Sanjay & Timothy:
Another excellent article! Thank you for analyzing the new PFO fixture, which appears to be a significant improvement over their original design. And I'm happy to see the caveat regarding substitution of a 250w DE for a 400w fixture. Perhaps this will cool off or prevent some of the flame wars.
I have an idea on an experiment to compare the 250w DE with a 400w bulb.
Basically, compare a few common bulbs, say Ushio & AB 10k bulbs, in the most common arrangement and in an optimal arrangement on a 120g regular tank, 48x24x24. I first though of 180g tank, but that would require 3 bulbs of each type instead of 2. By testing two bulbs along side at each time, the interference can be analyzed and shown. Also, two and three MH bulb configurations are more common than single bulb situations.
Suggested bulbs:
AB 10k 250w & 400w mogul
Ushio 10k 250w & 400w mogul
Use Diamond reflectors mounted on small wood planks, eye bolts & cables.
Ballast undetermined
AB 10k 250w DE
Ushio 10k 250w DE
Use PFO "New Design" reflectors with eye bolts & cables.
Ballast undetermined
No other supplemental lighting.
Test Tank Configuration:
Model a 120g tank, 48" long by 24" wide. Use the same type of board and sensors used in your reflector comparisons. Construct a wooden frame with plywood sides and top to simulate placement within a closed cabinet. Leave the inside as unfinished wood to best model a real canopy and the light reflection it introduces.
Test #1 - Mogul Common
Place reflectors in cabinet 24" apart with bulbs 9" above surface, which is a common configuration. Test all 4 mogul bulbs. Generate intensity plots covering entire 48"x24" area. The 250w mogul bulbs are tested to compare directly with their DE counterparts.
Test #2 - 400w Mogul Optimal
Using one of the 400w bulbs, adjust the reflectors horizontally and vertically until an "optimal" position is determined. Use your intuition and experience, and your readers will trust that you know what you're doing. Then test the other 400w bulb with the reflector in the same position.
Test #3 - 250w DE Common
Fixtures placed in cabinet 24" apart so that the bulbs would be 9" above surface. Test each bulb & generate intensity plots.
Test #4 - 250w DE Optimal
Using one bulb, adjust the reflectors horizontally and vertically until an "optimal" position is determined. Then test the other bulb with the reflector in the same position.
Tests #5 & #6 - Spider reflectors
I think these would be optional, and unnessary based on the March 2003 article. Replace the Diamond reflectors with spider reflectors and repeat tests #1 & #2. The optimal location will be different.
Results:
These tests will compare two brands of common bulbs that have comparable products, 10k bulbs, in 400w mogul, 250w mogul & 250w DE. Using two and only brands will give breadth of data while limiting the number of tests required. There is no need to compare a 400w 20k Radium against a 250w Iwaski! However, one might say that either AB or Ushio is better than the other at making one particular bulb or another.
Using the Diamond reflector will limit the critisms of "if only a better reflector had been used, then the results would be different."
This would give information on very common lighting schemes and would give insight into the "can we use the DE instead" question.
And it would give you yet another lighting article for winter or spring. I really enjoy reading all your articles. Thank you.
Another excellent article! Thank you for analyzing the new PFO fixture, which appears to be a significant improvement over their original design. And I'm happy to see the caveat regarding substitution of a 250w DE for a 400w fixture. Perhaps this will cool off or prevent some of the flame wars.
I have an idea on an experiment to compare the 250w DE with a 400w bulb.
Basically, compare a few common bulbs, say Ushio & AB 10k bulbs, in the most common arrangement and in an optimal arrangement on a 120g regular tank, 48x24x24. I first though of 180g tank, but that would require 3 bulbs of each type instead of 2. By testing two bulbs along side at each time, the interference can be analyzed and shown. Also, two and three MH bulb configurations are more common than single bulb situations.
Suggested bulbs:
AB 10k 250w & 400w mogul
Ushio 10k 250w & 400w mogul
Use Diamond reflectors mounted on small wood planks, eye bolts & cables.
Ballast undetermined
AB 10k 250w DE
Ushio 10k 250w DE
Use PFO "New Design" reflectors with eye bolts & cables.
Ballast undetermined
No other supplemental lighting.
Test Tank Configuration:
Model a 120g tank, 48" long by 24" wide. Use the same type of board and sensors used in your reflector comparisons. Construct a wooden frame with plywood sides and top to simulate placement within a closed cabinet. Leave the inside as unfinished wood to best model a real canopy and the light reflection it introduces.
Test #1 - Mogul Common
Place reflectors in cabinet 24" apart with bulbs 9" above surface, which is a common configuration. Test all 4 mogul bulbs. Generate intensity plots covering entire 48"x24" area. The 250w mogul bulbs are tested to compare directly with their DE counterparts.
Test #2 - 400w Mogul Optimal
Using one of the 400w bulbs, adjust the reflectors horizontally and vertically until an "optimal" position is determined. Use your intuition and experience, and your readers will trust that you know what you're doing. Then test the other 400w bulb with the reflector in the same position.
Test #3 - 250w DE Common
Fixtures placed in cabinet 24" apart so that the bulbs would be 9" above surface. Test each bulb & generate intensity plots.
Test #4 - 250w DE Optimal
Using one bulb, adjust the reflectors horizontally and vertically until an "optimal" position is determined. Then test the other bulb with the reflector in the same position.
Tests #5 & #6 - Spider reflectors
I think these would be optional, and unnessary based on the March 2003 article. Replace the Diamond reflectors with spider reflectors and repeat tests #1 & #2. The optimal location will be different.
Results:
These tests will compare two brands of common bulbs that have comparable products, 10k bulbs, in 400w mogul, 250w mogul & 250w DE. Using two and only brands will give breadth of data while limiting the number of tests required. There is no need to compare a 400w 20k Radium against a 250w Iwaski! However, one might say that either AB or Ushio is better than the other at making one particular bulb or another.
Using the Diamond reflector will limit the critisms of "if only a better reflector had been used, then the results would be different."
This would give information on very common lighting schemes and would give insight into the "can we use the DE instead" question.
And it would give you yet another lighting article for winter or spring. I really enjoy reading all your articles. Thank you.
