Difference between revisions of User:Divenal/sandbox

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Do feel free to improve it.
Do feel free to improve it.
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[[File:rgsunrise.svg|thumb|right]]
This combines the two ideas...

Revision as of 16:52, 15 July 2020

Welcome, {{#ifanon:anonymous|registered}} user.


click to enlarge

This is a tool that might be useful for distingushing https://endmyopia.org/astigmatic-cylinder-blur-vs-myopic-spherical-blur/

The gaps are intended to be calibrated to 1 minute of arc, equivalent to the gaps in landolt C test. The idea was that directional blur will close some of the gaps, but "blurry blur" will do them all. So when measuring cm's, you can distinguish the two.

Also the distance at which ghosting first appears, if you're also measuring that. For me, the ghosting appears in particular directions, so you can concentrate on the gaps on the lines where the ghost image is most-separated from the original. (ie if ghosting happens in a north-east direction, look at the gaps on the lines going north-west.)


Rgfocus.svg

This is a quick svg hack-up of the test page on Varakari's_Vision_Log_Tool. My intention was to be able to display it on my smartphone for measurement, but should work on any browser.

The image itself is svg, and so infinitely scalable. But the wiki tends to generate it as a png. So if you need to resize it, it's better to do it as svg rather than zooming in or out of the png. One simple way to do that is to add a reference to the image from your own wiki page, and adjust the size. Then the wiki will generate a png at that size, and you can download it locally.

To do so, just add a reference of the form [[File:rgfocus.svg|512px]]. The 512px is the image size you want, and you can set that to whatever you want. The wiki should render the svg to a bitmap of that size. (The original is 256px.) There are various other options that can go in - see https://www.mediawiki.org/wiki/Special:MyLanguage/Help:Images

If you click on the image, it will take to the page about the file. Clicking again should present the raw svg to the browser. You can use the browser's view-source option to see the (trivial) svg that creates the image. It should be fairly obvious how it works. The only slightly non-trivial thing is the <g ...> stuff. That just moves the origin to the centre of the canvas and sets the default text anchor, so that all the entities have an x-co-ord of 0. Just saves having to repeat stuff on every line.

Do feel free to improve it.

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Rgsunrise.svg

This combines the two ideas...