HPL 575 or 750 in your Source4?

[gafftaper]

I'm still working on my equipment inventory for the new theater and I'm debating going with HPL 575X vs HPL 750x in my Source4's. I definitely want to use the long life model for budget reasons. I was originally thinking about going with the 750x because it's about the same lumen output as the 575 but 5 times the life (see chart below).

HPL 750 300 hrs 21,900 lumens
HPL 750x 1,500 hrs 16,400 lumens
HPL 575 300 hrs 16,529 lumens
HPL 575x 2,000 hrs 12,360 lumens

On the other hand, it's a black box with a typical throw of 25-35 feet, so that extra punch isn't REALLY necessary. With 750's you are pushing it a little putting three on a single 2.4k dimmer. With 575's you can comfortably put 4 on a dimmer. 575's are cooler for the HVAC system, easier on gel, and easier on gobos.

Now after talking it over with a buddy I'm thinking of just going with the 575x and keeping a dozen standard 750's in stock in case I need some punch for a specific scene.

What do you use and why?

[Chaos is Born]

your looking at much easier on gel... i'm noticing that a good portion of the deep saturated colors don't come in a high temp version... and end up burning through the gel about half way through the show...

[SteveB]

Originally Posted by gafftaper

I'm still working on my equipment inventory for the new theater and I'm debating going with HPL 575X vs HPL 750x in my Source4's.
What do you use and why?

My 24 fixed lens S4's are 750 due to the throw (50-75 ft.)

My Pit wash S4 pars are also 750 as I need the punch and don't use color.

My Box Boom and overhead electrics S4 25/50 zooms are all 750 as 1) I want the punch and 2) They sometimes serve as backlights mixed with Par64 wides @1000. The S4 zoom @750 is a great light.

BUT, I need to use a 3" color frame extender on all the S4 zooms. With them most any color lasts OK.

If I had a large inventory of fixed lens S4's I was re-locating a lot, the color frame extender would be a PITA.
Thus I would follow your well thought out logic and stick with 575.

SB

[lightbyfire]

We originally lamped our theatre with all 575 and now two years later we are starting to transition to 750.

I have found that the dimmer limitations are usually unique and you can always lamp back down to 575 if you need to. the 750 while harder on gel and gobos makes a much nicer light in my opinion, particularly in amber drift. so for us it is less a practical decsision than visual.

[zac850]

For a 25-35 foot throw I'd say go with the 575s. The only real reason to go with a 750 is if you need the extra punch, and by the sounds of it, your not going to need that. The 575s are plenty bright for your throw.

The cooler lamp is also easier on the fixture its self, and the entire source4 should last longer with the lower wattage lamp.

If in doubt, you could always get a 575 and a 750, go in the first day, put two next to each other, and see if you really need/want the more powerful lamp.

[Lightingguy32]

Stay with 575, at those throw distances, 750s act like specials (centers, gobos etc.) Also the 575 is a more flexible lamp in terms of voltage ratings (anywhere from 100, 110, 115, 120). How ever if you do need a few 750s keep them in stock for specials only.

[icewolf08]

For your space and throw distance, you will probably be fine with the 575w lamps. The other thing that you should look into is what the actual output voltage at your raceways/drop boxes/etc. is. If you are running at 115v then buy 115v lamps, but if you are running at 120v you should get the 120v version of the lamps. It is a small difference, but using the correct lamps will give you the best output.

Also to consider on you lamp choice is that the long life and high output lamps have different color temperatures, listed below:

HPL 575/115/X 2000Hrs. 3050K 12360 Lumens
HPL 575/115 300Hrs. 3250K 16520 Lumens
HPL 750/115 300Hrs. 3250K 21900 Lumens
HPL 750/115/X 1000Hrs. 3050K 16400 Lumens

Given this, you will notice a difference in color between the long life and high output lamps, so if you need a whiter light you will want the high output lamps.

As for your question on what we use. I use all high output lamps in every fixture that there is an option. For my Source 4's I use 575s in all the 50˚, 36˚, 26˚, and 19˚ units. For my Zooms, 10˚, and 14˚ units I use 750s.

[ship]

Math question for someone that more easily does the calculations than I do. This might play a bearing on what HPL lamp would be best for your situation. I also agree with the higher wattage lamps for the longer throw situations - law of squares compensation and also giving you some head room on stage for installing brighter lamps where more punch is needed or doing say patterns. Than of course, once you go long life or 120v as options in extending life (there is also long life 120v lamps but they are for the most part worthless,) you can still use the high output lamps for your practicles when you need to so the 575w for specials headroom question is a bit lessened by way going high output.

Here is the formula for what could in theory work.

Take as a given (as modified by actual voltage at full,) 118v at the fixture.

The actual formula changes slightly dependant upon what text you read but the following formula should get you into the range if used to answer how it modifies the below lamps.

For every 1% change in supply voltage over the rate the lamp is designed for (or inversely), light output will rise by 3.6%, color temperature will increase by 0.4% and lamp life will be reduced by 12%.

Now for the lamps to consider - 575w/120v & 750w/120v high output or 575w/115v & 750w/115v extended life lamps.

Sample lamps to figure on would be the following: (note brand to brand actual output can also change - this is a base average figure not associated to any one brand to do the math with. Many more recent upgraded lamps have higher outputs.)

HPL-575/115v+; 3,250̊K, 16,520 Lumens, 300 hours @ 115v.
HPL-750/115v+; 3,250̊K, 21,900 Lumens, 300 hours @ 115v.

HPL-575/115vX; 3,050̊K, 12,360 Lumens, 2,000 hours @ 115v.
HPL-750/120X+; 3,050̊K, 16,400 Lumens, 2,000 hours @ 115v.

HPL-575120v+; 3,250̊K, 16,520 Lumens, 300 hours @120v.
HPL-750/120v+; 3,250̊K, 21,900 Lumens, 300 hours @ 120v.

Following the formulas re-calculated for 118v and compared. You now have something in common to work with in seeing what’s the best lamp for your situation in balancing output with lamp life and it’s not always lamp life that is the best solution but often can be once used to it. Also, color temperature of the lamp will effect what you think is brighter. Often you can live with a little less output - one’s eyes adjust, when given a bit more color temperature in still thinking it’s bright. This as opposed to more luminous output but less color temperature - your eye more notes color temperature than overall output.

[gafftaper]

Dang SHIP! I ask a simple question and you give me home work. School is supposed to be over for the summer!!




Thanks buddy.

[Pie4Weebl]

I have a question in comparing 750 lamps, when looking between the HPL 750 300 hrs 21,900 lumens and the HPL 750x 1,500 hrs 16,400 lumens, would running the brighting light at 75% and getting the same output as the long lasting one give you a longer life comprable to the extended life one. The reason I ask, is because if it did, you would still get the benifits of being able to use hte fixtures brighter when you need to.