Archive for the ‘HDMI’ Category

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.


What is it?

April 6, 2021

Ladies and gentlemen, children of all ages. It’s time for another exciting episode of “What is it?”

This episode is a little different because the name of the mystery item is printed clearly on the product itself. I guess the real mystery is two-fold: What does the acronym “HDMI” mean, and what does this video capture device do?

“HDMI” stands for “High-Definition Multimedia Interface.” The MavisLink Video Capture Card converts HDMI 4K 60FPS (from your digital camera) to USB 1080P 60FPS (on your computer) that can be either recorded or live streamed on video conferencing services.

“MavisLink” is a brand name that was recommended by Graham Houghton, a gentleman whose expertise I respect and opinion I value. It’s worth noting a quick Web search will reveal lots of video capture cards sold under different brand names that look identical to the MavisLink device shown above. Do they work as well as the one recommended by Graham? Who knows?

I plan to use the device in combination with Open Broadcaster Software (OBS Studio) to record the video and audio output from some of my digital cameras; the saved video clips will be featured in future “how to” blog posts.

So far I have tested the process with several of my cameras: My Panasonic Lumix DMC-FZ300 and Fujifilm X-T3 work; my Fujifim X-T1 doesn’t work.

I still need to test my older Canon EOS 5D Mark II. It should work but as far as I know the camera doesn’t feature “clean HDMI” output, that is, some or all of the info display on the camera viewfinder/LCD (e.g., the focus rectangle) is included in the output.

Related Resource: DSLR and Mirrorless Webcams Versus Capture over HDMI, by Graham Houghton (8:56). See the segment entitled “HDMI Capture” that begins at ~5:01 into the video.

Copyright © 2021 Walter Sanford. All rights reserved.

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