PARwise

[Nonya]

@crit21 Remember that the introduction of the other spectrometers were to challenge your position that cheap diodes don’t match their target spectrum. Your spectrometer is generally reading low below 470nm and high above. The conversation then went a bit bag of cats. Comparing the PARwise to real spectrometers is silly, but when the the PARwise comes home, I’ll reengage.

I look forward to you proving that point using single wavelength LEDs above and below 470nm; more specifically, 380 to 500nm. I could care less about green through red.

Even then, how do we know your $3,000 scope is correctly calibrated? Do you have a calibrated light source? Dollar value doesn't mean calibration, and even less so if it's no longer NIST-linked.

 

[Nonya]

@telegraham So do you have some spare single-wavelength LEDs to set aside for the testing? Are they labeled according to advertised wavelength, according to the seller?

 

[Nonya]

Regarding the PARwise, I bought one to try and share. It's currently hanging out with another reefer in South Carolina. When it returns, I'll compare it with the VBR and Apogee.

I'm a little slow today (COVID again), so it took too long for me to put 1 and 1 together. Why would you let a fellow reefer use a spectrometer you refer to as "crap" instead of the one you say is "good"?

 

[LgTas]

I look forward to you proving that point using single wavelength LEDs above and below 470nm; more specifically, 380 to 500nm. I could care less about green through red.

Even then, how do we know your $3,000 scope is correctly calibrated? Do you have a calibrated light source? Dollar value doesn't mean calibration, and even less so if it's no longer NIST-linked.

Must say you thought I was trolling when I asked for supporting evidence to your pretty broad brush statement regarding Chinese LEDs. Your responses are just as bad. Having compared the various graphs,its clear the parwise is a smoothed out graph compared to others.

 

[telegraham]

Having compared the various graphs,its clear the parwise is a smoothed out graph compared to others.

Significantly smoothed and inaccurate. Shifted left under 470. Shifted right above 470.

 

[telegraham]

I'm a little slow today (COVID again), so it took too long for me to put 1 and 1 together. Why would you let a fellow reefer use a spectrometer you refer to as "crap" instead of the one you say is "good"?

It was $300, not $650 (or more) and the borrower wanted to try it instead of buying it. Now he won't buy it. As mentioned in my HF review, I don't like the device but it could be better if the issues noted were addressed in software. I guess I could put it this way...if you don't know any better, it's a cool device. If I didn't have several PAR meters or several spectrometers, I wouldn't know that the PARwise is kinda crappy.

 

[telegraham]

I look forward to you proving that point using single wavelength LEDs above and below 470nm; more specifically, 380 to 500nm. I could care less about green through red.

I look forward to YOU proving yourself wrong. From this exchange, I've learned that you'll believe yourself, but I'm happy to share data.

You'll also get 500-660nm. They matter, too, and the PARwise doesn't quite get those right.

Couldn't care less, not "could care..." You're making the point is that you have more cares to go.

So do you have some spare single-wavelength LEDs to set aside for the testing? Are they labeled according to advertised wavelength, according to the seller?

Yes.

Even then, how do we know your $3,000 scope is correctly calibrated? Do you have a calibrated light source? Dollar value doesn't mean calibration, and even less so if it's no longer NIST-linked.

The UPRtek shipped NIST tracable, but we don't know that it's accurate. Agreed. That's why I'll use the Hopoocolor and the UPRtek. And if you'd like, I'm happy to send the diodes to others who have the Hopoocolor. We can average all those readings out or pick those that support your views.

Here's another comparison. G5 XR15 Blue.

From this graph, I can see that the PARwise tells me there's some blue, orange/red, and some UV that doesn't actually exist. How can anyone tune a light to what they're after if you can't see the individual spectrum peaks?

The PARwise is a mediocre PAR meter with crappy spectrometer functionality. In the US, the $190 VBR PAR meter from Amazon is less impacted by how it's held, measures dang near the same as an Apogee, and leaves you with $110 in your pocket. If you want a generally accurate spectrometer, the $650 Hopoocolor is my pick.

See...you got me engaging again.

 

[telegraham]

Sorry...one more. Under an open-air Gen 5 XR30 Blue, I get 200 umol/m²/s with an SQ-500 (no immersion effect multiplier, so appropriate for open air). Using the Hopoocolor, I get 235 umol/m²/s. With the PARwise set to open air, I read 179 umol/m²/s. That greater than a 10% difference. However, if I tilt the light over the PARwise, or tilt the PARwise, by about 45°, it reads 240 umol/m²/s. Placement is important. That means it's not easy to know if you're getting an accurate reading with the PARwise.

 

[Nonya]

Here's another comparison. G5 XR15 Blue.

From this graph, I can see that the PARwise tells me there's some blue, orange/red, and some UV that doesn't actually exist. How can anyone tune a light to what they're after if you can't see the individual spectrum peaks?

My focus is on single, discreet wavelength emitters. You're comparing a basket of fruit to a basket of fruit. I need one apple to the same apple. The graphs don't prove or disprove whether the PARwise can identify peak wavelength of a single emitter.

The PARwise is a mediocre PAR meter with crappy spectrometer functionality.

Not concerned about PAR. Spectrometer functionality is still to be verified. You can call it crappy all day, but unless you can demonstrate the peak wavelength measurement accuracy for a single emitter, you're just giving opinion. Someone with your resources should be able to do that--assuming you ever get the PARwise.

 

[Nonya]

You'll also get 500-660nm. They matter, too....

I've been successfully growing SPS and LPS under blue, royal blue and violet for several years. 500-660nm really don't matter. Neither do red or UV.

Here's another comparison. G5 XR15 Blue.
From this graph, I can see that the PARwise tells me there's some blue, orange/red, and some UV that doesn't actually exist. How can anyone tune a light to what they're after if you can't see the individual spectrum peaks?

If I can measure individual wavelength LEDs with a certain level of accuracy, I can build an array that suits my needs perfectly. Assuming 1-2nm accuracy is essential for corals is ridiculous. I've seen SPS grown under JUST 465nm blues.

 

[Nonya]

It was $300, not $650 (or more)

The Hopoocolor is $650 or more. I paid $240 for the PARwise new.

If I didn't have several PAR meters or several spectrometers,

It would never occur to me to fork out money for SEVERAL spectrometers, especially if I wasn't doing some kind of scientific work to justify the expense. If it wasn't for the low price, I wouldn't be experimenting with the PARwise.

I wouldn't know that the PARwise is kinda crappy.

Man, you really like that word.

 

[Nonya]

Sorry...one more. Under an open-air Gen 5 XR30 Blue, I get 200 umol/m²/s with an SQ-500 (no immersion effect multiplier, so appropriate for open air). Using the Hopoocolor, I get 235 umol/m²/s. With the PARwise set to open air, I read 179 umol/m²/s. That greater than a 10% difference. However, if I tilt the light over the PARwise, or tilt the PARwise, by about 45°, it reads 240 umol/m²/s. Placement is important. That means it's not easy to know if you're getting an accurate reading with the PARwise.

There's another thread discussing that issue. Mixed responses. The funny thing is that nobody knows whether any of the meters in use are accurate.

 

[Nonya]

Couldn't care less, not "could care..." You're making the point is that you have more cares to go.

No, I could care less, meaning I could care even less than you think about any other part of the spectrum. Really... It doesn't matter.

 

[Nonya]

Your spectrometer is generally reading low below 470nm and high above.

I do not deny the possibility. Craig Tims at ITC told me they "don’t have a corrective or comparative graph like [Apogee and LiCor] to share."

How about charting the PARwise, Hopoocolor and the UPRtek across entire visible spectrum using whatever discrete color LEDs are available (yes, even red). Now THAT would benefit the hobby. This is your opportunity to fill in the blanks with your array of spectrometers.

 

[Cichlid Dad]

 

[telegraham]

Now THAT would benefit the hobby.

The "hobby" would generally not care, and there would be zero benefit. However, my interest now is for my own enjoyment.

Word.

 

[Nonya]

 

[Nonya]

The "hobby" would generally not care, and there would be zero benefit. However, my interest now is for my own enjoyment.

Well, that's just crappy. So much for using your really expensive spectroscopes to actually contribute something.

 

[AKReefing]

However, my interest now is for my own enjoyment.

That's rude.

 

[Cichlid Dad]

This is my opinion based on years of playing a scientist on forums.... The hobby grade par and spectrometer is just like the hobby grade test kits, basically just a ball park to get you pointed in the right direction. To be able to see trends, if there is to little or to much of something somewhere in the tank. Nothing more nothing less. Is like arguing my salifert is better than your red sea because mine is closer to the lab results I got two years ago. Compared to true lab results they both are lacking.

JMO