Resolution, Scaling and CF24 questions...

reflex

reflex

Well-known member
I have a few questions that I would like to get straight. Maybe someone can help me.

  1. Can someone give me a stripped down explanation on vertical and horizotal resolution? What do the numbers mean ( i.e. 1440 , 1080 ) Take 1440 for instance... is that number the number of lines that go horizontal? Then what is vertical res? are there lines that go vertical too?
  2. Why does using CF24 ( or 30 I guess too ) lower your resolution?
  3. I notice when I play back 1080i footage on my 4:3 tv, the footage gets letterboxed ( or rescaled ) but when I try to playback SD 16:9 footage on my 4:3 tv, the footage gets streched. Why is that? Sometimes when I turn on Discovery ( channel ) some of the footage is letterboxed like that and some isn't. How to places broadcast their footage. How does the TV display stuff differently? I know that a ton of people stll have 4:3 tvs, So how do they broadcast stuff, so that it plays normally on a 16:9 tv but then gets letterboxed for 4:3 tvs?
 
1. 1080 vertical lines of resolution from top to bottom with 1440 pixels per line. (Regular HD is actually 1920 pixels per line)

2. As far as CF24 goes, I always thought it was the same size resolution (or frame size), but the difference is in the framerate. I could be wrong, but I believe your resolution is the same.

3. There is a setting in the camera for the tv aspect ratio that you're hooking up to. I would imagine that, since you are connecting with either S-Video or Composite, the auto settings are to display in letterbox for a 4:3 tv.

If you check the settings in the camera, you may be able to adjust for a 4:3 television to playback your 16:9 DV footage also. It might be set to display differently by default.

As far as broadcasting goes, I believe the majority of settings take place within the cable box/satellite box. Within the menu system there, you select what aspect ratio tv/monitor you have.

Now, saying all that, I may be wrong on #2 and/or #3, but I am sure I'm correct on #1.

Hope that all helps reflex.

Later,
 
Yes it does. Thanks. I know that (#3) I have my cam set at 4:3 which my tv is, and when I plug the cam in only HDV gets letterboxed on the TV.. the rest is streched and no setting changes it. I'm just wondering why that is.
 
Know what?

I was just looking at the manual for the FX1 and its really vague on the replay display methods.

Check page 40. I don't exactly understand, but it seems as if you might have to record in 4:3 mode to replay on a 4:3 television in DV mode. Weird and that cannot be right. I'm at work right now, but I will check it when I get home.

Also, take a look at page 48.

Nice clear directions Sony!!!
 
Yeah i know waht you mean. But yeah you do. to display DV in widescreen on a 4:3 its streched, but if you dont want that, you have to shoot 4:3. I would assume that HDV would be the same... but since HDV is native widescreen, you can't record that in 4:3 mode... but why it doesn't strech that, ... i dont know...
 
Hi Reflex, the res using the cf 24 or 30, either, drammatically decrease, being the z1/fx1 a purely interlaced camera. The result is that you'll capture exactely half of the res. Also the final result is defetely not beatiful. Much better to record a full res image, and then in post deinterlace and slow it down to 96%. In that way you'll be quite close to a 24f effect. Then, hd is ONLY 16:9, the native chip is 16:9, so of course you'll watch it on your 4:3 tv letterboxed. The broadcaster choice, well, it really depends; many use the letterbox while others go for other styles. Hope it helps
 
Yas Kassana said:
CF24 does loose resolution. SO it would be half of 1440, i don't know why though.
Click to expand...

CF24 (essentially) loses half the vertical resolution, so it's half of the 1080 lines (to approx 540 effective lines of res). The why has to do with how Sony is essentially deinterlacing the images (which is not clearly stated, that I know of).
 
CF24 loses a lot more than that. It does a weird field discombobulation process that results in each group of five frames having three different resolutions: the first two have 475 lines, the second two have 425 lines, and the fifth frame has 540.

CF30 and CF25 are a constant 540. But CF24 isn't.
 
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