Desperately seeking a lesson in WIDESREEN trigonometry

Discussion in 'Archived Threads 2001-2004' started by Keith_JS, Jun 14, 2002.

  1. Keith_JS

    Keith_JS Agent

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    I am interested in the new Samsung flat screen HDTV sets. One is a 30" 16:9 model and the other is a 32" 4:3 model. They are both $1200 with free shipping at circuit City. i want to get real numbers for the screen dimensions of the two sets both normal and with letterboxing.

    I asked the following questions on another thread but they haven't been answered yet andI thought they deseved a thread of their own...

    "Does anybody remember high school geometry? I don't. I'm interested in the real dimensions (height and width)of the two screens both naturally and when viewing material that must be letterboxed-- I remember that A squared, plus B squared, equals C squared, but after that I'm stuck.

    Here are a few dimension related questions which some of you scientific/mathematical types will no doubt find a piece of cake to calculate:


    1. What is the viewable screen dimension (height and width) of the 30" 16:9 Samsung.

    2. What is the viewable screen dimension (ht and width) of the 32" 4:3 ratio Samsung.

    3. What is the screen dimension of a 1.85:1 letterboxed movie on a 32" 4:3 tv.

    4. What is the screen dimension of a 4:3 letterboxed program on a 30" 16:9 tv.

    5. What do you think is the maximumum comfortable viewing distance for each tv?

    6. In terms of real estate lost which is the best value assuming that you will be spending equal time watching DVDs and non widescreen programs?"

    Thanks in advance.
     
  2. ChrisMatson

    ChrisMatson Cinematographer

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  3. Robert Mayrand

    Robert Mayrand Stunt Coordinator

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    Wow that's nice, I didn't ask the question but quite glad I got this link!

    Thanks!
    Rob
     
  4. Eric_M

    Eric_M Stunt Coordinator

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    Those were some pretty helpful links there.

    Going by those calculations, you aren't getting that much more viewing area between the 32 inch Samsung vs the 30 inch widescreen samsung set.

    It seems as though you are gaining only about an inch more actual picture(not the actual black bars) when watching a widescreen film on the 16:9 set.
     
  5. Keith_JS

    Keith_JS Agent

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    Chris that link is fantastic and it's helped me really focus on what's important---THE BIGGEST AND BEST PICTURE I CAN AFFORD. On that basis the 30" 16:9 tv falls well short of the 32" model.

    The 30 incher is only a scant 4.8% bigger than the 32 inch model when displaying widescreen video. WHEN DISPLAYING 4:3 IMAGES THE 32" SAMSUNG IS AN AMAZING 70.8% BIGGER THAN IT'S WIDESCREEN BROTHER!!!! OUCH!!

    Based on these findings and my desire to get t he biggest screen I can I have eliminated 16:9 televisions from consideration.

    Now I'm thinking about getting a 36" flat panel 4:3 tv When compared to a 32" 4:3 tv, the 36" is about 26% larger in both widesreen and native dimensions.

    A 36 INCH TV IS AN ASTOUNDING 115% LARGER THAN A 30" 16:9 TV WHEN SHOWING 4:3 RATIO MATERIAL and ABOUT 22% LARGER WHEN SHOWING WIDESCREEN MEDIA!!

    36" flat screen here I come!!!
     
  6. Eric_M

    Eric_M Stunt Coordinator

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    Yes, it is tough since the 30 inch widescreen isn't that much bigger than 32 inch 4:3 set. It is smaller obviously for just TV too.

    Still though when you consider the 16:9 30 inch set you ARE getting a nice 'widescreen' TV set to watch your DVD's in
     
  7. LorenzoD

    LorenzoD Agent

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    I'm a little confused about this 4:3 vs. 16x9 scenario...

    If the 4:3 display will give you a bigger 16x9 picture than the 16x9 display, what's the advantage of having the 16x9 display? Higher resolution?

    I'm thinking that the 16x9 picture on the 4:3 display, while bigger, has lower resolution. Or am I smoking crack?
     
  8. Jim FC

    Jim FC Stunt Coordinator

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    That calculator is handy, but it assumes you'd be watching a 4:3 image on the 16:9 TV without some sort of strech mode... all 16:9 TVs have the ablility to adjust the 4:3 image to fit the 16:9 screen.

    The advantage of a 16:9 display over a 4:3 one is twofold: (1)since all HD programming and most DVDs are widescreen you will get full use of your 16:9 screen without black bars (which can harm the tube) and/or distortion, and (2) there is typically more resolution in a 16:9 image on a 16:9 screen, as opposed to a 16:9 image on a 4:3 screen (although there are some 4:3 TVs which can display a full-resolution 16:9 image, albeit with black bars and somewhat mixed results).

    Of course, the 4:3 has its own advantage, and that is that with the vast majority of current TV signals -- and most likely for at least two or three years to come -- a 4:3 TV can display these without distortion or side bars, which of course can do just as much damage as top & bottom bars.

    Forget about comparative sizes for a minute and ask yourself this question: will your new TV be used more often for watching movies on DVD, or shows on television? If the answer is movies, then you should definitely lean towards a 16:9 set. If the answer is TV, the next question is to consider how much HD is available in your area. If the answer to that is "none," then I'd go with the 4:3. If there is HD available, I'd still say the 16:9 makes more sense.

    My $.02
     
  9. John-Miles

    John-Miles Screenwriter

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    Ok, finally a use for my engineering degree.

    its simple really your 4:3 ratio tv works as follows
    it has a height of x and a width of 1.33x
    the diagonal is equal to the square root of 2.7689x^2 (this is x^2 + (1.33x)^2) so basically you take the diagonal size of the tv and divide it by 1.66 this value is then your height of the screen, and multiplied by 1.33 you get the width.

    the same math will provide you with the dimensions of your 16x9 tv (except you must realize that 1.33 must be replaced with 1.78)

    this is where things get tricky, you have to realize that the width of your screen is fixed, and you must use the screen ratio of the format you are watching to determine the height of the screen being used, then you can calculate the area. the diagonal ,measurement is only used once to determine the height and width of the screen.

    here is an example you use the above calculations to determine that the width of a 4:3 tv is say 20" while the width of a 16x9 tv is 18" you can then compare the two tv's for a movie like gladiator that has a ratio of 1:2.35 so the used height of your 4:3 tv will now be 20"/2.35 and 23"/2.35 for the widescreen tv. you now have the usable height and width and can calculate the area (multiply the two)

    when looking at a 16x9 tv in 4:3 mode you have to realize that all the height is in use and the width will be 1.33 times the height of the screen.

    I hope this helps, if you want further explanation just ask, maybe i can make a excel spread sheet that works better
     
  10. Eric_M

    Eric_M Stunt Coordinator

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    Well with the stretch modes you can watch TV without the bars on the side so that will make up for problems arising from bars and you get the benefits of watching DVDs on a widescreen set.

    Though you will still get bars when watching a 2:35 film
     

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