Answers.Body: <p>Yes, digitization screws up the aspect ratio.  See the reasons for my conclusion after "EDIT" in the question.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-01-02T15:22:19.763Z
Answers.LastActivityDate: 2020-01-02T15:22:19.763Z
Answers.UserDisplayName: Betty Crokker
Answers.Body: <p>Pixels are <a href="https://en.wikipedia.org/wiki/Pixel_aspect_ratio" rel="nofollow noreferrer">not necessarily square</a>, they are rectangular. For example, both &quot;standard&quot; and &quot;widescreen&quot; formats on DVD have the same frame size in pixels, but widescreen pixels are wider. To complicate the matters, out of 720x480 frame only the 704x480 portion is expected to have content, and it is this portion that should have required display aspect ratio (DAR). In case of old-school &quot;standard&quot; TV it would be 4/3, it case of modern widescreen TV it would be 16/9.</p>
  <p>Depending whether you need &quot;standard&quot; or &quot;widescreen&quot; format, pixels may be narror (PAR 0.9 for &quot;standard&quot;) or wide (PAR 1.21 for &quot;widescreen&quot;).</p>
  <p>Super 8 has DAR about 1.36, so when the video is displayed correctly in a 1.33 frame, you should see thin black bars on top and bottom. But really, it is so close to 1.33 that you may want to scale it to full frame.</p>
  <p>If you see your video shown wider than it should be, then either the video is missing PAR information, or the video player does not process PAR information properly, or both.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2020-09-29T00:47:49.263Z
Answers.LastActivityDate: 2020-09-29T00:47:49.263Z
Answers.UserDisplayName: Rusty Core
Body: <p>I had some old super 8mm film digitized, and the result looks almost right.  I did a little poking around and I'm wondering if they squished the film into a standard (but wrong) aspect ratio.</p>
  
  <p>The resulting video files claim to be 720x480 which would be a ratio of 1.5, but according to <a href="https://en.wikipedia.org/wiki/Super_8_film" rel="nofollow noreferrer">Wikipedia</a>, the image portion of a super 8mm frame is 5.79 x 4.01 mm which is a ratio of 1.44.  If they did force it into a ratio of 1.5, that would be off by about 5% which would be noticeable.</p>
  
  <p>The video files are of course too large to upload, but I used "Photos" (comes free with Windows) to snip out a 4-second chunk.  I've got other video editing software, but thought Photos had the best chance of not doing anything to the video except extracting the desired scene.  It's shared on my Google Drive <a href="https://drive.google.com/open?id=1oUaBHFU2aJbvJJ0kLtEL_o7Er0cT0RFX" rel="nofollow noreferrer">here</a>.</p>
  
  <p>Just for fun, I laid the super 8mm film across my negative scanner and got an image, since the scan was at 2400 dpi I did the math and the images are about 5.58 x 4.27 mm which is approximately what you expect for super 8mm.</p>
  
  <p>Am I overthinking this?  Or should I take the time to drop each video file in my editor and squish it into the right shape?</p>
  
  <p><a href="https://i.sstatic.net/tzKLP.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/tzKLP.jpg" alt="scan of raw film"></a></p>
  
  <p>EDIT</p>
  
  <p>After posting I had a thought - what if they digitized it at the right aspect ratio by trimming?  So I found the image in the video that matched the frame I had scanned on the original film:</p>
  
  <p><a href="https://i.sstatic.net/AxReo.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/AxReo.png" alt="screenshot from video"></a></p>
  
  <p>At first it looked like I had the answer, as they had clearly trimmed my mother's hair in the digitized video.  However, by zooming in on the encyclopedias on the shelf:</p>
  
  <p><a href="https://i.sstatic.net/Kuzwz.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/Kuzwz.jpg" alt="encyclopedias on scanned film"></a>
  <a href="https://i.sstatic.net/q0KcW.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/q0KcW.png" alt="encyclopedias on video"></a></p>
  
  <p>In the scanned film, they are 99x69 = ratio of 1.434; in the digitized video they are 156x94 = ratio of 1.660.  So yes, the aspect ratio was in fact altered during the digitization process, and by about the amount expected from my original calculations.</p>
  
Tags: <digitisation>
Title: Digitized super 8 mm film - got wrong aspect ratio?
UserDisplayName: Betty Crokker
ThreadText: # Digitized super 8 mm film - got wrong aspect ratio?
  
  (Asked by: username_0 on 2020-01-02)
  
  I had some old super 8mm film digitized, and the result looks almost right. I did a little poking around and I'm wondering if they squished the film into a standard (but wrong) aspect ratio.
  
  The resulting video files claim to be 720x480 which would be a ratio of 1.5, but according to [Wikipedia](https://en.wikipedia.org/wiki/Super_8_film), the image portion of a super 8mm frame is 5.79 x 4.01 mm which is a ratio of 1.44. If they did force it into a ratio of 1.5, that would be off by about 5% which would be noticeable.
  
  The video files are of course too large to upload, but I used "Photos" (comes free with Windows) to snip out a 4-second chunk. I've got other video editing software, but thought Photos had the best chance of not doing anything to the video except extracting the desired scene. It's shared on my Google Drive [here](https://drive.google.com/open?id=1oUaBHFU2aJbvJJ0kLtEL_o7Er0cT0RFX).
  
  Just for fun, I laid the super 8mm film across my negative scanner and got an image, since the scan was at 2400 dpi I did the math and the images are about 5.58 x 4.27 mm which is approximately what you expect for super 8mm.
  
  Am I overthinking this? Or should I take the time to drop each video file in my editor and squish it into the right shape?
  
  [![scan of raw film](https://i.sstatic.net/tzKLP.jpg)](https://i.sstatic.net/tzKLP.jpg)
  
  EDIT
  
  After posting I had a thought - what if they digitized it at the right aspect ratio by trimming? So I found the image in the video that matched the frame I had scanned on the original film:
  
  [![screenshot from video](https://i.sstatic.net/AxReo.png)](https://i.sstatic.net/AxReo.png)
  
  At first it looked like I had the answer, as they had clearly trimmed my mother's hair in the digitized video. However, by zooming in on the encyclopedias on the shelf:
  
  [![encyclopedias on scanned film](https://i.sstatic.net/Kuzwz.jpg)](https://i.sstatic.net/Kuzwz.jpg)
  [![encyclopedias on video](https://i.sstatic.net/q0KcW.png)](https://i.sstatic.net/q0KcW.png)
  
  In the scanned film, they are 99x69 = ratio of 1.434; in the digitized video they are 156x94 = ratio of 1.660. So yes, the aspect ratio was in fact altered during the digitization process, and by about the amount expected from my original calculations.
  
  **Tags:** digitisation
  
  
  ---
  
  ## 2 answers
  
  ### Answer by username_0 on 2020-01-02. Score: 0
  
  Yes, digitization screws up the aspect ratio. See the reasons for my conclusion after "EDIT" in the question.
  
  
  ---
  
  ### Answer by username_1 on 2020-09-29. Score: 0
  
  Pixels are [not necessarily square](https://en.wikipedia.org/wiki/Pixel_aspect_ratio), they are rectangular. For example, both "standard" and "widescreen" formats on DVD have the same frame size in pixels, but widescreen pixels are wider. To complicate the matters, out of 720x480 frame only the 704x480 portion is expected to have content, and it is this portion that should have required display aspect ratio (DAR). In case of old-school "standard" TV it would be 4/3, it case of modern widescreen TV it would be 16/9.
  
  Depending whether you need "standard" or "widescreen" format, pixels may be narror (PAR 0.9 for "standard") or wide (PAR 1.21 for "widescreen").
  
  Super 8 has DAR about 1.36, so when the video is displayed correctly in a 1.33 frame, you should see thin black bars on top and bottom. But really, it is so close to 1.33 that you may want to scale it to full frame.
  
  If you see your video shown wider than it should be, then either the video is missing PAR information, or the video player does not process PAR information properly, or both.
  
  
  ---
  
  