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  • Frame rate clarification

    This seems quite a newbie question. I've looked through the forum for some clarification - if there's a good answer please point me to it.Well before I acquired my Wolverine Moviemaker Pro, I had some old family 8mm films digitized by a commercial service. This was about 6 years ago. Their procedure included splicing smaller reels together to form 200-ft, 5’ reels. I’d had some work done by them before and they’d done a good job. This time though, things came out very poorly in some segments. Among other things, they were very underexposed, which is what eventually prompted me to look for another solution and I wound up with the Wolverine unit.


    I’ve re-digitized some portions of my original films, and was able to adjust the exposure so the material is viewable. (There are other issues, which I may put in a later post.) I’m going to try some other things to improve it further, but first need to understand better what “frame rate” means in the context of a clip digitized to video, and what I should do with the clips that I’ve rescanned and edited.

    I’ve used the little Mac app MediaInfo to measure the frame rate for various results of scanning and editing this film. I’ve had three results:

    1. The digitized version of the original print provided by the commercial service was precisely 16 frames/sec, which I understand is correct for 8mm film.

    2. When I edited #1, above, down to recapture the original-length sequences in Final Cut Pro, it saved them at (very close to) 24 fps. They seemed to play at a reasonable rate, certainly not 1.5 times the original. So I’m not sure what this frame rate measure actually signifies. I'm not clear whether I should just re-edit the commercial operation’s version and set the frame rate to 16 in the project properties, or whether I can simply load the already edited clips into a new project, change the properties there, and save again. Will it actually make a difference in the rate at which the action is portrayed.

    3. When I re-digitized the underexposed portion of the film in the Moviemaker Pro, the frame rate of the output is exactly 20 fps, and I believe that that is the rate at which the action will play back. From other info I’ve read, I think I should probably load the result into FCPX, change the frame rate to 16 FPS, and re-save. I want to edit this section into the rest of the material, which is now 24 fps, as described in 2, above.

    I realize this is quite a newbie question, and I’ll appreciate any info. I’d been playing with 8mm for a long time, but hadn’t attempted conversion or confronted any related issues. I’ve found a few posts that address my question, including https://havecamerawilltravel.com/fin...sting-project/ and - from the earlier version of this forum - https://www.youtube.com/watch?v=1NAmItw1SL0 . Anything else you can add would be great.

    One more note - I wanted to ask this question as soon as possible, to give people time to read and post answers. That said, I’ll be unable to read or respond to any comments from Sunday May 8 through Thursday May 12. So if I don’t respond in that time, that’s the only reason why. I’m sure I’ll read and appreciate anything you can provide.

    Thanks for your help.

    Phillip

  • #2
    1. The digitized version of the original print provided by the commercial service was precisely 16 frames/sec, which I understand is correct for 8mm film.
    Yes, 16 FPS is the correct speed for 8mm.

    2. When I edited #1, above, down to recapture the original-length sequences in Final Cut Pro, it saved them at (very close to) 24 fps. They seemed to play at a reasonable rate, certainly not 1.5 times the original. So I’m not sure what this frame rate measure actually signifies. I'm not clear whether I should just re-edit the commercial operation’s version and set the frame rate to 16 in the project properties, or whether I can simply load the already edited clips into a new project, change the properties there, and save again. Will it actually make a difference in the rate at which the action is portrayed.
    FPS is the speed at which the film was shot, and should be projected. Yes you need to correct all the videos frame rates to 16 FPS. In Powerdirector you can do this in one project. See multiple frames on one video? on Youtube.

    3. When I re-digitized the underexposed portion of the film in the Moviemaker Pro, the frame rate of the output is exactly 20 fps, and I believe that that is the rate at which the action will play back. From other info I’ve read, I think I should probably load the result into FCPX, change the frame rate to 16 FPS, and re-save. I want to edit this section into the rest of the material, which is now 24 fps, as described in 2, above.
    If the video has a FPS rate of anything other than 16 FPS it must be corrected.



    Comment


    • #3
      Hello Phillip

      Fixing framerate is a perennial topic. 16fps is likely right for 8mm. My dad's 8mm camera had a windup spring. Not sure how constant that was. Still, I think it is better to be too slow than too fast. Sometimes the cameraman was not the best, slowing down the framerate helps.

      Anytime you are editing video, just render at the framerate you want. If not, this (Film_Crop) was written by someone in the forum a couple of years ago. It does not recompress the video, it is not really an editor, and can change the framerate. Free.

      Hard to find the posts, but here are a couple links.

      http://instipics.com/Film_Crop/

      https://8mmforum.film-tech.com/vbb/f...rscan-and-crop

      Comment


      • #4
        "Standardized" frame rate for Super8 is 18 fps. For Regular8 is 16 fps. But expect the "actual" frame rate to be wildly off the designated fps. They're at best servo-controlled DC motor drive (which would result in "approximate" speed) or worn out/maladjusted spring-driven mechanism (which would vary so wildly) at worst. It might be necessary to have some trial & error in certain cases.

        Assume the actual speed is found to be still that "standardized" speed (or anything else for that matter), then keep everything at that native speed. For example if running the raw scan file at 18 fps seems to yield the best result, it's best to set your project properties in your editing program, edit, then export at that speed as well.

        You may try some frame rate conversion, along with other restorations (dust removal/stabilization/grain removal/etc. - you name it) afterwards, but the original output with native frame rate must be kept available as well.

        Comment


        • #5
          Hi Phillip,

          I'm also an 8mm digitizing newbie, but I've been using Final Cut Pro X for a while and can share some tips on what has worked for me. First, it's important not to confuse the FCPX project rate with the film's frame rate. To keep things simple, just create your new project and select the default, "Video: Set based on first video clip properties." It will probably be 23.98p, which is fine—your video will play back at the Wolverine's 20fps rate regardless of whether the project rate is 23.98, 24, 29.97, 30, or some other setting. Once you drop your clips into the timeline, select them all and use the menu option: Modify-->Retime-->Custom Speed (or use keyboard shortcut Ctrl-Opt-R), and type "80%" into the rate window for 8mm or "90%" for Super8. Ensure that the "Ripple" box is checked to prevent gaps or overlap between clips.

          The tips offered in the YouTube video you linked are mostly good, except for the recommendation to use alcohol for film cleaning. In this article, Kodak says, "Use only well-known, high-quality film-cleaning solutions. Do not use alcohol of any kind because some types can soften the emulsion, or the base, and can increase the risk of abrasion during the cleaning process." A different Kodak article, however, suggests that it's safe to use isopropyl alcohol sparingly, although the water content in concentrations below 98% can "negatively affect the film's emulsion" (Kodak's pun, not mine).

          I decided to clean my films with FilmGuard, which is highly recommended on this and other forums. I purchased mine from Steve Osborne at The Reel Image website. It's not cheap at $39.99 plus shipping for a 16 oz. spray bottle, but it works well and lubricates the film. I suspect that many of the jamming problems like the "friction at the fourth guide post" noted in John Renzi's video can be minimized by using FG instead of alcohol. I cleaned all of my 8mm & Super8 films with FG and scanned them on the Kodak REELZ machine, which uses the exact same plastic guide posts as the Wolverine-branded version. All of my film went through smoothly, with the exception of one, really thick, glued splice. I replaced that one with Presstape and had no other issues.

          I'm now halfway through my digitizing project, with everything scanned and two more films ready to be edited in FCPX. My first two finished videos are posted on YouTube here.

          Regards,
          Harry

          Comment


          • #6
            Ed, David, Nantawat, Harry - many thanks to all of you. These are great suggestions and info; I'm just back "on-grid" and have read but not yet implemented them. Really appreciate your responses.

            Added note to Harry: First, thanks for the notes about FCPX. I will follow them. Also, I had read precautions about using alcohol for cleaning, and wound up ordering FilmGuard, also from Steve Osborn.

            And David, thank you for those links. I will check them out!

            All best,
            Phillip

            Comment


            • #7

              Again, hello all, and thanks again for your recommendations.

              Still using FCPX, I've tried changing the frame rate in my clips using the approaches described above. So far the one way I've (more or less) succeeded is to place a clip in the timeline, then select the Project in the Browser, then in the main menu choose Modify->Retime->Custom Speed. (If there’s no clip in the timeline, the Custom Speed item is greyed out, or not presented at all.)

              But there is a problem. When I drag the clip to the timeline - and now, even if I delete and restore the project - it shows in the Viewer as if it has been zoomed in, to the point where much of the frame falls beyond the boundary of the viewer. It looks fine in the viewer when I just select the project, but zooms in a way I don’t know how to control when I drag a clip to the timeline.

              I suspect I’ve altered something, like format or resolution, but changing these seems to make no difference. Likewise if I change parameters in the video inspector like Transofrm or Crop, it makes no difference. Could there be a setting for the viewer itself that would expand it? Or something equivalent that would shrink (but not reduce ultimate resolution of) the clip?

              Another question: It’s not clear that changing frame rate changes the duration of the clip appropriately, given the ambiguity about FCPX reported frame rate and true frame rate. How would you recommend verifying that clip duration / speed of action is accurate?


              Related: When I got some of my 8mm films digitized by a commercial vendor, they retuned videos with frame rates reported as 18 fps. But 8mm is filmed at 16 fps. I’m not sure whether the videos I got back are correct in terms of duration & playback speed. So again, is there a good, efficient way to test this?

              And … if the frame rate is incorrect, presumably I should change the frame rate for the entire batch of videos that were sent to me by the commercial firm, correct?

              Thanks. Apologies for these very elementary questions. Digitizing is different from editing film!

              Phillip

              Comment


              • #8
                Phillip,

                You're on the right track, and you are correct that all FCPX editing must take place in the timeline, not the browser. This is why options such as retiming will be grayed-out if you don't have any clips in the project timeline, or if none of your timeline clips are selected (surrounded by yellow box). For instance, if your timeline contains a mixture of clips digitized at different rates, you can shift-click to select all of your Wolverine clips and simultaneously retime them from 20fps to 16 or 18fps, then deselect them and shift-click the others to retime those, if needed.

                If you cannot see your entire frame in the viewer window, just click on the scale control above the upper-right corner of the viewer. The pop-down menu lets you choose from a variety of magnification settings, or you can select "Fit" and the software will set whatever percentage is needed to perfectly fit the entire frame in the viewer window. Similarly, you can easily change the magnification of your timeline. Zoom out by typing Command-Minus (⌘-) to see more of your clip(s) and zoom in by typing Command-Plus (⌘+). Regardless of how much of your project is showing in the timeline, you can type Shift-Z to resize so the entire project is visible. When only a portion of it is viewable, you can also grab the horizontal scroll bar at the very bottom of the screen and drag it left or right along the timeline.

                Regarding your next question, yes, retiming a clip to change the equivalent frame rate will also change its duration. Slowing it down will make it play longer and speeding it up will make it shorter. This is why it's important to check the "Ripple" box if you have multiple clips back-to-back in your timeline. Otherwise, there will be a gap after a sped-up clip and a slowed clip will overlap the one that follows it. Apple provides a good explanation of the retiming process here.

                Also, remember that your FCPX project rate and the 8mm film frame rate have nothing to do with each other. Your project could be 23.98p, 24p, 29.97p, 30p, or some other rate, but your clips will always play at the speed set by the system that was used to digitize the original movie. If it was done on a Wolverine-type machine, your clips will play at the equivalent of 20fps. If a commercial service digitized your film at 18fps (which is the correct rate for Super8), that is the rate at which FCPX will play it. FCPX cannot report a clip's equivalent frame rate as the program has no way of knowing what that is.

                If you still have the original film and a working projector, you can simply do an eyeball or stopwatch comparison to estimate the playback speed of projected vs. digitized clips. If you really want it to be precise, you'll need to ensure your projector is calibrated. You can pick up a digital tachometer for $20-30 on Amazon, then Google how to calculate frame rate from the measured rotation speed of the projector's shutter blade(s). Of course, this assumes the camera used for the original filming was speed-accurate. Otherwise, just bear in mind that slightly-too-slow playback is generally more pleasing to view than slightly-too-fast.

                Finally, if FCPX continues to give you trouble, there are some excellent YouTube tutorials out there. I've been using FCPX for over 10 years, but still find myself revisiting the tutorials frequently, especially if it's been a while since my last editing session (I'm terrible at remembering all the hidden commands & keyboard shortcuts). There are plenty of video and printed tutorials posted online, covering everything from beginner level to advanced editing, color-correction, and file management. Good luck!

                -Harry

                Comment


                • #9
                  Harry,

                  Thank you for this very helpful information! You've provided answers to my main questions. I particularly appreciate your perspective and pointers re: FCPX and its cluelessness about the rate at which the film was digitized.

                  Apologies for my slow response here... I have been away and will be again soon. But this time, I'll have access t network and expect tol be checking in here regularly.

                  On another point, indeed, I still have the original film, and I also use a Wolverine machine. Current challenge is getting the Wolverine to frame the images correctly; I think I need to zoom out more. But that's an entirely different question.

                  Thanks again!
                  Phillip

                  Comment


                  • #10
                    Working off of Harry Abramson's response above, I'm not sure I understand the concept of "retiming" vs. the frame rate. I have now played with changing the frame rate of clips all digitized at the same rate, and the duration of the clips does not change. Thus far, anyway. And I'm not sure if or how the duration of an 8mm clip filmed at 16 fps is changed when scanned at 20 fps in the Wolverine.

                    I'm hesitant to subject my film to a projector at this stage - since I no longer have one that I trust. But maybe that, along with a stopwatch test, is the only way to get clarity on how my digitized films are being retimed simply by the fact that they were scanned.

                    If that's the case, I'm also unsure how to "tell" the video application what the real (i.e., native) frame rate of the clip is.

                    (FWIW, I'm experimenting with Adobe Premiere Pro as well as FCPX, since I am getting help from a relative, a professional videographer, who works with Premiere. With Premiere, I'm having a lot easier time managing multiple parallel clips on the timeline - to compare different scans -, but maybe its functionality is different. Also FWIW, Premiere has a limited choice of frame rate, and doesn't seem to have a way of setting frame it to 16. 15 is the closest option.)

                    More generally, I still do not understand what frame rate means in the context of a digital video file. Are frames marked explicitly, or just scan lines? Are there ways to distinguish one frame from the next? Is it just bit rate that changes, or are frames rendered individually at different rates when the fps is varied? I suppose a review of the various encoding formats would be the place to start, but I'm not sure that that wouldn't just be a distraction from my real goal of getting these videos digitized in a way that reproduces the experience of viewing the original projected experience as closely as possible.

                    Lots of questions here. Any pointers welcome.

                    Thanks.

                    Comment


                    • #11
                      ... and I will be reviewing the link that Harry posted above, as well. It didn't sink in entirely the first time.

                      Comment


                      • #12
                        ... likewise David Brown's links above.

                        Just mentioning these here for the sake of consolidation. They'd be hard to find again otherwise.

                        http://instipics.com/Film_Crop/

                        https://8mmforum.film-tech.com/vbb/f...rscan-and-crop

                        https://support.apple.com/guide/fina...er40b00150/mac

                        Comment


                        • #13
                          Phillip Dibner

                          Premiere has a limited choice of frame rate, and doesn't seem to have a way of setting frame it to 16. 15 is the closest option
                          As far as I know...there are no limitations to setting frame rate in Premiere.

                          After importing the file into the project...Right click on that file and select Modify > Interpret Footage. Here you can select to leave the frame rate the same as the original or change it by entering a new frame rate.

                          Also in doing so any change in the frame rate will change the duration of the clip.

                          Comment


                          • #14
                            Great information, thank you, Janice! OK, this is something I can test directly, and it’s (obviously) exactly what I need.

                            Comment


                            • #15
                              There is film speed vs video frame rate. When I wrote Film_Crop, I included both. The Wolverine scans the film and records it at a rate of 20 frames per second. But the original film speed was shot at 16 FPS (18 fps for super 8). So I included a film speed adjustment to allow you to set the speed correctly. Then there is frame rate on the output video. This is the rate at which the video is refreshed on the display. At 16 FPS, a new picture is presented on the display every one sixteenth of a second. The idea is to trick your mind into seeing what you think is a continuous stream of video. At 16 FPS, most people observe this to be true. However, the European standard is 24 FPS and the US standard is 30 FPS. Some people are more sensitive to frame rate and at 16 FPS they will observer a slight flickering of the video. So I included a video frame rate in Film_Crop which actually creates intermediate frames as a composite between the previous frame and next frame to eliminate this. So, you can have a 16 FPS film speed but a 24 or 30 FPS video frame rate. Most editors allow you to specify the video frame rate for the output video, but this doesn't affect the speed of the video. Others allow you to specify a speed, but they do this by dropping or adding video frames to reach the desired speed. When you are scanning a film frame by frame, you have the unique opportunity to set the frame-by-frame speed without dropping or adding frames. So with Film_Crop you can have a film speed of 16 FPS but a video rate of 24 FPS.

                              http://instipics.com/Film_Crop

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