jusxusfanatic
Well-known
How to check if a light meter still works? (Hand held) thanks
How to check if a light meter still works? (Hand held)
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Chriscrawfordphoto
Real Men Shoot Film.
If its a meter that requires a battery (some meters like the Sekonic L-398 do not), install a new battery. Dead batteries can make a good meter look like one that doesnt work. Next turn it on; if it comes on and gives readings when you push the measuring button, then it works, though it may still need serviced if the readings are not accurate. To test that, borrow a meter that is known to be good and compare the readings they give.
jusxusfanatic
Well-known
Might need a different way of testing them, since it's gonna be my first light meter haha
Blind_spark
Established
As said, make sure the meter has fresh batteries if needed. If you have a camera with a built in (accurate) meter, you can use that as a comparison. Use an evenly lit wall - aim both the camera and the meter at said wall (probably from about the same distance) and compare the readings.
charjohncarter
Veteran
I have a wall in my house that I use, it is close to Zone V. I take a reading with the suspect meter. Then I use a meter that I trust. Often times it is a camera I use and get consistent negatives. I then compare. Be careful though, ISO, shutter speed and aperture have to be checked.
If there is an inconsistency then I check scenes with both or maybe a third meter. It can be a difficult journey. I have a prism meter on my Pentax 6x7 that is center weighted and I have never decided if it is accurate or not. Consequent to this, I have to use an trusted handheld every time I use it.
This of course is all about reflected metering. Incident metering is done the same but be careful that you don't use changing light or mixed shadowed light.
There are many good metering tutorials on the web. I like and have learned much from Roger Hicks online tutorial, and even more from his book dedicated to exposure.
EDIT: sorry blind spark jumped me.
If there is an inconsistency then I check scenes with both or maybe a third meter. It can be a difficult journey. I have a prism meter on my Pentax 6x7 that is center weighted and I have never decided if it is accurate or not. Consequent to this, I have to use an trusted handheld every time I use it.
This of course is all about reflected metering. Incident metering is done the same but be careful that you don't use changing light or mixed shadowed light.
There are many good metering tutorials on the web. I like and have learned much from Roger Hicks online tutorial, and even more from his book dedicated to exposure.
EDIT: sorry blind spark jumped me.
Nelson Tan
Established
You can use the Sunny-16 method. On a bright sunny day, the meter should give you a shutter speed reading equivalent of the ISO speed set at f/16. For example, set the aperture setting to f/16 and the suggested shutter speed should show 100th/sec if the ISO is set at 100. This is only a rough test, but the most accurate way will be to compare against a verified accurate incident light meter.
jusxusfanatic
Well-known
Alright thabks guys! 🙂
p.giannakis
Pan Giannakis
I test my light meters against the Nikon F5 - I have grey carpet in our bedroom. I take a reading from the carpet with the F5 in ISO 100 (aperture priority and, say f/5.6) and then a reading with the light meter (same ISO). I check to see if they are the same. I do it in the morning when it is very bright and then close the blinds a bit to see if it is just as accurate with low light.
If you want the best indication you should follow the general advice above, but also, ideally, ensure you are comparing like to like. The colour sensitivity of meters using different photo cells can vary. If you are trying to assess the accuracy of a classic meter using a selenium cell with a modern silicon cell you may find some variation between the two even if both are in optimum condition. Similarly CdS cells can be over sensitive to red if I recall correctly. Therefore the time of day in certain locations and seasons may have a significant impact on the veracity of your test results. For this and other reasons (touched on, below) it's best to avoid making comparisons early or late in the day when the suns light can take on a noticeable cast.
You also need to bear in mind that selenium meters are not particularly useful in low light conditions. They rely on the light source for their power supply to the galvanometer, and towards dusk as light levels drop, they will not generate enough output for an accurate reading. Some types are designed to run as a dual range system. You keep a slotted flap closed in bright light conditions and reference one scale or one setting mark, in dimmer conditions the flap is opened to expose the entire cell and increase its output, and a secondary exposure scale or setting mark is then referred to. Booster cells to be clipped on to the meter for very dull conditions were sometimes offered to increase the useful EV range of a meter (either as an accessory or as standard euipment), and these can improve matters but, inevitably, a selenium meter will not have the same ability to measure light in near dark conditions that a modern silicon cell battery-powered type is going to have.
CdS cell meters can also take a few seconds to stabilise on a reading, many of us know this point, and when using such a meter becomes second nature. If you are unaware of this, it can initially be a source of confusion when, in a constant light source, the meters reading alters, independent of distance to light source, and/or orientation of the meter to the source.
It may have been somewhat easier to offer suggestions if the type (or indeed, make and model) of light meter was known, but, you've not told us this rather critical bit of information. If you might tender these details, perhaps members can make some more useful, specific, comments about the actual type you're considering. Food for thought.
Cheers,
Brett
You also need to bear in mind that selenium meters are not particularly useful in low light conditions. They rely on the light source for their power supply to the galvanometer, and towards dusk as light levels drop, they will not generate enough output for an accurate reading. Some types are designed to run as a dual range system. You keep a slotted flap closed in bright light conditions and reference one scale or one setting mark, in dimmer conditions the flap is opened to expose the entire cell and increase its output, and a secondary exposure scale or setting mark is then referred to. Booster cells to be clipped on to the meter for very dull conditions were sometimes offered to increase the useful EV range of a meter (either as an accessory or as standard euipment), and these can improve matters but, inevitably, a selenium meter will not have the same ability to measure light in near dark conditions that a modern silicon cell battery-powered type is going to have.
CdS cell meters can also take a few seconds to stabilise on a reading, many of us know this point, and when using such a meter becomes second nature. If you are unaware of this, it can initially be a source of confusion when, in a constant light source, the meters reading alters, independent of distance to light source, and/or orientation of the meter to the source.
It may have been somewhat easier to offer suggestions if the type (or indeed, make and model) of light meter was known, but, you've not told us this rather critical bit of information. If you might tender these details, perhaps members can make some more useful, specific, comments about the actual type you're considering. Food for thought.
Cheers,
Brett
jusxusfanatic
Well-known
Thanks for the infos 🙂
