EL Panel – 25 x 25cm



  • This EL Panel has been developed with Telescope Flat-Field Correction in mind, however it can be used like any other EL panel.
  • Please select a driver from the range of options from mains (UK, US or EU), to 8xAA Battery Box, rechargeable Li-ion battery, 12v Crocodile Clips or car lighter attachment to put on your own 12v source.



We have made this EL Panel with Telescope Flat-Field Correction in mind

This EL Panel can be used like any other for the variety of uses people find for these EL Panels.

But if you need an EL Panel for flat-field correction then this is the type of Panel you may need.

If this Panel is too large for your telescope, then you may find this A5 panel (14cm x 20cm) would suite your needs better.

Or if you need a larger EL Panel for flat-field calibration, then you will have to use out A3 EL Panel (29cm x 42cm)

If you are using this Panel for flats then you may want to use some opalescent acrylic to diffuse the granulation of the EL Panel

We do not currently have any in stock of this opalescent acrylic, but it is available online (e.g. here)

The EL Panel comes with a Driver that can hot swap between mains (UK, US or Euro), 8xAA Battery Box, rechargeable Li-ion battery, 12v Crocodile Clips or car lighter attachment to put on your own 12v source

All these parts for the Driver are available in the EL Accessories

Here is the experience of one of our customers from using our EL Panels for flat-field correction:

You’ll remember that we exchanged emails following my purchase of an A4 EL panel from you last month via eBay.

In your last email you asked whether the Panel would be bright, white and even enough for telescope calibration, and I said I would let you know how it performed once I had it all set up.

For use, I sandwiched the EL Panel between a sheet of black acrylic and a sheet of opal frosted acrylic, bound the edges together with black plastic insulation tape, and fixed the assembly into a deep A4 picture frame.

The attached images show how the panel performs in producing flat-fields for the correction of astronomical images. A 6-inch reflecting telescope and astronomical camera with an APS-size CCD colour sensor were used. This is the maximum size of telescope that can be calibrated with the A4 panel.

flat field callibration image

The Panel was placed directly onto the telescope tube. With the particular camera I used, the exposure needed to give around 33% saturation of the sensor (the ideal value) was 0.25sec. So brightness is perfectly adequate for the purpose.

The attached images include the flat-field obtained and an analytical map of the brightness distribution. The vignetting is entirely due to the optics of the telescope. There is no detectable unevenness arising from the EL Panel alone.

analysis of a flat field calibration

I have not tested the spectral distribution of the panel. Many astronomical cameras use monochrome sensors and colour images are obtained by combining exposures taken through red, green and blue filters, as well as some special narrow-band filters designed to highlight specific radiation from hydrogen, oxygen, etc. I expect that flats obtained using these filters will need different exposures to compensate for differences in the emission spectrum of the EL Panel.

Two of the attached images show a picture taken last week of the galaxy pair M81 and M82, with and without correction using the flat field panel. The ‘without correction’ picture is a raw image before any processing – the ‘with correction’ picture shows the result of flat-field correction combined with processing using specialised software to manipulate the brightness range of the image.

These are a very good results and I think it fair to say that a perfectly adequate set-up can be made using your Panels.

Thanks for your help getting the Panel to me and sorting out the glitches.

Raw Image:

telescope image without flat correction

 With Flat-field Correction:

telescope image with flat correction