# How big is viewable screen for widescreen movies?

Discussion in 'iMac' started by lindygamer, Sep 14, 2006.

1. ### lindygamer macrumors newbie

Joined:
Sep 14, 2006
#1
On the 24in iMac, you will see black bars at the top and bottom when watching widescreen movies. This means that you are not seeing a full 24in diagonal picture. Does anybody know how big the picture is for movies with a normal 16:9 widescreen ratio on this computer? I think it is an important question since so many people are planning to use their 24in imac as a secondary tv/movie viewer in their homes.

- Josh

2. ### lightster macrumors newbie

Joined:
Sep 11, 2006
Location:
(Southern) California, USA
#2
Since I do not have a Mac at this point (hopefully I will tomorrow), I can only calculate the gap:

s=screen size
w=screen width=cos(x)*s
x=tan^-1(10/16)
w=cos(tan^-1(10/16))*s=.848*s
m=movie height=(9/16)*w
h=screen height=(10/16)*w
g=black bar=(h-m)*.5

So, for a 24" Mac:
w=.848*24=20.352"
m=11.448"
h=12.72"
g=(12.72-11.448)*.5=.636"
I would estimate that the black bars will be .636" each (a total of 1.272" of the 12.72" of screen height).

Since I ordered a 20" here are my estimates for the 20" Mac:
w=.848*20=16.96"
m=9.54"
h=10.6"
g=(10.6-9.54)*.5=.53"
Each black bar is just over half an inch on a 20" Mac.

These are just geeky estimates, so you may want to wait for actual measurements. Do not hold me responsible if my estimates are wrong

3. ### SilentPanda Moderator emeritus

Joined:
Oct 8, 2002
Location:
The Bamboo Forest
#3
Wdiescreen movies come in different aspect ratios. 16:9 is around 1.78:1. 1.85:1 is usually close enough to be considered in the same ballpark too. 2.35:1 or 2.40:1 is "the other widescreen". That's closer to a 7:3 ratio. And of course most TV is in 4:3 (although newer shows are more and more being filmed in 16:9).

Most widescreen monitors are 16:10. So even with a 16:9 movie you'll have slight black bars at the top and bottom. You won't miss any picture on the sides though.

Also I officially (and affectionately) declare the person above me a nerd.

4. ### lightster macrumors newbie

Joined:
Sep 11, 2006
Location:
(Southern) California, USA
#4
I am glad someone appreciates me ... and I think that might actually be the first positive response I have received on these forums

5. ### lindygamer thread starter macrumors newbie

Joined:
Sep 14, 2006
#5
Thanks!

Great, that gives me some idea!

So, if your estimate is correct then the height of the actual picture would be 11.448 inches, which paired with a width of 20.352 inches gives a picture with a diagonal of 23.351 inches. That is bigger than I was thinking it would be, so I am happy. And yes, I know that a movie in the "other widescreen" would have a still smaller picture and larger bars. Thank you all so much.

- Josh

6. ### pss3jlh macrumors newbie

Joined:
Sep 14, 2006
#6
Viewing Area

I have found that it depends on what ur viewing, Lost series 1 and Sin City DVD fill the whole screen. Something like Gladiator Widescreen is tiny.Also has anybody noticed that special features have black sections on the side not the top?