diy flat-field

[Epicyclus Dave]

Hello , i've knocked together a low budget flats box for my skywatcher ed80 , using some plywood and closed cell foam and an A5 size EL card sandwiched between the ply & foam.

I did a quick test during daytime , coupled my un-modded Canon 500d to the scope with reducer & focused on a far away tree , then put the flats box on the dew shield and set the camera to AV mode and the iso to my usual astro settings of 400 or 800 .

Aiming for the histogram to read nearly central , the best of my test shots seem a little light blue in colour , should i be looking for as white a light as possible?.

Dave.

[Andy_E]

I'm not an astro photographer (so feel free to shoot me down guys), but could you not set your WB to the card on your first shot? or would this be defeating the point?

[Epicyclus Dave]

Hi , ah yes , callibrate the WB as a custom setting and use that setting when doing flats , for my astro images i have the WB on daylight setting tho i don't know if that matters when the shots go into DSS .

Thanks.

Dave.

[fwm891]

What's the colour temperature of the light source (looks over normal daylight setting).

May also be your getting some bleed through the coloured foam your using...

[Epicyclus Dave]

Hullo , i'm not very sure what the light temp is of the EL card , no bleed through though, the rim of the dew shield sits against the card surface , i may be better re-designing again and going for strips of white led's behind a bit of opaque white perspex , but before that i'll try a few more tests , i think the EL card has a slight blue tinge to it anyway .

Has anyone else had success with these £15 EL cards from Hong Kong ??.