I had to burn a CD and I knew that 5 years before i had layed one next to my old PC, never use CDs since then…
So I searched a bit and found the CD and a cheap lux meter my brother had used to compare his DIY Beamer things.
Its a hp1010b in box with manual, i have seen the same in some threads here i don’t find anymore.
So how to use it and how to calculate lumen and how to find out the angle?
No one…? 
If all else fails I would read the Manual. 
That sound like this meter here.
I’m no expert, but you basically set your meter up at an accurately measured distance, say ten meters. Make sure the meter sensor is perpendicular to the light beam and shine the lights hot spot directly on the sensor and take a reading. You then convert that reading back to the standard one meter. If you want to find out the angle you will have to map a whole bunch of readings at different distances off center. That’s a lot of work for what is mostly useless information. Some people like to measure the size of the hotspot at a given distance to compare different setups, which is considerably less work.
What I explained will give you lux and an idea of throw distance. Lumen calculation involves an integrating sphere or some type of substitute. If nobody helps you out by tomorrow I’ll have more time then and can give you some ideas.
Yes its this style of luxmeter, just the printing is a bit different as it is some years old.
I asked about the angle because to calculate lumens from lux i need a angle.
And I am not sure if i point the light direct to the sensor or if i should light up a wall and measure what reflects from the wall…
White notebook paper reflects “about 60% (0.6) of the light at all visible wavelengths” but I’ve seen numbers as high as 0.8 and it may depend on the incident light intensity.
Also, you can get an “18% Grey Card” from camera stores.
Without an integrating sphere accuracy is less than optimal, but a sphere is not entirely necessary to get a general idea of lumen output. The simplest way is to take your meter into a small room and shut off all the lights. It’s important it’s dark before you turn your torch on. Fire up the torch and aim it at the ceiling. The small room substitutes for an integrating sphere. Check the readout on your meter. Now take a light of known output and repeat everything you just did as closely as possible but with the second light.
If your unknown light gives a meter reading of 50, and your known light puts out 200 lumens and gives a reading of 100 then your first torch lumens would be (50/100)x200 or 100 lumens.
I don’t have lux meter, so I’m not sure how the scale works, but if it is perfectly linear, as lumens are, this method actually works extremely well.
I personally use a DSLR in manual mode and “calibrate” my known light to a specific shutter speed by varying aperture and ISO. In dct73s example above, I would calibrate the 200 lm “known” light to 1/200ths of a second. Then the unknown light, if half as bright, will properly meter at 1/100ths (twice the time), or 100 lms… and you can meter any mode with the lumen result simply being the inverse of the newly metered shutter speed. This even works at sub-lumen levels, a 5 sec exposure reading means 1/5 a lumen or 0.2 lms.
Next is getting a good bounce…. ceiling works but is inefficient due to the distances involved and different beam sizes you’ll have on the ceiling bounce. I found the best bounce to be a horizontal bounce in a narrow hallway. Bounce off one wall, meter off the other. Accuracy and consistency greatly improves by matching the beam sizes on the bounce… I shoot for 8.5x11” size. You can even use one wall and just white cardboard taped to the back of a chair as the other wall. In the end, it’s just a sample of light bounced between two 8.5x11 sized targets. Lumens and time exposures are all perfectly linear and subject to the same proportions and ratios.
