Problem metering and setting the light level.

  • Thread starter BigBlonde
  • Start date
  • Tagged users None
BigBlonde

BigBlonde

264
63
This is kinda weird...

I have two Android phones with the Photone app installed. The PAR meter readings are very different. The left phone in the pictures is an S22 Ultra and the right phone is a Note8.

Here are the two phones side by side in the center of the tent:
Problem metering and setting the light level


Here they are at the left side of the tent:
Problem metering and setting the light level 2


Here they are at the right side of the tent:
Problem metering and setting the light level 3


To make matters even more interesting, setting the left light to about 20% lower (30%) than the right light (50%) results in the left-side reading being higher than the right side reading. Both lights are the Viparspectra XS2000 model and are hung at the same height. All the readings were taken with the door zipped shut except for enough room to poke a camera lens through to take the pictures.

Recommendations for a better meter (at a reasonable price) are welcome, but aside from that, what the heck could be going on here?

Here are the two phones in daylight:
Problem metering and setting the light level 4
 
C

CookiesLikeWhoa

110
43
Realistically you're never going to get very accurate numbers using your phone. You can reduce the range you will see by properly setting up your phones camera, but ultimately you'll have a very wide range to work with.

Consider those ball park numbers.

Also if different parts of your tent are getting different light levels, that means the light is not centered or something is blocking the light.
 
BigBlonde

BigBlonde

264
63
Realistically you're never going to get very accurate numbers using your phone. You can reduce the range you will see by properly setting up your phones camera, but ultimately you'll have a very wide range to work with.

Consider those ball park numbers.

Also if different parts of your tent are getting different light levels, that means the light is not centered or something is blocking the light.
If those are ballpark numbers, it must be a pretty big ballpark. I set a board across the pots to make sure the phones were positioned similarly. Nothing was blocking the light. Even outside in unobstructed sunlight there was a difference of 67. That doesn't inspire confidence.

I'm not sure what you mean by setting the phone's camera properly. I'll see if I can find information about it.
 
C

CookiesLikeWhoa

110
43
The camera can have a diffuser put in front of it to reduce glare and incorrect readings.

I usually considered the ballpark around 100PPFD on my iPhone.

I eventually got an apogee light meter and compared it to what my phone was putting out. Not even close lol. Usually my phone would be about 100 PPFD off, in either direction.
 
BigBlonde

BigBlonde

264
63
The camera can have a diffuser put in front of it to reduce glare and incorrect readings.

I usually considered the ballpark around 100PPFD on my iPhone.

I eventually got an apogee light meter and compared it to what my phone was putting out. Not even close lol. Usually my phone would be about 100 PPFD off, in either direction.
The Photone website says a diffuser is needed for iPhones, but not needed for Androids. An Apogee meter is probably in my future.
 
Smokey0418

Smokey0418

290
63
Not weird at all.

One must calibrated there app to a said par map for example to get a closer true reading.

Or better yet , a friend with a gauge.
 
BigBlonde

BigBlonde

264
63
Not weird at all.

One must calibrated there app to a said par map for example to get a closer true reading.

Or better yet , a friend with a gauge.
Thanks. I'll try to calibrate one of the phones after the holiday. The cost of the gauges too much for me.
 
freezeland2

freezeland2

2,759
263
Thanks. I'll try to calibrate one of the phones after the holiday. The cost of the gauges too much for me.
I wouldn’t get to hung up on the accuracy. Just pick one of the two and use that one exclusively. The ppfd number is just a point of reference. Watch the plants to know if the intensity is right. When the plants present their leaves horizontal and flat you are at their sweet spot.
 
Top Bottom