Well, this blog post is not about any famous cat-fight: ‘sabaash – sariyaane potTi!’

Frame grab from the song ‘Kannum Kannum’ from movie ‘Vanjikottai Vaaliban’ with danseuse rivals Padmini and Vaijayanthimala.

but about the more mundane issue of resolution of Tamil letters that maybe affecting visual acuity and usage in practical things like billboards. Yes, we know Latha (is Tamil font from Microsoft) and Bamini famous storied font created in 1980s. Bamini font is also used in the Chennai Metro, Colombo railway station among other places; creator of Bamini was recently felicitated with 2017 Tamil Computing award for the pioneering efforts in the dawn of digital era.

Back to resolution; ‘kannu theriyithaa ?’ is the usual expression but it really asks the question are you able to see the object/thing/place/person – and not literally ‘do you have vision?’

In optical science, it is well known that free-space – distance – acts as a filter introducing blurs into the image. This is the mechanism behind why we don’t see details of far-away billboards and they grow in detail as one may approach them.

Tamil billboard; credits – masanori_jpn via Flickr.

So if you are advertising in large billboards, obviously you want to be visible to audiences as far as laws of physics [Rayleigh resolution limit] will allow.

We can gather from simple considerations the following:

1. Larger the letters farther away they maybe visible
2. Longer wavelengths of light [Red (longer) – Violet (shorter)] farther they are visible without being scattered

So you can ask, if all the billboards are painted in large bold Tamil letters ‘adikkira maathiri’, will be visible for very long distances ? Yes. And they will also be boring.

This knowledge does not help us to choose between two fonts, since we can draw/write/pain letters in their character in any size and color – just the shape remains fixed.

Now to properly analyze the two fonts for best visual acuity, we may consider the following criteria:

1. All letters compared need to be same in both fonts
2. Viewer is considered to observe the projected font/printed text/billboard from progressively farther and farther distances.
3. Essentially font corresponding to the billboard which is visible from farthest distance is the winner/better font in this criteria

Before we start drawing conclusions you also want the test subjects to have 20/20 vision or wear corrective prescription eye glasses for the same level of vision.

Now, regardless of the color and size of the fonts we can use the criteria to compare the acuity of the fonts.

But wait, can we do this by computer modeling without paint, labor and 20/20 vision subjects? You betcha! This will be subject of next blog post.

Until then…. Vaazhga Valamudan.

-Muthu