Need help understanding spectral charts

[adamt]

I just ordered some new bulbs and they arrived today, while trying to figure out which combo I was gonna go with I started looking at the light output charts from the ati site. I guess what uim confused about is when I see the sharp peaks in certain ranges
Below is the chart for the ati blue+
http://www.atiaquaristik.com/de/t5-leuchtstoffroehren#
it has a strong peak right at 450nm but then has a gradual sloping towards the greener end of the spectrum with another spike in green and yellow

heres the one for the old school ati actinic

http://www.atiaquaristik.com/de/t5-leuchtstoffroehren#

This bulb has the same spikes in green and yellow and the same peak at 450 nm but slopes down towards purple .


Now since both of these bulbs peak at 450 nm why is one so dramatically different from the other when it comes to par (grimreefers numbers blue+: 311, ati actinic: 137)? Is it simply because the blue + has more output in the blue-green spectrum even though the intensity of that part of the spectrum is relatively low compared to where it peaks.

If someone could explain the peaks and their importance to par and over all color i would greatly appreciate it. Im currently using 5 blue+, 1 aquablue special, 1 kj fiji purple, and 1 ati actinic. I really like the ati actinic its super bright (significantly brighter than any other 420 actinic ive ever seen (current, wavepoint, uvl, giessman) im almost wondering if my bulb was mislabled or something, because its color looks way more like the output of the pro color than of a 420 actinic.

 

[adamt]

sorry the link isnt what i thought, if u click the bulbs they show the spectral chart

 

[MIKE NY]

the actinic overall puts out more in the 420 range..this why it's purple and has a lower PAR as opposed to the blue plus which puts out more in the 450 range, bluer, which gives it more PAR....I run both bulbs side by side for supplimental lighting and there is a big difference in brightness...

 

[adamt]

Im not saying for a second that the actinic is as bright as the blue, what Im confused about is how the sharp peaks in spectral charts in a very narrow spectrum where the output is extremely intense relate to the over all color rendering of the bulb

 

[MIKE NY]

sorry I don't know, but I think the color spectrum of the bulb will be determined by where the most is given out in a certain nm range not where there is a spike.....I would give Sanjay a PM..he could probably explain it better.

 

[adamt]

sorry I don't know, but I think the color spectrum of the bulb will be determined by where the most is given out in a certain nm range not where there is a spike.....I would give Sanjay a PM..he could probably explain it better.

Yeah thats how it seems to be. The dominanat color seems to be the one where theres a broad sweep through that spectrum even if the rel. intensity is lower than in a diff. color range where it spikes. This seems especially true in higher kelven, lower nm bulbs. The full spec bulbs and warmer seem to be very spikey compared to actinics and 20k's