Is this a rear screen projection presentation?
 

Ok, so this is still distribution, just for a large audience....

Most presentations I see are done with a small projector up on a lame slide up silver screen on an easel...and the speaker has to avoid walking in front of the light beam.

So if you want to be able to see the screen well, the speaker is dark, if you illuminate the speaker, the screen gets washed out...

So these large audience presentations done by Steve Jobs, any idea on how is the projection done on the screen in this video?

Steve Jobs Apple Keynote Presentation

yes it is probably a rear projection, there is also the hanging projector too though, where it hangs up high and projects down. they can even have pretty steep angles going with the high hanging projectors.
they use hanging ones on the stages sometimes, as long as the people on the stage stay about 3feet from the screen they dont get in the projection.
most projectors will do rear projection, you just hang what looks like a white bed sheet type scrim thing. then the projector has Inversion setting to invert the picture. Problem with rear projection is you have to have some Distance Behind the screen. where i have seen them used they wasted a LOT of floor space behind the screen closing up the room we were in.

Is the material it projects against expensive or specialized?

honestly you can use a bed sheet of the right thread count :-)
For Older big screen televisions they used what looked like plastic difussion, something that the light hits instead of goes right through, and that allows as much light to pass through as possible. So thin but without holes or mesh. the least ammount of blocking, with still the light strike point instead of passthrough.
the people doing portable setups are usually using Cloth like materials , because it doesnt have wrinkels after setup.
Projection Material

also the perfect shower curtian will probably work, if you want to save $150 :-)

Dave,
the last 4 or 5 seminars I've done entailed rear projection (actually very common for larger seminars and conventions) and while Marty is right that it can be space wasteful depending on the projectors used you can get a short throw lens that will cut down tremendously the amount of room needed for the projector. Of course they aren't the little portables you get at Bestbuy, these are generally very large units and on the shows where we use them, we usually try to put them on scaffolding instead of hanging them only because some of the venues either have a very high ceiling and it wasn't practical or there was really no where to hang the projectors from and while you can use materials other than a rear projection screen when working on a 3 day show where the client has paid say 10 to 25K for gear rental and crew they don't want to see bedsheets hanging they want to see those nice big 14X10 fastfold screens with nice pipe and drape on either side and a bottom skirt as well as a top valance. Maybe some won't say anything but the people I've done the work for well, they would. I"m just sayin'.

Rear projection indeed does better at not washing out when lights are mis-aimed. The reason is that most light is transmitted instead of reflected.

Front projection is brighter and higher perceived resolution, in general, though, resolution rarely comes up as a problem with RP. And, a brighter projector would be speced for RP.

Either may be used, depending on a bunch of factors. For either, the key is good lighting. There are reasons why there are professional specialties in these areas. Many techniques for dealing with the specialized problems that occur.

Fly of equipment should not be done by inexperienced technicians. Some venues will only allow certified riggers to fly, in consultation with venue engineers so as to stay within safety limits of the hang-points ("picks").

Ground support (scaffolding, etc.) can be set without rigging training, one doesn't have to wait for the scissor lift or the rigger for setup or strike - generally, ground support is used whenever possible.

so would you say generally speaking that there will be MORE light from the projection with a good rear projection screen or from a super glass beaded wizz bang front projector that is more reflective, meaning it has a lesser viewing angle at high brightness?

I see a couple of sources for different grades of 12' x 9' rear projection plastic material, but the jury is still out how it would be set up as far as an inexpensive portable frame with valances, etc.

The organization that is having me do a presentation has pretty much no budget. Even a 1920 x 1080 projector will be like pulling teeth. I just want to do something a little more polished, and their lame roller reefing projector screen on a tripod is, well, lame looking, and so is the speaker roaming the room front avoiding the projector light that is illuminating dust floating about, and I have never seen the venue with a means to elevate the projector.

Dave,
It sounds like by the time you were to buy some material and then jerryrig a way to make it work you might be able to rent a fastfold screen and perhaps a projector. I would start calling rental houses in you area, I'm sure there are a couple. As for raising the projector again IMO the best way is to use scaffolding and would likely be something a rental hous would have. I realize ther is little or no budget (there never seems to be no matter who the client is) but there are somethings that just require money and without it the presantation just doesn't go off as well as it could.
If it were me, I'd make some calls, get some pricing and present to the client as an option and explain why it's the right thing to do. they may not but at least you'd be able to say you tried.

Hmm... Somewhere here I have a book that discusses this in detail, but haven't seen it in a few years.

If you look on the manufacturer's websites, you'll find "gain" information for various screen surfaces. If we assume a given projector's brightness, RP will lose some light, something like 35%. FP on a matte screen will be our standard at 100%. Glass beaded and silver lenticular gain some reflectivity over matte, at the sacrifice of viewing angle, as you noted.

However, when we go into the av rental market, we'll find that all the front surfaces are matte white - they don't want to deal with gain vs. narrower viewing angle, they'd rather rent you a more expensive projector if you need more brightness. This approach works, and doesn't require laying out the projection and audience in a CAD program to determine viewing angles.

Matte has proven to be the most usable and adaptable front surface for general use, but, some permanent installations use lenticular so that the image is both brighter and isn't as washed out by ambient light.

thanks, i havent tried to go rear project myself yet. i use a screen that is NOT glass bead, but its not as flat as matte, and brightness was one of the things we specifically "bought into" to survive various locations.

I never heard of fast fold screens. The material doesn't sound like it is all that expensive, but I am wondering about the frame, who makes them and the portability of that.

I believe fast-fold was originally what Da-Lite called their frames, but, now all the major manufacturers make similar frames. Different snap patterns, though, so, surfaces/frames are not interchangeable between manufacturers.

It's basically 1-1/4" square aluminum tube, put together with hinges and latches. Larger screens use flat welded truss made of the same material, sides hinge/latch, then are screwed together with speed cranks.

9x12' is a big-ish standard size, when collapsed, it might be about 1.5'x1'x4.5'. Then, there are screw-on legs made of the same material.

These systems work pretty well, though after a few years of rental use there can be some considerable sag in the frame when the surface is stretched on it.

I had seen the Da-Lite, but I don't recall seeing any that were rear projection Fast-Folds.

Also, it it didn't seem to have any nice black border flat pieces around the perimeter....so they look sort of unpolished.

It would be fairly easy to make something about 12' x 6.75' that portable for less than $200 excluding screen, but the issue is attaching screen material with no wrinkles.

Da-Lite Deluxe Complete Screen Fast-Fold Portable Front Projection Screen - 10.6' x 14' - 211" Diagonal - Video Format (4:3 Aspect) - Cinema Vision
This is from B&H- just one of many.

Actually they have a nice black border all the way around, have draping that snaps right on, including side drapes, bottom skirts and top valance and the ones I've used over the last years have 2 screens. One is front projection and the other is for rear projection.
The fast folds can be a real pain to set up and can even be dangerous to strike but it's been my experience they are pretty much an industry standard, if not by name type.
Kinda like Kleenix. there's only one brand of kleenix but pretty much all tissue is called that no matter who manufactured it.

BTW, the screen is snapped into place and is a 2 person job. Good luck trying to make one but personally, I think you'd be better off renting or buying the real thing. They have down cold and there's a reason it's an industry standard.
Just my $.02 worth

Ok, that lead me to find online the Draper Rear Projection Portables

The 120" x 69" portable looks like a decent size and price. Anything larger and the spaced needed in a room for the projector behind the screen may start to become an issue.

The valances they have look sort of coffin-ish with their multiple folds whereas a smooth matte black cloth mike look a little more contemporary.

You guys are putting me on the right track.

Dave there are points to consider if you really want it done right.

1. How many people watching the presentation determines the size of the screen. The general rule is 1" per person (diagonal measurement of the screen). So basically if there are 100 people watching, the screen size should be 100 inches diagonally. Is there enough ceiling height? Note that 9'x 10 feet is just the screen size, the screen legs can make the height 14 feet.

2. If your are going rear, do you have enough space (throw distance). Throw distance= projector lens (1.2 0r 1.5) x diagonal size of the screen, determines the distance you need. And as Don Mentioned, short throw lens (.8) can minimize the distance. Please note that not all projector have interchangeable lens.

3. Lastly, brightness of the projector. Does brighter means better? Not 100 percent of the time. If the room brightness can be controlled you can't differentiate a 2K projector from a 5K projector.

4. Steve Jobs presentation at the very minimum would have 2 Projectors converged at the rear, if one fails you won't notice coz the other projector will be there to save the day. The reason they use black drapes is it absorbs light, white would be hard on the eyes.

Renting would be the way to go, and I don't think your client will spend more than 1K for renting the screen/projector/cart.

My 2 cents.

The major manufacturers, so far as I know:

http://www.draperinc.com/index.asp
The Screen Works
Da-Lite Screen Company
WELCOME TO STEWART FILMSCREEN (this co. does lots of custom work, if you need bits and pieces)

They all do fast-fold style, front, rear, drape kits.

Rentals highly recommended, available in all major cities.

As Don said, very difficult with less than 2 people. Most sizes take 2 people about 20+ minutes. New screen surfaces are particularly hard to snap.

If someone has an idea as to how to build a portable screen for less, more power to them!

Another commonly overlooked front screen type is the roll-up screen, in a cradle. You put it on a table, usually, really good in 6-10' widths. 1 person setup in 2 minutes.

Transportation can be an issue - you start getting into pieces that are 6 feet longer or more, and you'd better have a van or truck.

Fast-fold is an industry standard for good reason - it mostly works pretty well.

I will check out all those links., thanks, and same for the formulas.

As to audience numbers, it is going to vary throughout the country, from maybe 20 to 150. Slightly too large is better than too small. Most rooms are convention center rooms, so ceilings are high.

I found a few rental places, and they want about $300 for everything, which is about 1/3rd the cost of buying one.

It looks like even the large ones use an extruded aluminum runner system that folds into something about 4' max. As long as it all weights less than 50lbs for airlines....

The people I will be doing these presentations for will probably want me to use their convention center in-house vendor to provide their customary regular roll up telescoping top front projection screens with no valances. That is my issue; the presentation production is a reflection upon me so I am more concerned with the wow-factor the first few times around. If I can get them to spring for the rental cost, I might as well buy it all and have them pay me the rental fee.

I don't know that any of this is flyable on an airline as checked luggage. Even a 5x7' lightweight weighs in at 42lbs, and that's without a dress kit or 2nd screen surface. Probably just a bottom skirt takes you over 50 lbs, on a small-ish screen.

Another way to deal with this is to spec something like:
"7.5'x10' fast-fold style screen, with full dress kit to include top valence, side bars, and bottom skirt" for your client's dealings with hotels and convention centers. They (almost) all have this gear. A quick phone call will confirm.

Seth is right. The fastfold is generally in 2 cases and I have never moved one that's less than 50 pounds or at least they all seem like they weight in at about 60+, I must be gettin' old.
As for flying you can fly with them but today be prepared to pay some money and honestly, there's no reason to take them with you. All major cities have AV rental companies which is where 99% of hotels and convention venues get their gear from so what I've done in the past is one of two things. I either talk to the hotel and have THEM rent it and add it to the clients bill or I call my contact HERE and have them contact their contact THERE, rent it and add it to the clients bill. Either way the client pays of course.
I forgot about the fold in cradle screens, I used to have one and they are great for smaller groups but I found the size limitation to be a real problem so I got rid of it and when I need one I either rent it back from the guy I sold it to OR rent the fastfold in the right size from one of my AV contacts here.
Lately though there hasn't been a lot of call for either. [sigh] :-(

Sounds like you guys are really pushing me to buy my own! lol ;)

I have a call in to my people for the contact info of the convention center AV people.

As to projectors, if there is material shot in HDV 1080i that is deinterlaced into 16:9 footage within a presentation program, what resolution projector would you recommend can handle presenting that with no resolution loss of the video footage?

Ok, the projector people tell me it needs a 1920x1080 projector to properly display 1080 content at full resolution.

It amazes me how many audio/visual houses that do trade show and convention presentation gear that do not have 1920x1080 projectors.

Right they don't because most of the presentations are not being done in HD AS OF YET! Many companies are still using stuff that was done a couple of years ago so it's still SD but slowly it's coming around as new stuff is shot for the companies. Even when just doing IMAG most companies feel that they don't need HD, "after all, who can tell the difference from the back row". At least that's their thinking but again, it's coming around a little at a time.

OH yeah, let's not foget the economy and the cost of those little gems. Right now business is slower for even some of the big AV houses so they're watching their nickles and dimes.

I will be using Apple's Keynote presentation program, but I am beginning to think, if the maximum resolution in pixels of an Apple Macbook Pro laptop screen is 1440 x 900, doesn't that mean that is won't reproduce 1920x1080 on a 1920 x 1080 projector anyway?