Flat Field Generator DIY

[Vaughan512]

I read some older threads on this topic here and so, inspired, I started looking around at Flat Frame Generators (many names, I know) and the prices took my breath away, and my wallet shrivelled in fright!!!

Having employed the white cloth/shirt/t-shirt/handkerchief over the lens pointed at the sky away from the sun at dawn or dusk, I thought there must be a better method.

Buying a specially made generator is out of the question, given the prices. So, I researched DIY methods - here and other forums.

There are lots of suggestions about, but being lazy by nature,  I'm business solution analyst, I looked for an easy, ready-made solution.

I came up with this: Aibecy A5 Tablet for 12.99 euros, so it wasn't going to break the bank, if it didn't work. The biggest issue described in the forums was that the LED lights were too powerful at 10W, 12W and above. This one has three light settings starting at 5W as the brightest.  I haven't tried it "in anger" with a full night's shoot, but these initial results look promising.  The vignetting is apparent, which is good, and the light is very even / diffused.

If you do try this, don't be put off by the black grid on the tablet surface. It's how it comes, hence the hanky.  I am going to see if I can find a sheet of thin, white, translucent material to replace the hanky.

My experiment still uses a (clean and ironed) hanky folded four times as you can see in the first picture.  I think it should work.  Being A5 it will cover a maximum 140mm aperture, which is adequate for most applications.  There are A4 to A1 models available, but this will do me for the foreseeable future.

Picture Reference:

1. The set up Camera in Av Mode at ISO 800, from my last shoot
2. Full power - 1/80s
3. Medium power - 1/30s
4. Low power - 1/10s
5. Off - 1s -  this shows there is light leakage between the tablet and the hanky, so maybe a collar to plug the gap may be in order