, it is nigh impossible to get the large moon effect with an altitude (angle) of 32 degrees here is why:

Calculating the Angles

Calculating the Angles

Just how far away do we need to be in order to get the moon the same size as an object of interest:

114.6 x object size

In other words, an object that is one foot tall, requires us to stand 114.6 feet away to make the 1/2 a degree angular size of the moon the same angular size as that 1 foot tall object.  The number “114.6” is from this calculation:

1 / TAN (0.5 degrees)

Yeah, that is trigonometry. Using still more trigonometry it is possible to calculate how high above the horizon a 9 inch tall object has to be so that it is “moon sized”.  We did that for you in the “Calculating the Angles” diagram above. Once you calculate the distance from the camera of 85.9, you can multiply that by the sine of the angle to calculate a height of about 46 feet! Here is the trigonometry:

Height = 85.9′ * SIN (32 deg)

You can go one step farther and calculate the distance from the object with ‘distance = 85.9 * COS(32 deg)’.

Of course after all that calculating you will still need to find a location, have contingency plans for weather and so on. At StarCircleAcademy we have built some tools and put together materials to help in all these endeavors.  We teach these things in our NP111 Catching the Moon Webinar.

The Road To The Temple

Below is where we ended up. This image is from our friend and co-conspirator Andy Morris.

Lunar Eclipse over Temple by Andy Morris of PhotoshopScaresMe

Four of us plotted and schemed to get an interesting shot. Above is Andy Morris’ result.  Click the image and you can read a great article about how he created the shot using Photoshop Skills at his site: In fact, it’s a great article which we strongly encourage you to read. You’ll learn how he composited the images together in Photoshop as layers.

The Long Conversation to Pick a Location

Andy has more details including how alcohol played a part in the process. Mostly I, Steven, was the wet blanket explaining why the geometry was all wrong.

  • The Stanford (Hoover) Tower looks like it is shrouded in trees from the needed angle
  • Bank of Italy (formerly BofA) in SJC doesn’t work
  • The main problem with the wind turbines is that the angle to the top of them is something around 12 degrees above the horizon which is 40 moon diameters below the eclipse.
  • Here is why the GG Bridge doesn’t work…
  • This seems to be the best solution I could find: the Coit Tower…
  • Darn. It would appear the coast is out. Forecast calls for Fog from SF to HMB
  • This might make an interesting foreground (see below)… Somebody want to check if they will mind us being on their property in the wee hours?

*Ok, we lied, it was actually a 70-200mm lens with a 1.4 TC on a full frame camera, but the net is the same: 280 effective mm focal length.

Where did you go and what did you get in your planning efforts?  Post a comment and link below… we’d love to see what you came up with!

Off Topic Post Ahead: Combating Robocalls

Boy have we been busy at StarCircleAcademy. Eric has been burning the midnight oil in his day job being a mad scientist and all.  Steven survived layoffs at his day job and found his workload tripled, and Harold keeps plugging away writing, teaching and creating full time.

We are going a different direction with this article which we hope you’ll regard as a public service announcement.  Even though Steven lives in the Silicon Valley, his only high-speed option was Comcast/Xfinity which rates an “F” on the Better Business Bureau. But this article is not about Xfinity, their egregiously intentionally confusing pricing, or their inept customer service.

Death to robocallers

Death to robocallers

We Are Tackling Robocallers – And Saving You $

With high speed internet, it’s now possible for Steven to more effectively run Webinars at home as well as work from home part of the week on his day job. But this gave rise to severe annoyance. . One day while working at home Steven got 11 “robocalls” from telemarketers including a call you’ve probably gotten before.  The most famous fraudulent (and illegal) caller is “Rachel of CardHolder Services“. You probably have gotten robocalls yourself, even if you, like us, have been on the Do Not Call list for a long time. Even though Steven has successfully sued telemarketers in the past the RoboCallers with their automated voice messages are hard targets to assault via small claims courts. Robocallers spoof phone numbers and you can not find out who they really are without following the money (i.e. paying for the scam).

The FTC even held a contest to find a way to stop robocalls. The winner was NoMoRobo is rather ingenious.  You configure your phone to simultaneously ring a number at NoMoRobo which analyzes the calling number. If the calling number is a suspected robocaller – NoMoRobo answers the call for you and your phone stops ringing.  In short, you don’t have to hang up on the RoboCaller yourself, NoMoRobo will do it.

BUT There is a catch.  Many, many services do not support simultaneous ring, including AT&T, or Xfinity’s (overpriced) voice offering.  AT&T has all sorts of very expensive plans to “help”, but mostly they help themselves to your money and provide next to zero value.

At AT&T a landline phone with CallerID, Anonymous call rejection and number blocking will cost about $45 / month after all fees and taxes. There will be a significant limit to how many numbers you can block while the robocallers can spoof any number they wish.

But if you already have a decently fast internet, you can get VoIP from providers for less than $11/month.  Who? PhonePower for one. But we will get to that in a minute.

Here is how I set up my service:

  1. Call AT&T and tell them the Robocallers and telemarketers are annoying (IMPORTANT STEP!)
  2. Call AT&T and tell them I want “simultaneous ring” service so that I can use NoMoRobo to stop RoboCallers.
  3. Open an account with PhonePower and waited for their device to arrive.  I *could* have moved my phone number to them, but decided it will be better to get a new number.
  4. Called AT&T and told them I’d had enough and to cancel all services on my landline except call forwarding.  This gives me a few months to notify folks of my new phone number… and I get more features out of PhonePower at a lower price.
  5. Installed my PhonePower device and configured my landline to forward to the new number. Interestingly while I don’t get caller ID information on my landline, I *do* get it from the PhonePower line.
  6. Unplugged my cordless phone from my landline jack and plugged it into the jack on the PhonePower device (an ObiHai).
  7. Signed up with (free).
  8. Registered my new phone number (and reregistered my old numbers) to the US Do Not Call list.
  9. Configured my PhonePower line to first ring the NoMoRobo number for 6 seconds, then to ring my PhonePower number.  This is BETTER than simultaneous ring because it doesn’t ring the phone in my house until AFTER NoMoRobo has had a chance to disconnect it for me.

What Can You Do?

You can report the number to the FTC here.  Too bad their site is painful to use.

Change your answering machine greeting

“Please Hold for a second…..  (several second pause) You’ve reached us. Leave a message”.

Why? Because robocaller software listens to the line and when they think they’ve got a live person speaking, they play out their message or connect you to an agent. By leaving a pause and using a short greeting, you convince them into thinking your answering machine is a live person which causes them to leave a message or summon a live person whose time you want to waste as much of as possible (see next item). Also, if it’s a Robocall and you fooled it into leaving a message you will have proof of their call should you need it in court!

Answer It Yourself… and Do THIS if you get a Live Person

The worst thing you can do for your fellow man is to immediately hang up. The worst thing you can do for you own sanity is to scream or shout obscenities (though sometimes it is quite therapeutic). As soon as you realize it is a telemarketer say:  “Sounds interesting, Tell me more.” Then put your phone on mute, put it down and do not hang up until you hear the “re-order” (phone off hook) tone.

Why? A> Every second they spend on you they cannot annoy someone else.  A few days ago I had a caller who called back three times. The second time he called he said “so are you interested?”  I said: “I’m sorry, I couldn’t hear you very well, could you explain again?” (MUTE). The third time “I’m still confused, explain the benefits…”
B> Most telemarketers are trained to not hang up until they are clearly dismissed… if you make it easy for them to move on they will.

Isn’t it mean to waste their time?  Perhaps, but remember they called you in violation of the Do Not Call rules!

NEVER Do Business with a Telemarketer

If you’re on the Do Not Call list and they are calling you anyway they are unethical and willing to get business illegally. Does that sound like a business you want to do ANYTHING for you?

Do Not Answer Any Questions in a “Survey”

First, many surveys – which are permitted under the Do Not Call rules – are actually marketing scams pretending that they are surveys. Either you’ll get the sales part right away, or you’ll be placed on a list to recall if they find out ANYTHING useful from you. As soon as they ask anything or give an inclination that they are a “survey” I tell them to “Put this number on your do not call list and send me a copy of your do not call policy.”  While survey takers are not required to do either, it’s worth a try.  If they press or say “we are exempt” then my response is: “And for that reason I will not participate in any survey.”

Will These Tips Stop All the Calls?

Sadly, no. Political organizations, charities, and several other exemptions exist that allow those organizations to call you notwithstanding your status on the Do Not Call list.  Robocall scofflaws have also started spoofing (pretending to dial from) local numbers and businesses. You might even get what appears to be a call from your own number.  The only way to put an end to all the calls is to get a service that pre-answers and requires the user to press some (random) digits to connect to you.


What About Phone Power?

PhonePower is one of many companies providing Voice over IP service. You’ve no doubt heard of Vonage, for example. But Vonage charges $28/month (do not be misled that $9.99 price is temporary and doesn’t include all fees).  At Vonage you have to pay extra for a SoftPhone (computer based phone), for example.  Phone Power on the other hand acquired BroadVoice a company with whom I had service for several years with good service.

If I have any complaints about PhonePower, it is that it is a little nerdy to configure, their user interface is a tad clunky, and they do not have a feature like “call intercept”.

Are There Other Alternatives?

Oh yeah. Google Voice, which is super cool and free and it has some spam caller detection features.



Bad Bridge Behavior (2014)

This discussion applies to Windows machines in particular. We welcome your comments on whether the same problem occurs on Macs.

In Summary

Installing Photoshop CC 2014 on a Windows machine may have unpleasant side effects and one of those side effects is being forced to use ONLY Photoshop CC 2014 from Adobe Bridge.

The Details

Adobe Bridge is a rather powerful tool. In fact, we recommend it when using the Advanced Stacker PLUS. However during a live webinar recently Bridge stymied us.

Despite the release of many CC 2014 versions, there is currently no Adobe Bridge CC 2014 – the latest available is CC. Within Adobe Bridge CC a double click of a JPG or RAW file opens the file clicked in the most recently installed version of Photoshop EXCEPT if there is already a version of Photoshop running. If, for example you have Photoshop CS5 running and the most recent install is CC, then a double click would open the file in CS5 rather than CC. Adobe Bridge default file open still behaves the same way even after upgrading to Photoshop CC 2014. However other parts of Adobe Bridge do not behave the same.

The Tools -> Photoshop -> Batch operation previously worked just as described. No matter what the default version of Photoshop, using the Tools -> option would kick the currently running Photoshop and elicit Photoshop’s Batch menu. UNFORTUNATELY, The “Tools -> Photoshop -> Batch” operation does NOT work the same way once you install Photoshop 2014 CC.  With Photoshop CC 2014 installed, Tools -> Photoshop -> Batch will ONLY open Photoshop CC 2014. If you have another version of Photoshop already running, the Tools operation effort silently fails.

You can determine what version of Photoshop will be invoked by the Bridge -> Tools menu by selecting a file and doing  a “right click” and inspecting what is listed in the Open With list.

Default association

Default association


Also particularly unpleasant is the fact that only ONE of the Photoshop CS versions is listed as a choice in the Open With dialog even though on our windows machine we have 4 versions of Photoshop installed (CS5, CS6, CC and CC 2014). We’d love it if we could choose which Photoshop to open, but Photoshop CC 2014 confuses Windows into thinking that ALL versions of Photoshop are CS 2014. Normally in the the windows file browser you can right-click a file and “choose a default” program to open it.


Here we’ve chosen to associate a default to a PNG file.

Window_FileAssociation_Step1 The next step is to navigate to the program we want to open with by default… Here we will select the Photoshop CS5 folder, and next the photoshop.exe

After selecting photoshop.exe in the CS5 directory, we are disappointed to see the result look like this:WindowsPSCC2014_Confused

To Change Associations For Different File Types

While Photoshop does continue to make useful improvements, not all of those improvements are as easy to navigate. If you would prefer that Adobe Bridge open a different default version of Photoshop you can change the file associations within Adobe Bridge as shown. (Select Edit -> Preferences or Ctl-K).

Changing File Association

Changing File Association – click for a larger view

What is so Super about a Super Moon?

August 10, 2014 just passed. It was the most recent Super moon. The term “Super moon” was coined by astrologers not astronomers and refers to a moon which is both full and also within 4 hours of its closest approach to earth.

The media gleefully report the super moon and show pictures of huge moons (many of which have been photo manipulated).  Here is the straight scoop on the subject. If you’re wondering whether that photo you’ve seen of the “too big to be true moon” has been doctored, we have an article on that.

Extreme SuperMoon [5_059193]

The most “Extreme” Supermoon of the Century occurred in 2012.  Here it was photographed in Yosemite approximately 15 minutes after it reached perigee.

What Makes the Moon Larger or Smaller When Seen from Earth?

Because the orbit of the moon around the earth is not circular, the distance from earth to the moon varies and thus the apparent (angular size) of the moon changes. Every lunar cycle the earth-lunar distance varies between its closest approach called perigee and its farthest distance, called apogee.  How big is the difference? The closest approach is 363,104 km (225,622 miles) and the farthest, 406,696 km (252,088 miles). 

What is the difference in apparent size?  At apogee, the moon is 22,293 km farther away or -5.8% smaller than an average moon.  At perigee the moon is 5.54% larger than the average moon. Comparing apogee and perigee moons, the difference is a maximum angular size difference of about 12%  The average angular size of the moon, by the way, is half of a degree or 30 minutes of arc. That angle is slightly smaller than the size of the nail on your little finger when held at arm’s length. Those of you with significantly mis-sized pinky nails or unusual arm length might want to find another object to measure with at arm’s length.

In short: You’d have to be a very keen observer to notice a 12% difference in size between a super moon and a “wimpy” (apogee) moon.

Because the moon is slowly spiraling away from earth eventually the perigee moon will grow smaller and smaller in apparent size until one day, we will no longer experience total solar eclipses. The perigee moon will be too small to cover the angular disk of the sun which also happens to be almost exactly one half of a degree. From that point on, all solar eclipses will be “annular” like this one in May, 2012. Had the moon been closer to the earth, this may have been a total solar eclipse.

Annular Eclipse Sequence [C_040079+5s]



How is a Full Moon Determined?

A full moon is defined as the moment in time when the sun, earth and moon are in syzygy. Syzygy is not only an interesting Scrabble(tm) word, but it defines when three bodies are in alignment. When the sun and moon are 180 degrees opposite one another relative to the Earth, we have syzygy which is the instance in which the moon is Full Moon. Many of us think of a “full moon” as that period during the month when the moon appears to be fully lit. That period lasts almost 70 hours, so we understand how reckoning a full moon as a moment in time is a bit confusing.

If you didn’t observe the August moon within 4 hours either side of when it was full, you did not see the super moon.  On the United States West Coast the super moon was not visible. Why? The moon set at 6:10 AM almost 5 hours before the moon was full. Those in Hawaii could just catch the super moon setting.  Those on the East Coast of the US had no chance at all. The whole super moon window occurred during the time the moon was not visible on the East Coast.

The Last (and Next) Visible Super Moons

If you missed the May, 2012 Extreme Super Moon (my term, photo above), you’ve missed the largest possible full moon for more than a century into the future. On May 5, 2012 fullness and perigee occurred within less than two minutes of one another.  But don’t fret.  The difference in size between the extreme super moon an the average super moon is too small to notice unless you measure carefully.  If you paid close attention you probably also noticed that the May 20, 2012 annular solar eclipse followed nearly half a lunar cycle after the May 5, 2012 super moon. That is not a coincidence! The moon was closest to us on May 5th so half of a lunar cycle away it must be farthest from us!

On August 10, 2014, full moon and perigee occurred within about 1 hour of each other. The next super moon is in September 8, 2014. The moon will not be as close to perigee at the moment when it becomes full, but the moment of full moon occurs at 9:38 PM PDT, just as the moon rises. It will be a true super moon!

Catch One Yourself

We plan to schedule a “Catching the Moon” Webinar well in advance. Stay tuned.  One complication is that the wonderful Photographer’s Ephemeris Tool will cease to work in desktop mode soon. It is being replaced with a browser version. While the tools is excellent, and we highly recommend it (and that you donate if you use it!) TPE still leaves some important bits of the puzzle unresolved – we will fill those in for you and give you a crack at our tool(s).

The moon caught between El Capitan and Half Dome - Actual size, no manipulation

The moon caught between El Capitan and Half Dome, Yosemite National Park – Actual size, no manipulation