Re: A clean slate? (or should that be granite?) | Forum

Trethevy Quoit 11

Image by Meic

A clean slate? (or should that be granite?)

StoneGloves May 4, 2011 06:30:16

Replying to nigelswift

What they're seeing is lens flare. Part of the eye is a lens, after all. Shame really, as I thought they were on to something. Still no measurement of the aperture, anything but ...

A load of surveyor's possessions went through the local auction yesterday. Cameras, squares, walking sticks. Lovely cameras - almost pristine. Ruminated on the uncaring nature of descendants. Found an interesting, but tiny, stater amongst the Roman detectorists' coins. Sonicator going flat out today!

nigelswift May 4, 2011 06:40:55

Replying to StoneGloves

StoneGloves wrote:

What they're seeing is lens flare. Part of the eye is a lens, after all.

Good call. That, but converted to a retained image perhaps.
What is NOT possible to see IMO is the corona or "boiling", whatever the qualities of the hole.

When I had younger eyes and they were more frequent and bigger I often saw sunspots at sunset. Haven't seen them lately though.

stonefree May 5, 2011 21:43:25

Replying to StoneGloves

[quote="StoneGloves"]What they're seeing is lens flare. Part of the eye is a lens, after all. Shame really, as I thought they were on to something. Still no measurement of the aperture, anything but ...

The 'lens flare' you're talking about, whilst extremely common with cameras whose lenses are comprised of multiple glass elements, does not occur with the Mk I human eyeball, being a single, perfect, organic lens!

The capstone aperture is extremely difficult to 'measure'. It has a complex 3 dimensional, assymetric profile. I have produced engineering drawings in the past, using isometric and orthographic projection views, but these require specialist measuring instruments such as internal micrometers or at least a range of external and internal calipers. It depends what you want to do with the information really. If necessary one could hire the services of a measurement specialist for around £100/hour.