New Video: Planning the Full Moon at DIA

Planning a Full Moon Shoot at Denver International Airport



Thank you for such a helpful video. You demonstrated several features of which I had yet to be aware. I’ve used other apps to plan moon alignment to various objects. This video exposed me to a plethora of features available on TPE Web that allow me to plan these types of shots precisely.

Your video showed a disparity between your and my Azimuths (reported from red to gray pins). I carefully placed both pins in the exact (or nearly so) positions you had placed them. I was able to verify accurate placement using details such as zooming in on Google satellite view, the distance between pins (4.06 miles), elevation (+334 ft), altitude (+0.87°), etc. My pin locations are:

 Red Pin:  39.887183°N 104.732156°W (Elev Offset:  5 feet)
 Gray Pin:  39.849248°N 104.673855°W (Elev Offset:  126 feet)

I’m intrigued by the disparity in the Azimuth values between your video (130.16°) and mine (122.67°). I suspect it might be related to the difference between magnetic and true north, but I’m not certain. A magnetic declination map suggests that Denver is roughly 10° East, but I’m not sure how this affects the Azimuth values.

I have looked in your help files (clicking the help flyout at the bottom-right of TPE Web). In doing so, I found the article titled “Does TPE use True North or Magnetic North?” This article states that TPE iOS allows the user to choose between True and Magnetic North, but it implies that TPE Web does not allow the user to choose between the two—rather, that TPE Web always uses True North.

Do you understand why our two Azimuths might vary? I am using Microsoft Edge (currently up to date, version 126.0.2592.81) on macOS Sonoma 14.5 (again, currently up to date). I have searched for any setting available within the TPE Web interface that might allow toggling between True and Mag North, to no avail.

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Hi Roger - glad you discovered some new stuff in the video!

This link is for the actual shot plan we used on the day:

I think the azimuth difference is due to magnetic declination. I don’t have it enabled in the web app (you can enable it in the Settings page), so the values you see in the video are relative to true north. When I enable it, I get an azimuth from red to grey pin of 122.94° based on the pin positions linked above.

It’s extremely rare that you would need magnetic north adjustment to be enabled nowadays. The only circumstances are if you plan to use an old fashioned field compass that does NOT have any adjustment for declination built-in. The only group of users I’ve been told that use that are film location scouts, and even that situation may now be changing.

So unless you’re one of those folks, I’d suggest disabling magnetic north.

There’s more detail in this article:

I updated the general article to better reflect the current state of play - that was originally written during the days of the v1 web app, which did not support magnetic declination.

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That clarifies perfectly. I was mistakenly under the impression that TPE Web only allowed true north. I see that I was wrong on that point. My TPE Web “north” settings were toggled to magnetic north. Switching to true north fixed the issue.

Thank you again.