Scanning Printed Materials for 4K

[C Barker]

Hi there,

I need to get a number of printed materials (photos, letters, articles etc) scanned by numerous people across the U.S. for a current project.

I would like to get the material scanned at the highest resolution possible to allow for zooming/re-framing.

I am wondering what is/if there is a recommended dpi for scanning printed materials for 4K screening?

From calling every place I can find in the first location, for some of the most important material, the highest resolution print/copy places offer seems to be 600dpi.

I am wondering if 600dpi is usually the max limit for scanning printed materials or if 1200dpi and upwards is typical and I somehow haven't managed to find the right places (although I have called literally every print/scan shop on google for the first city)?

Many thanks...

 

[Nick Pasquariello]

600dpi = 600 pixels per inch. A standard 8.5"x11" sheet of paper would be scanned at 5100x6600 pixels. So, larger than 4K regardless of portrait or landscape orientation.

Math!

 

[C Barker]

600dpi = 600 pixels per inch. A standard 8.5"x11" sheet of paper would be scanned at 5100x6600 pixels. So, larger than 4K regardless of portrait or landscape orientation.

Math!

Thanks for the info - I'm aware of the calculations but some of the material is quite small and additionally I would like as much room as possible for re-framing in general (and was also concerned that going too high may cause problems with quality).

 

[Dr. Sassi]

Take a piece of paper and draw a frame that resembles the smallest area that you like to have (magnify if you will). As you said, you have the math down, so no further comment needed for that.

However, let me add what I teach normally to my students:

This small area should be 6K in terms of scan. I go here from my minimum values that we use in 3D (animation, not stereo) to get good texture representations. If you mix pixels or have rotated or even perspective representations of several pixels per final pixel: the rule of thumb is 1.5 higher from the greatest magnification area.

As it is already scanned, I would do this anyway in 3D, as you can set up the smoothest camera move or even zoom that you like, without getting crazy with light and polarization filter (to avoid problems). You can add during the rendering even depth of field and motion-blur as well as (!) anti aliasing during that. You get the most pristine images.

Just my two cents. My best wishes


(P.S.: typically if scanned and then printed, the following discussion is, that scanned pixels are not the same as printed "pixels". But I skip that here.)

 

[Christopher Barrett]

You could also set up a copy stand with a still camera with decent resolution and knock a ton of these out pretty quickly. The images would be sharper than flatbed scans.

 

[Marc Wielage]

One key with a rostrum/animation camera set up is that you need much more light than you might think. It's important to get a lot of depth of field for cases where the page or photograph doesn't lie perfectly flat, and you need to make absolutely sure the lighting is providing a flat field.

The problem with a lot of documentary projects is that you wind up having many, many different-sized sources, so you might have a 2-1/2" square negative, vs. a standard slide, vs. an 8x10" photograph, vs. some old archival plate. The effective resolution will change depending on how close you need to get to the photograph and how much of a calculated dynamic move you need to make in the process. Speed ramps and other kinds of moves are tricky, but most good editors and graphics people know how to handle them nowadays.

BTW, check out the recent HBO specials on Sinatra and also James Brown for examples where they took a lot of posters, still photographs, and other kinds of images and made them work very well in terms of telling the story and providing good background footage to augment the live-action film and video material.