A microfilmer's job is to capture everything you give them. If they're filming a bound volume...

• they should capture the covers (they rarely seem to do this in old film)
• if pages were bound out of order, they were filmed exactly as they are bound
• bound volumes tend to interleaf supplements, sometimes physically smaller, inside an issue. Modern standards would have supplements filmed (bound) after (behind) the proper issue

Ideally, the pages are unbound and filmed individually. Older microfilm tends to let these loose pages stack one atop the other

• This can affect the resolution (not in a good way)
• If there are excisions, like obituaries, you won't necessarily notice unless you read the paper or, in the case of digitization, assign bounding boxes and/or article classifications

Ideally the microfilmer will place a black sheet of paper behind said cutout (again, this rarely happened in older film)

The best possible orientation for a newspaper is 1A. Older papers were often filmed in a 2B orientation to save space, even if it meant filming at a reduction so high that the paper barely fit inside the exposed frame

• This is especially problematic in NDNP digitization as the specifications demand no less than 300dpi

Microfilmers are easily distracted, the usual result is duplicate, even triplicate page images

• Giving credit where credit is due: Not all duplicate images come from the microfilmers! Darkroom technicians would often splice a refilm into a reel without removing the section that needed refilming!

Pre-standards film didn't care what a microfilmer used to hold down and flatten bound volume pages (arms, pencils, ashtrays, you name it, they used it)

Microfilm cameras have a device called a "gate". The gate increases or reduces the size of the frame being exposed. Ideally the gate is closed such that there is a 1" margin around the page. Older film didn't always care about the gate so, many times you'll see cords, shirts, adjoining tables, and even the camera head tower