Just as with image sensor megapixel counts, people don't fully understand the difference between dot counts in electronic viewfinders. The dot count exaggerates the resolution impacts of higher numbers, because the dots are spread over an area, not a single axis.
Here's where we stand with EVFs and what each means:
- 921k dot — 640 x 470 pixels, or VGA.
Cameras that use this include the Nikon V1, V2. - 1.44m dot — 800 x 600 pixels, or SVGA.
Cameras that use this include the Fujifilm X-Pro1 (hybrid); Olympus E-M5, E-M10; Panasonic G3, G5, G6, GH2; Sony A6000, A6100. - 2.35m dot — 1024 x 768 pixels, or XGA. 28% resolution gain over 1.44m.
Cameras that use this include the Canon RP, M5, M50; Fujifilm X-Pro2 (Hybrid), X-E1, X-E2, X-E3, X-T1, X-T2, X-T10, X-T20, X-T30, X-T100, X-T200, GFX 50S; Hasselblad X1D; Leica CL; Nikon Z50; Nikon Zfc; Olympus E-M1 (all), E-M1X, E-M5 Mark II/III, E-M10 Mark II/III, Pen F; Panasonic GH4, GX-8, G7, G80, G90; Sony NEX-6, NEX-7, A6300, A6400, A6500, A6600, A7 (all), A7R I/II, A7S I/II. - 3.69m dot — 1280 x 960 pixels, or SXGA. 25% resolution gain over 2.35m.
Cameras that use this include the Canon R, R6; Fujifilm X-Pro3 (Hybrid), XT-3, XT-4, X-H1, GFX 50R, GFX 50S; Nikon Z5, Z6, Z6 II, Z7, Z7 II, Z9; Panasonic GH5/GH5s/G6, G9, Sony A7 Mark IV, A7R Mark III, A9 I/II. - 5.76m dot — 1600 x 1200 pixels, or UXGA. 25% resolution gain over 3.69m.
Cameras that use this include the Canon R3; Canon R5; Fujifilm X-H2s; Fujifilm GFX 100; Leica SL2; OMDS OM-1, Panasonic S1, S1R, S1H; Sony A7R Mark IV. 25% resolution gain over 3.69m. - 9.44m dot — 2048 x 1536 pixels, or QXGA. 28% resolution gain over 5.76m.
Cameras that use this include the Sony A7S Mark III; Sony A1.
More variables apply, including refresh rates and types, magnification, and supplemental optics, and a few earlier mirrorless cameras have used non 4:3 EVFs. But a basic rule of thumb is that the cameras using the higher resolutions have better viewfinders than the ones using lower resolutions.
Another point: the 3:2 image sensor cameras using 4:3 EVFs tend to have at least one display mode where the image area at top is unobstructed, with camera settings in a bar below. The m4/3 cameras have to overlay the image area to present information in all display modes.
