The short answer: choose pixel pitch from where your closest viewers stand, not from a spec sheet. As a rule of thumb, the pitch number in millimetres is the minimum viewing distance in metres, and viewers are comfortable at about 1.7 times that. Buying a finer pitch than your viewers can resolve costs more and adds nothing they can see.
What pixel pitch actually means
Pixel pitch is the distance in millimetres from the centre of one pixel to the centre of the next. A P2.5 module has a pixel every 2.5 mm; a P10 module, one every 10 mm. That one number decides three things:
- Resolution: a smaller pitch packs more pixels into every square metre, so the image is sharper.
- Viewing distance: stand too close to a coarse pitch and you see dots, not a picture.
- LED count, and cost: pixels per square metre rise with the square of the pitch. Halve the pitch and you need four times the LEDs. Going from P2.5 to P1.5 takes you from 160,000 to about 444,000 pixels per m², roughly 2.8 times as many.
Most modules we stock are built on the standard 320 × 160 mm board, so pitch translates directly into module resolution:
| Pitch | Typical module | Module resolution | Pixels per m² | Typical use |
|---|---|---|---|---|
| P1.25 | 320 × 160 mm | 256 × 128 | 640,000 | Boardrooms, control rooms |
| P1.5 | 320 × 160 mm | ≈ 213 × 106 | ≈ 444,000 | Premium indoor video walls |
| P1.86 | 320 × 160 mm | 172 × 86 | ≈ 289,000 | Showrooms, lobbies |
| P2.5 | 320 × 160 mm | 128 × 64 | 160,000 | Indoor retail, stages, halls |
| P3.91 | 250 × 250 mm (rental) | 64 × 64 | ≈ 65,500 | Rental and events |
| P4 | 320 × 160 mm | 80 × 40 | 62,500 | Outdoor shop fronts, facades |
| P5 | 320 × 160 mm | 64 × 32 | 40,000 | Outdoor hoardings |
| P6 | 192 × 192 mm | 32 × 32 | ≈ 27,800 | Large outdoor hoardings |
| P10 | 320 × 160 mm | 32 × 16 | 10,000 | Highway hoardings, text signs |
The viewing distance rules
The industry uses three distances for every pitch. All three scale with the pitch, so once you know them for one pitch you know them for all:
- Minimum viewing distance: the pitch number in metres. P4 is watchable from 4 m. Closer than this, viewers see individual pixels (Unilumin).
- Comfortable viewing distance: about 1.7 m per millimetre of pitch, the distance most viewers find the picture acceptable, based on real installations (Planar, AVIXA).
- Visual acuity distance: pitch × 3,438, in millimetres, or about 3.44 m per millimetre of pitch. Beyond this, a person with 20/20 vision can no longer make out individual pixels (Planar).
| Pitch | Minimum (pitch × 1 m) | Comfortable (≈ pitch × 1.72 m) | Pixels invisible (pitch × 3.44 m) |
|---|---|---|---|
| P1.5 | 1.5 m | 2.6 m | 5.2 m |
| P1.86 | 1.9 m | 3.2 m | 6.4 m |
| P2.5 | 2.5 m | 4.3 m | 8.6 m |
| P3.91 | 3.9 m | 6.7 m | 13.5 m |
| P4 | 4 m | 6.9 m | 13.8 m |
| P6 | 6 m | 10.3 m | 20.6 m |
| P10 | 10 m | 17.2 m | 34.4 m |
So the question is never “which pitch is best?” It is: where will my closest regular viewer stand? Pick the coarsest pitch whose comfortable distance is at or below that point.
Mistake 1, over-buying: P1.5 for a screen viewed from 6 m. At that distance even P2.5 is past its comfortable point (4.3 m), so the extra pixels of P1.5 are invisible. You pay for about 2.8 times the LEDs and nobody sees the difference.
Mistake 2, under-buying: P4 in a showroom where customers walk up to the screen. Closer than 4 m they see dots, and no content polish will fix it.
Indoor vs outdoor changes the answer
Pitch is only half the spec. Indoor modules are built for indoor light: bright enough for a mall or boardroom, nowhere near bright enough for direct sun. Outdoor modules are many times brighter and sealed to IP65 at the front. If sunlight falls on the screen, buy outdoor modules. There is no such thing as an indoor module with a rain cover.
For outdoor modules, the brightness you can rely on follows the refresh class:
- 3840 Hz outdoor: 4,500 to 5,000 nits.
- 7680 Hz outdoor: 5,000 to 5,500 nits.
- Lumina Blaze P4 (3840 Hz): 5,000 nits. Lumina Blaze Pro P4 (7680 Hz, silicone-potted rear): 5,500 to 6,000 nits.
 Lumina Prism P2.5 indoor module, 320 × 160 mm, 128 × 64 pixels |  Lumina Blaze Pro P4 outdoor module, 320 × 160 mm, 80 × 40 pixels, 7680 Hz |
Refresh rate: the spec that decides how your screen looks on camera
Refresh rate is how many times per second the module redraws the image. To the naked eye, 1920 Hz and 3840 Hz look the same. On a phone camera they do not: lower refresh rates show rolling dark bands in video. 3840 Hz is the standard for clean phone footage. 7680 Hz, as in the Qiangli Pro series and Lumina Blaze Pro, is the safe choice for broadcast, weddings and events where cameras are always on.
Quick test: point a phone camera at any screen showing a white image. If you see rolling lines in the viewfinder, its refresh rate is too low for filming.
Worked example: a 10 ft × 6 ft showroom screen
A 10 × 6 ft wall is 3,048 × 1,829 mm. With 320 × 160 mm modules that is 9 modules wide by 11 tall (2,880 × 1,760 mm), so 99 modules either way.
- In P2.5: 1,152 × 704 pixels, sharper than 720p. Comfortable from about 4.3 m.
- In P1.86: 1,548 × 946 pixels, close to 1080p. Comfortable from about 3.2 m. About 1.8 times the pixels of P2.5, and the cost rises with them.
If most customers look at the screen from 4 to 5 m, P2.5 is the right buy and the money saved is better spent on a good processor and reliable power. If they stand 2 to 3 m away, P1.86 earns its cost. Then add cabinets or frames, a receiving card per cabinet, the right 5V or 4.5V power supply, and a sending card or player.
Quick decision cheat-sheet
- Boardroom or control room: P1.25 to P1.5 indoor, 3840 Hz minimum.
- Retail showroom: P1.86 to P2.5 indoor, chosen by where customers stand.
- Rental and events: P2.5 to P3.91 in die-cast rental cabinets, 7680 Hz if cameras are involved.
- Shop front or petrol pump: P4 outdoor, such as Blaze (5,000 nits) or Blaze Pro (5,500 to 6,000 nits).
- Roadside hoarding: P5 to P10 outdoor. Nobody reads a hoarding from 3 m.
- Whatever the pitch: get the refresh rate and driver IC in writing before you order.
Shop the modules
- Lumina Prism P2.5 indoor modules
- Lumina Blaze P4 outdoor modules
- Qiangli LED modules, P1.5 to P6.67
- GI vs die-cast cabinets: which to use
Tell us the wall size and where the viewer stands. We will send the module count, the power calculation and the controller spec, with the maths shown. Authorised Qiangli partner, genuine stock ex-Mumbai, GST billing and pan-India delivery. WhatsApp +91 97655 58000.