>>510945279
Found my old math.

We'll be using AS17-134-20387, find a source that shows the film strip.

Lens focal length 60mm, SO-368 70mm film, 70mm Hasselblad 500EL camera.

Using a basic calculator: https://www.omnicalculator.com/other/focal-length

So the object size is the earth, which has a diameter of 7917.5 miles. This is a known value we can plug into our calculator. So is the distance(238900 miles), and the focal length. With all this we already have enough to figure out the size of the earth in frame: 1.9885mm

The film is 70mm across, and the image I'm using of the actual film has the film about 1086 pixels wide. So each millimeter is 1086/70 = 15.5 pixels. So how wide's the earth here? About 35 pixels, give or take some inaccuracy due to resolution, the earth's shadow, and some earth glow. Given we're looking for 1.9885mm, it should be...30.85 pixels.

Based on that, not only is the earth too small, but the earth appears slightly larger than it should be if you take the napkin math at face value.
tl;dr you're stupid as fuck