Scanning resolution differences

[Ralph Edelbach]

I am going to have some old 8mm film (silent) digitized and have the option of normal resolution (720 X 540) or 2K (2048 X 1536). How much difference might I expect to see between the two, given the relatively low quality of the film shot 40 or more years ago? Any samples online that I could check out?
It is amazing that one place charges $ 12 per reel for the 2K, no matter if it is 3" or 7" reel. while another charges $10 per reel for a 3' roll or every 50' on a larger reel. Pricing is always fascinating to me.
Thanks for any info.

[Ralph Edelbach]

I mistaken typed "3' roll" when I meant to enter "3" roll." A 3 foot roll would be difficult to handle wouldn't it?

[Ty Reynolds]

Are you sure the price is $12.00 for a 7-inch reel? That's a heck of a loss leader, even at standard definition.

[Joerg Polzfusz]

Hi!

I would always opt for the highest resolution that I can afford.

The higher the resolution, the easier it is to do corrections later on. And it’s easier to combine with today’s videos (e.g. for a „now and then“ comparison).

And please keep in mind that HD-capable TVs are yesterday's standard - with UHD becoming tomorrow's standard. On a HD-TV, the 540-lines version has to be stretched being multiplied by the factor two, on UHD it has to be multiplied by factor four. Some devices produce a decent result when stretching, others only show annoyingly larger pixels. Hence, with the 540-lines version, you might easily end up with the decision to buy a better TV/beamer or to get the films scanned again in a decent resolution.

BTW: There are several websites that claim that you would need 3K resolution for Super8 to achieve the same level of detail as stored on the film (showing the real grain instead of grain aggregated to pixels). But unless you own an UHD beamer and a very large screen, I would assume that 2k is enough for amateurs.
But you could also simply check Pro8mm‘s many samples for Super8 or Standard8 scanned at 4K and beyond on vimeo and YouTube, e.g.:
https://vimeo.com/240317206
https://m.youtube.com/watch?v=S_0ys8KEGJE

And here’s an old home movie scanned by Pro8mm at 2k:
https://m.youtube.com/watch?v=rcm2zJXBwnE

(There are many more samples for all kind of resolutions on both platforms.)

[Nantawat Kittiwarakul]

I've been doing super8 scan using my DIY setup for a few years. Resolution-wise I can say that the sweetest spot is around 1080p - 2K. Going beyond QHD 1440p is literally the dimishing return - it'll be 80% increast in cost for 20% increase in quality.
Oh and that $12 flat rate regardless of reel size really sounds too good to be true. Therefore it is more than likely to NOT to be true...

[William Olson]

In fact, 8mm film has very good resolution. An HD scan will bring this out.

[Claus Harding]

One common thing people tend to believe is that because its "Just Super-8" or "Just old film", it has no benefits from a 4k scan.

Consider this:
Are you planning to just scan the image as framed on the film, frame-border to border? Then you live with how the film looks and behaves during the scan (vibration or jumping in the frame) and that is that. At that point you may not need more than 2K.

If you want to stabilize the film after the fact, you need to over-scan the image.
That means the scan will have a large frame that shows the sprockets and the outside of the image areas. Then in 'post' the image area is cropped to the actual image frame for reference, and the computer "locks down" the image based on that reference while your final file is rendered. You will now, ideally, have a very stable transfer, assuming your original film scanned without problems. This will help showcase all the detail the original film possesses.

The other thing a higher-resolution scan helps with is grain.
A good amount of the overhead of a larger scan (say 4K) is to have extra processing space to resolve the grain correctly, so it looks like film grain and not digital noise. This is especially important for a small format like 8mm. You want the grain to 'dance' cleanly like it does on your original film, not turn into vaguely pixillated noise that interferes with the viewing.

The above is of course subject to the quality and condition of your original films.

I am slowly getting my '70s Kodachrome S-8 reels together to have them transferred. They are shot at 24fps with sync sound and I am absolutely planning on a 4K scan of them. They have survived all this time, and I want to have them as good-looking as modern transfer tech can manage.

Claus.