Need input: what do you want to see & do at SELEM 2010?

[Stuka]

...

Getting back on topic, does anyone else have any comments or opinions about what they want to see at SELEM 2010?

As it stands right now, I'm very tempted to eliminate the presentations from this year's event, as it seems that there is little support for them. Thoughts?

Adam

Maybe it would be a good idea to do an early poll of possible presentations, and include the additional costs that would be involved in getting that particular person to attend.

Being a fan and owner of several of his productions, I for one would definitely like the chance to meet and hear directly from Mike Dunn. Plus, for me at least, it's always nice to be able to directly interact with the folks from ILDA and Pangolin.

I would recommend maybe a 2-hour block set be aside for auditorium presentations, with all other non-show-related activites taking place outside the auditorium.

My nickel's worth...

[Lazerjock]

I would love to meet the legend Mike Dunn.

[flecom]

Also, more graphics shows.

I have spent countless hours (days/weeks) and bashed my head into the desk many times making graphics shows (since thats all they do at the planetarium here) and it would be nice to see some graphics shows... I think when I went to SELEM (2008) I saw maybe one, and Linea (we were seeing who's projector could project it the worst apparently? lol)

I know they dont have the gee-whiz factor of beams flying everywhere but they can be cool in their own right

so ya, I agree, I would love to see more graphics shows

also I really enjoyed the lectures and would attend them in whatever forum they are held

[Stuka]

Pretty sure we'll have several Mike Dunn graphics shows on hand (I know DZ, myself, and possibly some others have accumulated a decent collection) -
Not to sure about original shows from the SELEM bunch, though - everyone seems to go for the beam shows!!
(And there are some good ones!! )

[flecom]

I'd rather not post the whole schematic at this point, as we're still refining it. (Besides, I don't have it with me in any case.) However, the basic idea is to use an op-amp in a unity-gain configuration to buffer each signal.

Here's a link to a basic schematic that will buffer a single color signal. I put this together for Marc (gottaluvlasers) to solve the low input impedance problem on the modulation circuit for the Laserwave driver he was working with. (Note that it assumes single-ended color signalling.) For the X and Y data, the circuit will be slightly different, as you'll need a pair of op-amps for each.

Also, the splitter we're building will have quite a few extra features that are not shown in the schematic linked above. But this will get you started if you want to try to build one yourself.

Adam

why not just use a BUF634 vs a unity gain opamp?

http://focus.ti.com/docs/prod/folders/print/buf634.html

they can sink 250mA so you could probably hook quite a few projectors up to them... you can parallel them too if you need more current capacity...

i have used them successfully in some of my audio designs, and they are designed for video so they have high bandwidth and a nice flat response till well above any signal your going to send its way

[buffo]

You really don't need a lot of current. 20 ma per port is more than enough. But you need a separate buffer for each port so you can tweak the gain for each projector individually. So yeah, you could use the IC you linked to, but you still need 8 of them per output port, 5 of which (R, G, B, X+ and Y+) will need gain adjustment.

Adam

[DZ]

Simple answer:

BUF634 is a single op-amp: $5.59 from Mouser in quantity of 25 or more (<100)
TL084 is a 4 channel op-amp: .57 from Mouser is quantity of 25 or more (<100)

Project needs 80 op-amps.

Cost with TL084's using 20 four channel op-amps: $11.40
Cost with BUF634's using 80 of them: $447.20

This doesn't include other characteristics, such as certain configurations yield an input impedance of 200 ohm!

why not just use a BUF634 vs a unity gain opamp?

http://focus.ti.com/docs/prod/folders/print/buf634.html

they can sink 250mA so you could probably hook quite a few projectors up to them... you can parallel them too if you need more current capacity...

i have used them successfully in some of my audio designs, and they are designed for video so they have high bandwidth and a nice flat response till well above any signal your going to send its way

[mixedgas]

electronic goldmine is dumping tubes of prime tl074s and tl084s right now for 5.95$ a tube. I bought four tubes.

Steve

[Stuka]

Speaking of shows -

Now that some of you hard-core multi-LEM attendees have had the opportunity to "field test" some multi-projector shows, might I suggest that the "proven" planning techniques, zone assignments, palette considerations, etc. be shared with anyone who plans on building a multi-projector show for SELEM.

Multi-projector shows are, no-doubt, VERY cool, but I could also see it presenting some very time -consuming issues to address if we don't approach our show planning with a similar set of "blueprints".
Additionally, I would suggest that we don't depend on any one person / computer being the "master" for every multi-projector show -
Let it be a learning experience so everyone can enjoy the experience - and/or feel the pain - of completely preparing for and running a multi-projector show, from start to finish.

Also -

Maybe it would be a good idea to start a list of potential shows (graphics and/or beams) that we hope to present, so we could get an idea of the time blocks we need to dedicate.
For those that want their shows to be a surprise, just list it as "To be announced"...

Just my additional 10 cents worth...

[MechEng3]

How about more BST items...thats always a good thing. There needs to be more in the area of show creation and ... well a Pangolin class of sorts may help. Professional crash course of sorts. Not for beamshows...graphics manipulation and that sort of isuue. There are a few secrets to obtaining a nice abstract and other tricks I have played with...I am certain there are a LOT more .... at least with regards to my skillset with it.