How much color shift on dimmed lights?

soundman

Member

• Sep 8, 2017

• #1

Curious if anyone knows how bad, or if any, color shift happens when dimming a 600 watt HPS to 450 Watts?

I may have to dim mine in mid late flower if the plants get too tall.

 

8

810FireFarm

Active member

• Sep 8, 2017

• #2

i dont have any science on this, but i also do it from 600-500 if tops too close to burn....the plants still turn out fine, although will lose some density on lower buds.

it seems when lowered the spectrum is more red ? when full power at 600 is brighter and seems more white in the mix, could be me though

 

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BakedBandit

Member

• Sep 8, 2017

• #3

Curious on this as well. I sometimes dim 1000 down to 750 or 600 at beginning or end of cycle. Have heard spectrum shifts, always wonder how much.

 

soundman

Member

• Sep 9, 2017

• #4

I have to calls into manufactures. Ushio and Eye Hortilux. I bet they say the bulb is out of spec at lower wattage. I read about people using the dim function without negative effects all over the internet. I am very curious to find a factual answer. Will let you know what I hear on Monday.

 

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BakedBandit

Member

• Sep 9, 2017

• #5

I've had what seem to be fine results with those exact bulbs 1000w varieties dimmed at 600 and 750.
Just wanna know what I'm really actually doing.
Curious to see what info your calls yield!

 

Snook

Still Learning

Veteran

• Sep 9, 2017

• #6

I've asked this same question before, never did get a definitive answer (I hope you do get one) but let me go one question further... can one run a 600w bulb powered by a 1k adjustable ballast turned down to 600w and retain the spectrum profile as advertised by its' manufacturer?

 

Natural high

Member

• Sep 9, 2017

• #7

Snook said:

I've asked this same question before, never did get a definitive answer (I hope you do get one) but let me go one question further... can one run a 600w bulb powered by a 1k adjustable ballast turned down to 600w and retain the spectrum profile as advertised by its' manufacturer?

Click to expand...

Hey Snook I believe you can, because a 1000w ballast turned down to 600w becomes a 600w ballast. This is a better option than dimming, because dimming a higher wattage bulb will permanently alter the spectrum output of that bulb, even when re-run at the rated wattage.

 

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prune

Active member

Veteran

• Sep 9, 2017

• #8

dimmed light is bad food, especially with enhanced spectrum bulbs. the doping used for the correct (and advertised) spectral output is temperature sensitive and dimming screws that pooch.

and anyway, shouldn't need to dim a 600 unless it's over your bed....

 

soundman

Member

• Sep 9, 2017

• #9

prune said:

dimmed light is bad food, especially with enhanced spectrum bulbs. the doping used for the correct (and advertised) spectral output is temperature sensitive and dimming screws that pooch.

and anyway, shouldn't need to dim a 600 unless it's over your bed....

Click to expand...

I hope to dim because two 600s in a 5 x 5 gets 79 degrees in the shade and about 85 degrees under the lights. My lung room is 72 degrees and I pull plenty of air through small hoods. Daystar 6s. I pull 400 CFM through hoods and 400 CFM dialed back slightly as exhaust. Hoods are cooled directly from lung room air.

If I dim my 600s to 450s I get perfect temps and humidty. Also can set ac at 74 and hold 76-78 in tent.

Two 450s are much better than one 600 in that tent.

From what I read cooler bulbs reduce blue spectrum first. With a bulb like Eye Hortilux they are enhanced in the blue range. A slight reduction in blue may not be that bad?

Still curious. If it is bad juju I will get two 400s and fire up some old ballasts.

 

Cvh

Well-known member

Supermod

• Sep 9, 2017

• #10

Subbed

 

positivity

Member

Veteran

• Sep 9, 2017

• #11

soundman said:

Curious if anyone knows how bad, or if any, color shift happens when dimming a 600 watt HPS to 450 Watts?

I may have to dim mine in mid late flower if the plants get too tall.

Click to expand...

Pics of the setup? Type of reflector used, ballast and stuff?
Sounds like you need to still tune in your lighting. Flex 6/750 lamp has a range of 4-850 or something on their specs
Dimming in veg has been fine. Red levels drop more last I remember so it would be more a flowering thing. Depends on the lamp though. Flex lamp still pumps red while the blue dropped slightly
I'd have to go back and check but moral is just use the right lamp in flower and dimmed in veg works a treat
Spectrum so far has always returned to full when at the right wattage

 

Snook

Still Learning

Veteran

• Sep 9, 2017

• #12

Natural high said:

Hey Snook I believe you can, because a 1000w ballast turned down to 600w becomes a 600w ballast. This is a better option than dimming, because dimming a higher wattage bulb will permanently alter the spectrum output of that bulb, even when re-run at the rated wattage.

Click to expand...

I can live with that logic but what happens when the guy running the ship forgets to put a 1K back in while still dialed to 600w? I have no concept of the results but nothing 'good'. and the permanent alteration of its spectrum is part of the original question: which, and i'm not saying youre wrong but, hasent been definitively answered

 

Natural high

Member

• Sep 10, 2017

• #13

Snook said:

I can live with that logic but what happens when the guy running the ship forgets to put a 1K back in while still dialed to 600w? I have no concept of the results but nothing 'good'. and the permanent alteration of its spectrum is part of the original question: which, and i'm not saying youre wrong but, hasent been definitively answered

Click to expand...

If a 600w bulb is put into an adjustable ballast run at 600w then the bulb will behave as designed. If the ballast was then turned up you will exceed the current rating and you will blow it up!

If you put a 1000w bulb in a ballast set to 600w then the spectrum will be less than optimal, and as some bulb manufacturers have advised, some of the change in spectrum can be permanent.

 

soundman

Member

• Sep 11, 2017

• #14

Still waiting on calls. I did find this buried in Google from Eye Hortilux. I can't read the graph with my eyes and the quality of pic.

 

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810FireFarm

Active member

• Sep 12, 2017

• #15

soundman- you can and will get a high quality yield running bulbs dimmed down...i run 1000w digital ballasts with 1000w eye hps bulbs but dialed down to 600...and sometimes even to 500 if the plants stretch too close to the lights and could burn up with the room heat and low ceilings.

The buds are smaller and a little less dense, but quality/terp wise seems very equal

the chart you have seems to be a similar spectrum and peaks, just lower intenisties

 

soundman

Member

• Sep 12, 2017

• #16

Thanks for the input everyone. I still cant get anyone on the phone. Was busy today but will hound them tomorrow. That pic of color output is interesting. Im not afraid of that little shift. I grew with 400s for years. I still think my best weed came from those little lights.