Electronic calibration is simply often remapping colors to colors, e.g. mapping pixel intensities 0-100% to pixel intensities 10-90% range (making blacks a little greyer, and whites a little darker). Electronic contrast adjustment does exactly this. The GtG behaviour of specific voltages (for source pixel value) to specific voltages (for destination pixel value) are unchanged, you have to think of the display as a processing pipeline of multiple layers that handles all kinds of things. Things like HDR displays does more advanced remapping stuff, where a signal might have a much more massive dynamic range (like pixel intensities below 0% and pixel intensities above 100%) that needs to get remapped to the dynamic range of the display. <Advanced LCD Technology Explanation>
At the very end of the day, what really matters is how quickly to transition a specific pixel to another pixel color (specifically: subpixel gray value, that's covered by a red or green or blue filter -- but there's essentially 3 gray subpixels per LCD color pixel -- LCD crystals is just wristwatch grey -- but colors made possible using filters on each subpixel -- see color filter structure of an LCD
Crystal in an LCD (L
isplay) panel are moving objects of mass with momentum. It's impossible to make objects of mass move instantaneously. They can overshoot or undershoot (creating ghosting/coronas/overdrive artifacts -- LCD Motion Artifacts
-- LCD Overdrive Artifacts
). Imagine trying to drive a car from one parking space to a different parking space as quickly as possible, with the car precisely parked to 1 millimeter. If you're a razor margin too far your color is darker. If you're a razor margin too near, your color is lighter. Trying to move (rotate) the crystals from exact position A to exact position B as quickly as possible, creates problems. If you're even just 1% off, you see a greyscale banding difference -- you need to essentially be pretty much 99.9% perfect (i.e. 1 part in 1000) for EVERY possible grey color to EVERY possible grey color -- GREY to GREY, aka "G" to "G", or "GtG". (Remember: An LCD color pixel has 3 grey subpixels, each covered by a color filter).
Going from dark grey to light grey might be like moving a car a shorter distance almost instantly to an exact stopping position (not a millimeter too far, not a millimeter too near! Or you get a ghosting/overdrive artifact.) Going from full white to full black might be like moving a car as quickly further as possible all the way to the edge of a brick wall and stopping perfectly gently touching it, without accidentally bumping into it hard and wrecking the car. LCDs have to do accurate GtG at a billion subpixels per second (300,000,000+ pixels per second, times 3 subpixels) for a 144Hz 1920x1080p monitor, every subpixel on the screen, every refresh cycle. Behind the scenes, there's often multiple voltage pulses per pixel refresh, e.g. a GtG initiating pulse (begin momentum) and a GtG stopping pulse (end momentum). That's often how overdrive works, to transmit a sudden opposite voltage to a pixel approximately 1ms after the first pixel pulse. So there's often at least 1 chase scan shortely behind the current LCD scan. They are (very) approximately at the bottom edge and the top edge of the "blurry zone" you see in high speed video at http://www.blurbusters.com/lightboost/video
... (non-strobed portion) .... That's the gas-pedal pass (first G in GtG) and the brake-pedal pass (last G in GtG), often ~1/8th of a screen height apart (at 120-144Hz) for a ~1ms transition. The blurry zone scans rapidly top-to-bottom, like a CRT, the zone is blurry because of the GtG time. A 120Hz refresh cycle is 8.3ms, so the blurry zone for 1ms GtG is approximately 1/8th screen height, as seen in the high speed video. Now given the gas-pedal and brake-pedal pulses that needs to be impossibly perfectly exact to stop that metaphorical car in an exact stopping position... No wonder imperfections (ghosting, overdrive, coronas, etc) often happen, and for the more perfect ones, we often have to pay extra (e.g. NVIDIA technology, which often has very good overdrive -- not perfect, but average overdrive in GSYNC mode and ULMB mode is often better-than-industry-average). We know how more expensive GSYNC monitors typically are. Yes, it can be even better (but could be even more expensive, too!).
It's an engineering achievement that the world has mass-market LCDs capable of 1ms GtG nowadays, but there are still rather severe problems with accuracy. And the accuracy often changes between panel runs, panel factories, temperature, etc. Only a very few has done it so extremely well (Getting better GtG, but with pros/cons like less contrast ratio, for example) -- for many years, LightBoost had far less contrast ratio than non-LightBoost, in order to help more accurate GtG transitions.
There are many metaphors to explain an LCD, but hopefully this metaphor helps people appreciate how difficult it is to get very accurate _AND_ very fast GtG response (simultaneously).
Confused? Well, let's just say -- achieving perfect pixel transitions on any LCD is a very complicated problem for manufacturers to solve.</Advanced LCD Technology Explanation>