How big is a needle size of 5/10 in mm?

Question

I'm making a pinhole camera, and I have a needle to make the pinhole, however I've read that the pinhole should be a particular size. The size of these particular needles is stated as 5/10 and I don't understand what that means, because I don't know a lot about sewing. I need the measurement in millimeters. Can you help, please?

Answer 1

Hi try this web site.

Answer 2

Needles are sized according to an arbitrary numbering system, basically, it means that you can use anything between a #5 and a #10 needle.  The size of the hole in a pinhole camera would be analogous to the fstop of a modern camera.  This means that you would get a different depth of field in your images from different size holes.  The various sewing needle sizes run approximately as follows:

1     .046"     1.17 mm

2     .043"     1.09 mm

3     .040"     1.02 mm

4     .037"     0.94 mm

5     .034"     0.86 mm

6     .030"     0.76 mm

7     .027"     0.69 mm

8     .024"     0.61 mm

9     .021"     0.53 mm

10   .018"     0.46 mm

11   .016"     0.42 mm

12   .014"     0.35 mm