iPad Pro 12.9 5th gen code screen LED blur on black backgrounds?

What you describe is entirely normal - and for the most part, will only be visible in a dark environment. In normal ambient lighting conditions, this effect is unlikely to be visible.

You new iPad uses an entirely different backlight technology. Instead of edge backlighting - that evenly illuminates the entire screen - the new mini-LED backlight panel has 10,000 individual LEDs divided into 2,500 dimming zones. Each dimming zone illuminates the corresponding area of the LCD screen pixels. As such, each of the 250 dimming zones covers many pixels.

What you are seeing is a halo effect. On dark backgrounds, the surrounding LEDs in the surrounding zones may be switched off - but the pixels illuminated by the active LED zones (including “dark” pixels) are fully illuminated. As such, you may see this halo effect as a side effect of showing very high-contrast images.

The older LCD screen technology, with edge backlighting, evenly illuminated the entire screen - including the “dark” pixels - hence no halo effect. This screen technology has a limited contrast range.

For OLED screens, such as those used in some models of iPhone, there os no backlight; individual pixels are their own light source.

Choosing an iPad model that uses a “standard” LCD display will indeed remove the halo effect that you see with white against a full-black background. The haloing is an unavoidable characteristic of zoned-dimming in miniLED screens. It should be noted that this technology substantially improves power efficiency, as the screen backlight is a major power consumer.

In common with all devices that use a “standard” LCD, in a dark room, you will instead see a general “bloom” across the entire display that reduces overall contrast.

Should iPad ever enjoy an OLED screen, you will benefit from both improved power efficiency and no haloing (as each pixel is a “point” light source). However, OLED technology does have other significant limitations…