> You can take TWO screenshots, moments apart, open in GIMP, paste one over the other and choose any one of these laying modes:

You actually don't need any image editing skill. Here is a browser-only solution:

1. Take two screenshots.

2. Open these screenshots in two separate tabs on your browser.

3. Switch between tabs very, very quickly (use CTRL-Tab)

Source: tested on Firefox

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milkshakes 5 days ago | parent | next [-]

reminds me of this: https://www.reddit.com/r/LifeProTips/comments/5jdzsx/lpt_use...

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JadeNB 4 days ago | parent | next [-]

This was used in some early-20th-century astronomical setting, I think to detect supernovae. I can't find any documentation now, but my memory is that it was called "blink testing" or something similar, where one switched rapidly between two images of a star field so that changes due to a supernova would stand out.

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rogerrogerr 4 days ago | parent [-]

https://en.m.wikipedia.org/wiki/Blink_comparator

	▲	JadeNB 4 days ago \| parent [-]
		That's it exactly! Thanks.

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CGMthrowaway 4 days ago | parent | prev [-]

I went cross-eyed on my screenshot, and I couldnt read the word, but I did notice some artifacts

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axiolite 4 days ago | parent | prev | next [-]

What does that accomplish? You can just read the web page as-is...

Are you going to share your two screenshots, and provide those instructions, with others? That seems impractical.

Video recording is a bit less impractical, but there you really need a short looping animation to avoid ballooning the file size. An actual readable screenshot has its advantages...

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chinathrow 4 days ago | parent | prev | next [-]

> use CTRL-Tab

Thank you forever for this, I ever used Ctrl-Page up/down for that.

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azinman2 4 days ago | parent | prev [-]

You could also just record a video.

	▲	jama211 4 days ago \| parent [-]
		Hah, indeed, that was my first thought. This is clearly for fun though, it’s a cool project idea