31 Replies Latest reply: Jun 11, 2012 5:14 PM by SimonHy RSS

    Video shooting help

    kdoc2 Community Member

      If this isn't the place to ask this, feel free to redirect, although any help would be appreciated. Using a Sony Nex 7, shooting 24fps, 1080p my question is how crucial is it to keep the shutter speed at 1/25 or 1/50 sec? Let's say I want to control my Aperture, either to get a very narrow DOF or one large enough to be sure I nail the focus. I can try and control the ISO to achieve a correct exposure, but, particularly if I don't have my ND variable filter, I may be shooting at a significantly faster shutter speed. To what degree does this pose flicker problems, and how correctible are they in PrP? How would you do so? Also, is a multiple of 1/25 more likely to give a decent video than is one which isn't a multiple, such as 1/320 sec?

       

      Thank you

       

      kdoc

        • 1. Re: Video shooting help
          Jeff Bellune ACP

          [moved to lounge]

          • 2. Re: Video shooting help
            SCAPsinger Community Member

            Not sure you'd have a shutter speed of 1/25 or 1/50 shooting at 24p. Did you mean 25p...?

             

            At any rate, what happens when you lower the shutter speed is you end up allowing more light in and a side effect is that you increase motion blur. Objects in motion in the frame will be smudgy. Opening the shutter would be better for things like a nighttime exposure where you need more light and there is NO motion in the picture. You might use a slower shutter speed for recreating a crime scene, where you're emulating a "dream sequence" type effect and want the motion blur and reduced implied frame rate of a slow shutter. You will almost always need to use an ND filter when operating at the very lowest shutter speeds under normal lighting conditions.

             

            Faster shutter speeds are going to reduce the amount of light you get into the sensor but reduce motion blur, with highest shutter speeds delivering an almost strobe-like appearance (think about some of the action war epics of the last 15-20 years, with bullets flying, soldiers running around, etc). If you were shooting a soccer match or football game, higher shutter speeds could deliver an excellent image so long as you maintained enough light.

             

            So generally speaking, you DON'T want to mess with the shutter speed too much in terms of trying to use it as an exposure control, because it affects the picture in such noticeable ways. Obviously an iris or ND filter affects ONLY the luminance values on your image with no other noticeable effects (again, speaking in generalities).

             

            You're not usually going to see flicker "problems" unless you're shooting a television monitor or working under HMI or flourescent lighting since there are so many variations in the frequencies those all use (you always want to match your shutter in those instances with direct multiples above not below, and you wouldn't want to mix frequencies).

             

            As for correcting the flicker/strobe artifacts of a FASTER shutter speed, you really can't. Same for slow shutter...the motion blur created by the slower shutter speeds are not fixable.

             

            As for shutter multiples that aren't an integer multiplier you won't really see much of any difference, especially up at 1/320. Same rules apply as I mentioned above for higher shutter speeds, nothing else really.

            • 3. Re: Video shooting help
              kdoc2 Community Member

              Thanks for that very complete response. Concerning one thing you said though:

               

              "Not sure you'd have 1/25 or 1/50 shutter speed at 24p; did you mean 25p?" 

               

              I thought one would have to round off to the nearest shutter speed, since there's no way to shoot at 1/24 or 1/48 second in most DSLR or other mirrorless cameras, right? What are my options other than 1/25 and 1/50 when shooting 24p? The camera (Sony Nex 7) does allow 60p and 60i, but that poses other problems, doesn't it?

               

              kdoc

              • 4. Re: Video shooting help
                SCAPsinger Community Member

                kdoc2 wrote:

                 

                I thought one would have to round off to the nearest shutter speed, since there's no way to shoot at 1/24 or 1/48 second in most DSLR or other mirrorless cameras, right? What are my options other than 1/25 and 1/50 when shooting 24p? The camera (Sony Nex 7) does allow 60p and 60i, but that poses other problems, doesn't it?

                 

                You can shoot 1/24 on the AF100 in 24p. There's also synchro scan in 24p that allows anything between 1/24.0 and 1/250.6, so there's your 1/48.

                 

                I don't remember if 1/50 is an option or not in 24p. Now that you mention it, I think I remember seeing that, but not sure. 1/60 is fine for most all shooting modes and many flicker-causing devices.

                 

                Nothing wrong with 60p  and 60i. Keep in mind that 60p is really only fully supported in 720 and 60i is exclusive to 1080. Both 1080 and 720 are industry standard in 24p, as is NTSC, so many people sending out footage to multiple formats do tend to prefer 24p, but shooting 720p60 is excellent - and preferable most times - for live action events like sports and such.

                 

                I'd recommend checking out this article by Barry Green (he's primarily a Panasonic guy and hangs around DVXUser.com, which was built on Panasonic users but is now much more than that). Barry compares the AF100 and the FS100 and image-wise you'll see they compare favorably. It's some other non-image-specific issues that tend to make the AF100 a better bargain.

                 

                http://www.dvxuser.com/V6/showthread.php?260461-FS100-and-AF100-compared

                • 5. Re: Video shooting help
                  kdoc2 Community Member

                  Thanks; the 60i and p info is helpful. I'm not in the market for a camera presently, having just bought the Sony Nex 7, so I won't get into that part of  the discussion. How about others of you, If you had the choice of shooting 24p or 60i, which would you choose?  I WILL experiment with these...just asking ,

                   

                  kdoc

                  • 6. Re: Video shooting help
                    J. Simon Community Member

                    For a video look, shoot 30i (there technically is no such thing as 60i, that term is a misnomer).

                     

                    For a film look, shoot 24p.

                     

                    Both have their uses.

                    • 7. Re: Video shooting help
                      kdoc2 Community Member

                      I'd be interested in hearing your explanation of why there's no 60i, technically.

                      • 8. Re: Video shooting help
                        Community Member

                        Christian's post was very comprehensive, not just about buying a camera, but about options..whether yours has them or not.

                        my impression is you're not sure what the difference is between video and film digital. video is traditionally ' tv cameras ' for shooting stuff you see on tv ( like football games live ).  film digital is more like film cameras that are now ' digital '... and there's a huge difference between the two....

                         

                        jim is saying 60i is a manufacturer of cameras using the term incorrectly...misleading users.

                         

                        the basics is this:

                        in the USA ( based on 60 cycle per second AC ( alternating current electricity ) )...the tv cameras shoot 30 frames ( half of 60 ) interlaced for broadcast.

                         

                        thats what you get for " video "... to broadcast on tv.  its based on the AC current.

                         

                        film cameras going digital is different. It assumes you have a 180 degree shutter ( film camera mitchell movement ) and typically they shoot at 24 FPS.

                        That means ( with 180 deg shutter ) you have exposure of 1/48 sec.

                         

                        These things are different animals ..and it wouldn't hurt to figure that out as best you can by reading etc....then you can decide what you want to do with the cameras you buy etc... ????

                         

                        film cameras ( real ones ) DO SHOOT 30 FPS if you make them do that... ( you can adjust the fps and shutter ).  Many pro film people shoot tv commercials at 30 fps so that in the transfer to video it is 1 frame of film for each frame of video ... just so you know that...

                        Now that film cameras are becoming digital you have the same " choice "....

                        So you see, it depends on what you want as your end product and how you want it to look, and what you want your shutter speed to be.... what you decide to do...( this also has to do with how much LIGHT you have to expose the shots .. what choices you make... or how much ACTION there is ( see Christian's post ))

                         

                        there is no simple answer really to your curiosity ...but manufacturers of cameras would have you think it is VERY simple, so they can sell lots of cameras.. its normal...

                         

                        hence, 60i

                         

                         

                        • 9. Re: Video shooting help
                          kdoc2 Community Member

                          I spent part of the day experimenting, using the  Sony Nex 7, then looking at the results on computer with Premier Pro--the sequence being the correct one for the  file. 60p gives the smoothest and clearest results, and it doesn't seem to matter whether I shoot 1/125, 1/320, or 1/1600 sec.

                           

                          24 p gives more shutter jag.

                           

                          60i viewed on a computer (I didn't look at a TV image) gave a strange shimmering blur.

                           

                          If I make a BluRay disk, I'll probably use 60p, right?

                           

                          I'll have to do some more reading on this stuff.

                           

                          thanks so far

                          kdoc

                          • 10. Re: Video shooting help
                            J. Simon Community Member

                            I'd be interested in hearing your explanation of why there's no 60i, technically.

                             

                            The longhand convention is to list out the horizontal resolution, followed by an i or p for interlacing or progressive, followed by a slash, followed by the FRAME rate (never the field rate).  Like this:

                             

                            480i/30

                            480p/24

                            720p/60

                            1080i/30

                             

                            The shorthand is to drop the resolution and the slash, and simply move the i or p after the FRAME rate (never the field rate).  Like this:

                             

                            30i

                            24p

                            60p

                            etc.

                             

                            So...60i really means 60 interlaced FRAMES per second (because you NEVER list the field rate), and there just is no such standard as 60 interlaced frames per second.  It's 30 interlaced frames.

                             

                            You actually can have 60 progressive frames per second, as 60p, but not 60 interlaced.

                            • 11. Re: Video shooting help
                              J. Simon Community Member
                              If I make a BluRay disk, I'll probably use 60p, right?

                               

                              At 720 you can, at 1080 it won't work.  1080 needs to be 30i or 24p.

                              • 12. Re: Video shooting help
                                kdoc2 Community Member

                                So let me make sure I understand: I'd like to shoot at the highest resolution, and let's assume that the way to show it at the highest res would be a BluRay disk. I'll be doing editing and output via Premier Pro and Encore. Are you saying that, although the Sony Nex 7 will record AVCHD 60p, 60i and 24p, I can only make a BluRay at 24p?  Or alternatively, might I shoot at 60p (if that gives me smoother video), and then have Premier or Encore convert to 24p later? (Assuming that gives smooth conversions) As you can see, I'm still quite ignorant about what works and what doesn't, although certainly Premier certainly makes it easier.

                                 

                                Edit: This just in: DPR says that the newest version of Sony's PMB software allows lossless editing directly to BluRay. (And certainly the *.MTS file goes smoothly into Premier, though I don't yet have BluRay burning software to test the next step.)  Comments?

                                 

                                Thanks very much,

                                Kdoc

                                • 13. Re: Video shooting help
                                  kdoc2 Community Member

                                  I'll be testing, but let me ask additionally: If, when working with the Sony Nex 7:  60p gives me somewhat superior videos  than 24p (both 1080), and assuming I'll edit in Premier Pro and Encore, which will give me the best BluRay?: 1. Shooting 60p and going to BluRay with this? 2. Shooting 60p and converting in Premier export to 24p?  or 3. Shooting 24p, and staying there in BluRay? (I see that in Premier, if I put a 60p clip into a 24p sequence, it plays, but with the same or greater jitteryness as a 24p shot placed into a 24p sequence--so that doesn't help to smooth it out and give the quality of a 60p)

                                   

                                  kdoc

                                  • 14. Re: Video shooting help
                                    J. Simon Community Member

                                    Are you saying that, although the Sony Nex 7 will record AVCHD 60p, 60i and 24p, I can only make a BluRay at 24p?

                                     

                                    No.  I'm saying that of those three, Blu-ray can only hold 24p or 30i at 1080 resolution.  (Remember, no such thing as 60i.)  1080p/60 can be recorded with many newer cameras, but it won't go onto Blu-ray as is.  This is not an Adobe or Encore limitation, it's a Blu-ray limitation.

                                     

                                    So if you want 1080 on Blu-ray, your best option is to shoot at 24p for a filmic look, or at 30i for a video look, and avoid 60p altogether.

                                    • 15. Re: Video shooting help
                                      kdoc2 Community Member

                                      OK, I understand. As a follow up, is BluRay always 1080, or are some of them 720p/60? Also why does the 30i look so bad on my computer--can't computers show interlaced properly?

                                       

                                      kdoc

                                      • 16. Re: Video shooting help
                                        SCAPsinger Community Member

                                        kdoc2 wrote:

                                         

                                        Are you saying that, although the Sony Nex 7 will record AVCHD 60p, 60i and 24p, I can only make a BluRay at 24p?  Or alternatively, might I shoot at 60p (if that gives me smoother video), and then have Premier or Encore convert to 24p later?

                                         

                                        Nope...60p CAN go to 720p60, 720p24 or 480i60, or 480p24. Very versatile.

                                         

                                        Any of those formats, by the way, can be published to Blu-ray disc. Only 480i60 and 480p24 will work on DVD of course.

                                        • 17. Re: Video shooting help
                                          SCAPsinger Community Member

                                          kdoc2 wrote:

                                           

                                          If, when working with the Sony Nex 7:  60p gives me somewhat superior videos  than 24p (both 1080), and assuming I'll edit in Premier Pro and Encore, which will give me the best BluRay?: 1. Shooting 60p and going to BluRay with this? 2. Shooting 60p and converting in Premier export to 24p?  or 3. Shooting 24p, and staying there in BluRay? (I see that in Premier, if I put a 60p clip into a 24p sequence, it plays, but with the same or greater jitteryness as a 24p shot placed into a 24p sequence--so that doesn't help to smooth it out and give the quality of a 60p)

                                           

                                          You are discussing the "jittery" effect of shooting in 24p as though it is inferior to 60p which appears to you to be superior. Be aware, that jittery effect you're seeing is 100% dictated by your style of shooting. 60p has 2.5x more frames than 24p, which isn't so much of a superior/inferior relationship, it's just a consideration based on your style of shooting. Fast moving objects will be updated frame-by-frame only 40% as frequently in a 24p recording as they are in a 60p recording. If you were shooting a track runner going past your camera in 24p, it'd be completely noticeable versus the same shot in 60p. If you are shooting a still motion or slow-pan shot of an open meadow, you likely will never notice any difference at all between 24p and 60p. Again, it's not a quality issue, it has to do with what you are actually shooting and HOW you are shooting it. I've done plenty of fast motion subjects (dancing, running, sports, etc) at 24p and if you operate the camera a particular way, it's not a very big issue at all.

                                           

                                          ALSO - if you put any footage in a 24p sequence and have it playing back in real time (not slo-mo), then any footage, whether 60i, 60p, or 2,000p is going to look like it was shot as 24p, there will be no difference whatsoever. The only benefit gained from shooting 60p and putting it in a 24p sequence is that you have about a 2.5x slow motion capability (also you are going to end up with fewer frames overall compared to 60p, which will produce smaller files during encoding, but only marginally so, certainly not a factor of reduction of 40%)

                                          • 18. Re: Video shooting help
                                            SCAPsinger Community Member

                                            kdoc2 wrote:

                                             

                                            OK, I understand. As a follow up, is BluRay always 1080, or are some of them 720p/60? Also why does the 30i look so bad on my computer--can't computers show interlaced properly?

                                             

                                            Blu-ray can playback 1080i60, 1080p24, 720p60, 720p30 (I think), 720p24, 480i60 and 480p24.

                                             

                                            As for interlacing on a computer monitor....if you set your computer's resolution to 640x480, the interlacing might not be so noticeable. Your computer is trying to playback interlaced fields on a progressive monitor that is likely substantially larger than the interlaced footage resolution, and in some cases your particular media player may be trying to playback ALL of the interlaced fields simultaneously rather than in order (in other words, instead of playing back the 60 interlaced fields in their consecutive sets refreshing 60 times per second, it is likely trying to playback all 30 frames with the interlaced fields combined each second). This will give the appearance of coming in the footage, especially noticeable during periods of the video where the fields change dramatically from 1 1/60th of a second to the next.

                                            • 19. Re: Video shooting help
                                              kdoc2 Community Member

                                              Very helpful--all of you !! Thank you very much . By setting Premier "Playback" to Full Res, the 60i shimmer goes away, and there's less flicker, as expected. So let me ask, if my final destination is not entirely known, and may be variable, in what format should I shoot and what format should I edit? Let's say I might be going out to BluRay, DVD, my TV (from my computer), YouTube or Vimeo. I'm guessing that shooting in 24p/1080 would be fine? And that 1080p/60 might be good for the internet but useless for the BluRay? (I've been told in the past to avoid shooting in 60i, as it's "outdated," and won't play in many systems, but I'm not hearing that here). Would 1080i/60 be the best overall format to shoot at and edit in Premier? Will most systems play it, once it's output and re-encoded for these uses? (I realize that DVD won't play at the high res).

                                               

                                              In effect, for these uses, how are you all shooting and editing.

                                               

                                              kdoc

                                              • 20. Re: Video shooting help
                                                SCAPsinger Community Member

                                                If you have no idea where it will end up then shoot 720p60.

                                                • 21. Re: Video shooting help
                                                  kdoc2 Community Member

                                                  If the primary end product is a Blu Ray (the others would be less critical), how would you shoot? I typically combine still images with video, and want optimal quality in both those and in the video. Given that, would you still shoot the video at 720p60? To what degree visually would that degrade the Blu Ray quality of the still and also of the video video images--i.e. to be viewing them at 720 instead of 1080? Certainly I've seen a huge difference with DVD quality degredation of image.

                                                   

                                                  (I made a sequence 720p60, and put the 1080p60 clips in it in Premier and it looks pretty good. More tests are indicated, but I'd be interested in all of your experiences with 1080 vs 720's effect on Blu Ray image quality)

                                                   

                                                  kdoc

                                                  • 22. Re: Video shooting help
                                                    J. Simon Community Member

                                                    can't computers show interlaced properly?

                                                     

                                                    Actually no.  In fact, there are no flat panel displays that can properly show interlaced material.  They all 'deinterlace' it in some fashion as flat panels can only show progressive signals.  If you want proper interlaced display, you'll need an older CRT for that.

                                                    • 23. Re: Video shooting help
                                                      J. Simon Community Member

                                                      if my final destination is not entirely known, and may be variable, in what format should I shoot and what format should I edit?

                                                       

                                                      I'm facing a similar situation with a documentary series that will be published to the web, Blu-ray and DVD.  I decided on the 720p/24 format because the frame rate is usable for all three delivery mediums without any frame rate conversion, and that's always a good thing.  I chose 720 instead of 1080 because the primary delivery channel is via web, and you really need a 50" or larger set to see any significant difference between 720 and 1080.  Since very, very few people view the web on a 50" set, 1080 was less important for this project.  And with a smaller raster, you can get a better image at any give bitrate.

                                                       

                                                      If the primary were Blu-ray, I would probably choose 1080p/24 instead.

                                                       

                                                      As for what format to edit with?  The same as you shoot with.

                                                      • 24. Re: Video shooting help
                                                        SCAPsinger Community Member

                                                        Remember that shooting at 1080 still gives you excellent reframing capacity for all formats including 720  Blu-ray.

                                                        • 25. Re: Video shooting help
                                                          kdoc2 Community Member

                                                          Yes, I was wondering about that after seeing Jim's response. Actually, what, if anything, is lost by shooting 60p1080? As I understand you fellas, one can always reframe to 25p720 for a Blu Ray (or go to 30i1080--I assume once it's on a Blu Ray the 30i will play well from a standard player and a standard flat screen TV, ... but perhaps not???). And, one can keep it at 1080p60 for the internet--which will show the still and video images at their highest res. Anything wrong with his logic?

                                                           

                                                          (This conclusion assumed a preference for 60p over 24p. I also gather from what's been said that one may not be able to distinguish image quality between 720 and 1080).

                                                           

                                                          One other point, it's my impression--and just a preliminary one--that (on my setup) the little 24p flicker acts on the brain to apparently pseudo-degrade image quality very slightly--hence my preference for the 60p so far. The flicker is mildly unpleasant to this brain.

                                                           

                                                          kdoc

                                                          • 26. Re: Video shooting help
                                                            SimonHy Community Member

                                                            1080 60p will give you the best quality and the most options down the way. You can always downres to 720 on export, and if you end up exporting it as a 30p file for Bluray it just drops every other frame, so looks as good as if you've shot it at 30p.

                                                             

                                                            Larger file sizes, but if I didn't know how a project was going to be output, I would err on the side of shooting at better quality than I needed rather than the other way round. Plus any slo-mos you do will always look better if there's more frames to work with to begin with.

                                                             

                                                             

                                                            Jim Simon wrote:

                                                             

                                                             

                                                            Actually no.  In fact, there are no flat panel displays that can properly show interlaced material.  They all 'deinterlace' it in some fashion as flat panels can only show progressive signals.  If you want proper interlaced display, you'll need an older CRT for that.

                                                             

                                                            Your average computer monitor can't display interlaced material, but there are plenty of grading quality broadcast flat panels that can emulate CRT interlacing.

                                                            • 27. Re: Video shooting help
                                                              J. Simon Community Member

                                                              1080 still gives you excellent reframing capacity for all formats including 720  Blu-ray.

                                                               

                                                              True I suppose.  But I prefer to do my camera work in the camera, and not in post.

                                                              • 28. Re: Video shooting help
                                                                J. Simon Community Member

                                                                if you end up exporting it as a 30p file for Bluray

                                                                 

                                                                You can't put 30p on a Blu-ray, only 30i.

                                                                • 29. Re: Video shooting help
                                                                  SimonHy Community Member

                                                                  Jim Simon wrote:

                                                                   

                                                                   

                                                                  You can't put 30p on a Blu-ray, only 30i.

                                                                   

                                                                  Hmm, how strange. I live in PAL land, we don't deal with 60/30 much. My point still stands, it's easy to make 60p into 60i. And a 30p movie converted to 60i is effectively still 30p.

                                                                   

                                                                  I don't really agree with your "there's no such thing as 60i" either. It might be standard practise never to list the field rate where you are, but the convention here is to talk about 25p or 50i. Frankly I think 50i is a much better way of putting it, as there are 50 intervals of time recorded, so it's a more descriptive phrase.

                                                                  • 30. Re: Video shooting help
                                                                    J. Simon Community Member

                                                                    the convention here is to talk about 25p or 50i. Frankly I think 50i

                                                                     

                                                                    Nope.  Even in PAL land, it's 25p or 25i.  There's no such thing as 50i either, because following the convention, that actually means 50 interlaced frames per second, and there is no such thing.  So if a lot of folks there say 50i, then a lot of folks there say it wrong.  (Just like here.)

                                                                    • 31. Re: Video shooting help
                                                                      SimonHy Community Member

                                                                      What a strange way of looking at it. Convention just means"custom", it's not some sort of hardwired rule of the universe to NEVER list the field rate. If it's the custom here to talk about number of fields, then that's the convention and people aren't wrong for using it that way, you're just choosing to interpret it that way. Plus, as I said earlier 50i, meaning 50 interlaced fields, is a better summation of what's really happening with the footage.