Camera obscrua, with real lenses.


I work for a VFX company, which means that I get access to rather expensive software that makes pretty things, for “free”*. The very same company has recently purchased modo (or MODO in its new ridiculous marketing parlance). A few friends have been rabbiting on for years about how wonderful modo  MODO is for modelling. I decided that now would be the time to see what all the fuss is about.


I was cleaning my 50mm Nikon lens, in preparation for an experiment with freekin’ lasers.  I was reminded of my youth, playing with magnifying glasses and focusing tiny inverted pictures on paper. I tried doing this with the 50mm lens. It turns out that you do indeed get the very same inverted picture. Sadly the focal point is only ~40mm away from the back of the lens. This makes it rather difficult to draw around in the style of the <<INSERT REF TO PAINTING DEVICE>>

However, I now have access to 3D modelling software and all the cool kids are talking about 3d printing. I decided to make a tube that fits onto the back of a Nikon lens and allows you to focus a picture onto a paper screen.


Firstly, I’m no modeller. Second there are many things I had forgotten about since doing my VFX degree.

The first thing you have to take into account is all models must be watertight. This is fairly simple for things like cubes they only have 6 faces. Where you try and join two separate objects together is where the fun starts. The crucial thing that I had forgotten was how hard topology is. (Topology being the fancy word for surface. )

Model view 1

Pro tip: make sure that you never get yourself into a position where you have prime number in any of your models. It makes it really really difficult to join it to other things cleanly.

model view 2

The final model is quite simple, modified lens cap, tube and paper holder. You can clearly see where each of these sections join. Sadly for me the lens cap has a prime number of faces, which makes joining the paper holder to it much harder.

Image ProjectionCamera obscura, with lens

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