# Frame rates and instant replays **URL:** \ **Category:** Factual Questions\ **Created:** [October 24, 2005, 2:58am UTC](https://boards.straightdope.com/t/frame-rates-and-instant-replays/327608 "2005-10-24T02:58:33Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![FlippyFly](https://avatars.discourse-cdn.com/v4/letter/f/e95f7d/32.png) [@FlippyFly](https://boards.straightdope.com/u/FlippyFly)\ **Post date:** [October 24, 2005, 2:58am UTC](https://boards.straightdope.com/t/frame-rates-and-instant-replays/327608/1 "2005-10-24T02:58:33Z")
Is there a reason sports broadcasters don’t film at a higher frame rate, so when they show a slow motion instant replay, it wouldn’t be so choppy? Do any broadcasters do this? Seems like they could broadcast at the standard, using computers to remove the extra frames from the live feed. ---
**Author:** ![Fredescu](https://avatars.discourse-cdn.com/v4/letter/f/73ab20/32.png) [@Fredescu](https://boards.straightdope.com/u/Fredescu)\ **Post date:** [October 24, 2005, 3:19am UTC](https://boards.straightdope.com/t/frame-rates-and-instant-replays/327608/2 "2005-10-24T03:19:07Z")
Channel 4 in England did that for this years Ashes series (Cricket contest between Australia and England). Very smooth super slow motion. It’s the first time I’ve seen it. I’m not sure how long Channel 4 have been doing that for. ---
**Author:** ![filmyak](https://avatars.discourse-cdn.com/v4/letter/f/94ad74/32.png) [@filmyak](https://boards.straightdope.com/u/filmyak)\ **Post date:** [October 24, 2005, 5:27am UTC](https://boards.straightdope.com/t/frame-rates-and-instant-replays/327608/3 "2005-10-24T05:27:27Z")
> [@FlippyFly](#): > > Is there a reason sports broadcasters don’t film at a higher frame rate, so when they show a slow motion instant replay, it wouldn’t be so choppy? Do any broadcasters do this? Seems like they could broadcast at the standard, using computers to remove the extra frames from the live feed. Well in the US and any country that uses NTSC, everything is shot at 30 FPS. I’m actually not aware of any video cameras that shoot at faster speeds. Remember, unlike film cameras with shutters, video cameras do everything electronically, so I suppose it’s possible, but it opens up a huge can of worms when it comes to conforming with existing systems. Really amazing slo-mo’s are shot on film at high speed. Even though football games are broadcast live via video, the NFL also films the games for their useage. I’ve used the NFL footage doing a commercial for one of the football teams, and most of it is shot in high speed (which translates to slo motion in playback). I just don’t think most sports need to be replayed at more resolutin than 1/30 frame at a time. ---
**Author:** ![Ms2001](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ms2001/32/18463_2.png) [@Ms2001](https://boards.straightdope.com/u/Ms2001)\ **Post date:** [October 24, 2005, 10:48am UTC](https://boards.straightdope.com/t/frame-rates-and-instant-replays/327608/4 "2005-10-24T10:48:29Z")
> [@filmyak](#): > > Well in the US and any country that uses NTSC, everything is shot at 30 FPS. I’m actually not aware of any video cameras that shoot at faster speeds. HDTV cameras can do 60 frames per second (non-interlaced). ---
**Author:** ![filmyak](https://avatars.discourse-cdn.com/v4/letter/f/94ad74/32.png) [@filmyak](https://boards.straightdope.com/u/filmyak)\ **Post date:** [October 24, 2005, 6:44pm UTC](https://boards.straightdope.com/t/frame-rates-and-instant-replays/327608/5 "2005-10-24T18:44:43Z")
> [@Mr2001](#): > > HDTV cameras can do 60 frames per second (non-interlaced). Sure, and interlaced it’s 60 fields per sec. But sports aren’t shot in progressive rates like that, and if they were, I know of no way to simultaneously strip out every other frame during the live feed, nor do I know what happens if you shoot 60 fps and broadcast 60fps (theoretically, it’d be smoother motion in real time…?). ---
**Author:** ![Ms2001](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ms2001/32/18463_2.png) [@Ms2001](https://boards.straightdope.com/u/Ms2001)\ **Post date:** [October 24, 2005, 7:10pm UTC](https://boards.straightdope.com/t/frame-rates-and-instant-replays/327608/6 "2005-10-24T19:10:58Z")
> [@filmyak](#): > > Sure, and interlaced it’s 60 fields per sec. But sports aren’t shot in progressive rates like that, and if they were, I know of no way to simultaneously strip out every other frame during the live feed, nor do I know what happens if you shoot 60 fps and broadcast 60fps (theoretically, it’d be smoother motion in real time…?). You wouldn’t strip every other frame, you’d just strip every other field for the live feed. Progressive frames A, B, C become interlaced fields Atop, Bbottom, Ctop. But then when it comes time for instant replay, you’d show Atop, Abottom, Btop, Bbottom, etc. to slow it down to half speed. ---
**Author:** ![filmyak](https://avatars.discourse-cdn.com/v4/letter/f/94ad74/32.png) [@filmyak](https://boards.straightdope.com/u/filmyak)\ **Post date:** [October 24, 2005, 7:15pm UTC](https://boards.straightdope.com/t/frame-rates-and-instant-replays/327608/7 "2005-10-24T19:15:17Z")
> [@Mr2001](#): > > You wouldn’t strip every other frame, you’d just strip every other field for the live feed. Progressive frames A, B, C become interlaced fields Atop, Bbottom, Ctop. But then when it comes time for instant replay, you’d show Atop, Abottom, Btop, Bbottom, etc. to slow it down to half speed. Wait… and sorry for the hijack here… HD progressive frames still use fields? Obviously I haven’t worked with HD yet, though I’m sure it’s in my imemdiate future. :eek: ---
**Author:** ![Ms2001](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ms2001/32/18463_2.png) [@Ms2001](https://boards.straightdope.com/u/Ms2001)\ **Post date:** [October 24, 2005, 7:38pm UTC](https://boards.straightdope.com/t/frame-rates-and-instant-replays/327608/8 "2005-10-24T19:38:08Z")
> [@filmyak](#): > > Wait… and sorry for the hijack here… HD progressive frames still use fields? Obviously I haven’t worked with HD yet, though I’m sure it’s in my imemdiate future. :eek: Well, no, you’d digitally split it into fields. Broadcast the odd lines from frame 1, the even lines from frame 2, and so on. That would give the same result as if you’d shot the game with an interlaced camera in the first place. ---
**Author:** ![SmackFu](https://avatars.discourse-cdn.com/v4/letter/s/53a042/32.png) [@SmackFu](https://boards.straightdope.com/u/SmackFu)\ **Post date:** [October 24, 2005, 8:50pm UTC](https://boards.straightdope.com/t/frame-rates-and-instant-replays/327608/9 "2005-10-24T20:50:48Z")
High speed cameras need more light, since the exposure time per frame is less. This would be a major problem at night games.