Edit: March 27th 20019 Polymega have provided some more screenshots of this effect. While I am not 100% convinced either way anymore of which is a picture from a CRT and which isn’t, I am not revising history (Git has taught me that this is wrong) because the article below did reflect my opinion at the time and that will remain here forever whether it is right or wrong. For the record I have not changed my opinion. Moreover the article ALWAYS stated that this could in fact be a “very good software filter” so everyone needs to calm down.
Here is a comparison between Polymega’s latest screenshot compared to the original. I feel these are different filters, if not different screen technologies altogether… you be the judge:
Your direct feed only made you look worse. The direct feed should be perfect, but clearly the the CRT filter does still not work correctly in the solid backgrounds. I included the original sonic image for comparison again. pic.twitter.com/NSrG90XK8i
— Dan Kunz (@citrus3000psi) March 27, 2019
Original Article Starts Here
I recently stumbled upon these two posts from Polymega’s Twitter feed boasting 2 filter modes for the Polymega: a “Composite Filter” and an “RGB Filter”. The composite filter caught my eye immediately. I theorize that the picture of the Composite filter they posted is fake and is in fact an actual picture of CRT. I must admist it’s entirely possible that the Raspber.. eh Polymega outputs to a CRT – or that this is in fact a very good software filter which somehow gives the perfect illusion of an offset shadow mask. Either way, the following article illustrates my reasoning.
Screenshots include here in case they delete these posts in the future.
|RGB Filter||Composite Filter|
The problem has to do with how a CRT is constructed as opposed to how an LCD is constructed.
Pixels on an LCD are presented in a square grid. Each adjacent pixel is directly next to each other pixel as shown below:
A CRT doesn’t have pixels per se, but the grid of colour elements on consumer CRTs is presented in an offset grid. Each adjacent pixel is offset to each other pixel as shown below:
And here is a lovely side by side of different technologies of “pixel” grids for consumer displays.
Let’s now look at a closeup of the supposed Polymega filters side by side. FYI polymega is a small computer, outputting HDMI to a modern display. On the left is the supposed “CRT Composite” which clearly shows a CRT geometry and in my opinion is not a photo of a CRT filter on an LCD display. It appears to be a closeup picture of a CRT playing Sonic The Hedgehog.
On the right is their “RGB Filter”. This image clearly is a closeup of an LCD.
Why would Polymega try to pass off a picture clearly taken on a CRT as a “Composite Filter” for their computer? Why would two different displays altogether be used to demonstrate filters which presumably are a simple menu click away? Am I wrong? Can modern technology fool me into thinking this is in fact a CRT when it isn’t?