LED poster pixel pitch: P1.5, P2 or P2.5 - which one do you need?
The pixel pitch of a LED poster is decided by one question: from how close will it be viewed? The difference between P1.5, P2 and P2.5 is not better and worse but how many metres away the image comes together, from where it is comfortable to view, and how much information fits legibly onto one surface.
What the P number means exactly on a LED poster
The number after the letter P gives the distance in millimetres between the centres of two adjacent pixels. P2.5 therefore means a 2.5 mm grid, P2 two, P1.5 one and a half. A single division gives the pixel density too: a square metre contains as many pixels as 1 divided by the square of the pixel pitch in metres. So P2.5 contains exactly 160,000 and P2 exactly 250,000 pixels per square metre. The nominal value for P1.5 by this formula would be 444,444, yet the datasheet for the P1.5 poster panel in our range states 422,753 px/m². Working back from that, the actual pitch is not 1.5 but 1.538 mm. This is not an error or a trick: manufacturers adjust the pitch to the physical size of the panel so that a whole number of pixels falls across the 640 mm panel width - 640 divided by 1.538 is exactly 416. If a quotation states a round 444,000 px/m² for P1.5, ask for the resolution in pixels alongside it, because the two are not the same, and only the latter is usable for content design.
The decisive question: from how close is it viewed? Three distance thresholds, regularly confused
There are three clearly distinct distances, and most misunderstanding comes from using the same name for all of them. The first is the datasheet minimum: on our module datasheets, the minimum recommended viewing distance in metres equals the pixel pitch in millimetres, so 2.5 metres at P2.5, 2 metres at P2, 1.8 metres at P1.8 and 1.5 metres at P1.5. Closer than that, the image no longer comes together: the eye sees the pixels individually, and the surface looks more like a grid than a picture. The second is the comfortable viewing distance, and the same rule applies across this site: 2.5-3 times the pixel pitch in millimetres, taken as metres. At P2.5 that is 6.3-7.5 metres, at P2 5-6, at P1.8 4.5-5.4, at P1.5 3.8-4.5. Our main article on pixel pitch uses the same multiplier for large LED walls (P4 → 10-12 metres, P10 → 25-30 metres), and there is no reason to say anything different for posters. The third is the resolution limit: the angular resolution of a sound human eye is about 1 arcminute, so two pixels merge completely when the pixel pitch subtends a smaller angle than that. That works out at roughly 3.44 metres per millimetre of pixel pitch, that is, 8.6 metres at P2.5, 6.9 at P2, 6.2 at P1.8 and 5.3 at P1.5. It is clear that the comfortable band is 2.5-3 times the pitch for a reason: it ends just below the distance at which the pixel grid physically disappears. And here comes the poster's particularity. The viewer is typically within 1-3 metres, so no poster build reaches its comfortable band, not even P1.5. With a poster, therefore, the datasheet minimum is the governing lower limit, and you have to accept that the pixel grid stays visible at close range. That is not a fault: the aim here is not for the surface to look like a photograph but for the message to land within two seconds. Pixel pitch is therefore decided by two practical questions: does the datasheet minimum hold for the nearest real viewing point, and does the content fit legibly?
P1.5, P2 and P2.5 side by side on the 640 x 1920 mm panel
The backbone of the range is the 640 x 1920 mm portrait poster panel - there are also 60 x 160 and 80 x 200 cm builds, but comparing pixel pitches is cleanest on this one size. 640 x 1920 mm is exactly 1.23 square metres of active surface, and at this fixed size the pixel pitch directly determines the resolution. At P2.5 it is 256 x 768 pixels, 196,608 pixels in total. At P2 it is 320 x 960 pixels, 307,200 in total. At P1.5, the actual 1.538 mm pitch gives 416 x 1248 pixels, 519,168 in total. A P1.5 therefore contains 2.64 times as many pixels as a P2.5 and 1.69 times as many as a P2. It is worth looking at this difference in pixels rather than percentages, because that is exactly the number that matters in content design: that is the canvas the designer has to work on. A modern smartphone display is typically more than 1,000 pixels wide; a P2.5 poster gives roughly a quarter of that horizontally - while being physically 64 centimetres wide. The table below shows the data for all three builds together, with the intermediate P1.8 added.
How much information fits? Letter size, line count and QR codes
In practice, pixel pitch is a question not of aesthetics but of information density, and there are two separate constraints to run into. The first is physical cap height. Throughout this site we work with the same rule of thumb: 1 centimetre of cap height gives about 1.2 metres of design, that is, comfortable reading distance, with the just-decipherable limit roughly three times that. For screen content there is also an explicit allowance: for a multi-line, denser text surface, reckon on three times the basic rule, that is 2.5 centimetres of cap height per metre, because there the viewer is not recognising a single word but reading several lines through. The second constraint is the grid, and on a poster it is the stricter one. Mixed upper and lower case text starts to look grainy and uneven below a body height of about 12-16 pixels, so 16 pixels is the sensible lower limit in content design. That means a physical cap height of 40 mm on P2.5, 32 mm on P2 and 25 mm on P1.5. By the basic rule, those are comfortably readable from 4.8, 3.8 and 3 metres respectively; but with the stricter multi-line screen allowance, from 1.6, 1.3 and 1 metre. The two figures together describe the real situation: a single short headline message is readable on all three builds from the far end of the room, but nobody will read multi-line, information-dense content through except at close range. The difference shows up in the number of lines: with 16-pixel type and one-and-a-half line spacing, that is a 24-pixel line height, the 1920 mm tall panel theoretically fits 32 lines of text at P2.5, 40 at P2 and 52 at P1.5 - though with real, airy layout it is worth designing for about half that. QR codes show the difference even more sharply. A 25 x 25 module, version two QR code is 33 modules wide including the four-module quiet zone required by the standard, and it is design practice to allow at least 3 physical pixels per module so the grid does not blur the module boundaries - that is 99 pixels. On P2.5 that is a square 25 cm on a side, on P2 20 cm, on P1.5 15 cm. On a 64 cm wide poster, then, a P2.5 QR code occupies 39 per cent of the full width. If there is a QR code in the creative, that single number often settles the pixel pitch on its own.
P2.5: the right answer for most venues
In a retail floor, a restaurant, an exhibition stand, a corridor or a waiting area, the viewer typically does not stop closer than 2.5 metres to the surface, because there is no reason to: they walk past it, or queue a few metres away. At these venues P2.5 meets its datasheet minimum, and if the space is large enough that most viewers see it from beyond 6 metres, it is already in its comfortable band - there the finer build has no visible advantage to the naked eye, while delivering the same business result with fewer LED chips and less driver electronics. In the band between 2.5 and 6 metres, P2.5 remains a good choice for large, contrasty, few-word compositions; but if the creative includes a detailed product photograph, a small logo or a QR code, it is worth stepping up to P2 in that band. The P2.5 poster is available in both indoor and outdoor builds, which is an important difference: the outdoor version is made in a weatherproof housing and delivers considerably higher brightness so it stays visible in direct sunlight. P2.5 is also the most forgiving choice in terms of content: there are fewer pixels to design for, so the designer is forced into the large, contrasty, few-word composition that works best on a LED poster anyway. If you are replacing a paper poster, P2.5 is typically enough, and the difference is better invested in content production or a second unit.
P2: the balance point for shop windows, receptions and bank branches
P2 is justified where the nearest viewer stops between 2 and 2.5 metres away, so the datasheet minimum for P2.5 is already tight - or where the viewing distance is greater but the content is detailed. Typical cases are the two metres of pavement measured from shop window glass, the surface beside a reception desk, the waiting zone of a bank branch, or the narrower part of a shopping-centre corridor. The datasheet minimum for P2 is 2 metres, its comfortable band 5-6 metres, and the pixel grid disappears entirely at 6.9 metres. The 320 x 960 pixel grid already carries a more detailed product photograph, a smaller logo and a 20 cm QR code. The premium 80 x 200 cm P2 poster available in the range is made with 1,000 nits brightness and a 4K-capable Android media player, which allows both proportionate luminance for the larger surface and more complex content. The 640 x 1920 mm P2 is also available in a GOB potted build, which gives the surface impact and scratch protection. If the decision has to be simplified to a single rule: with a nearest viewing point between 2 and 2.5 metres, P2 is the lower limit, and between 2.5 and 6 metres it is the safe middle course if the creative is detailed - going to extremes neither in image quality nor in cost.
P1.5: when the viewer stands at arm's length
P1.5 is justified when people really can and will step up to the surface: the interior wall of a premium retail store, a hotel reception, a meeting-room foyer, a brand showcase space, where the visitor looks at the image from one and a half to two metres and the surface itself is part of the brand's promise of quality. It is important to know that P1.5 is the finest poster pitch in the range, and its datasheet minimum is 1.5 metres too - if the viewer stops closer than that, no poster build will give a grain-free image, and the content then has to be designed with larger elements. In our range this build is made with GOB or COB potting technology, at 3,840 Hz refresh, with a base brightness of 700-800 nits that can be raised to 1,500 nits on request, a 160 degree viewing angle and a noise level under 20 dB. That last point rarely comes up, yet in a quiet hotel lobby or a medical waiting room, audible fan noise noticeably spoils the impression. Connectivity is broader too: alongside HDMI, DVI and SDI inputs, the datasheet lists Wi-Fi 6 and Bluetooth 5.0, so the poster can be driven from a live signal source, even a camera, not just from a cloud-scheduled playlist. P1.5 is therefore not simply finer but a different technical class, and it is worth treating as a separate question when requesting a quotation.
P1.8: it exists on the market, but we do not stock it
Between P1.5 and P2 there is an intermediate build on the market, P1.8, in the same 640 x 1920 mm poster housing. IMPORTANT: our manufacturing partner does NOT offer one - indoors there is P1.5 GOB, P2 GOB and P2.5, and outdoors P2.5 and P3 in a cabinet build. We write about it all the same, because you may come across it at other distributors and it is worth knowing what it means. 640 divided by 1.8 does not give a whole number, so on P1.8 panels the actual grid almost certainly differs from the nominal value - there it is well worth asking in writing for the resolution in pixels. In practice the difference between P1.8 and P1.5 comes to a few decimetres of viewing distance, so if you need the surface for viewing that close, with us the answer is the P1.5 GOB.
The GOB surface: often more important on a poster than the pixel pitch
In the GOB, or glue on board, process, the LEDs are potted in clear resin on the surface of the panel, creating a continuous, flat protective layer. This matters particularly on a LED poster, because the unit stands at floor level on a wheeled base, typically in among people: it meets trolleys, suitcases, children's hands, cleaning machines and damp wiping. On a surface fitted with traditional, protruding SMD LEDs, these can cause damage, and the surface cannot be wiped safely. A GOB surface, by contrast, is impact and scratch resistant, can be cleaned with a damp cloth, and the resin also keeps moisture away from the electronics. The finer the pixel pitch, the more densely the LEDs stand and the greater the mechanical risk, which is why the P1.5 poster in our range is made in GOB from the outset and the P2 is available that way too. For posters intended for events and moved frequently, though, it is worth considering even at P2.5, even if the pixel pitch alone would not justify it. We have written in detail about the construction of LED chips and the differences between SMD, DIP and COB technologies in a separate article.
Brightness: 800 nits is enough indoors, not in a sunlit window
Indoors the requirement is 600-1,200 nits, and our own indoor modules deliver 800-1,200. Our poster product pages move within that band: the 60 x 160 cm P2.5 build is 800 nits, the 80 x 200 cm premium P2 is 1,000 nits, and the P1.5 GOB poster starts from 700-800 nits and can be switched up to 1,500. Under artificial lighting that is enough. In a window exposed to sunlight, though, that level is too low, and we are talking about a completely different order of magnitude: the professional minimum is 4,500-5,000 nits with automatic brightness control, and our own outdoor LED modules deliver 5,000-8,000 nits - the outdoor P2 is rated at 5,000 and the outdoor P2.5 at 5,500 nits, with coarser-pitch outdoor modules going higher still. There may also be an upper limit: local rules commonly cap the permitted brightness of advertising displays, typically lower after dark than by day. On an outdoor poster facing the street, therefore, automatic brightness control is not a convenience extra but the means of complying - and incidentally it reduces consumption too. This is one of the most common and most expensive misunderstandings in buying a LED poster, because from the outside the indoor and outdoor builds look almost identical, yet an indoor poster simply fades out behind glass in midday light. Deciding does not need an instrument: if the sun ever shines directly on the intended position, you need an outdoor, weatherproof build, and a P2.5 poster like that is available in the range.
3,840 Hz: why it matters if it ever goes in front of a camera
The poster panels in the range are made with a 3,840 Hz refresh rate, and that is not a marketing figure. At lower refresh, footage shot on a phone or a video camera shows horizontal bands and flicker, because the camera's shutter speed and the LEDs' switching rhythm do not coincide. If you ever want the poster to appear in social content, a press photograph, an event video or a corporate film, 3,840 Hz is the practical lower limit. One of the most important business benefits of LED posters is precisely that they become a visible element of brand communication, so they are very likely to end up in front of a camera even if that was not a consideration at purchase. Refresh rate is not related to pixel pitch: in our module database, the fine-pitch indoor modules are all 3,840 Hz, while coarse-pitch outdoor builds intended for distance are also made at 1,920 Hz - so ask for this figure as a separate line in the quotation rather than assuming it.
The logic of pricing: why it is not proportional to pixel count
Rather than specific figures, it is worth understanding the structure, because from it any quotation can be checked. A P1.5 panel has 2.64 times as many LED chips and proportionately more driver circuitry as a P2.5, so the material cost of the panel is significantly higher - but not in exactly that proportion, because the substrate, the frame and part of the electronics do not depend on pixel density. The final price follows the pixel count even less, because several elements of the poster are the same regardless of pixel pitch: the aluminium housing and the wheeled base, the power supply, the media player, the control system, the delivery, the installation and the training. Those items are unchanged on the finer build, so they make up a proportionately smaller share. Two practical conclusions follow. First, the difference between P2.5 and P2 is proportionately smaller than you would expect from the pixel count, so if the viewing distance is borderline, P2 is often worth it. Second, comparing panel prices alone is misleading: always ask for an itemised quotation in which the panel, the stand, the control system, the media player, the delivery, the installation and the training appear on separate lines, because that is the only way two quotations can be compared.
Consumption: driven by brightness, not pixel density
A common misconception is that a finer pixel pitch automatically consumes much more. Consumption is determined primarily by the brightness setting and the lightness of the content displayed, not by the number of pixels: set to the same nits, the denser panel produces the same luminance with more LEDs each drawing less current. As a general, site-wide figure, the average operating consumption of a LED surface is 150-300 W per square metre. Within that, our own module datasheets give 220-280 W/m² for indoor builds and 200-300 W/m² for outdoor ones in average operation, with a peak - on a full white image - of 580-650 W/m² on our indoor modules; in the catalogue data the average is 38-43 per cent of the peak. Based on the 1.23 square metres of active surface on the 640 x 1920 mm poster, that means roughly 270-345 W in average operation and 710-800 W at peak, and rather the lower half of the band on an indoor setting at 800 nits. That is in the order of a desktop computer's consumption, not an air conditioner's. Scheduled switch-off at night together with automatic brightness control significantly reduces the annual bill and slows the ageing of the LEDs too.
Expansion: a 6.14 square metre video wall from five posters
One of the most underrated properties of modern LED posters is that they can be daisy-chained and controlled in software as a single continuous surface - the range even includes a ready-made five-panel video wall configuration. Five 640 x 1920 mm panels side by side give a surface of 3200 x 1920 mm, that is, 6.14 square metres. The combined resolution depends on the pixel pitch: 1280 x 768 at P2.5, 1600 x 960 at P2, 2080 x 1248 at P1.5. Under our own sizing engine's classification, the first two are HD class, while the P1.5 assembly falls into Full HD class, so it is more than enough for brand films and live signal sources. The significance for the decision is that you do not have to fix the final size now: you can start with one or two panels and expand as the budget allows - provided you choose a chainable type at first purchase and every expansion uses panels of the same pixel pitch. That said, it is worth flagging the expansion at the first order: a visible colour difference can remain between panels from different production runs, which we have written about at greater length in our article comparing LED technologies.
A decision sequence in five steps
The whole choice can be simplified to five questions, in this order. First: how many metres away does the nearest viewer actually stop? The datasheet minimum is the hard lower limit, so above 2.5 metres P2.5, between 2 and 2.5 metres P2, between 1.8 and 2 metres P1.8, and between 1.5 and 1.8 metres P1.5 is the starting point - and if most viewers see the surface from beyond 6 metres, P2.5 is already in its comfortable band and stepping up is unnecessary. Second: does direct sunlight ever fall on the surface? If so, you need an outdoor build, because in terms of brightness that overrides everything else. Third: what will be the smallest element in the creative? If it is a QR code or small print, calculate its physical size with the multipliers above before you choose a pixel pitch. Fourth: how physically protected is the surface? If it stands among people or you move it a lot, ask for a GOB build. Fifth: are you planning to expand? If so, choose a chainable type and set down in writing that future expansion will use panels of the same pixel pitch. Once you have worked through those five questions, the remaining decision is only a matter of size and housing, on which a free site survey helps quickly.
Expert tip
The cheapest and most reliable check you can do at home in five minutes: open the intended creative in an image editor and resize it to exactly the pixel resolution the poster gives - 256 x 768 at P2.5, 320 x 960 at P2, 416 x 1248 at P1.5. Then look at the image at 100 per cent zoom on your monitor. What you cannot read there you will not read on the poster either, because the poster builds the image from exactly that many pixels. This test filters out most wrong pixel-pitch choices before the quotation is even requested, and it gives the designer an exact canvas size. As a supplement, measure with a tape on site where people actually stop and where they merely walk past - do not estimate, because that is the one input from which all the other numbers follow, and it decides whether the datasheet minimum viewing distance is met at all.
Common mistakes
1. Ordering an indoor, 800 nit poster for a sunlit window, where the image fades in midday light - such a position calls for an outdoor, weatherproof build, where brightness starts above 5,000 nits. 2. Choosing the finest, P1.5 build for a venue where the viewer never comes closer than 6 metres: there P2.5 is already in its comfortable viewing band, so nobody sees the 2.64-fold pixel surplus - it only appears on the invoice. 3. Not measuring where the nearest viewer actually stops, so the poster ends up closer than the datasheet minimum - within one and a half metres, even a P1.5 image breaks up into a grid. 4. Transferring the content of a printed A4 poster to the display unchanged, small-print footnote and all, which stays unreadable on a 256-pixel-wide grid. 5. Putting a QR code in the creative without checking its size, when on P2.5 a simple version-two QR code with its quiet zone is 25 cm on a side - 39 per cent of the panel width. 6. Not settling the GOB question, when the poster stands at floor level among people, where protruding SMD LEDs are damaged by impact and the surface cannot be wiped safely. 7. Not asking about the refresh rate, and then finding the image bands on social video and corporate footage: 3,840 Hz is the practical lower limit, and it is not related to pixel pitch. 8. Comparing only the price per square metre of the panel, without the stand, the control system, the media player, the delivery, the installation and the training, and so choosing between two incomparable quotations.
| Pixel pitch | Pixels / m² | Resolution on the 640 x 1920 mm panel | Datasheet minimum viewing distance | Comfortable viewing distance (pitch x 2.5-3) | Pixel grid fully disappears (1 arcminute) | QR code side length (33 modules, 3 px/module) | Typical venue |
|---|---|---|---|---|---|---|---|
| P1.5 (actual pitch 1.538 mm) | 422,753 (datasheet figure) | 416 x 1248 px = 519,168 pixels | approx. 1.5 m | approx. 3.8-4.5 m | approx. 5.3 m | 15 cm | Premium retail, hotel reception, meeting-room foyer - with a viewing point of 1.5-2 metres |
| P1.8 (not available from us) | approx. 309,000 (nominal) | grid varies by manufacturer - ask in pixels | approx. 1.8 m | approx. 4.5-5.4 m | approx. 6.2 m | 18 cm | Intermediate step where the nearest viewing point is 1.8-2 metres |
| P2 (2.0 mm) | 250,000 | 320 x 960 px = 307,200 pixels | approx. 2 m | approx. 5-6 m | approx. 6.9 m | 20 cm | Shop window, reception, bank branch, shopping-centre corridor - from a viewing point of 2-2.5 metres |
| P2.5 (2.5 mm) | 160,000 | 256 x 768 px = 196,608 pixels | approx. 2.5 m | approx. 6.3-7.5 m | approx. 8.6 m | 25 cm | Retail floor, restaurant, exhibition stand, waiting area - above 2.5 metres |
A few questions and you get the recommended pixel pitch, the size and an indicative price.
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