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Main => Builders Discussions => Topic started by: NeoMorph on October 04, 2011, 02:51:26 AM

Title: Light Bleed Is Frustrating - SOLVED!
Post by: NeoMorph on October 04, 2011, 02:51:26 AM
I really, REALLY wish I had come across this problem earlier in the year. I also wish that I could have passed Panel Master Ian's wonderful suggestion regarding painting the panel with a thick black coat before painting the final colour coat to stop light bleed through.

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I've tried reducing the brightness and distance from the front panel and even though it helps it's still not quite right. That is the LED dimmer I got off ebay on recommendation from this really good cockpit site... Can't remember where I heard it though. ;)

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As you can see the light is coming through the paint. In one way I was lucky because Ruscool made a booboo with that first panel above. See if you can spot the slight error. Several of my other panels are suffering from this too (and other than the bleed through there is nothing wrong with them). I've tried using black plastic but it doesn't work right as the plastic has to be thin to fit between the buttons. I'm probably going to either have the rest of the panels repainted and engraved again or I will have to build thin metal light dams to manage the light bleed.

I don't really blame Ruscool for the problems because the guys were doing my order in the middle of that earthquake that affected New Zealand and demolished Christchurch this year. When stressed out in situations like that mistakes can happen to the best of them...

Anyone got any suggestions on how to limit the light bleed on these panels without having to repaint/re-engrave?
Title: Re: Light Bleed Is Frustrating
Post by: XOrionFE on October 04, 2011, 06:05:34 AM
you could try masking off the areas with lettering on the backside then paint the back black except for those areas.  Then put another layer of opaque white plastic behind that with leds behind that layer so it difuses the light more.   another trick is to lightly sand the leds (scuff them up) which helps cause more diffusion and less of a hot spot.

Scott
Title: Re: Light Bleed Is Frustrating
Post by: Trevor Hale on October 04, 2011, 06:05:57 AM
Neo, move the light further away from the panel. You can see the hotspur of the light. Your led is way too bright. Better to have many dim lights then one really bright one.

If you put a back box around the panel and put a reflector behind the light pointing the light at the back box the ambient light will more evenly flood the panel. No more hot spots.

Trev
Title: Re: Light Bleed Is Frustrating
Post by: jackpilot on October 04, 2011, 06:44:29 AM
[ebay]290406980563[/ebay]

Use these with an orange acetate against the back of the panel.
If you apply them on a support about 1" away from the panel you will get even lighting.
Search/Check David's post on his overhead backlghting.
JP
Title: Re: Light Bleed Is Frustrating
Post by: Bob Reed on October 04, 2011, 06:49:47 AM
I too think your led is just too bright. I was going to sugest Trevor's idea, Jack's may do the trick too if you really cut the brightness of the leds back.
Title: Re: Light Bleed Is Frustrating
Post by: fordgt40 on October 04, 2011, 10:00:15 AM
John

It would appear from your photos that you have only one led lit - that is not the way to trial things. As Bob says your led is too bright/close. Try the fololowing in this order

More leds
More dimming
More distance as Jack says
Scuff the leds as Scott suggests
Jack`s suggestion re orange acetate is good, also, try putting some decorating masking tape over parts of the panel rear and then start again. This should tell you whether you have a good chance of getting the balance right

Are you using flat top leds? these are the best and give a wide range of light spread. Standard leds tend to give you the "headlight" effect. Try the search function on this forum for more info

David
Title: Re: Light Bleed Is Frustrating - SOLVED!
Post by: NeoMorph on October 04, 2011, 09:37:23 PM
I'd pretty much tried all the above solutions but had varying degrees of success. Dimming worked but needed to be too low to look right. More LEDs made it look better but it made the whole panel glow (paint and all). Moving the LEDs back worked great... until I put switches in which meant that it caused shadows.

So I went to bed last night with the problem on my mind and awoke at around 4am with the answer.

Here is a taste of the fix... I'm going to do a full panel later today and see what it looks like but my idea seems to work really well and no hot spots either. This is with just one LED btw.

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I wonder if anyone can guess how I did it...
Title: Re: Light Bleed Is Frustrating - SOLVED!
Post by: Bob Reed on October 04, 2011, 09:43:17 PM
YOu are pointing the led backwards.....
Title: Re: Light Bleed Is Frustrating - SOLVED!
Post by: NeoMorph on October 04, 2011, 10:02:43 PM
Quote from: Bob Reed on October 04, 2011, 09:43:17 PM
YOu are pointing the led backwards.....

Nope! :D

Here is a hint... Found the answer in the kitchen.
Title: Re: Light Bleed Is Frustrating - SOLVED!
Post by: phil744 on October 05, 2011, 01:18:25 AM
Quote from: NeoMorph on October 04, 2011, 10:02:43 PM

Here is a hint... Found the answer in the kitchen.

You asked your wife?

**phil runs**
Title: Re: Light Bleed Is Frustrating - SOLVED!
Post by: Trevor Hale on October 05, 2011, 02:21:35 AM
A tin foil reflector.
Title: Re: Light Bleed Is Frustrating - SOLVED!
Post by: NeoMorph on October 05, 2011, 06:06:20 AM
Quote from: Trevor Hale on October 05, 2011, 02:21:35 AM
A tin foil reflector.
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WINNER! WINNER! WINNER! WINNER! 


It's to match my tin foil beanie to stop my brain waves being read by the men in black! :idiot:

Actually it's more of a tin foil blocker than a reflector. That test picture above is actually a piece of foil 1" square sitting between the panel and the LED. I've actually sat the LED away from the line and legends which actually sorts out the hotspot problem too.

The good thing about the foil is that it's a both a really good reflector and perfect for blocking out the light from areas you don't want it.

On top of that I've actually been doing a bunch of reading fron links of Jack and Phil. I think I've figured out how to seperate the coloured from the white now thanks to your suggestions of using coloured acrylic and using all white LEDs for the background (I was originally going to use various coloured LEDs for that... problem is the colour mixing sucks.

This has really been doing my head in even after trawling this site and the rest of the net. I knew there could be an answer but just couldn't get past using aluminium sheets (not foil) to make light-proof boxes. I was close but couldn't quite reach the finish line.

Oh and Phil, thanks for the hint regarding painting the panel black before brown to prevent light bleeding... Dean from Ruscool is going to start doing my replacements panels using that method.

Well I'm off to start work on my test panel now. I've finally just received my final package from Farnell (2 days late, cheers UPS) so I've got all the parts I need now.

Tally Ho!