# How big is viewable screen for widescreen movies?

#### lindygamer

##### macrumors newbie
Original poster
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

#### lightster

##### macrumors newbie
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

#### SilentPanda

##### Moderator emeritus
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.

#### lightster

##### macrumors newbie
SilentPanda said:
Also I officially (and affectionately) declare the person above me a nerd.
I am glad someone appreciates me ... and I think that might actually be the first positive response I have received on these forums

#### lindygamer

##### macrumors newbie
Original poster
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

#### pss3jlh

##### macrumors newbie
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?