Apologies, common question i know but.. 25 or 50i...

[Peter Ford]

I all - sorry, i know this type of question crops up a lot, but i could do with a little advice.

I'm hiring in an EX3 for a job next week. Its a day documentary shoot. Final delivery will be youtube, but client wants it shot in full hd so it can be shown to sponsors in full HD glory, either via laptop or played back from blueray.

Im uk based, so i need to decide whether to go 25p or shoot 50i. What are peoples thoughts?

My experiences with 25p so far with other cameras- i've found 25p just a little too juddery for documentary style shooting. But since delivery is on the net, is it just easier to shoot progressive and modify my shooting style? keep shots simpler, and dont wave it around like im shooting for mtv.

Other thoughts- I could shoot 50i, use the 50i version for blueray, downscale and deinterlace to 720p for delivery to youtube. Would be nice to have the full 1080 version on youtube (even though youtubes encoding for full 1080 size is a bit ropey at best)

bah- i cant work out what would be best. any thoughts would be much appreciated!

ps: while ive got your attention, on a different note, roughly how long does a standard ex3 battery last in operation? just be useful to know

[Alister Chapman]

A BP-U30 will last about 2 hours.

I would shoot 25P with a 1/50th shutter. If you going to show it on YouTube, that is progressive, if you are going to show it on a Laptop or computer, that is progressive.

If you shoot 50i and then convert to 25P for youtube you will still have the same motion issues as the frame rate ends up as 25P either way. Just dont pan at middle speeds. Slow is fine, fast is fine, it's just mid speeds that will judder.

[Piotr Wozniacki]

Originally Posted by Alister Chapman

Just dont pan at middle speeds. Slow is fine, fast is fine, it's just mid speeds that will judder.

A very good information.

I have long noticed that as far as progressive judder goes, whip pans are not nearly as bad as middle-speed ones (the slowest being best, of course, from any other viewpoint) - but I never had a guts to tout it, as I'm not a real pro like Alister ;)

[Matt Davis]

Originally Posted by Peter Ford

Other thoughts- I could shoot 50i, use the 50i version for blueray, downscale and deinterlace to 720p for delivery to youtube. Would be nice to have the full 1080 version on youtube (even though youtubes encoding for full 1080 size is a bit ropey at best)

bah- i cant work out what would be best. any thoughts would be much appreciated!

Thoughts? Sure!

So, assuming that all HD devices (other than early exotica) are, by their nature, progressive devices, your 50i will get deinterlaced, whatever happens. But BBC HD is currently broadcasting 1080i50. Go figure.

So cheaper units will throw away every other field, so you get 540p - but most HD ready sets are now using a method that only loses 25% of the original resolution. So you're down to 768, not far off 720p.

And then there's the research that shows that, unless you want a screen so big, or so close, that it fills your field of view, most people are going to be fine with 720p.

Have been delivering 720p over SD and had happy comments, move from 720p to 1080p doesn't seem to have any difference to current audiences. But what I find is that I get less compression artifacts from 720p (in both 25p and 50p flavours) than I do from 1080p, but if I take 1080i down to 720p50, I may as well have shot in 720p50 in the first place.

So, for anything with less than a useful 5 year lifespan, I shoot 720 for the extra quality given by the bandwidth, and the flexibility for SD, overcranks & 'realistic' HD delivery.

Your Mileage May Vary.

[Peter Ford]

interesting post, i'd had similar thoughts myself regarding 720p and the bang for buck with the bitrate.

Going to be shooting in quite a low light environment, so dont want too many compression artifacts lurking in the blacks.


Had another thought- shoot 1080p, downscale to 720p for delivery. Would any extra compression artifacts be lost in the down conversion? Why take this extra bothersome step? - shooting 1080p and delivering 720 would allow me to do some image stabliazation in post (using motion)- im an experienced cameraman, but have not done a huge amount of on the shoudler work. Im using a decent shoulder mount rig with the ex3, but i know by the end of the day my footage might be getting a bit unsteady. So shooting 1080p and knowing i can stablise a little might be a comfort.

hmmm - i think only answer is for me to do a load of tests on my prep day. Do some low light tests in 1080p and 720p, and compare. if 720p is that much cleaner and nicer, i'll go with that. If 1080p still looks good, i'll run with that. I'll also test shoot 720p, and then 1080p downconverted to 720p, to see how 720p and downconverted 1080p to 720p compare. I'm a geek, and this stuff interests me! will post up my tests if anyones interested?

Mad really- at the end of the day, the client wants a top quality video- hows its shot, and what i shoot, how i conduct the interviews, getting a real sense of the mood of what im shooting, is what the client wants. - niggling things like is 720p or 1080p to them, probably wouldnt matter!

One things certain- i'll shoot p. What youve both said makes sense- primary delivery is youtube, so why shoot anything other than progressive. I also prefer doing titles and graphics for progressive projects- no weird interlace problems, twittering, or jagged edges and so on.


Thanks for your input guys, really helped me out

[Matt Davis]

Low light? Well, you get an extra stop with 720p, which is much appreciated. That might sell you from the get-go.

If you shoot 1080p to allow for SmoothCam to un-wriggle things, a couple of thoughts here:

- You'll have to shoot wide and re-crop in the edit

- The EX steadyshot, combined with a good shouldermount, shouldn't be that bad, surely?

- If the Motion steadying is SmoothCam, it can be a little truculent with 'roll' based motion

There is one area which possibly is a 'good thing', but that depends on delivery: You could shoot 1080p in the 4:2:0 colour space and shrink it down to a 4:2:2 720 colour space for better colour definition (e.g. event/concert/theatrical lighting and environments that have a lot of 'lit' colour surfaces - again, theatrical/conference sets), but then it all gets a bit 'meh' if you have to then go out to DVD, DV or even to a certain extent YT.

A colleague regularly films 'one take only' interviews at 1080p so he can do all the zooming, cut from wide to close (to remove fluffs or to edit for time), knowing full well that the output is only SD. It works for him, but I'll admit I find that method a little 'diabolical' (in my best Name Of The Rose 'Venerable Jorge' impression).

But you're right - it all comes down to 'suck it and see' - I would recommend giving 720p25 a long hard lick.

[Vincent Rozenberg]

@ Matt: Have you ever seen the smoothcam function in FCP? It comes from the expensive "shake" post production software and it's (tell-sell voice) amazing... it analyzes and zooms just the bit needed for the shot and gives a perfect result. If i don not tell you you can even not tell if it's zoomed in a native HD timeline.

[Peter Ford]

the smotthcam is great, but its even better in motion - same engine, but motion has more controls.

I got apple certified in Motion last year, and it was a great course. After a project i worked on a while ago, im pretty effecient with how it works and how to control it. Can be a mare at times, but works best when used subtley, and often best just on one axis. I dont like things overly smooth, and i hate loosing too much resolution. Also helps when things have been shot on a higher shutter speed- stablisd footgae from a shakey cam shot at 1/50 can have a bit of motion blur on the shakey frames- when stablised, you have steady footage, but the occasional frame has slightl motion blur, and it looks a little odd. Higher shutter speed = more chance all frames are sharp = steadyed footage looks awesome.

im rambling on again...


Matt - will certainly give 720 much more thought than id previously thought. An extra stop would be very useful, and i hate noise / compression artifacts.

everyones help and thought is really appreciated, thanks all

[Matt Davis]

Yes, have tried SmoothCam. It can produce amazing results when you shoot with it in mind, but if you have 'damaged' footage or trying to cover up poorly shot stuff, the results can be a little less convincing.

I've done some handheld shots that became dolly shots, which are impressive. I've also tried to rescue some hand-held DSLR footage (no OIS), which was a fail.

So I've found it something 'to work with' rather than applied as a 'fix-it'.