A lot of the photogrammetry models I make, and that I generally see online are of decent sized objects, or even large buildings and terrains. But as long as you can take a decent photo of something, you can digitize it.
A while ago I tweeted some nice Macro images of a fossil fish specimen from my collection, testing out a Macro lens I’d bought myself.
To give you an idea of the scale of these things:
I made a model of it shortly after:
So here I just wanted to talk about what went into it.
The model was made with 200 photos. Here’s some samples of the photos from the full set of 200:
To show you how they were taken, take a look at this reconstruction in Agisoft Metashape:
You can see I’ve made two circular passes, then gone in close – right up to the fossil (the macro lens I was using lets you focus with the lens basically touching the object).
I will note here that Meshroom and Reality Capture fail to get the whole specimen, and only reconstruct the close-up areas, hence why the video in my tweet above has all the white guff around it. However, I re-made the model recently in Metashape and it absolutely nailed the whole thing.
Anyway, the model is now available on Sketchfab, where you can see the quality of the reconstruction. Keep in mind that scale bar in the first image in this post:
There’s almost no topography at all. Taking the model and colouring it according to height in Cloud Compare, we get this, where blue-red is 0.5mm:
So yeah, the level of detail attainable is pretty incredible.
 Some time after writing this post, I made this animation in Blender of the model above:https://platform.twitter.com/widgets.js