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I'm curious as to what the limitations are in regards to uv radiation on LCD screens when subjecting them to high intensity light sources such as camera flashes (such as a nikon or canon speedlight).

What measures can you take in order to protect against this damage? Dichroic filters? Hot mirrors?

Thanks in advance!

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    \$\begingroup\$ Why do you think it's somehow vulnerable to flashlight? It survives direct sunlight with no damage marks at all. \$\endgroup\$ – Gregory Kornblum Sep 6 '18 at 9:15
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A common camera flash/speedlight should not emit very much UV at all, unless you modify the device. UV will be blocked quite efficiently by most plastic materials (such as the ones used in camera flash "lenses")

See example transmission spectra below: enter image description here

Source: https://www.gsoptics.com/transmission-curves/

enter image description here

Source: https://www.hitachi-hightech.com/products/images/8414/uh4150_data1_e.pdf

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  • \$\begingroup\$ Thank you for your reply! When you say camera flash "lenses" you mean the transparent plastic lens at the "end" of the device? What would cause an LCD to turn off when flashed by one of these common speedlight flashes? My guess would be thermal issues but if you are correct in your statement, I'm left only with the possibility of electrical interference? \$\endgroup\$ – cwinhall Sep 6 '18 at 12:10
  • \$\begingroup\$ That is correct. It's not related to thermals. And frankly, why would it? I mean - a flash lamp gives off energy as heat - that's true, and if you hold your hand directly in front of the lamp as it goes off on full blow, it would probably be uncomfortable, but there is not nearly dense enough energy flow to be able to thermally damage anything as soon as you start moving away from directly in front of it. You would also feel it on your face when being flashed, if that was the case. Imagine the amount of power that you would have to dissipate to be able to heat an LCD monitor to overtemp[1/-] \$\endgroup\$ – MrGerber Sep 6 '18 at 12:58
  • \$\begingroup\$ [2/2]erature within the short duration that a flash lamp is on (<1ms). More likely that the flash is sending some EMI when going off, that is impacting the LCD. \$\endgroup\$ – MrGerber Sep 6 '18 at 13:03
  • \$\begingroup\$ Thanks again MrGerber. One last follow up question if I may... Would it make a large difference regarding the type of LCD being used? TFT vs IPS for example? \$\endgroup\$ – cwinhall Sep 6 '18 at 13:14
  • \$\begingroup\$ Regarding the EMI, I won't say too much. Regarding the thermal or UV radiation, I can't see that matter. Like I said, the flash doesn't give off enough thermal radiation to damage the display - as witnessed by it not heating your face when flashing, and not enough UV to do any damage, as witnessed by the transmission spectra for some typical plastics (and also by the fact that photographers doesn't get way more skin cancer than other people) \$\endgroup\$ – MrGerber Sep 6 '18 at 13:23
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A standard hot mirror that reflects energy between 750 and 1200 nm can be used for IR energy being conveyed to the LCD panel. In addition, a UV blocker can attenuate energy below 400 nm.

I'm not an expert, however, Abrisa Corp is.

Reduce LCD panel failure from excessive IR and UV light.

http://abrisatechnologies.com/2009/03/reduce-lcd-panel-failure-from-excessive-ir-and-uv-light/

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  • \$\begingroup\$ Who's the expert who voted -1 without a comment? \$\endgroup\$ – Sunnyskyguy EE75 Sep 6 '18 at 19:33
  • \$\begingroup\$ LCD's are known to have damage from UV and IR but the question does not define the levels, path loss and repetition rate. \$\endgroup\$ – Sunnyskyguy EE75 Sep 6 '18 at 19:34
  • \$\begingroup\$ Thanks Tony for the comments. I will try to source these hot mirrors and test if this affects the LCD further. \$\endgroup\$ – cwinhall Sep 7 '18 at 14:48

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