Discussions on building large pixel matrixes

[AussiePhil]

I think what does need to be noted though is that these panels are not as bright as using other methods like strip with 5050 LEDs or other types of panels on the market. But at night these will still work great

I wonder if these are being driven hard enough as they definetly dont look like the LEDs are being driven at full intensity when compared to similar designs. But at US$11 a panel these are much cheaper than what im comparing with.

So a great deal for the price

They are 1/8 scan so no will never be as bright but seriously we as a hobby need to get over the obsession with brightness, we use these things at night time, nearly every single pixel display would benefit from being "turned down", we don't need to blind the audience or the neighbours.
Most displays could run 50% brightness and even the owner wouldn't notice with the corresponding savings in power and less voltage drop on cables.
The Major failing of EVERY xmas related sequencer and playback device is the lack of ability to set the master output level and reduce the brightness of the entire display in real time.
My 8x2 panel has 4096 LEDS crammed into a 1.2M x 320mm space... brightness is the last concern.

 

[AAH]

AussiePhil did a measurement of a panel on full white and it works out to about 1A per panel (at 5V) which roughly equates to 20mA per RGB led or 6.6mA per led per colour. A traditional pixel drives a led at between 18 and 20mA per led per colour. This means that there is likely to be only 1/3 of the brightness compared to a pixel. The difference is that with 10mm pitch you have a lot of leds per metre and metre squared so the brightness overall may not be significant. For a P10 30x16 led panel the RGB leds work out to about 2c apiece without pcb, mounts, cables etc. This is incredibly cheap.

I think what does need to be noted though is that these panels are not as bright as using other methods like strip with 5050 LEDs or other types of panels on the market. But at night these will still work great

I wonder if these are being driven hard enough as they definetly dont look like the LEDs are being driven at full intensity when compared to similar designs. But at US$11 a panel these are much cheaper than what im comparing with.

So a great deal for the price

 

[fasteddy]

At the mini with a side by side comparison to strip i personally thought the panel was noticeably duller than the strip. It still works great though but thought it was something that needed to be pointed out as some may be expecting a brighter panel than what i observed.

Normally a panel like this is also designed for daytime presence so they need to be bright, but for what these are being used for then i dont really see a big issue with the brightness because we will only be using them at night.

 

[AussiePhil]

At the mini with a side by side comparison to strip i personally thought the panel was noticeably duller than the strip. It still works great though but thought it was something that needed to be pointed out as some may be expecting a brighter panel than what i observed.

Normally a panel like this is also designed for daytime presence so they need to be bright, but for what these are being used for then i dont really see a big issue with the brightness because we will only be using them at night.

Partially right... these are indoor panels hence 1/8scan.... the outdoor panels are usually 1/2 scan and therefore considerable brighter

 

[i13]

When factoring costs for the P10 panels as a matrix, in addition to the BBB and its accessories , if one is not already using 5V PSUs, then you would need to factor in 5V PSUs plus backups.

Also on the topic of different voltages, remember to consider DC-DC converters. They're not something I fully understand but if they'd work then they'd be worth considering. http://auschristmaslighting.com/forums/index.php?topic=5932.0

AussiePhil did a measurement of a panel on full white and it works out to about 1A per panel (at 5V) which roughly equates to 20mA per RGB led or 6.6mA per led per colour. A traditional pixel drives a led at between 18 and 20mA per led per colour. This means that there is likely to be only 1/3 of the brightness compared to a pixel. The difference is that with 10mm pitch you have a lot of leds per metre and metre squared so the brightness overall may not be significant. For a P10 30x16 led panel the RGB leds work out to about 2c apiece without pcb, mounts, cables etc. This is incredibly cheap.

That's worth considering with other pixels too. The relationship between current draw and perceived brightness also applies when choosing pixels that draw 30mA per pixel versus 60mA. The 30mA ones should suffer less from voltage drop but not be quite as bright. It can be hard to tell which type you'll get if you buy from Ray. 12V 60mA aren't really worth it. Is the relationship between current draw and perceived brightness typically linear? I thought it might not be.

 

[gerry]

Also on the topic of different voltages, remember to consider DC-DC converters. They're not something I fully understand but if they'd work then they'd be worth considering. http://auschristmaslighting.com/forums/index.php?topic=5932.0

Thanks ! I am tempted now ... on second thoughts I'll work on progressing my in-train stuff some more and then look at this again in a few weeks time.