Light question

bk78

bk78

Well-Known Member
LeastExpectedGrower said:
You probably saw, I recently bought a Phantom Photobio and compared it to Phontone on iPhone (XS Max)...I ran both side by side at a different distances from my lights, different dimming from the lights and found that with the diffuser that Photone asks for (20# copier paper) directly on top of the phone lens. My results were less than 10% variance. Photone generally was reading 4-8% higher than the PhotoBio, so with that phone hardware, yes it is pretty accurate.
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Do you have a link to your side by side test? My numbers were nowhere near yours when I did said tests
 
LeastExpectedGrower

LeastExpectedGrower

Well-Known Member
bk78 said:
Do you have a link to your side by side test? My numbers were nowhere near yours when I did said tests
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Yeah, I posted it in that thread where we discussed it last. Text copied below, but there's a handful of pics too in the original post. I did two diffusers, since one of the reviews suggested lifting the paper off the sensor by half an inch, I found that threw off the accuracy and that paper wrapped around the phone worked better.

Any recommendations for a par meter

Just got done feeding and watering, but also got some time to play with meters. Didn't have a tape measure at hand, so I basically took 4 measurements (with boxes of different heights) with both iPhone XS Max/Photone (with diffuser that's .5" off of the lense) and the Phantom PhotoBio. Then I...
www.rollitup.org

Just got done feeding and watering, but also got some time to play with meters. Didn't have a tape measure at hand, so I basically took 4 measurements (with boxes of different heights) with both iPhone XS Max/Photone (with diffuser that's .5" off of the lense) and the Phantom PhotoBio. Then I did 4 more sets (as I removed the boxes), but with a basic diffuser on the iPhone that was just 20lb paper wrapped around the phone (not raised off lens).

iPhone XS Max (raised diffuser) vs. Phantom:

Photone: 470 Phantom: 411 Photone: +14%
Photone: 628 Phantom: 550 Photone: +14%
Photone: 852 Phantom: 767 Photone: +11%
Photone: 1262 Phantom: 1135 Photone: +11%

iPhone XS Max (wrapped diffuser) vs. Phantom:

Photone: 1198 Phantom: 1122 Photone: +7%
Photone: 750 Phantom: 735 Photone: +2%
Photone: 672 Phantom: 644 Photone: +4%
Photone: 573 Phantom: 530 Photone: +8%

A few things.
-I'm surprised that most of the previous substantive reviews put Photone/iPhone at 10% UNDER Apogee readings. Every reading I took was over.
-After one of the reviews going on about how a raised diffuser helped accuracy, but obviously for me it was better with one right on the lens.

Maybe they've tweaked the app after all the feedback of 10% low to read a bit higher? Anyway, in my instance (phone type & version, etc.) it actually isn't as far off as other people have with other phones.
 
hillbill

hillbill

Well-Known Member
$5 for a month to set your lights. That’s a pack of off-brand cigarettes.

I did find Photone Pro kelvin readings exactly matched manufacturers’ specs on a variety of LEDs as well as HPS and CMH as well as some old CFLs.
 
LeastExpectedGrower

LeastExpectedGrower

Well-Known Member
hillbill said:
$5 for a month to set your lights. That’s a pack of off-brand cigarettes.

I did find Photone Pro kelvin readings exactly matched manufacturers’ specs on a variety of LEDs as well as HPS and CMH as well as some old CFLs.
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I did buy the profile I needed and that was it. Again, I think it all depends upon the phone you're running it on, works better on some, less so on others. In some ways that's pretty not great, because you may not know if you're using one of the accurate ones or one that's way off. And of course, you won't know until you compare to another accurate meter. I couldn't rent an Apogee in the area, so I bought a reasonably priced meter to check against/have on hand if it wasn't great. But I'm a weirdo that way.
 
LeastExpectedGrower

LeastExpectedGrower

Well-Known Member
Bullmark said:
The app was spot on with my IPhone 11, but reads 30-40% low on my new iPhone 13.
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I think that @bk78 had similar issues with the iPhone 13 as well. After his readings I was surprised to find mine was much closer. I wonder how much is based upon the architecture of the phones that they originally used while developing. Either way, people will have widely divergent experiences with it depending on hardware.
 
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