Homemade pinhole camera

These are not pinhole photos.

Kings Heath and Birmingham pinhole photos with Fuji Velvia and cross processed with C41
Building a pinhole camera
Making the pinhole
Using a pinhole camera and reciprocity failure.
Developing the film
I made this pinhole camera for 120 film from a wooden chess set and various odds and ends:

Sample images
I used an online pinhole size calculator to get 0.2mm for the 36mm focal length, but decided to test what difference the size makes.
Ignore the odd colours, I used slide film and cross processed it in C41.
This is the basic setup: The lego man is about 5 cm from the camera and the bikes and Bertie Bassett moneybox are about 2 meters away.

I did tests with pinholes from 0.15mm to 0.45mm and these are crops of the results:
From left to right the pinhole sizes are; 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm and 0.45mm