Build DIY light meter for photography, cheap, simple, and handy

I have been making this for along time ago, since I don’t like my K1000 light meter, maybe it already weak, and my metering feeling was much better than the meter it self , but every time I tried to make it, I always fail, until the last experiment.

my idea for the scheme was so simple. Give a power, an Light Depend Resistor series with potensiometer and a meter. Yes it work, definitely work but with very un accurate result. The meter cannot read difference on bright condition , but able to read even in candle light. If I modified the potensiometer and the LDR the result are inversed. Also there some mistake in taking light metering. Even a light beside me are measured too. If I make a hood on the LDR, it makes a metering so narrow. Every time you move, the meter needle will be move everywhere.

Than, I almost give up and keep training my feeling. No need metering anyway. Just use your feeling or exposure mat and ultimate exposure( check the link if you want). But I keep try to find the mistake I have made.

After using a multitester, I finally realized the mistake that I have made. The resistance of LDR are drop on kilo ohm in the low light. While in bright light the meter are at 1 ohm scale. It’s a big difference. There is no way a a needle meter can read such a big difference without any switch.

So I get an idea, why don’t I sink the LDR on my small multitester. Than buy another one for my tester?

So is start to build it. And for light measurement, I also add a view finder from broken plastic camera with 38mm view. It make the light only measured on glass of view finder, 38 mm, not to wide and not to narrow.

For adjusting I just use my fuji S700, set to iso 100, and metering to average. I have compare with Minolta Light meter its have a same reading.

Its time to test, its have a good metering.

a little bit over develop. but good enough for me, i am not ansel adams

the size is not big, its fit on my palm

And I just compare with my feeling. Of course object in open shade on sunny day will be 1/250 at 5,6. check the meter its same too, check with my digital fuji, its at a range too ( digital can read 1/225, 1/230 but at least it still at range). just make sure you metering with scale 1 kilo ohm for bright day. And scale 10 ohm in indoor. It just cheap meter. Only cost me $3.