who is running 250 watt, Iwasaki 6500K bulbs
 

The R designation is for the newest version of the 6500K iwasaki. It allows the bulb to burn at a higher Kelvin. Or to appear more white. R stands for resistor.

who is running 250 watt, Iwasaki 6500K bulbs
 

darren
i'm not sure i understand -- the 6500K refers to the theoretical temp that we all know about. if the R does refer to resistor and allows the lamps to run at higher temp, then i wonder if would it then be called an 8000k or a 10,000k? also, higher than 6500k in my eye becomes more blue, at least with the 400W we run.
as i posted yesterday and i expect you know, but for others, the 6500k iwasaki was reportedly designed as a conversion lamp for MV, and when redesigned to properly run on MH they added the R designation.
shane

who is running 250 watt, Iwasaki 6500K bulbs
 

Shane,

It runs slightly higher at about 7000K now. THEy have kept the original name so as to not confuse I imagine. The new resistor allows it to run more efficiently.

And the R is for resistor. I'll go get the thread on RC where it is brought up. Or it may have been on Fishnet.

[ 23 February 2002: Message edited by: DJ88 ]</p>

who is running 250 watt, Iwasaki 6500K bulbs
 

ok.. here is the quote from RC. the article about the 250W Iwasaki and the R rating is in the magazineit is actually the 2002 Marine & Fish Reef annual.

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>This very topic was just covered in the 2002 edition of Marine Fish and Reef USA Magazine. Which indicates that the "R" designation denotes the new carbon resitor but also goes on to say the new resistor is responsible for a better light than before. Actual kelvin value on the 6500K bulb goes from 6535 to 7660 so the bulbs appear less yellow than before.
I use them and wasn't aware of the change in the bulb however the new does appear much more blue than the old. Good Luck

<hr></blockquote>

who is running 250 watt, Iwasaki 6500K bulbs
 

Darren, could this R have been created to adress the problems when running it on a MH ballast? aparently the main effect of running the 6500 Iwasaki's on a MH ballast was a decrease in color temp compared to running them in a MV ballast. also the higher starting power of the MH ballast decreased the life of the bulb. so by adding a resister they might have lowered the starting power going to the bulb solving that problem and bumped up the color a bit so when run on a MH ballast it won't look like a 5000K.

I am not positive on this yet i am waiting for a e-mail from eye internation which will clear this up, but from reading between the lines and readign what people say this could be a accurat guess.

In that article you refered to in the 2002 anual they only tested the new bulb and it preformed better on a MH ballast than the MV ballast. the old bulb in every test and trial was more blue and had more par on a MV ballast as aposed to the MH ballast. they do have a new section lables "aquarium" in there product catagorys now. I suspect that is the new "r" type bulb, even thouht there is no mention of a "r" bulb anywhare on there site.

oh your numbers are for the 400watt bulb, the 250 went from a color temp of 6707K, to 7211K (thats why you probably hardley noticed it.)

Steve

[ 23 February 2002: Message edited by: StirCrazy ]</p>

who is running 250 watt, Iwasaki 6500K bulbs
 

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quoteSteve,

Thank you oh so much for informing me of my lack of literary skills. Concidering I don't have a copy of the annual here and that I quoted a thread on RC I don't see how I could make the mistake you so thanklessly pointed out. The numbes quoted were a close approximation to show the difference between the original to the newer 'R'designation of Iwasaki bulbs.

who is running 250 watt, Iwasaki 6500K bulbs
 

Sorry Darren,
I knew you use the bulbs and I thought the

"I use them and wasn't aware of the change in the bulb however the new does appear much more blue than the old. Good Luck"

was you talking... the impression I got is that you were quoting your own post from somewhare else. I do know you use the bulbs, but did you ever use the non "r" bulbs?

in the 400 watt bulbs is ~1100K which would be a huge difference in look, but the difference in the 250 watt bulbs is only 500K ..this is what I am curious about.. how noticeable is 500K difference? and how hard is it to compensate for it with a couple actinic bulbs.

Steve