Tuesday, July 28, 2026

Another GoPro Panoramic Sky Lapse

The following panoramic time lapse video shows the sky above Fairfax County, Virginia USA on 21 July 2026 beginning at 1:06 PM EDT. The video was recorded using my GoPro HERO4 Black action camera mounted on an inexpensive mechanical one-hour kitchen timer.

21 July 2026 | Fairfax County, Virginia USA


The GoPro video was recorded after the "22 degree halo" all sky time lapse video featured in my last blog post. Regrettably the halo isn't visible in the GoPro video.

Panoramic Image

The following panoramic composite image was taken using the "Camera" app on my Apple iPad mini 6, set for "Pano" mode.

21 JUL 2026. 1:38 PM. Panoramic view. (14487 x 3785 pixels.)

RadarScope

Low level cumilform clouds (shown in the preceding panoramic composite image) were growing larger and darker ahead of an area of thunderstorms advancing from west to east.

RadarScope (app) animation | 1:39 PM to 1:58 PM EDT.

Tech Tips

The camera was set for "Video" mode / "Time Lapse Video" submode at a resolution of 4K and an interval of two (2) seconds.

I don't set the kitchen timer for a specific amount of time -- I just turn the dial clockwise until it's set for one hour. Then I compose the shot (by rotating the ball head to check the end points of the panoramic view) and start recording for as long as I need/want.

"CommerciaLapse," one of my earlier blog posts, features photos and a detailed description of the magnet-free rig I use for mounting the one-hour mechanical kitchen timer on a tripod plus a description of how the GoPro is mounted on the timer.

Related Resources

Copyright © 2026 by Walter Sanford. All rights reserved.

Thursday, July 23, 2026

22 degree halo

A time series of 412 photos was taken during the afternoon on 21 July 2026 using my Fujifilm X-T1 camera and a Meike 6.5mm circular fisheye lens. The first photo was shot at 12:37 PM; the last photo at 12:58 PM.

The camera was mounted on a tripod with the lens facing the zenith. The entire dome of the sky is shown in the circular field of view; the horizon is located around the outer rim of the circle.

21 July 2026 | Fairfax County, Virginia USA

A 22° halo around the Sun is visible high in the sky.

The small halo appears as a white or mostly white luminous ring of 22° radius with the light source (Sun or Moon) at its centre. ... The sky inside the ring is conspicuously darker than the rest of the sky. The halo always has a 22° radius regardless of its position in the sky. Source Credit: 22° halo, International Cloud Atlas, World Meteorological Organization.

Camera Settings

The camera was set for manual exposure and manual focus. The Meike lens features a "clickless" aperture ring. The Aperture was set for the f/8 mark on the aperture ring. The manual focus ring was set near the 3 ft mark. The Shutter Speed was set for 1/4,000 s, the fastest mechanical shutter speed featured on the Fujifilm X-T1. 

The camera was set to record FINE+RAW, in L 3:2 format (4896 x 3264 pixels). The film simulation was set for Provia/Standard. A three (3) second interval was used to allow sufficient time for the camera to save the photo files to a memory card.

Panoramic Image

The following panoramic composite image was taken using the "Camera" app on my Apple iPad mini 6, set for "Pano" mode. The iPad was mounted on a tripod located at my usual vantage point on top of a seven-story parking garage.

21 JUl 2026. 1:28 PM. Panoramic view. (14402 x 3877 pixels.)

Notice the low- and middle level cumuliform clouds.

Wind (mph), Weather and Sky Condition

"Wind (mph)," "Weather" and "Sky Cond." are highlighted by red rectangles in the following excerpt from a table of three-day weather observations for KDCA on 21 July 2026, nearest the times when I recorded the time lapse videos and panoramic composite photo.

Source Credit: KDCA | National Weather Service

The preceding table shows the surface wind direction is from the south-southwest. High level cirrostratus clouds (Cs) were streaming across the sky from west to east, as shown in the time lapse video. The difference in wind direction indicates vertical wind shear.

Tech Tips

The camera-lens combo was mounted on a ball head/tripod so that the lens is pointed at the zenith. Notice the green plastic spirit level mounted on the X-T1 hot shoe, used to level the camera body in this orientation.

Camera-lens combo mounted on ball head/tripod.

Apple "QuickTime Player" was used to render 412 JPEG images from the photo set into a time lapse video. The video was edited lightly using Apple "Photos." The post-processed video clip was made into a YouTube movie using "DaVinci Resolve."

Related Resources

Copyright © 2026 by Walter Sanford. All rights reserved.

Tuesday, July 14, 2026

Backdoor cold front

For locations in the northern mid-latitudes, weather systems usually move from west to east. Usually, but not always.

A backdoor cold front is a weather boundary that moves south or southwest, bringing cool air from the east or northeast. Unlike typical cold fronts that push west to east, it arrives from an atypical direction—entering through the "back door." Source Credit: Backdoor cold front (Wikipedia).

On 12 July 2026, weather radar showed a backdoor cold front located over the mid-Atlantic United States.

RadarScope (app) animation beginning at 12:00 noon EDT.

The precipitation echoes moving from east-to-west (to the north) and west-to-east (to the south) trace an invisible boundary between different air masses -- that's the "backdoor" cold front!

RadarScope (app) animation beginning at 2:18 PM EDT.

Tech Tips

Set the RadarScope (app) "Radar Frame Count" for 30 frames, the maximum number of frames.

Settings / General / Data / Radar Frame Count

A 30-frame time lapse lasts ~25 to 30 minutes. That's not very long, so I recommend you set the preceding videos to Play in a "Loop."

Click the white "Play" button. When the button turns red, right-click on the video and select "Loop." Then press the "Play" button again and the video will loop over and over. Alternate procedure (for mobile devices): Click the "Settings" button; select "More options" then select "Loop."

Related Resources

Copyright © 2026 by Walter Sanford. All rights reserved.