mark_s Posted June 21, 2007 Share Posted June 21, 2007 Hey all ;) I'm doing lighting design for an upcoming school production, and I'm slightly stuck :D The problem is that, due to a lack of dimmers and lanterns to do otherwise, we intend on having a white and neutral full stage wash, using Quartet and Acclaim fresnels. To add to this, we will have 6 Cantata (or Selecon High Performance) fresnels with scrollers for backlighting. The rationale is that we wouldn't get much output from a Quartet with the more saturated filters. But this raises an additional problem. If we want an open white wash across the entire stage without our backlighting being significantly brighter and without the amber shift from dimming them, what would be the best way of doing this? More specifically, using an ND filter, how would one know which value of ND to use without experimentation? The idea is to either include an ND filter in the scroll in addition to or in place of a clear filter to get the output roughly the same as the Quartets. But not having a 1.2kW fresnel and a sheet of various NDs handy, I can't experiment with it to get the right intensity. Is there a method for easily calculating roughly the ND value that you'd need, or is the best way trial and error? And another semi-related question: Is there much difference between the Cantata and Selecon 1.2kW fresnels? Are there any advantages or disadvantages that might make one more attractive to use than the other? Many thanks,Mark Link to comment Share on other sites More sharing options...
Jivemaster Posted June 21, 2007 Share Posted June 21, 2007 Get the filter colour guide from your supplier and look in the data shown! ND 0.3 should be half light output. Sadly ND is very wastefull of what little light there is. Could you open the beam wider to get and use all the light. Link to comment Share on other sites More sharing options...
Andrew C Posted June 21, 2007 Share Posted June 21, 2007 Are you sure hiring more dimmers wouldn't be cheaper and/or easier? Link to comment Share on other sites More sharing options...
woody74 Posted June 21, 2007 Share Posted June 21, 2007 Are you sure hiring more dimmers wouldn't be cheaper and/or easier? Cheaper than buying gel? :) Maybe I am reading the OP wrong, but I was under the impression that dimming wasn't the issue since he was worried about CT from doing that ("...and without the amber shift from dimming them"). And if the color changers have a gel frame holder on the front, I'd put the ND there instead of between the lens and the changer. And don't forget that you'll lose light as soon as you color the beam anyway. I was once told (a long time ago in a job far far away) that one stop ND reduces output by about one-third, two stop is one-third again (off of the new level, not the original) and so on. If so (assuming I'm doing the math right), two-stops would get you close to a 650 (closer than one-stop). This is only numeric closeness; aesthetic closeness would be based on the quality of light you get from the fixture as a whole. I would say that jivemaster has a point: if you flood the lamp, you will lose light without compromising CT. Of course you also lose specificity. Maybe I'm on too little coffee?-w Link to comment Share on other sites More sharing options...
GridGirl Posted June 21, 2007 Share Posted June 21, 2007 And another semi-related question: Is there much difference between the Cantata and Selecon 1.2kW fresnels? Are there any advantages or disadvantages that might make one more attractive to use than the other? IMHO, the Selecon fresnels are superior to the Cantatas. Better light output, better focusing system (I do admit that the sliders do sometimes get a bit sticky, but a bit of silicone spray usually sorts that out, and I hate the way Cantata focus knobs come off in your hand!) and for some reason - and this is completely unscientific - I've always found the Selecons don't burn gel as quickly. Link to comment Share on other sites More sharing options...
paulears Posted June 21, 2007 Share Posted June 21, 2007 If you are worried about the yellowish tinge when dim, and it's that critical, why not dim a steel blue, this'll be almost white Link to comment Share on other sites More sharing options...
Renny Posted June 22, 2007 Share Posted June 22, 2007 ] IMHO, the Selecon fresnels are superior to the Cantatas. Better light output, better focusing system (I do admit that the sliders do sometimes get a bit sticky, but a bit of silicone spray usually sorts that out, and I hate the way Cantata focus knobs come off in your hand!) and for some reason - and this is completely unscientific - I've always found the Selecons don't burn gel as quickly. An unbiased Kiwi opinion! :) In all my time using Cantatas (too long) I have twice had the focus knob come off. And As to the slide focus? I don't like it. Generally when focussing LD's say things like "back out a turn". A bit tricky with a slide focus. Link to comment Share on other sites More sharing options...
dbuckley Posted June 22, 2007 Share Posted June 22, 2007 An unbiased Kiwi opinion! Ha! The mechanical construction of the Selecon frezzies does annoy me, particularly as they are optically fab tools. I've now had two of the 650W barn doors come apart at the welds on me whilst up a ladder, in both cases nearly clonking someone below, and given how little I go up ladders thats far too many. Link to comment Share on other sites More sharing options...
GridGirl Posted June 22, 2007 Share Posted June 22, 2007 An unbiased Kiwi opinion! :) In all my time using Cantatas (too long) I have twice had the focus knob come off. And As to the slide focus? I don't like it. Generally when focussing LD's say things like "back out a turn". A bit tricky with a slide focus. I might be a Kiwi but I try to be objective and non-biased! I've extensively used both the Cantatas and the Selecon fresnels and what I wrote was based on my opinion of the units, not recommending Selecon because it's a Kiwi company! I worked in a venue which had Cantatas, Selecon fresnels and Patt. 743s and being bored one day we did some experimentation with all three lanterns and everyone agreed that the Selecons came out ahead of the Cantatas. Plus I've never heard an LD say "back out a turn" - usually I find it's "spot that back a fraction" or "flood it out a bit"...maybe it's just me though... Link to comment Share on other sites More sharing options...
Trunker Posted June 22, 2007 Share Posted June 22, 2007 I can get get the same amout of light out of a quartet 22/40 (650w) as a harmony 22/40 (1000w). It all depends on your lanterns and how good the optics in the lanterns actually are. Newer lantern tend to be more economic in terms of output vs power. Link to comment Share on other sites More sharing options...
Andrew C Posted June 22, 2007 Share Posted June 22, 2007 Are you sure hiring more dimmers wouldn't be cheaper and/or easier?No; but cheaper than hiring scrollers, and buying / making ND scrolls. Unless I've got the wrong end of the stick... Link to comment Share on other sites More sharing options...
mark_s Posted June 22, 2007 Author Share Posted June 22, 2007 No; but cheaper than hiring scrollers, and buying / making ND scrolls. Unless I've got the wrong end of the stick... Possibly. The scrollers are pretty much now a set part of the design, as it would be totally unfeasible to hang (and hire) the number of lanterns we'd need otherwise. We'd also be stuffed for circuits, dimming and control (curse Strand and their 25-channel limited GSX :(). On the dimming front, if it's really necessary we could probably run some soca and DMX to the drama studio directly behind our hall (after running the idea past someone who is competent enough to say that it's safe to do of course), and gain an extra 6/12 channels of dimming. But I'd like to avoid taking that route for a number of reasons anyway. The original question was that I have some 1.2kW fresnels which happen to have scrollers attached, and will have scrolls made to my specification. I'd like them to match the colour temperature and output of a Quartet, and thought about having a frame of ND in the scroll to be able to do this. I assumed that'd be the easiest way, but... If you are worried about the yellowish tinge when dim, and it's that critical, why not dim a steel blue, this'll be almost white That is a very good suggestion indeed (especially as the scroll will contain a CTC-type blue tint anyway). I did give that a bit of thought, but I wasn't sure whether it'd end up matching the 'white' from the Quartets or appearing more blue. And it would seem that I like to make things over-complicated ;) IMHO, the Selecon fresnels are superior to the Cantatas. Better light output, better focusing system (I do admit that the sliders do sometimes get a bit sticky, but a bit of silicone spray usually sorts that out, and I hate the way Cantata focus knobs come off in your hand!) I think my friend would disagree about the focusing system - he experienced the sticky slider syndrome, tried to force it, and accidentally used a bit too much force. Result - blown lamp :) Thanks for the help so far everyone ;) Regards,Mark Link to comment Share on other sites More sharing options...
Genus Posted June 22, 2007 Share Posted June 22, 2007 Personally, I think the optics on a selecon are far superior to the cantata F, though I have managed to blow a lamp (or two) because of sticky sliders. In response to the question, I think it would be quite difficult to get one type of lantern to faithfully reproduce the quality/CT of another type of lantern. On the other hand, using a ND filter might work. Then again, you could always use "artistic license", and there are other blues other than Steel that might work, like a Lee201 (I'm having a lee201-203 phase at the moment). As it's your design you have the chance to go through a swatchbook and choose what you want, also, depending on how tight the schedule is I always think it's worth experimenting to find a look you're happy with. Though I am aware that there is NEVER enough time. Genus Link to comment Share on other sites More sharing options...
MrBoomal Posted June 22, 2007 Share Posted June 22, 2007 Then again, you could always use "artistic license", and there are other blues other than Steel that might work, like a Lee201 (I'm having a lee201-203 phase at the moment).The Lee filters 201-203 are extremely useful. I nearly always put a bit of 203 in a source 4 if I have a female singer. Gives them a more natural look but still with a bit of healthy looking warmth.Plus I've never heard an LD say "back out a turn" - usually I find it's "spot that back a fraction" or "flood it out a bit"...maybe it's just me though...I always say "can you make that narrower" or "can you make that wider". Maybe I just like the easy life. P.S can someone please tell me how to get the quote thing to work. As with all the bbcode, you need to match each start instruction with a close.[quote]Thus[/quote] Link to comment Share on other sites More sharing options...
mark_s Posted June 27, 2007 Author Share Posted June 27, 2007 Well, I think I've found my solution. Instead of faffing on with ND in the scrolls, I'm just going to hang some Quartets in the same positions as the 1.2kW fresnels. We just about have the dimmers for it, and it makes life a lot easier. It also has the added benefit of being able to have open white and a colour wash in the same place at the same time :D The reason I didn't think of this at first is we're pressed for dimmers and lanterns, and after a few little tweaks to my design, enough lanterns and dimmers have magically appeared to make this a possibility (circuits are a different matter, but that is more easily dealt with!) Link to comment Share on other sites More sharing options...
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