Light source for Flats

[Gina]

I've tried various ways of taking flats based on using light from the sky but with dubious results.  I'm thinking of making a light box but wondered what other's use and what you all would recommend.

I'm mainly interested in widefield narrowband imaging.

Thank you in advance. 

Edited July 8, 2019 by Gina

[Buzzard75]

I do the t-shirt method and use my laptop screen with a white background, usually a blank MS Word document. Only takes a few minutes to capture a series of flats so I just hold it up against the objective. I've only ever done small aperture though and it seems to work well enough for me. If you have the time, money and ability though, a light box is probably the better solution.

[PaulR1]

this is what I use :

https://www.bigbathroomshop.co.uk/biard-led-20w-300mm-x-300mm-panel-light-white-frame-64873

it was £13 but now seems to be 18

Worth a punt ?

[mihaighita]

The biggest concern in a lightbox for flats is light diffusion. You can always make a box out of an old paint bucket and stick a LED strip as evenly distributed as possible. Than you can diffuse the light with sheets of flat transparent fiberglass. Use more than 4 to distribute the light as evenly as possible. 

 

[Gina]

I was recommended an LED flat panel from Amazon that gives a nice flat light and works alright with NB filters.

A4 Tracing Light Box - LitEnergy 9x12 Inch Light Pad Ultra-Thin Only 5mm USB Power Light Table for Artists, Drawing, Sketching, Animation

Thank you all for your replies.

[Jkulin]

I bought one of them Gina and it is a 5v affair which means I can't control it from my Pegasus Ultimate Power Box, so I switched to one of These

It runs on 12v and I have never had such perfect flats, in SGP I use the calibration wizard for 30,000 ADU

for LRGB I use a lighting Gel and an opaque sheet of perspex to get the brightness down and for NB I just use the opaque sheet, I can send you details of where I got the gels and sheet perspex from if you need it.

 

[martin_h]

I use a led flat panel and Dim it down with 3 layers of .5 nd lighting gell and difuse it with a soft focus lighting gell

[MarsG76]

Personally I just point he scope (parallel) at a white wall in my observatory and shine a bright work light at it. This gives me a evenly illuminated wall at the scope and camera FOV.