Lux meters to check Led????

[mcarroll]

If I put the phone right at the water, close enough to get my fingers wet, I am reading 21,000 lux.

That sounds like how I do it and it sounds like a reasonable reading – possibly accurate.

Like Salty said (again) scan around over the surface in the same manner and see what you get. Remember to angle the sensor to pick up the maximal reading you are able to get from each location. You can put your phone in a zip bag if you wanna take underwater measurements....they seem to come out reasonably accurate.

 

[rgaston]

I'm not trying to cause a problem with or for anyone on the forum - Just passing along Info!

I have very little knowledge on the subject of converting lux to par with a lux meter. So, I called Milwaukee Instruments and talk their representative. He told me that their is no way to convert lux to par for led lights. He also said that Milwaukee does not want anyone to buy a product from them with the wrong assumption that you could use their lux meter to convert lux to par for led lights. He said the only way to get accurate par readings for led lights is with a par meter.

 

[saltyfilmfolks]

I'm not trying to cause a problem with or for anyone on the forum - Just passing along Info!

I have very little knowledge on the subject of converting lux to par with a lux meter. So, I called Milwaukee Instruments and talk their representative. He told me that their is no way to convert lux to par for led lights. He also said that Milwaukee does not want anyone to buy a product from them with the wrong assumption that you could use their lux meter to convert lux to par for led lights. He said the only way to get accurate par readings for led lights is with a par meter.

Look at the apogee website.
https://www.apogeeinstruments.com/conversion-ppf-to-lux/

And it is an estimate , and not a 100% accurate way to measure par. As corals are highly adaptable , imo, a 25 to 75 par error is not an issue.

 

[clsanchez77]

I'm not trying to cause a problem with or for anyone on the forum - Just passing along Info!

I love controversy, don't hold back! This isn't 100% correct (I hate absolutes) but there is a lot of error in the conversion. I use photo red LEDs on my fuge tank and these show up as near 0 on my Lux app on the phone, but hits 700 PAR on the PAR meter. The true reds and photo red LEDs just don't contribute much to Lux just as the UV LEDs also do not. This was my point on my original post to this thread that PAR cannot always be represented by LUX. But the overall point in here is that it can be approximated by LUX within reasonable/acceptable margin of error and for overall general use. The reason being is that the majority of our lights source is Royal Blues, Blues and Cool Whites, all of which a LUX meter readily picks up. I hope to have time to play with that this weekend.

 

[saltyfilmfolks]

I love controversy, don't hold back! This isn't 100% correct (I hate absolutes) but there is a lot of error in the conversion. I use photo red LEDs on my fuge tank and these show up as near 0 on my Lux app on the phone, but hits 700 PAR on the PAR meter. The true reds and photo red LEDs just don't contribute much to Lux just as the UV LEDs also do not. This was my point on my original post to this thread that PAR cannot always be represented by LUX. But the overall point in here is that it can be approximated by LUX within reasonable/acceptable margin of error and for overall general use. The reason being is that the majority of our lights source is Royal Blues, Blues and Cool Whites, all of which a LUX meter readily picks up. I hope to have time to play with that this weekend.

Interesting, I would reccomend , beg maybe, lol, try an actual lux meter on that test. Cameras actually have limiters on them in the software and is also a phone and some work far differently.
I ask, because at 700 par you have intensity. Quite a bit actually. If you did not have intensity in FC or lux, I could not take a picture of anyone using only red light.

In fact if you take a picture of your fuge you can look at the exposure data and settings as determine the approximate intensity.

 

[mcarroll]

Cameras actually have limiters on them in the software and is also a phone and some work far differently.

Clipping IR is typical, correct? Seems like I could never get >650nm to show up in pics.

Probably UV as well?

 

[saltyfilmfolks]

Clipping IR is typical, correct? Seems like I could never get >650nm to show up in pics.

Probably UV as well?

We don't see ir on sensors. It's Clipping the R Chanel on both the sensor and and the analogue digital converter. Over exposing in fact.
Most software needs all theee Chanel's to be exposed correctly or show some value for proper exposure. In short it fools the sensor into not thinking it doesn't have enough light. So it under exposes.

It's the drawback to phone/camera meters. It may use the ambient light sensor or most often, it's using an RGB color sensor that acts as a spot meter (reflectance values). Rather than the standard hand held meter that has the cosine corrected photocell that has a wider natural special gamut. And no software limiters. I.e. Its not color biased like an RGB sensor and software has to be.

An SLR(ask your parents kids), uses a photocell to indicate exposure based on the amount of light it recieves (reflectance), a DSLR, is using the sensor and averages the three Channels .

 

[mcarroll]

You're right! I was conflating my old digital camera with my cell phon cam.....think my old Casio UV2000X had an IR filter to prevent fun IR photography.

 

[Mark Gray]

Ok maybe a dumb question but why not just use a spectrometer?

 

[saltyfilmfolks]

Ok maybe a dumb question but why not just use a spectrometer?

For what.

 

[Mark Gray]

Well I am way behind on how to get the most out of my lights.But ok I think I understand the difference between lux and par meters but wouldn't a full range spectrometer give you all you really need?

 

[saltyfilmfolks]

Well I am way behind on how to get the most out of my lights.But ok I think I understand the difference between lux and par meters but wouldn't a full range spectrometer give you all you really need?

Im not super familiar with models of spectrometers, Mine is a hobbyist brand(a prism is similar). but it assume its breaking downs not only the spectrum into individual parts. It does not measure the amount in intensity(lux/FC) nor the amount of Photo/active radiation.

So a spectrometer is whats in the light, FC/Lux is how much total, Par is how much is usefull. So......

In short, lux is intensity, intensity + spectrum is PAR.

A spectrometer will allow you choose the spectral peaks (in NM) by mixing colors, once you have chosen those colors, you increase the intensity until you achieve the desired PAR.

 

[Mark Gray]

Off subject but here's my view at breakfast this morning

 

[Mark Gray]

Im not super familiar with models of spectrometers, Mine is a hobbyist brand(a prism is similar). but it assume its breaking downs not only the spectrum into individual parts. It does not measure the amount in intensity(lux/FC) nor the amount of Photo/active radiation.

So a spectrometer is whats in the light, FC/Lux is how much total, Par is how much is usefull. So......


A spectrometer will allow you choose the spectral peaks (in NM) by mixing colors, once you have chosen those colors, you increase the intensity until you achieve the desired PAR.

Hum so I guess I got to buy both

 

[saltyfilmfolks]

Hum so I guess I got to buy both

lol. Lux meter $15, my "spectrometer" $4. My Par par meter .

 

[Mark Gray]

lol. Lux meter $15, my "spectrometer" $4. My Par par meter .

Hum interesting the spectrometer I was looking at was I think 450, got to wait till I get home the internet is very slow here but great place

 

[saltyfilmfolks]

Hum interesting the spectrometer I was looking at was I think 450, got to wait till I get home the internet is very slow here but great place

Your in Fiji. I may just pout and not talk to you.

Have fun Mark...Get in the water.

 

[Mark Gray]

Your in Fiji. I may just pout and not talk to you.

Have fun Mark...Get in the water.

Yes I am working today and tomorrow for sure I am staying I Suva on the edge of the Rainforest

 

[mcarroll]

@Mark Gray Try this R2R search: spectrometer and this search: lux

Not that I would turn my nose up to higher end gear if it was offered to me, but I'm still happy with my $12 lux meter and $25 spectrometer. My $12 microscope is the latest low-end addition to home laboratory.

Unless budget is no object, I think it makes a lot of sense to start out with these.

Once you get a feel for what you're doing and see what each tool is actually capable of (very different from just reading about them) you can feel a lot more confident about either keeping the tool or upgrading – and you haven't spent any real money yet, not even if you add up all these tools together.

FYI, at those prices I think a lux meter and microscope ought to be standard equipment for any hobbyist these days. The Spectrometer is nice and informative, but it's not as directly useful as the other two.

 

[Mark Gray]

@Mark Gray Try this R2R search: spectrometer and this search: lux

Not that I would turn my nose up to higher end gear if it was offered to me, but I'm still happy with my $12 lux meter and $25 spectrometer. My $12 microscope is the latest low-end addition to home laboratory.

Unless budget is no object, I think it makes a lot of sense to start out with these.

Once you get a feel for what you're doing and see what each tool is actually capable of (very different from just reading about them) you can feel a lot more confident about either keeping the tool or upgrading – and you haven't spent any real money yet, not even if you add up all these tools together.

FYI, at those prices I think a lux meter and microscope ought to be standard equipment for any hobbyist these days. The Spectrometer is nice and informative, but it's not as directly useful as the other two.

Thank you I will look into both, this is something I have not messed with, I have been onto saltwater and reef tanks for over 35vyears now