samrennie Posted May 27, 2006 Share Posted May 27, 2006 Hi there, over the summer I'm doing an event involving a large 16:9 screen projection. From the throw distance, it is necessary to put the projector (Hitachi 2000 lunim (ish)) into 16:9 mode, but this obviously compresses the image sent from the computer. What sort of resolution should I be outputting from the computer? 1024x800 (ish) or an aspect ratio closer to 16:9? Is it going to matter? Should I also film in 16:9 or 4:3?! Mixture of edited video, powerpoint etc projected. But all from a laptop. Thanks Sam Link to comment Share on other sites More sharing options...
ampcats Posted May 27, 2006 Share Posted May 27, 2006 From the throw distance, it is necessary to put the projector (Hitachi 2000 lunim (sic)(ish)) into 16:9 mode All standard (4:3) projectors have a display area of fixed pixel width and height - all that 16:9 mode does is blank the top and bottom 3/16 of the display area and either processes the incoming image to fit the window, or just displays the center section of the incoming image... put the projector in 16:9 mode in a darkened room, and you will see the unused areas as a slightly lighter rectangle (you might need to crank up the brightness and drop the contrast in a lit room) different projectors have different options for handling the incoming image - check your manual as to how you film, since you have the choice, I'd go for 16:9 since it is the end output format. Link to comment Share on other sites More sharing options...
Fletch Posted May 27, 2006 Share Posted May 27, 2006 Hi Sam, I've found this a bit tough to explain my thoughts on, but here goes.... Firstly, are you aware of what 16:9 and 4:3 actually mean? if not then here goes... (sorry for teaching you to suck eggs if you do...) In summary 4:3 is considered normal and 16:9 wide screen. Basically the numbers are the ratio of the left to right part of the screen compared to the up and down part. So for 4:3 your screen could be 4 feet wide by 3 feet tall, or 2 feet wide by 1.5 feet tall (or some proportion of those numbers). If you scale the ratios to use the same "denominator" (something from fractions I think!) 4:3 is the same as 16:12, right, so compared to 16:9 it is just more square. So 4:3 is like your normal telly and 16:9 is like your wide screen one. The larger numbers do not necessarily mean the image will be bigger. This would depend on how the projector works. As far as I am aware the higher the resolution the better. Although for your reference TV originated footage - i.e. from a camcorder - is approx equivalent to 600x800 dpi (that's 576 visible lines at a horizontal scan rate of approx 15Khz) , it's only if you are doing stuff with graphics or have a high definition camcorder you'll want to use a higher resolution. So which format to use for filming.... In summary I would say that it is essential your film footage is in the same format you are going to display in (so if you opt for 16:9 wide screen then film in 16:9) If you use 4:3 as your filming format and want to display in 16:9 you will have to convert this at some point to be 16:9 (also know as Aspect Ration Conversion or ARCing). Many projectors will not carry out this conversion for you, and if they do, they may not do it in a very clever way thus you loose parts of your image, or it gets stretched/sqaushed horribly. To your question about whether to use a resolution from the computer set at 16:9... if you film in 16:9, then put the computer in 16:9 and also put the projector in 16:9. It's far easier that way. Basically, yes, choose a resolution that is 16:9 in the computer. Also be aware that your laptop screen won't be 16:9 (unless you have a nice laptop), so if you go full size on the laptop screen the image will look strange and squashed - although that's OK if you want it to look fine on the projector. This is a whole world of confusion and even large broadcasting companies don't get it right. I see lots of programmes, especially old repeats, transmitted for 16:9, but the original footage is 4:3, so it just stretches to fit the screen and makes everyone all look very fat. Apologies if that has just confused you more - it's one of these things that once you get it, it's easy, but very difficult to explain concisely. Fletch Link to comment Share on other sites More sharing options...
samrennie Posted June 15, 2006 Author Share Posted June 15, 2006 Hi there, thanks all really helpful!! I'll have a quick poke around the projector and see which way it modifies the image. Thanks as well for the advice on filming and computer ratio's. From memory, although I'm going to check I think the 4:3 ratio is actually a smaller width than the 16:9, it almost seems that rather than simply cropping it must actually pull some hidden width from somewhere!! odd!! Many thanks all Sam Rennie Link to comment Share on other sites More sharing options...
SeanT Posted June 15, 2006 Share Posted June 15, 2006 Hi there, over the summer I'm doing an event involving a large 16:9 screen projection. (Hitachi 2000 lunim (ish)) The audience are gonna have to squint - just how large is "large" coz 2000 lumens is no good for "large" - 3500 lumens is about enough for "above average" if large is taken to be 10x7.5 ft or so..... (or 10x5.6 for 16:9) Link to comment Share on other sites More sharing options...
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