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[Ivan Beaver]

I have been out of the lighting business for quite a few years and a lot has changed.  So I am looking for some input on current fixtures-I prefer not to go the used route.

So here is what I am looking for:

Either rotating mirror or rotating yoke units-no real preferance.

I only need white (but yes, all the other colors come for free ) -basically saying I don't need a pile of colors or mixing.

I would prefer an adjustable iris (like a spot light) but could possibly live with a couple of gobos that are various sizes and are round in shape.  It does not need to have rotating gobos-yeah like that would do any good with a ROUND gobo  

Does not need to be a high brightness-so most smaller wattages would be fine-I don't need to cut through a bunch of smoke or bright stage lights.  I am just looking for something to spot objects in a normal lite room about 40' away.

So basically a simple low wattage unit with an adjustable iris (yeah-that is probably the hard part) or multiple round gobos.

I do not need it to spin all the way around-a 90

[Rob Timmerman]

I don't know of any moving lights with irises that use smaller than a 575W lamp, which is likely overkill for your application.  

Another approach would be to build what you need using readily available components.

Something like a Source 4 + a Rosco I-Cue + a DMX Iris + a dimmer (a BakPak dimmer will work).
http://www.rosco.com/us/lightingequipment/dmxiris.asp
http://www.rosco.com/us/lightingequipment/icue.asp
http://www.etdimming.com/index.php?src=directory&view=pr oducts&srctype=display&id=22&category=IGBT_Dimmi ng

This is assuming that the 19 degree Source 4 has enough output for what you want.

[Ivan Beaver]

WOW- being the DIYer that I am, that may be just the ticket I am looking for.

I don't care about looks and it will get treated gently.

THANKS!

[Duane Massey]

Ivan, I've done several projects over the years similar to what you are looking for. The low$$ fixtures will probably be bright enough but the resolution of the p/t motors may be an issue if you're looking for pin-point accuracy. Definitely won't find an iris on anything less than a 250w discharge (Design Spot has an iris), but you'll either need something with removable gobos or just find the right size and glue it over the "open" position.

If you're not opposed to used fixtures, a Trackspot might fit the bill; it's got decent p/t resolution and it has one removable gobo slot.

If you want a moving head, and need hi-res p/t, the Design Spot is just about the only choice with an iris. If you don't need hi-res p/t, an ADJ AccuSpot would be a good choice with the replacement gobo idea; AccuScan if you can use a scanner instead.

Any of the low$$ fixtures will use 8 or fewer channels.

[Craig Leerman]

Quote:

If you're not opposed to used fixtures, a Trackspot might fit the bill; it's got decent p/t resolution and it has one removable gobo slot.

The standard Trackspot gobo wheel has one removable slot. I have some wheels that have 4 removable slots. I can't remember where I got them.

And of course you could get a custom wheel with all different sizes of circles (or any gobos you desire)

Plus, Trackspots are only 7 DMX channels!

[Duane Massey]

Craig, I used to have 4 wheels with all open slots. Came out of some fixtures that were used in a dance studio, and had a whole bunch of break-up gobos in 'em. When Core shut down, I tried to grab everything that might prove useful later before it all got pitched in the dumpster, but I'm not sure if I still have the wheels.

We used to do some strange things with custom gobos, broken dicros, and clear RTV, especially on older IBeams......

[Karl P(eterson)]

That said the Rosco option will let him use a very robust fixture with common and cheap lamps and have only 4 channels of dmx control. It is true that it is more cabling and more individual pieces, but by the same token it also helps ivan in that so long as his physical layout is the same time and again he can get his presets in the right ballpark by simply physically moving the fixture.

I love ETC fixtures.....

Maybe a revolution with an iris motor? Although that would more than likely have to high of an electric draw

Otherwise the Design Spot would be a good option.

Karl P

[Ivan Beaver]

I don't need really fine resolution and the gobo or iris would in most cases change size with each position.

The light will not be moving a whole bunch-maybe just a couple of hundred (or much less) times a day.  Think stay in one position for a couple of minutes and then move to another position for a couple of minutes and so forth.  No sweeping or other typical moving type functions.

Thanks for all the insights-I am going to look at a couple of different options.

[jeffhtg (Jeff Kenney)]

8 bit movement at 40' or so can literally mean each step moves the circle 4 feet at a time. So I would think it IS important

[Ivan Beaver]

jeffhtg (Jeff Kenney) wrote on Tue, 24 March 2009 13:17

8 bit movement at 40' or so can literally mean each step moves the circle 4 feet at a time. So I would think it IS important

See that is just showing off my ignorance of the subject .

The distances may be shorter, but I am thinking between 30-40' in general.  I may need to modify my overall thinking of the layout.

So exactly what is "8 bit movement"? Is it 8 steps through out the full sweep range?

I have been out of lighting for a while and a lot has changed.

[Brian Houchin]

Ivan Beaver wrote on Tue, 24 March 2009 14:00

jeffhtg (Jeff Kenney) wrote on Tue, 24 March 2009 13:17 8 bit movement at 40' or so can literally mean each step moves the circle 4 feet at a time. So I would think it IS important See that is just showing off my ignorance of the subject . The distances may be shorter, but I am thinking between 30-40' in general.  I may need to modify my overall thinking of the layout. So exactly what is "8 bit movement"? Is it 8 steps through out the full sweep range? I have been out of lighting for a while and a lot has changed.

2 to the 8th power, so 256 steps for each channel.

[jeffhtg (Jeff Kenney)]

Basically 16 bit movement is going to require 4 DMX channels and give you twice the resolution - which you will more than likely need.

[Tony "T" Tissot]

Or to put it another way -

16 bit gives you possible values from 0 to 65535  (2 channels each, pan/tilt)
8 bit gives you values from 0 to 255 (1 channel each, pan/tilt)

The two big issues have always been smoothness of motion (no "jumpiness") and precise aiming.

8 bit on Martin SCX gives me .7 degrees resolution on pan position, and .28 degrees on tilt. Good enough for pointing in many applications, - all of mine.

Do the math on 16 bit, and the resolution can be way more than twice as precise.

The other issue - Smooth movements - are handled on the cheaper units by letting the instrument control pan/tilt speed, or not.

The Martin SCX scanners, for example, have an extended DMX mode that lets you control pan and tilt speed to prevent jumpiness. (or not). So even if I send it poorly written, jumpy movement cues, the instrument "fixes it."

The higher-end of the Martin line all has 2 channels for pan and 2 channels for tilt.

[Justin Rygel]

FWIW, the Rosco I-Cue has an 8-bit and 16-bit mode.  Looking at the specs, you get 0.9 degrees for Pan and 0.225 for Tilt in 8-bit mode, and you get 0.028 degrees for Pan & Tilt in 16-bit mode.

Practically, you will use two DMX channels for each movement in 16-bit mode, a coarse control and a fine control.

[Duane Massey]

Ivan, how far apart are the targets? What is your budget per fixture, and controller?

[Ivan Beaver]

Duane Massey wrote on Sat, 28 March 2009 01:43

Ivan, how far apart are the targets? What is your budget per fixture, and controller?

The "targets" will be in a area about 20' (or less) wide and from the floor to maybe 12' tall.

The controller is one that I am building that is a analog control, switchable scene from relay control.

I am in the process of building it now.  For a quick setup each of the "scenes" will be adjusted by using seperate pots.

That way you do not have to know how to program it-just press the botton for what you want lit up-adjust the pots to put the light where you want it-then go to the next one.

As long as the pots are not moved-the scene is "saved".

I am thinking of using a single course control to put the light in the center of the block and then have fine control for each of the scenes.

No budget as per say-but I don't want to spend a pile of money for features that I don't need.