I'm currently planning PJ No.2.
I have just got hold of a 400W HQI light rig. I have a basic
design for the light box and PJ, but my main concern is
overheating and fire, as these HQI/MH lamps run quite hot!😱
Not wanting to mess about, here are my questions.
Please refer to the diagrams below: -
1) Am I correct in thiking that "A" is the focal length fo the reflector?
2) What would be a good disatance from the lamp to the enclosure wall "B" (made from sheet steel or aluminium)?
3) Am I correct in thinking that "C" is the focal lenth of the condenser lens?
4) What would the distace "D" be (i.e. would this again be the focal lenght of the condenser lens)?
In the second diagram I'm looking to assist natural convection to disapate the heat from the unit. I'm curious to know what sort of CFM fans people are using and what would be recommended?
I have just got hold of a 400W HQI light rig. I have a basic
design for the light box and PJ, but my main concern is
overheating and fire, as these HQI/MH lamps run quite hot!😱
Not wanting to mess about, here are my questions.
Please refer to the diagrams below: -
1) Am I correct in thiking that "A" is the focal length fo the reflector?
2) What would be a good disatance from the lamp to the enclosure wall "B" (made from sheet steel or aluminium)?
3) Am I correct in thinking that "C" is the focal lenth of the condenser lens?
4) What would the distace "D" be (i.e. would this again be the focal lenght of the condenser lens)?
In the second diagram I'm looking to assist natural convection to disapate the heat from the unit. I'm curious to know what sort of CFM fans people are using and what would be recommended?
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
1) Yes
2) ?
3) No. This distance is related to the condensor focal and condensor diameter and the fresnal focal and lcd diaganal.
4) No. This distance is related to the fresnal focal and the condensor diameter and lcd diaganal.
Q3 and Q4 are not real easy to calculate as all the optics are critical of each other. If you change one, all of the others change aswell. Use a focal calculator, it's much easier.
DJ
2) ?
3) No. This distance is related to the condensor focal and condensor diameter and the fresnal focal and lcd diaganal.
4) No. This distance is related to the fresnal focal and the condensor diameter and lcd diaganal.
Q3 and Q4 are not real easy to calculate as all the optics are critical of each other. If you change one, all of the others change aswell. Use a focal calculator, it's much easier.
DJ
Ok I have seen some calculators, but they confuse the hell out of me 
now once I have found out how to use and understand the results of the calculator
I have to punch in the focal lengths of the optics I will be using.
This is where I come into a little problem! I was hoping to use most of the optics
from my elite OHP, but I do not know the focals for the objective/projection lens
or the fresnel. Are there any practial way of finding this info out (i will look for
focal lenght on the lenses themeslves).
now once I have found out how to use and understand the results of the calculator
I have to punch in the focal lengths of the optics I will be using.
This is where I come into a little problem! I was hoping to use most of the optics
from my elite OHP, but I do not know the focals for the objective/projection lens
or the fresnel. Are there any practial way of finding this info out (i will look for
focal lenght on the lenses themeslves).
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