DIY Lightbox finished

[daz]

LOL ;-)

The EL panel will take a while to get here, coming from Hong Kong ;-)

I'll keep thinking about how to make a cheap bigger box. The best solution would be if I could buy the diffuser sheets used in these panels in bigger sizes and then just cut them. Then use LEDs behind them. These are 4 or 5 layers of thing plasic sheets with different patterns on then to spread the light evenly.

Another alternative would be using thin, white or frosted acrylic to diffuse the light of, say, super bright white LEDs. I could test that but I have no idea how I could measure how evenly the light has been diffused. I'm quite sure it will not be as good as the panels.

I'll keep thinking .. ;-)

The histogram would tell you, surely.

[yesyes]

To be honest, I have only just really learned doing flats with a white t-shirt and trying my best to get the twilight light to do them

I was asking around for ideas, not asking you specifically..

I've only just started imaging as well. So I'm no expert in what a perfect flat frame should look like...

I was even thinking, there would not have to be a massive apeture opening with it, just a border/ sides to hide shadows and because it will be so close, if hung on a wall for example, the EL, could in theory be large enough for the appeture... dont know, clutching at straw....lol

I didn't get that I'm afraid. Any chance you could make some drawing of that idea? I think the further away you get with the panel, the bigger it would need to be...

[yesyes]

The histogram would tell you, surely.

That's what I was thinking. But I wouldn't want to build the whole box only to find out that it's not up to the task. I was hoping I could simulate this with a much smaller bit of plastic and only a few LEDs.

If I had a, say, 10x10cm piece of acrylic with LEDs behind, would it be enough to hand-hold the EOS over that (trying to be as perpendicular as possible) with the lit acrylic completely filling the frame, and then take a shot and look at the histogram?

[dyfed0_0]

I didn't get that I'm afraid. Any chance you could make some drawing of that idea? I think the further away you get with the panel, the bigger it would need to be...

Sorry, what I meant is, especially in a tight space like an Observatory or something on those lines, instead of having a large circle the size of the apeture just have something like this Alnitak EL panel... granted, an EL panel is out of the question but I was thinking along the same principal.

Just a thought, as I said, I am clutching at straw here.....lol

[dyfed0_0]

Hi there,

Just wondering how did you get on with the "larger" light frame ? sorry, just eager to find if it was a success.

Regards

Dyf

[yesyes]

Ah, yes.... I had almost forgotten about that. Too many projects going on at the moment..

I have started experimenting with LED strips. I've drawn a circle the size of my scope's aperture on a board and then put 2 LED strips, 72cm and 72 LEDs each) in a spiral pattern into the circle (see attached pics).

I haven't done anything further though as at this point I would need some white acrylic. I am waiting for the next time I need to order more acrylic so that I don't need to order a single sheet.

And I still have the problem of measuring how equal the light will be distributed.

I have also received the small EL panel. It works fine but I haven't done anything further with that.

[yesyes]

Oh and I now have 3 working 15" TFT backlight panels (good for scopes up to 8") and one 10" panel (for scopes up to 6"). So if anyone wants one of these lightboxes, just let me know.

[Astrokev]

I'll start by confessing I'm no expert when it comes to monitor panels, but TFT's I believe come in a range of types. Bulk standard panels can suffer from uneven illumination depending on the viewing angle. When I recently upgraded my PC system, I opted for an IPS panel (I understand this stands for "in-plane switching" for the teccies out there) which I'm chuffed to bits with, seemingly having completely uniform illumination regardless of the viewing angle. This makes it so much easier to review and adjust screen colours, contrast etc than my old panel.

For your lightbox (which looks fantastic, by the way) what type of panel did you use, and how much is viewing angle an issue in your design? Perhaps this isn't an issue, since I guess the light from the box is travelling as parallel rays down the tube to the mirror, rather than to a point-source receiver such as the eye? In this case, I guess the term viewing angle does not apply.

[yesyes]

No, as far as I can tell it does not apply.

The viewing angle would only apply to the actual TFT panel that shows the "picture" from the computer. What I did is remove that TFT panel (the "pixels") completely and use only the backlight panel that usually sits behind the TFT. That leaves an evenly illuminated surface without the viewing angle limitations of the screen as a whole.

[Astrokev]

No, as far as I can tell it does not apply.

The viewing angle would only apply to the actual TFT panel that shows the "picture" from the computer. What I did is remove that TFT panel (the "pixels") completely and use only the backlight panel that usually sits behind the TFT. That leaves an evenly illuminated surface without the viewing angle limitations of the screen as a whole.

Ah gotcha, thanks for clarifying.

Kev

[dyfed0_0]

Ahhhh, I can see where your coming from with the concentric circles but as you say, the distance between the increasing circles need to be just so to prevent uneveness..... (my assumption that is....lol)

How many projects have you on the go at the moment?

After Xmas, going to get a pier-tech 2, the distance as it stands at the moment, the top of my scope and the roof, dont want to co-operate so need to get this pier tech to over come the problem then.... this is the biggy....lol, Ive bought a Meade Research Grade EQ mount and my plan is to upgrade it to Go-To, but need some parts first, where, Barrie from Beacon Hill is assisting me and then over to Alan at AWR...... these are the reasons really I want to keep the costs of a Flat Light Box down to the most practical minimum layout and as you rightly say, an EL panel for a 14"er wont do that.

Wife is going to kill me when she finds out how much these projects are going to cost.......lol