Dear Steve
I do not know how you are planning to cut and fabricate your plastic sheeting.
But if you have not looked, there are many many bi-colour double layered UV
resistant acrylics used by the sign-writing industry. See, for example,
There is no single optimum reflectance for a flat dial face. Obviously
under dim sunlight the optimum reflectance would be 100 per cent,
i.e.perfect white.
Under intense sunlight, contrast sensitivity would be optimised for a lower
value of reflectance. Thousands of papers have been written on
When taking light meter readings for photography, it is common to use an
18% grey card in place of the object which will actually be photographed.
This is generally considered to give a reading which will accurately
balance light and dark.
See: https://en.wikipedia.org/wiki/Gray_card
Might be
Hi Kevin,
Yes, I plan to use laser engraving and cutting. There is a local
community maker workshop that charges $2 per minute of cutting time for
using their machine with exactly the setup you describe - I choose line
colours in my PDF depending on whether I will want the areas or line
My experience is use a mat finish sand color. It
also matches with nearly every colorscheme.
At 03:25 26-2-2017, Michael Ossipoff wrote:
It seems to me that Steve's question has been
mostly disregarded rather than answered.
Not having experience with translucent
dial-faces, I didn't know
18% gray is used because that was thought to be the average
reflectance of photographic subjects.
- Original Message -
From:
"Patrick Vyvyan"
To:
"John Lynes"
Cc:
"sundial list"
Sent:
Sun, 26 Feb 2017 13:01:10 -0300