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Annie M.
30-Jan-2008, 15:24
... raining here... I was just perusing the images in the raindrops on my window and I am wondering is there a way I could make a water lens with sufficient coverage for my 7x11... any ideas on how this could be accomplished.

Thanks Annie

...also wondering... when rain is falling is it actually billions of little lenses transmitting actual images as they fall...

Jim Galli
30-Jan-2008, 15:56
The drops are just too small. Think about your sensor size. 7X11 you'd need like 80:1 magnification. Things seem to get weird after about 5:1. A digital camera with a little tiny sensor area like 1/3 inch might work best. A 2 or 3:1 macro lens would at least make a decent image on that size sensor that could be enlarged.

Peter K
30-Jan-2008, 16:01
Hi Annie,

small droplets but from glass where used by Antony van Leeuwenhoek (1632-1723) for his microscopes. For visual observations this kind of lenses will work because the eye and the brain compensate chromatical and other lens errors.

Later Thomas Sutton (1819-1875) made the first wide-angle lens from two menisci filled with water. But this lens was only f/30 because of the lack of correction for spherical and chromatical abberations. Also the plate has to be curved around the lens.

To make an achromatic lens one needs two transparent materials, one with a low and the other with a high refractive index. Water is the one with the low refractive index (1.333). The other one could be e. g. cinnamon oil (1.602) But how to hold both fluids in the needed shape?

Peter K

Justin Cormack
30-Jan-2008, 16:04
... raining here... I was just perusing the images in the raindrops on my window and I am wondering is there a way I could make a water lens with sufficient coverage for my 7x11... any ideas on how this could be accomplished.

Thanks Annie

...also wondering... when rain is falling is it actually billions of little lenses transmitting actual images as they fall...

Freeze the rain into a lens shaped mould (keeping it as clear as possible)?

Annie M.
30-Jan-2008, 18:42
I imagine I would have to get to a place with zero gravity to get a water drop large enough for the 7x11... the oil and water concept is interesting... I did some images a few years ago with ice (cube) lenses. I thought it would be very interesting to have a lens that had the qualities of water... surface waves can focus light in beautiful ways ... you see this often in the shallows at the beach.

Thanks for your posts I learned something... Annie.

gregstidham
30-Jan-2008, 19:35
....also wondering... when rain is falling is it actually billions of little lenses transmitting actual images as they fall...
This is fun thought. Thanks :)

Struan Gray
31-Jan-2008, 01:05
Water is highly dispersive - it has different refractive indices for different wavelengths - which is why rainbows happen. The same dispersion will make for some funky colour fringing if you make a water lens, or if you enlarge small water droplets to fill a ULF negative.

Some of my favourite photograms have been made with caustics formed by light passing through water and ice. ULF makes sense for this, although Susan Derges and Adam Fuss have done great things by dispensing with cameras altogether.

Somewhere, a long, long time ago, I saw some nice contact prints of frozen soap bubbles. You need an air temp below about -15°C for that though.

Water in glass containters is probably going to be more productive than just water - unless you can get a residency in the Space Shuttle and photograph through free-floating globules. Friedlander's "Stems" and the new Kertesz "Polaroids" book are two of my favourites.

Peter K
31-Jan-2008, 05:48
Water in glass containters is probably going to be more productive than just water - unless you can get a residency in the Space Shuttle and photograph through free-floating globules.
Water in glass containers was a common tool to increase the brigntness of a lamp. The "shoemaker's bubble" was used to collect the light of an oil lamp on the working place in this dark workshops. Also Robert Hooke (1635-1703), the guy who coined the word "cell" for this small areas in living tissue, used such a water filled glass-ball to illuminate the specimens observed in his microscope.

Peter K

Struan Gray
31-Jan-2008, 06:36
Not water, but "ball lenses" are the common cheap way of coupling light into optical fibres. A common make-you-think" question in physics exams is "Estimate the focal length of a goldfish bowl" :-)

My favourite use of a large transparent sphere is as a sunshine recorder:

http://www.sciencemuseum.org.uk/images/I044/10313155.aspx

http://www.nmm.ac.uk/searchbin/searchs.pl?exhibit=it1655z

A big one of these might fit with your time concerns Annie.

Annie M.
31-Jan-2008, 09:03
hmmmm... I see the liquid lens is in production for cell phones (Varitoptic Liquid Lens) they seem to be similar to the achromatic lens suggested by Peter... a water/oil mix with zoom capability... no moving parts 'it uses electricity to change the focus of the lens by altering the border between two drops of liquid'.

Also I discoverd a photographer Roger Newton...

http://www.photoeye.com/templates/mshowdetailsbycat.cfm?catalog=TR222

He used lenses constructed of oil, water and corn syrup... when I Google him there is an interview in the NY Times but it crashes my computer... if someone has an inclination could they locate the article and see if he gives any details about his lenses.

Struan...what a lovely object the sunshine recorder is... seems there could be a combustion issue... very exciting. The goldfish bowl is interesting also... just wondering... would the species of fish in the bowl make a difference in the final image... hmmmm

Greg... I was thinking about the raindrop thing when I walked in the rain to my mailbox yesterday... changed the entire vibe!

Cheers & thanks... Annie