Post-Script: In my many years of dabbling in pinhole photography, I've taken up the challenge of maximizing details and tones to excess, to the point where a downsized copy might appear to have been created with a conventional lens.
Exploring further the limits of visual clarity has meant employing devices as ill-suited to sharp rendition as possible, among these being a much larger sized aperture than what the typical pinhole camera might employ, what I've termed, for obvious purposes of symbolic contrast, a "pencil hole camera," using as a crude, pseudo-image-forming device an aperture about as wide around as a pencil, which forms an image possessing the merest suggestion of the shapes, textures and tones of objects, where sharp edges or fine detail are entirely absent, requiring of the viewer a more active degree of participation in the image comprehension process.
Along with this pencil hole technique I've also explored other methods well-suited to the visually obscure, such as the Pixellator Grid and the Light Pipe Array, which I shall write more about in the near future.
The inspiration for these ideas might have come from observations I've made over the years of shadows of objects cast at various distances by the sun, whereby the further from the object its shadow extends the less sharply defined is its shape, with edges gently transitioning into a softened blur.
Studying the shadows of a plant's leaves cast upon the ground or a nearby wall, for instance, some sense of three-dimensionality can be deduced by the relative sharpness of the shadows' outlines, as those leaves closer to their shadow remain more distinct and denser in tone than those further away.
I write these words, fountain pen to composition book, in the shadow of a garden trellis in a late winter's afternoon light, soft diamond patterns of light-gray trellis shadow contrasted upon paper by the sharp-edged shadows of my hand and pen.
Here's a thought experiment I'd like you to consider, which is to suppose that we live inside a giant camera obscura, and the sun is an aperture, an opening into a distant world of pure, radiant light beyond. All of our activities are merely shadows cast upon the back wall of our chamber, and the closer we approach that light the less distinct as individuals we become.
If, as physicists would inform us, time and space are interlinked, then those more distant shadows, soft-edged and less distinct, seem to resemble something of the past, distant memories more gently recalled, while closer up the pen's nib upon paper seems yet so much more immediately in the present tense, as if in this one small corner of my yard the entirety of history were somehow playing itself out in a microcosm of light and dark and gray in between.
Typecast via Olivetti Lettera 22 and Sony A390, top image via F/25 pencil hole aperture in 4x5 Speed Graphic upon silver gelatin paper negative.