DPReview.com is closing April 10th - Find out more

Diy honeycomb grid - calculation

Started Aug 25, 2017 | Discussions thread
ForumParentFirstPrevious
Flat view
JRM PT Regular Member • Posts: 180
Diy honeycomb grid - calculation

Hi,

I am struggling to find the right formulas to calculate the length of the grid given the desired angle and grid diameter (black straws - a nice excuse for some end of summer mojitos😈).

I've already seen some online calculators (Paulo Rodrigues' and others) and some honeycomb grid manufacturers data but things don't match! Most of the calculators don't show the formulas and no one shows theory references.

The explanation based on geometry that looks OK but it still misses theoretical validation, will lead to alpha=2×atan (d/l) or l=d/tan(alpha/2), where alpha is the angle of the light, "l" the straw length and "d" the straw diameter. It works for alpha=90° leading l=d. It would work for alpha=0, giving an infinite grid. But when one compares this with the honeycombgrids.com data, no other angle is right! That is something that is hurting my poor brain. The guys actually sell the grid for diyers... I would buy from them if the shipping cost to Lisbon wasn't so high. But I am very puzzled with this.

 JRM PT's gear list:JRM PT's gear list
Nikon AF-S Micro-Nikkor 105mm F2.8G IF-ED VR Nikon D5300 Nikon AF-S DX Nikkor 35mm F1.8G Nikon AF-S Nikkor 70-300mm f/4.5-5.6G VR Nikon AF-S DX Nikkor 18-140mm F3.5-5.6G ED VR +11 more
ForumParentFirstPrevious
Flat view
ForumParentFirstPrevious
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow