Archive for the ‘Apple MacBook Air’ Category

Interactive infrared weather satellite image

May 9, 2023

The AMS interactive infrared [weather] satellite image resulted from the collaboration between the American Meteorological Society (AMS) education initiatives and the Cooperative Institute for Meteorological Satellite Studies, University of Wisconsin-Madison.

Infrared imagery is one of three types of weather satellite imagery. Black, white, and shades of gray are used to represent temperatures from the tops of clouds and the land & water surfaces on Earth. Black is the hottest temperature; white is the coldest. Sometimes this type of weather satellite imagery is color-enhanced for use by broadcast meteorologists.

The first image (shown below) is the non-interactive version of two screenshots from my Apple iPad mini 6. All three images in this blog post are from the same date and time.

08 May 2023 at 19:00 UTC (03:00 pm EDT).

As you move the cursor (red reticle) over the interactive image, the temperature (in degrees Celsius) and location (latitude and longitude) are listed.

The first screenshot shows the cursor (red reticle) over a dark area located somewhere along the Florida peninsula where the temperature is 27°C (78.8°F or 299.2 K). At such a warm temperature, we are almost certainly looking at land rather than water.

Cursor (red reticle) located somewhere along the Florida peninsula.

The the second screenshot shows the cursor (red reticle) over a bright white area located somewhere in/above Alabama where the temperature is -55°C (-67°F or ~218.2 K)! At such a cold temperature, we can be certain we are looking at the tops of very high clouds. This could indicate hazardous weather is occurring at the Earth’s surface.

Cursor (red reticle) located somewhere over Alabama.

Science can and should be fun. Have fun exploring using the AMS interactive infrared [weather] satellite image!

Related Resources

Tech Tips

The interactive infrared [weather] satellite image was tested using my Apple iPad mini 2 and 6, Apple MacBook Air (13″, M1, 2020), and Apple iMac desktop computer (vintage 2009) and is compatible with all of those devices.

Did you notice both the non-interactive and interactive infrared images are GIF files?

The [GIF] format supports up to 8 bits per pixel for each image, allowing a single image to reference its own palette of up to 256 different colors chosen from the 24-bit RGB color space. Source Credit: GIF, by Wikipedia.

In the old days before the AMS interactive infrared [weather] satellite image, we would use a scientific image-processing tool such a NIH Image (now ImageJ) to infer temperature from pixel values (0-255). Labor intensive, but it was fun!

Copyright © 2023 Walter Sanford. All rights reserved.

Comedy of errors

March 14, 2023

My first big focus stack turned out to be a comedy of errors. Lots of little things, all of them avoidable, but the one that broke the stack was when the camera battery died approximately two-thirds of the way through the project.

My new Fujifilm X-T5 has a much larger battery than my Fujifilm X-T3 so I never imagined it wouldn’t last long enough to create the stack.

I might have been able to salvage the stack by changing the battery without removing the camera from the focus rail, but the Manfrotto quick release plate partially blocked the battery door. Doh!

l use Arca Swiss L-brackets for all of my cameras. Good L-brackets are designed so the bracket doesn’t block any camera doors or ports. But I don’t have one for the X-T5 because it’s new enough that the selection of compatible L-brackets is poor.

I have two ways to provide continuous power for the X-T5 but I couldn’t use them because the battery door was partially blocked. Double doh!

Making lemonade from lemons

Long story short I used Helicon Focus to stack all the photos up until the power failure and the results look fairly good, as shown below. Oh what might have been. Triple doh!

ISO 400 | 80mm | 0 ev | f/8 | 1/250 s

The preceding composite image was created from 192 of 328 photos. I used a safe step size of 50 µm (microns) between photos. Each JPG photo is ~13 MB, 7728 × 5152 pixels.

The coin is acceptably in focus from the top of the coin to a point about two-thirds of the way toward the bottom. Zoom in on the horse’s head and you should notice sharp focus is lost beginning below its eye.

The amount of detail in the composite image is astounding, as shown in the close-up of the upper-right quadrant.

Close-up, upper-right quadrant.

Related Resource: Post update on 11 April 2023.

Copyright © 2023 Walter Sanford. All rights reserved.

Focus bracketing and focus peaking

March 10, 2023

Focus peaking can be used to visualize areas of a photograph that are acceptably in focus. This can be especially helpful when creating focus stacked composite images.

I recorded two videos that show simulated focus bracketing using my NiSi NM-200 manual focus rail. Notice how the focus peaking band moved across the subject from back-to-front as the carriage moved along the lead screw of the focus rail. The videos aren’t rock steady because I was turning the larger adjustment knob as I was recording the HDMI output from two of my Fujifilm X Series digital cameras.

The subject in both videos is a quarter, that is, a 25-cent coin in U.S. currency. President Theodore Roosevelt is shown on one side of the coin.

The diameter of a quarter is 24.257 mm (0.955 inches). The APS-C sensor used in Fujifilm X Series digital cameras is 23.5 mm x 15.7 mm. A good indicator of the magnification is how much of the quarter is visible in the photo frame.

Fujiffilm X-T3 camera plus Laowa 25mm Ultra Macro lens

The following YouTube video shows a simulation of focus bracketing using a Fujiffilm X-T3 digital camera plus Laowa 25mm Ultra Macro lens. Focus peaking (shown in red) helps to highlight areas of the image that are acceptably in focus.

Video of Roosevelt quarter at 2.5x magnification using an aperture of f/4.

Fujiffilm X-T5 camera plus Fujinon 80mm macro lens

The next YouTube video shows a simulation of focus bracketing using a Fujiffilm X-T5 digital camera plus Fujinon 80mm macro lens. Focus peaking (shown in red) helps to highlight areas of the image that are acceptably in focus, same as in the preceding video. Although it’s not an apples-to-apples comparison, I set the lens aperture to f/4, like the X-T3/Laowa macro rig.

Video of Roosevelt quarter at 1x magnification using an aperture of f/4.

Safe step size and focus banding

After watching the preceding videos, I think it should be clear why macro photographers use focus bracketing to create focus stacked composite images that show more depth of field than is possible from a single photo.

Focus peaking helps to highlight areas of an image that are acceptably in focus. Focus banding occurs when there isn’t enough overlap between the areas that are in focus from one image to the next. This is why it’s critically important to calculate the safe step size BEFORE you begin a focus stacking project.

Tech Tips

The following YouTube video shows how to set my Fujifilm X Series cameras for “clean HDMI” video output. Sometimes it’s helpful to turn “ON” the info display, for example, when creating “how to” videos like this one. You can see my camera settings at the beginning and end of the video.

Video of Menu settings for “clean HDMI.”

A micro-HDMI cable was used to connect my cameras to a MacBook Air (13″, M1, 2020) laptop computer via an inexpensive HDMI Video Capture adapter (HDMI to USB). I used Apple QuickTime Player (free) to record the HDMI video output from my cameras.

Open Apple QuickTime Player. File / New Movie Recording. Click the down arrow disclosure button located to the right of the red Record button and make the following settings.

  • Camera = USB Video [= HDMI adapter]
  • Microphone = MacBook Air Microphone [for narration, voice over]
  • Quality = Maximum [1920 x 1080p, 25 fps]

Movies are recorded as .mov files.

Related Resources

Copyright © 2023 Walter Sanford. All rights reserved.


Please stay tuned …

March 7, 2023

I’m working on a blog post that isn’t ready for publication. It should be finished sometime within the next day-or-so, so as the title says, please stay tuned.


GoPro two-for

May 6, 2022

This blog post is a GoPro two-for. First I will prove that there are only two user-selectable settings that can be made using the GoPro HERO4 Black action camera set for Video Mode / “Time Lapse Video” submode. Second I will demonstrate two settings that you should make under Setup Mode in order to use your GoPro camera as a Webcam.

I used a relatively inexpensive MavisLink Video Capture Card to connect my GoPro HERO4 Black to an Apple MacBook Air. Open Broadcaster Software (OBS Studio) was used to record two video clips showing the small LED screen on the front of the HERO4 Black.

Video Mode / “Time Lapse Video” submode

The following short video (0:34) shows all of the settings that can be made in Video Mode / “Time Lapse Video” submode. First I cycled through all of the submodes under Video Mode. Next I cycled through all of the setting options under “Interval.” Finally, I cycled through the settings under “Resolution.”

Like I said in my last blog post, there are two user-selectable settings in the “Time Lapse Video” submode: Interval; and Resolution.

At the end of the video clip, the screen goes black (there was a lens cap on my camera) except for information displayed in white text at the top and bottom of the LCD screen. GoPro calls that “On Screen Display”; some people refer to it as a “heads up display.” More about that in the next section.

“Clean HDMI”

“Clean HDMI” output and continuous power are considered to be essential if a camera is suitable for repurposing as a Webcam. Two settings are recommended in “Setup Mode” in order to use the HERO4 Black as a Webcam.

Use the Power/Mode Button (front of camera) to scroll down through the menu items until you reach “On Screen Display.” This setting can be toggled ON or OFF; set it to “OFF” by pressing the Shutter/Select Button (top of camera). The next menu item is “Auto Off”; set it to “Never” so the camera won’t power-off automatically. Finally, press the Settings/Tag Button (side) to exit the Setup menu.

Notice the “On Screen Display” is gone when the screen goes black at the end of the video. Ah, “clean HDMI!”

Thanks to YouTuber “Tech Explores NYC” for showing me how to setup my GoPro HERO4 Black for use as a Webcam!

Related Resources

Copyright © 2022 Walter Sanford. All rights reserved.

Can “Panasonic Image App” for iOS run on a MacBook Air?

March 4, 2022

I read a recent article from Macworld entitled “How to run your favorite iPhone and iPad apps on an M1 Mac.” Naturally I wondered whether the “Panasonic Image App” for iOS would run on my MacBook Air (13″, M1, 2020). I’m pleased to report it works!

I followed the directions in the Macworld article and downloaded/installed the Panasonic Image App from the Mac App Store, shown on the left in the following screen capture from my MacBook Air.

Next, I opened the app. Notice the “Home” screen on my MacBook Air is almost identical to the “Home” screen on my Apple iPad mini 6. I clicked on the “Wi-Fi” button.

Then I looked under Settings/Wi-Fi (on my MacBook Air) for an access point to connect with the camera.

After the Wi-Fi connection was established successfully, I clicked on the “Remote operation” button on the “Home” screen and voilà, the “Live Control” panel appeared on-screen.

I wanted to see a larger view of the window, but the app doesn’t allow the user to click-and-drag in order to resize the smallish window. No problem. I clicked the green dot in the Menu Bar and the app filled the screen!

I tested a few camera functions. In particular, I changed the aperture and shutter speed and recorded a few photos. There was noticeable lag when I moved the tripod head to change the camera view, but it’s not something with which you can’t live.

When I minimized the app in order to check my folder of screen captures, that resulted in the unexpected loss of the Wi-Fi connection.

A few surprises might be expected given the disclaimer for “Panasonic Image App” that appears on the Mac App Store: “Designed for iPad. Not verified for MacOS.” From my proof-of-concept testing, I can verify the app runs on my MacBook Air and almost everything I tried works.

I really like being able to see a larger display of the “Live Control” window on my MacBook Air than on my iPad mini. Still wireless; still portable, with a larger display. In my opinion. that’s a win-win!

Related Resource: How to run your favorite iPhone and iPad apps on an M1 Mac, by Roman Loyola, Senior Editor, Macworld.

Copyright © 2022 Walter Sanford. All rights reserved.

Apple Sidecar

December 17, 2021

Apple “Sidecar” is a free utility that enables you to use an iPad as a secondary display for your Mac.

Sidecar is only compatible with relatively newer devices such as my MacBook Air (M1, 2020) and iPad mini 6. [Note: Significant capability is added to my iPad mini by pairing the tablet with a Logitech “KEYS-TO-GO” wireless keyboard (compatible with both my iPad mini and MacBook Air) and Apple Pencil (2nd generation) or Logitech Pebble M355 Wireless Mouse.]

I tested Sidecar recently and I’m pleased to report it works as advertised. I’m just starting to think about how to utilize Sidecar. Any suggestions? If so, then please comment on this post.

Must-see TV

The show notes for the following video by Apple Support lists a link to a Web page entitled “Use an iPad as a secondary display for a Mac.” The first section is called “Get ready” and includes a sub-link to another section called “Sidecar system requirements” (located near the end of the same page). Also see the next section, “Additional requirements.”

The next video by Tech Gear Talk provides lots of useful guidance for making settings, how Sidecar works, as well as some practical applications.

The last video by Terry White answers the obvious question, “Can your iPad be used as a graphics tablet for use with mac OS applications such as Adobe Photoshop?” The answer, in a word, is “Yes!”

As you might have guessed I’m wondering whether Sidecar can be used to enhance my Photopea workflow. More later after I experiment.

Copyright © 2021 Walter Sanford. All rights reserved.

“Tech Tips” Tuesday

November 30, 2021

In this blog post I’m going to show you how I add special characters to some of my annotated images, such as the pictograph for “male,” shown below.

Photo used with written permission from Michael Powell.

I’ll show you how to do it on my older Apple 24″ iMac desktop computer (Early 2009), then I’ll show you (in more detail) how to do the same thing on my newer Apple 13″ MacBook Air laptop computer (M1, 2020).

macOS Yosemite (Version 10.10.5)

Open “System Preferences” and select “Keyboard.” Click on the tab labeled “Keyboard” and check the box for “Show Keyboard & Character Viewers in menu bar.”

As you might expect, a new icon will appear in the menu bar, located on the right side of the screen. When you click on the icon you should see three (3) options (listed from top-to-bottom): Show Character Viewer; Show Keyboard Viewer; and Open Keyboard Preferences… Select “Character Viewer” and navigate to Pictographs. (The last option takes you back the same screen that is shown above.)

macOS Monterey (Version 12.0.1)

After I was unable to figure out how to make the same setting on my MacBook Air, I referred to the “macOS User Guide” that is a built-in feature of the computer. A screenshot of the guide is shown below.

Open “System Preferences” and select “Keyboard.” Click on the tab labeled “Input Sources” and check the box for “Show Input menu in menu bar.”

A new icon will appear in the menu bar, located on the right side of the screen. When you click on the icon you should see the three (3) options shown below. Select the first option, “Show Emoji & Symbols.”

A new window will open on-screen. Navigate to Pictographs. Some sample Pictographs are shown below, including the female and male symbols (fifth row from the top).

Practical example using Photoshop

Here’s an example of part of my workflow to annotate a photograph using Adobe Photoshop.

Open a photo file in Photoshop. Select the “Text Tool” and create a new layer called “male symbol.” Click on the image to add an insertion point, then click on the “Show…” icon in the computer menu bar and select “Show Emoji & Symbols.” Navigate to “Pictographs” and select the “male sign.” You should see a list of “Font Variations.” I always use “Arial Bold.” Double-click on the icon and it should appear on the photo. ♂ Use the “Move Tool” to, well, move the symbol wherever you like on the image.


I stumbled across an application recently called “Photopea” that is a free alternative to Adobe Photoshop. Photopea is a Web-based clone of Photoshop — Photopea doesn’t do everything Photoshop does but it could be used to annotate photos using a workflow similar to the one I just described. Look for one or more Photopea-related blog posts in the near future.

Related Resources

Copyright © 2021 Walter Sanford. All rights reserved.

Dragonfly socks

June 4, 2021

A good friend sent a special gift to me. I love me some dragonfly socks. Thanks, Susan!

I know you’re thinking “Gee, I wish had a pair of dragonfly socks.” But you don’t. Hah!

Copyright © 2021 Walter Sanford. All rights reserved.


April 13, 2021

“Tethered.” What does that word mean to a photographer? In its simplest sense, it’s when a camera is connected to a computer either by some type of cable or sometimes wirelessly.

“Tethered shooting” implies the photographer is able to control the camera remotely, either partially or completely.

Is there really a distinction between the two terms? I think so.

In my last two blog posts I mentioned that my older Fujifilm X-T1 mirrorless digital camera cannot be used for tethered shooting using either the free Fujifilm X Acquire 2 software or via some sort of HDMI Video Capture device. That being said, the Fujifilm X-T1 camera can be tethered to my computer in order to display the output from the HDMI port on the camera.

The section entitled “Viewing Pictures on TV” that appears on p. 108 of the Fujifilm X-T1 Owner’s Manual is shown below.

When the Fujifilm X-T1 is connected to my Apple MacBook Air computer via a MavisLink Video Capture Card and displayed on-screen using OBS Studio, the camera thinks the computer is a TV. Well, sort of.

OBS Studio | Properties for ‘Video Capture Device’

First, add a “Video Capture Device” to a “Scene” in OBS Studio. Select “USB Video” since the “HDMI Video Capture” device connects to the computer via USB. A colorful test pattern appears on screen, even when the camera is turned on.

When the “Play” button on the back of Fujifilm X-T1 camera is pressed, a small green LED in the upper-right corner of the camera turns on and the photos saved to the memory card in your camera are shown on-screen, one image at a time. Use the “D” pad on the back of the camera to cycle through all of the photos on the memory card. Press the “Play” button when you’re finished and the test pattern reappears in OBS Studio.

By the way, the photo shown in the preceding “Screenshot” of OBS Studio is one of the images I shot for Sumo Citrus still life, a recent blog post.

Copyright © 2021 Walter Sanford. All rights reserved.

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