View Full Version : When would I want to choose to NOT shoot in 1080, and go for 720 instead?


Mike Barber
January 2nd, 2008, 03:16 AM
The EX1 has the ability to shoot in either 1080 or 720 resolutions. What I am wondering is why would I want to shoot in 720 if I have full 1080 available to me? Under what circumstances would I want to consider forgoing 1080 and choose the smaller resolution?

I suppose more recording time and the higher overcranking options are two reasons, but are they compelling enough to drop down?

I don't think I would ever record in SP mode ( vs. HQ mode) for the same reasons I never shoot in LP on my DV cam (or would record in SLP mode on my VCR back in the day). . . isn't 720 to 1080 what SP is to HQ, or is there something else to 720 that I am not considering?

If one was to shoot with the intention of eventually going out to film, wouldn't they want to avoid 720 like the plague and stick to 1080?

Piotr Wozniacki
January 2nd, 2008, 03:19 AM
. . . isn't 720 to 1080 what SP is to HQ, or is there something else to 720 that I am not considering?

Well, you seem to be forgetting it's only 720 that you get the full 50(60)p in - which means full 50 (PAL) or 60 (NTSC) non-interlaced frames per socond. You can't have this in 1080!

Mike Barber
January 2nd, 2008, 03:45 AM
Well, you seem to be forgetting it's only 720 that you get the full 50(60)p in - which means full 50 (PAL) or 60 (NTSC) non-interlaced frames per socond. You can't have this in 1080!

When would I want to work in 60p? What is the practical application?

Eric Pascarelli
January 2nd, 2008, 03:58 AM
The EX1 gives you a choice of temporal vs. spatial resolution at its chosen data rate (35Mbps).

Film production is has traditionally favored spatial resolution over temporal - a relatively slow frame rate and very high resolution images. Attempts to change this (Showscan, for example) have not been embraced thus far.

For anything with really fast action that you want to capture more precisely, 60p is the choice. It's refresh rate more closely matches that of human vision. It's more like being there (but at the cost of some sharpness and with the "stigma" of the "video look").

Sports are almost always shot with 60p - it has the look of live TV. It's the difference between watching the Super Bowl on network television vs. an old NFL film from decades past, which have the feel of something more timeless and archival.

Andrew Wilson
January 2nd, 2008, 04:04 AM
You would use 60p when overcranking the camera to give a slomo look when playing back at 29.97p

Here's a follow-up question: If I'm shooting HD but finishing to Standard-Def - what are the pros and cons to the different recording modes?

I would think that for finishing to SD-NTSC I would use 1920x1080 at 29.97p. Would that be right? I'm not a big fan of shooting 24p unless doing a film-out.

Mike Barber
January 2nd, 2008, 04:09 AM
The EX1 gives you a choice of temporal vs. spatial resolution at its chosen data rate (35Mbps).

. . .

For anything with really fast action that you want to capture more precisely, 60p is the choice. It's refresh rate more closely matches that of human vision.

So the choice is based solely on frame rate, not resolution, is that fair to say?

If the same frame rates were available in both 720 and 1080, would there be any reason -- other than squeezing more recording time out of the media -- that I would want to consider 720 over 1080?

Thomas Smet
January 2nd, 2008, 07:38 AM
Well mpeg2 doesn't work that way. 35mbits/s is used no matter what framerate you have. So if you shoot 1080p or 720p the video will take up just as much space on the card.

With that said what 720p does give you is less compression for higher quality.

720p 24p at 35mbits/s has much less compression then 1080p 24p at 35mbits/s. So by shooting 720p 24p you end up with footage with less resolution but that isn't compressed as hard and could look virtually uncompressed in visual quality. To some people the amount of lack of compression is more important then the resolution.

Like was also said 720p is the only way you can shoot slow motion footage. 1080p has no options at all for shooting slow motion unless you want to shoot 1080i and bob deinterlace it to fake 60p.

720p 60p is also the broadcast standard for 720p HDTV. If you ever plan on shooting for any 720p HD channels such as FOX, ESPN or ABC then you will want 720p 60p. Sure you could shoot 1080i 60i and convert to 720p 60p but not without artifacts.

While the numbers for 720p and 1080 seem a lot different you cannot think of it that way. Video doesn't work in numbers. There is no such thing as "1080p looks like it has twice as many pixels." In most cases 720p can look just as good as 1080p with just a slightly softer look to it. To those who say drama doesn't work with 720p then clearly they haven't watched any shows on ABC or Fox such as Lost or 24.

Finally graphics render so much faster with 720p 24p. I do a lot of 3D work and compositing and the entire production goes so much faster and easier when working with 720p and the quality is still very high.

Mike Barber
January 2nd, 2008, 08:18 AM
. . . what 720p does give you is less compression for higher quality.

720p 24p at 35mbits/s has much less compression then 1080p 24p at 35mbits/s. So by shooting 720p 24p you end up with footage with less resolution but that isn't compressed as hard and could look virtually uncompressed in visual quality. To some people the amount of lack of compression is more important then the resolution.

. . .

While the numbers for 720p and 1080 seem a lot different you cannot think of it that way. Video doesn't work in numbers. There is no such thing as "1080p looks like it has twice as many pixels." In most cases 720p can look just as good as 1080p with just a slightly softer look to it. To those who say drama doesn't work with 720p then clearly they haven't watched any shows on ABC or Fox such as Lost or 24.

Finally graphics render so much faster with 720p 24p. I do a lot of 3D work and compositing and the entire production goes so much faster and easier when working with 720p and the quality is still very high.

I see, so I have been getting hung up on the numbers. Your explanation makes sense.

I suppose the reason I am getting hung up on the 1080 thing is that I am looking at venturing into a few new realms: a) shooting and editing in HD; b) producing a feature-length film (documentary with dramatic recreation) that will be going out to film. Thus, I am very interested in this camera for my documentary film projects.

Have you by chance done any work that has been shot in 720p and went out to film? What I think my chief concern is about which format/resolution I shoot at is what best facilitates the film-out process. My reasoning -- which may be very flawed due to lack of knowledge/experience -- is that 1920x1080 is darn close to 2k which makes it great for a film-out (as far as my understanding goes), so that's what I should be shooting in.

So now I am wondering if I would get the best film-out picture quality from 1080p24 (which would have more compression) or 720p24 (which would have a slightly softer image). . . my head is spinning (partly from the insomnia, i am sure)

Rob Collins
January 2nd, 2008, 10:35 AM
I have a similar dilemma and would appreciate any advice. I'm shooting a corporate project in a few weeks based on a car race (Rolex 24 at Daytona--the company is sponsoring a car and has some of its workers on the pit crew).

Final destination is Blu-ray, to be shown in house on a large 1080p display. Do I shoot 1080/30 or 720/60? I want more of a filmed documentary than TV sports look, so leaning towards 1080 to avoid resizing. I'll be sure to get a few shots of the racing cars at 720/60 to have options though.

Thanks for any suggestions.

Brendan Pyatt
January 2nd, 2008, 01:55 PM
Really interesting posts!

I film surfing and other watersports and have been considering the EX1. On my V1U i shoot 1080i but from what I have read here I could shoot 720p @50p (PAL). If this correct and I would get a better end product - it seems another (big) reason to get this cam...

Brad Vaughan
January 2nd, 2008, 02:09 PM
This is a great thread!

Lots of valuable info in here.

Bookmarked!!

Ali Husain
January 2nd, 2008, 02:54 PM
I see, so I have been getting hung up on the numbers. Your explanation makes sense.

So now I am wondering if I would get the best film-out picture quality from 1080p24 (which would have more compression) or 720p24 (which would have a slightly softer image). . . my head is spinning (partly from the insomnia, i am sure)

unless you shoot lots of waterfalls handheld or track moving birds against trees, almost certainly 1080p24 is going to look better. when there isn't enough motion to use up a lot of bits, you won't get significant compression artifacts using XDCAM 35mbps with either 1080p24 or 720p24... at least based on my few days of testing the EX1.

and if you're delivering in 720p24 and not going to filmout, i'd still shoot in 1080p24 and downscale. that would give more color to work with.

Alister Chapman
January 3rd, 2008, 02:27 PM
I find the difference between true full resolution 720P and full resolution 1080P when viewed on a large full resolution monitor or projected to be very obvious, almost as big a difference as that between SD and 720P. Until recently it was very difficult to find places where you could actually see such comparisons as either the 1080 material was not full resolution 1080P or the monitor was not capable of displaying full native 1080P.

With the SMTPE, BBC, Nat Geo, Discovery and the majority of broadcasters pushing towards 1080P production the only time I would shoot 720P is when I need to overcrank. The BBC has recently declared that all new HD productions must be 1080 and that the use of 720P Varicams (once a BBC favorite) will not be allowed.

Steven Thomas
January 3rd, 2008, 02:46 PM
I find the difference between true full resolution 720P and full resolution 1080P when viewed on a large full resolution monitor or projected to be very obvious, almost as big a difference as that between SD and 720P.

Totally agree. When viewing 1080P on a 1080P monitor it's quite amazing to say the least.

Seun Osewa
January 3rd, 2008, 03:07 PM
Wow. I really need to see a true 1080p image soon.

Paul Joy
January 3rd, 2008, 03:14 PM
"Why would I want to shoot at 720?"

One good reason is if like me your footage is not destined for TV's, but for computer screens. 720p is plenty of res for me, it allows me to produce nice quality web based footage as well as being able to supply good HD footage should a client want something for delivery on a TV at a later date.

I'm getting my first HDTV on Saturday, I can't wait to see how much better it looks than our 8 yr old CRT. That might be the thing that swings me over to 1080!

My next problem will be figuring out the best way to get my own footage on to it, although I'm sure that's covered in plenty of threads here.

David Elkins
January 5th, 2008, 06:46 PM
So, the message seems to be 1080p is the way to go for most applications if you are going for the best looking picture (yes, I am simplifying here). My question is what if you want to overcrank and are forced to shoot in 720p but you shoot the rest of your project/film in 1080p? What issues will this raise in post? Will there be noticeable differences when inter-cutting this footage? Would this be a place for up-rezzing? This thread has been quite interesting to follow, thanks all.

Dave

Mike Barber
January 5th, 2008, 06:54 PM
Would this be a place for up-rezzing?

I would think most certainly, no? Would it not be important to have all your footage conform to the same resolution?

(I'm not answering with questions, I'm actually asking as a follow-up.)

Steven Thomas
January 5th, 2008, 10:09 PM
No big deal, up-rez your 720P shots for slo-mo. 720P off of the EX1 is excellent.