Automated Fixtures - Inverting Pan/Tilt

[epimetheus]

In the past couple of months I've been getting more regular exposure to movers and that has resulted in quite a few questions on best practices concerning them. The CB search engine has answered quite a few of my questions but this particular one I couldn't find.

When do you invert the pan and/or tilt of a mover?

My anal-retentive strive for symmetry makes me want to invert the pan between units on opposite sides of center. I also have the urge to invert the tilt on stage mounted units verses overhead units.

It hasn't really been an issue at my church in the past. We only have 2 MAC 500's and we're controlling them on our Express 48/96, not as fixtures, just with channel faders. We're fixing to add 8 more movers and an Ion though and I'm thinking ahead to programming on that.

Thoughts?

[Grog12]

Your anal retentive side for inverting pan is a good one, as is your though on overheads vs floor mounts.

Its just another tool at your disposal.

It also helps when the crew hung one light in the opposite direction for the other 10.

[DaveySimps]

For me, this is all about who is programming the units. The option to invert is just another tool to make programming easier and quicker for whoever is at the board. If you will be the one programming the board and this makes more sense to you, then go for it. The less you have to think about while programming, the more smoothly it tends to go.

~Dave

[rschwimmer]

Pan and tilt invert also comes in quite handy when you are doing either a tour, or a one off, and the tech's have hung the fixture the wrong way. Sometimes they hang one completely back wards, and they will have to rehang it, but if it only takes a tilt, or pan invert, hell, leave it up, and lets get to programming.

[derekleffew]

Originally Posted by epimetheus

...My anal-retentive strive for symmetry makes me want to invert the pan between units on opposite sides of center. ...

Resist with all your muster the urge to do this--you'll find it makes programming much more difficult. All fixtures should pan/tilt the same direction when an encoder is moved. If you desire symmetry, the FAN function available on most consoles accomplishes this.

It might be noted that if a fixture is hung backwards (with its display facing 180° the wrong way) INVERT TILT will fix it, as Pan direction is not affected. Rarely does one need to use both INV PAN and INV TILT on the same unit.

If a fixture is hung from a vertical pipe, such as an upright truss as a sidelight, I like to have the fixture body either US or DS of the position, with yoke parallel to the floor, and then SWAP P&T, to make the axes move the same.

The standard for moving heads is 540° Pan and 270° Tilt, but moving-mirror units have a much narrower range, so INV is used much more often with them.

Another hint: When programming, the FLIP function on many consoles can get you out of trouble when you've gotten a fixture the wrong way. If you get into the habit of TILTing the fixtures first, then PANning them, you're less likely to get the fixtures wrong. I've said before that I prefer rotary encoders over mice, trackballs, and trackpads for positioning, as I've found the latter category too easily allows getting an ML turned around the wrong way, but maybe that's just me.

[MNBallet]

My lightboard (Colortran Innovator) has a trackball. I can use it for the pan and tilt on my Meteor Ellipscan (I-Cue) and I often have to use the invert pan/tilt feature so that the direction of the trackball equals the direction on stage. Once I get set up right I can use the trackball to follow a dancer live during the show as a spotlight from the first electric. Roll right, the light goes right. Roll up and the light goes upstage...etc...etc..
Most equipment gives you the option to do an invert either on the equipment itself, as well as at the board in a profile edit. Very usefull. Just be carefull that an edit at the board in a profile edit will invert all your fixtures. For fixing just one unit that might be hung bckwards, it's better to invert at the fixture.

Ken Pogin
Production / Tour Manager
Minnesota Ballet

[derekleffew]

[QUOTE=MNBallet;146041]...Just be careful that an edit at the board in a profile edit will invert all your fixtures. .../QUOTE]True, if editing the fixture personality/profile, but consoles designed for moving lights allow editing on a per-fixture basis from the patch screen.

[QUOTE=MNBallet;146041]...For fixing just one unit that might be hung backwards, it's better to invert at the fixture. .../QUOTE]"Better" is debatable. If a console allows, I'd rather do it at the console. No having to get to the fixture (if you're already there, why not rehang the fixture correctly?), and no having to remember to change settings if a unit needs to be swapped out.

[epimetheus]

I'll be running on an Ion, which as far as I can tell, via the OLE (we don't have the board yet), will let you invert pan, tilt, or swap on a per fixture basis. I like Derek's suggestion of setting it up such that all fixtures respond to the encoder the same. Moving the pan encoder CW always pans the fixture left (or right, whatever it may be), no matter how the fixture is mounted, floor, overhead, or vertical. I think this will work best with the way I think. The moral of all this I think is to leave the invert options on the fixture itself at default. Any changes I need to make can be made in the Ion patch.

[len]

The problem with inverting is that if you start off with a fixture hung 6" more or less away from the center than its counterpart, all that will be for naught.

[Lotos]

Inverting Pan on half a rig (one side of center) *CAN* be useful, but it can also kill some consoles abilities. (The new Strand Palette VL's "Fan" tool, for example, can no longer fan the lights out)

Inverting 'Tilt' on a mover hung backwards comes with its own host of issues... Unrelated to the actual inversion.

Because the light is hung upside-down, simply inverting the tilt, means that grabbing it, and a regular fixture and tilting them, results in two heads POINTING the same way, but one head will actually be 'upside-down'... This isn't a huge deal, normally... But consider:

You have a rig of, say, 20 moving heads. You point them all down, turn them all on, and spin a colour in. On 19 of the heads, it will spin in clockwise, on the remaining one that was hung backwards, it will spin in counter-clockwise. The same is true for gobo's... And not to mention the actual 'rotation' feature of the gobos... Set the entire rig to a 3-Dot gobo, and tell them all to spin CW... One will spin CCW...

Do a 'live' colour change on stage slowly, and you'll notice... It's akin to hanging a scroller upside-down... It's not a HUGE deal, but it'll drive you nuts from the moment you notice, to the moment you fix it.

The 'right' way to fix this, would be to convince the console that 'Home' for this move is +/- 180 degree Pan. But in the long run, you'll short yourself some travel distance doing this. And with a head that only offers one complete rotation from home in either direction (720 degree's of Pan) that can be a kick in the pants.

I've run into this more times than I like... Making sure the rig is all hung in the same direction goes a long way to saving sanity


As for the pan inversion, as I said... It can be useful... Depending on the mood I'm in, I'll use it... It makes lots of things easier... For instance you can 'Copy' a fixture position between mirrored lights SL and SR and cut your position creation time in half. But, if you flip all the lights out to the house, and want them to pop house left and then house right, it'll become a right pain.

My two cents.