Friday, September 11, 2015

Carl Bosch Museum Heidelberg Special Exhibit Fascination Color with simulated bee and butterfly vision images II

Today about the opening event of the "Fascination Color" exhibit at the Carl Bosch Museum, Heidelberg Germany which will be open from 12. September 2015 - 3. April 2016. Some of my best works will be shown in human vision, in simulated bee and butterfly vision.

Here the introductory text: "How do colors come into existence? What are colors used for? What really is color? These and many other questions are answered by the exhibition and illustrates how broad ranged the subject of colors actually is. With many exciting exhibits, visitors learn that we see colors not only with our eyes and experience how other people and animals see the colorful world. The symbolic and social meanings of colors are explained, as is the extraction and use of historic natural colors, up to modern industrial dyes." [translation by me]

The scientific background of colors are demonstrated with live experiments, how it was found out, color models from history up to now explained, color temperature and the effect of different light sources, as well as natural pigments and dyes from ancient times to todays are being shown.

The last two pictures shows the animated video with my works showing the difference between human, butterfly and bee vision with various flowers with a very prominent UV pattern. Beneath there is an explanation how evolution has started with tetrachromatic vision and how that has developed over millions of years into the various types of vision today.

If you find time to, pay it a visit, it will certainly be worth going with your whole family!
The Carl Bosch Museum Heidelberg has been founded and is being actively supported by Gerda Tschira, wife of recently deceased SAP founding member Klaus Tschira . The non-profit Klaus Tschira Foundation promotes the advancement of natural sciences, mathematics, and computer science and strives to raise appreciation for these fields.

Stay tuned, more will follow on that fascinating subject...

Tuesday, September 1, 2015

How to modularily mount a projection or other large diameter lens

This is to show how to mount a projection or other rather large diameter lens. The front adapter can be changed, as well as rear camera mount (can be basically any camera).

Remark: This is mainly intended to test and use a variety of lenses and not does not replace a full conversion of such a lens (adding iris, focusing, camera mount), as it allows to switch lenses in seconds using an Allen wrench.

Works from infinity (depending on lens back focal length) to very closeup. Setscrews allow to calibrate the infinity position. The basic idea is to allow the lens to "dive into" the larger helicoid, hence quite a short optical length can be achieved using such a contraption, also for lenses with shorter focal and back focal length.

Lens --> Lens Adapter to M65 --> M65 to M42 Helicoid --> M42 to Camera mount Adapter (the latter two may be just one M65 --> camera mount X)

 It is not a slim elegant and lightweight solution, but the benefits are:
  1. no lens modification needed
  2. non rotating front for sunshade/filter (needs additional clamp holder)
  3. accepts a variety of lens types and lens diameters, switch within seconds
  4. mount may hold ND filter (better in front though using variable ND filter) or an adjustable iris
  5. allows a variety of camera mounts (M42, Nikon-F, Sony-E, Canon EF, m4/3, Hasselblad V, Mamiya 645 etc.)
  6. needs only about 15mm net optical length (plus camera register) for lens diameter 62.5mm or smaller
  7. safes money and time for not having to go to the gym, as it is quite heavy :-)
The design was originally made to accept 35mm russian film projection lenses with a standard 62.5mm diameter. Smaller ones (52.5mm etc.) are fitted using a different front ring, also some larger ones can be fitted, but infinity focus may often not be reached using the latter, as such lenses then cannot dive into the helicoid.

Those two adapter rings (front and back) are made by based on my design. Front one has three hex nut setscrews which hold the lens in place and allows to adjust infinity focus (if the lens has enough back focal length) Rafcamera offers several camera adapter rings for the rear, incl. Nikon-F, Sony-E, m4/3, Hasselblad, Mamiya 645 etc. Orders may be done directly through their site or through (I have no connections with Rafcamera except that I'm a happy customer...) That M65 helicoid is made in China and may be found on ebay.

[my name is on the rings was a curtesy of rafcamera and is a non standard feature]

I have written about using such helicoids previously HERE
Stay tuned, more will follow on that fascinating subject...