While making enhancements to the “Sohdo” Long time-lapse device at Innovo, while 3d-printing a camera mount for final pre-production refinements. We had a little time. A friend there was showing me a new PCB milling machine, and I saw that it had very thin drill bits; the thinnest was 0.3mm (300 microns). So I had the idea of doing a “clean” pinhole. So we followed these steps.

shooting the time lapse, with two cameras, one with the pinhole and the other with a 16mm fisheye

shooting the time lapse, with two cameras, one with the pinhole and the other with a 16mm fisheye

shooting the time lapse, with two cameras, one with the pinhole and the other with a 16mm fisheye

shooting the time lapse, with two cameras, one with the pinhole and the other with a 16mm fisheye

Measuring the inside circle of the cap

pinhole timelapse

Measuring the surface to make even by removing the embossed Nikon logo

Usually, to locate a center I would go spinning the subject. I fix a fine tipped object (the best is a pencil) and make it draw a circle; I adjust the pencil position until the circle becomes a point. We had nothing that could rotate, so we sought another fix.We precisely measured the circle on the back of the cap. On a hobby CNC we routed a gap in which the cap fit tightly.

pinhole timelapse

Routing the slot in which the cap will fit tightly

pinhole timelapse

the cap now sits tight and fully centered

The cap was thick, so we opted to have the pinhole on a thin sheet. That needed to have the plastic cap even in surface so we “de-Nikonized” it. We drilled a relatively big center hole, and did engraving in which the thin metal sheet would be inserted. And that also helped in preventing any eventual light leak.

pinhole timelapse

Scraping the Nikon logo to have a flat surface

pinhole timelapse

A large center hole is done as well a circular engraving in which the pin hole sheet will fit tightly

Then we used PCB milling machine to drill the 0.3mm hole in the center of the sheet which was cut in a circle that fits the previous engraving of the plastic cap.

pinhole timelapse

The 0.3mm hole in the center, the 3 other holes (fiducial markers…a new word that I learned yesterday, i thought they were called registration marks like in printing)

pinhole timelapse

Drilling the pin hole

pinhole timelapse

Cutting the circle

 

The circular sheet with a pin hole size marking fits tightly in the engraving of the cap, so no glue is necessary

The circular sheet with a pin hole size marking fits tightly in the engraving of the cap, so no glue is necessary

Actually I did two circular sheets, one with a pinhole of 0.3mm and the other with a 0.6mm hole.

I took few test shots and saw what were the flaws of the current process.
The sheet should be very thin, and the one I used was 1.3mm, so heavy vignette occurred on the 0.3mm pinhole. I made a 0.3mm pinhole on a 0.5mm metal sheet in which the above time-lapse video was shot. vignette has gone. The video a bit color processed and not deflickered (I am now more sure that most of the flicker is due to un-precise apertures.)

I found this calculator to be very useful
and here are some quick test samples, hoping to make a decent pinhole timelapse very soon…forget not to have your sensors very very clean. and remember to close the viewfinder if going for long exposures.

Register below, and stay updated

No need if already registered anywhere on my sites)




You can always find more information at www.alexfr.org
or join the facebook page Alexy Joffre Frangieh
or follow on instagram alexyfrangieh

 

Comments

comments