jds10011
Posted: Tuesday, July 30, 2013 3:12 PM
Joined: 7/5/2014
Posts: 5
In one of our venues, we're finding that 36 degree barrels don't quite seem big enough, but 50 degrees is far too big, resulting in a loss in brightness as we shutter them down. I called ETC and they advised using this forum to see what demand was like for a middle ground option for a barrel, such as a 42 degree. Similar demand has resulted in production of the 14 degree and 70 degree barrels in recent years. Anyone else see a need for this?
We are aware of the possibility of using the Source Four Zoom fixture to achieve this beam angle, but the cost is much higher. Also, we have used the Jr Zoom fixture, but the brightness is much less compared to the standard Source Four.
Kjhfwaites9885
Posted: Tuesday, July 30, 2013 10:42 PM
Joined: 7/5/2014
Posts: 8
Could you lamp the 50s up to 750? Or are they already lamped that high?
I can't imagine you are getting that much of an output loss. Trying to get yet another barrel made for this seems a little over the top.
jds10011
Posted: Tuesday, July 30, 2013 11:05 PM
Joined: 7/5/2014
Posts: 5
Yes, we're using all 750W lamps. The issue is that the upstage (behind the proscenium) is about ten feet wider than the downstage area, so if we use 36's on the downstage (which works great), and shutter down 50's on the upstage, there is a dramatic difference in intensity when you walk upstage. Of course, we can program the cues so that the 50's are always at a higher intensity than the 36's, but then the color temperature difference means different gels, etc for the color to match... And yes, we could use shuttered 50's for the downstage also, but the point is that we're happy with the intensity of the 36's, and don't want everything dimmer. Also, yes, we could I suppose use additional 36's on the upstage, but at that point we're talking about enough of a cost increase that we could spring for the zoom fixtures. It just seems that with the present repertoire of 5, 10, 14, 19, 26, 36, 50, 70, 90, the jump from 36 to 50 is one of the biggest in the more commonly used sizes. After all, if the 9 degree jump between 10 and 19 was unacceptable, shouldn't the 14 degree jump between 36 and 50 be even more so?
P.S. _You_ don't have to agree, I'm just trying to see if some users do.
Steve Bailey
Posted: Wednesday, July 31, 2013 6:40 AM
Joined: 7/4/2014
Posts: 533
I own a set of 8 spare 50 deg. barrels that I think have been used once. The standard inventory has 36 deg., 26 deg. and 19 deg. fixtures (FOH) as well as a ton of 25/50 and 15/30 zooms (80 total). Note that in my rep. plot the 26 & 36 are are side lighting, with the zooms either box booms or overhead and pipe ends.
The 25/50 unit pretty much solves your problem, as it does for a lot of mine and I;d recommend them. They are more cost effective then a 36 deg unit, plus a spare 50 deg. and 26 deg. lens tubes. With a zoom you hang once and zoom as needed. They are extremely useful for gobo imaging as you can very the size.
Steve Bailey
Brooklyn College
Kjhfwaites9885
Posted: Wednesday, July 31, 2013 8:26 AM
Joined: 7/5/2014
Posts: 8
Interesting way to look at it.
I think there have to be some limits on lens tube choice otherwise we are all going to find ourselves with piles of extra lens tubes floating around our shops. We all know that if an LD has an option to change something or request something they will.
What is reasonable for you you a lens tube for every 5 or 7 degrees from 5 to 90?
Nick Emerick
Posted: Tuesday, August 6, 2013 6:48 PM
Joined: 7/5/2014
Posts: 2
The Jr definitely won't help you in this situation since you are lamping at 750 (Jrs are 575 only). But, I am curious to see what using an EDLT 50deg does to your brightness issue. The increased light output may be enough to make up for the shuttering.
jds10011
Posted: Tuesday, August 6, 2013 8:36 PM
Joined: 7/5/2014
Posts: 5
Well... if you remove the screw (iirc), the 750W lamp works fine in the Juniors... granted I'm sure there are those who will say this ruins the reflector, shutters, lenses, etc... but anecdotally, we've never had an issue with doing it.
Yes, we should probably try the EDLT tubes, although again, there is the added cost.
GregThomas
Posted: Wednesday, August 7, 2013 9:50 AM
Joined: 7/4/2014
Posts: 62
Modifying the lamp base to accept a 750w lamp in a S4 Jr fixture is not a recommended practice. It would at the very least invalidate the terms of the regulatory agency marking on the product. Degradation of the components due to the additinal heat generated may not be readily apparent and may create undetected safety or liability issues down the road.
jds10011
Posted: Wednesday, August 7, 2013 3:07 PM
Joined: 7/5/2014
Posts: 5
The same thing was said about the original 575W-only S4. Then we were told by engineering that replacing the cap with a 750W cap was actually entirely fine for the reflector etc, and then that actually the original cap could accomodate the 750W lamp in the first place... So, yes, I understand the caution, but am somewhat skeptical.
GregThomas
Posted: Wednesday, August 7, 2013 4:21 PM
Joined: 7/4/2014
Posts: 62
The problem with your assertion that if it is okay with a full size fixture it will be okay with the Jr, is that a full size SourceFour and a SourceFour Jr are very different fixtures.
There are two critical areas to be considered here.
1.) The reflector is a smaller size than a full size S4 reflector, and is therefore also physically closer to the lamp.
2.) The cooling chamber surrounding the lamp / reflector area in a Jr is significantly smaller when compared to a full size S4.
Both of these factors together combine to create an increase in the operating temperature of the fixture. Furthermore, the fixture cannot properly dissipate the additonal heat created, which can cause a variety of heat related issues with the fixture long term. Paint issues, cracking reflector, lamp life, fixture temperature and so forth.
if it were considered to be safe and proper operation to lamp a Source 4 Junior with a 750w lamp, it would be marketed as having this capability. Unfortunately the Source4 Junior is one of two fixtures in the entire Source 4 Line that cannot be rated for use with a 750w lamp. The other fixture being a Source4 MCM Par. Both of these fixtures should not be lamped higher than a 575w lamp for safe and proper operation.
Making this modification is strongly advised against by ETC, and would invalidate any warranties or UL / ETL / CE regulatory approval ratings assigned to the fixtures.
jds10011
Posted: Wednesday, August 7, 2013 4:30 PM
Joined: 7/5/2014
Posts: 5
I'm not actually asserting that one should do this; just saying that it isn't immediately catastrophic. However, we're quite far afield from my original query...
Nick Emerick
Posted: Wednesday, August 7, 2013 5:02 PM
Joined: 7/5/2014
Posts: 2
I'm not sure where you are located, but if you are able to contact a local ETC Dealer or Rep Agency they might be able to get you a loaner of some 50deg EDLTs to try out.
Even if ETC decided today that they were going to make a 40ish degree lens tube it would take some time before one would actually be able to purchase it.
Obviously, there is a cost difference between an EDLT and a standard lens tube. But, if it solves your problem just as effectively as using 25-50 zooms, then spending a little more for the EDLT (which is significantly less $ than a Zoom) seems like the right move with the current product offering.
The EDLT can give you up to 20% more output from the fixture, see the cut sheets for the EDLT and the Standard 50deg:
http://www3.etcconnect.com/docs/docs_downloads/datashts/7060L1042_S4_EDLT_Spec_Sht_vC.pdf
http://www3.etcconnect.com/docs/docs_downloads/datashts/7060L1010_Source_Four_50_Spec_Sht_vG.pdf
Geoffrey George
Posted: Thursday, August 8, 2013 11:48 AM
Joined: 7/4/2014
Posts: 60
Personally, I'd go for a 41 degree (mf=0.75) or a 44 degree (mf=0.
Paul Toben
Posted: Thursday, August 8, 2013 12:43 PM
Joined: 7/5/2014
Posts: 108
I can honestly say this has never been a problem for me... If I was faced with a slightly wider space to light, I'd just add one more 36°. Even if you had a 41° lens tube, there would still be a noticeable change in the brightness between the 36's on your apron and the 41's upstage.
The 9° jump between the 19's and the 10's was a problem because that was a 47% change in beam spread. The change between 36° and 50° is 14°, but that's only a 28% change, which is actually quite in line with the other jumps.
If you find that you really need an exact beam spread, the Zooms are a good option. The Source 4 Zoom is actually slightly brighter than a fixed lens Source 4 at the same beam spread (the larger optics are more efficient, though they don't project gobos quite as well), which might be perfect for your application.
Geoffrey George
Posted: Friday, August 9, 2013 2:31 PM
Joined: 7/4/2014
Posts: 60
there would only be a noticeable change in intensity if the throw distances of the 36s and 41s were the same. The reason I would like a 41 and or a 44 is more choice when you have a very short throw.
jbenghiat
Posted: Friday, July 11, 2014 1:40 PM
Joined: 7/4/2014
Posts: 172
Unless I'm dealing with a specific effect or piece of scenery, I generally pick instrumentation based on throw distance, looking for a consistent brightness. Units can always shutter or double to affect size. The chart below shows at what distance each barrel type outputs 100 footcandles with a 575w lamp.
From 50 to 14, the ideal distances are fairly regular. The 70 and 90 are fairly close, while 14 to 5 have longer gaps between useful distances. Fortunately, longer throws seem more forgiving in terms of evenness. I also think the 26 and 14 have the best optics, followed by the 19.
S490 10'
S470 12'
S450 17'
S436 27'
S426 37'
S419 50'
S414 60'
S410 85'
S405 109'
-Josh