LIGHT BOX

[Guest]

Hello,

I am looking to make a light box for a 4" Refractor, I have priced out the parts for one that I found on U-Tube which came to around £40.

Since doing that I have found an AGPtek utra thin Light box LED copy board drawing pad tracing table with brightness control, on Amazon at around the same price, my question is would this sort of thing be suitable for taking flat frames if I just held it up against the telescope.

Thanks

Neil

 

[symmetal]

Yes, the LED light panels are very handy for taking flat frames. It depends on the method used for brightness control, as to whether the variable brightness is suitable. Variable current (no problem) or PWM (rapid switching on and off at high frequency), which can cause problems at short exposures. Many people run them at full brightness and put sheets of paper in front to get exposures at an optimum length.  (0.1 to 1 second or thereabouts.)

Alan

[Guest]

Hi Alan,

Thanks for your response, the one I am looking at I am told is dimmmable by the variable current method, so I think I will go for that as it will mean avoiding an attempt at a DIY one.

Many thanks for your help.

Neil

[Davey-T]

I use an A4 LED light pad less than £15.00off E'Bay, powered from laptop USB and dimmable, just cut a suitable size circle in the box it comes in to fit over the end of the scope.

Needs a few sheets of white A4 to adjust brightness for suitable length flats.

Credit to @carastro

Dave

[Guest]

Ingenious, saves recycling the box as well?

[adyj1]

29 minutes ago, Davey-T said:

I use an A4 LED light pad less than £15.00off E'Bay

That is a very simple-looking solution. I don't suppose you have a link? There's so many to choose from... 

Thanks

[Davey-T]

21 minutes ago, adyj1 said:

That is a very simple-looking solution. I don't suppose you have a link? There's so many to choose from... 

Thanks

Sorry it was a few months ago, just had a look and the link says not found.

Dave

[adyj1]

1 hour ago, Davey-T said:

Sorry it was a few months ago, just had a look and the link says not found.

Dave

No problem - thanks for checking. 

Ady 

[carastro]

Quote

Credit to @carastro

Thanks but I got the idea from Roland Kol. So credit to Roland. 

[carastro]

I don't know how to bring up Roland's name with an @ in front how Dave didn't it for me.  @RolandKol

 

 

[carastro]

The one I and probably Dave bought, and I think Roland bought too seems to have sold out.  But it was something like this one, but I can't vouch for this exact one as it is not the same.   Mine needs some typing paper on it to diffuse the light as is is lit with loads of dots, but works just fine. 

https://www.ebay.co.uk/itm/A3-A4-LED-Stencil-Board-Light-Box-Artist-Tracing-Drawing-Copy-Plate-Table-Gift/292529521172?hash=item441c1e4214:m:mLkobHqc7-f9EnUvUrh1ahA:rk:6:pf:0

[adyj1]

52 minutes ago, carastro said:

The one I and probably Dave bought, and I think Roland bought too seems to have sold out.  But it was something like this one, but I can't vouch for this exact one as it is not the same.   Mine needs some typing paper on it to diffuse the light as is is lit with loads of dots, but works just fine. 

Carol, thank you - I appreciate you can't guarantee it's the right one, but your guess is better than mine ? 

Oh, and thanks to @RolandKoltoo (I'll do it for you, on my smartphone a list pops up as soon as I type @ and start typing letters...) 

Ady

 

[Davey-T]

Picture of mine, it's really compact being A4 size with no big frame and has a dimmer switch.

Make says Fleiz

Dave

[Davey-T]

This one is similar except the dimmer is built into the light and mine has it in the power lead.

Says flicker free technology.

Really cheap, think I'll buy another one for a smaller scope to save making 2 holes in the one I've got.

Dave

https://www.ebay.co.uk/itm/A4-LED-Drawing-Board-Tracing-Light-Box-Tattoo-Art-Stencil-Slim-Lightbox-Pad/312244417317?hash=item48b337b325:m:mF2fUPD-mX833--tm9FMSJg:rk:40:pf:0

[symmetal]

1 hour ago, Davey-T said:

Really cheap, think I'll buy another one for a smaller scope to save making 2 holes in the one I've got.

Dave

Good idea Dave. I've just ordered one. For the price you can't go wrong. I've gone for the 3 brightness one (being constant current drive should be no problems.) My current continually variable one I always leave at full brightness as that's the only setting you get a known brightness. The stepped one is more controllable and may negate the need for paper filters. 

Alan

[Guest]

Hello All,

After much deliberation and research, I decided to make a light box instead of using an LED copy board.

I made it out of 3mm Foam Board, used 3mm thick matt white Perspex for the diffuser and the light source was from an 8w Energy saving bayonet bulb, which I turn on about 30 seconds before I use the box.

I had to make 2 different inserts to fit my telescopes – Sky-Watcher Esprit 100 ED PRO Triplet and a skywatcher Explorer 200p, the Esprit insert was quite simple but the 200p was a bit more complicated. I also made the back removable so I could change the light bulb.

I did plan to take Images as I made it, but got carried away and finished it before I remembered, but I think you can get the general idea from the pictures below.

I have tried out the light box this evening and it seems to work very well, when I drag out the levels it shows up the dust spots on my DSLR sensor and also the vingetting, so the final test will be when I can get out to take some real images.

Although I have gone a different route from my initial question, I would like to thank you all for your advice, as it did help me make my mind up which way to go in the end.

If anyone is interested, I have listed down the items I used to make it below & basically designed it as I went: -

1   10 off sheets White A3, 3mm thick Foam Board.

2   1 off sheet Matt White A3, 3mm thick Perspex.

3   1 0ff Ceiling Rose Batten Lamp Holder.

4   2m length rubber electrical cable & a 3-amp plug.

6   60w Hot Melt Glue Gun with Glue Sticks.

The total cost for it all including the glue gun was under £40 from that well known online store with unlimited 1 day deliveries.

 

[Davey-T]

Good job, looks similar to the one I made for the 10" SCT.

Dave