Retrofocus

Y-Mac + Div’lens

Behind the lots of experimental / homemade lenses, I got mountain of diverging lens which came from mountain of discarded lenses. —– Converging lens can be easily used as an image projecting lens in many occasions though, not many use of the diverging lens. I did used it to make Wide-angle Pinhole and for Two element homemade lens which was to extend the focal length of the disposable (one time use) camera lens for 35 mm SLR camera.

The diverging lens was simplly stack to the front of the Yashica macro lens (focus was made by its zooming helicoid) and the size of the image was depend on the distance between the Yashica lens and the diverging lens = if it was made adjustable it will become a zoom lens.

Scavenged homemade lens / Yashica Macro is quite good lens though, it got rather limited use only for the macro shot. — Why macro ? Because its focal length was too short to be used on the 35 mm SLR even on the mirrorless camera = When such lens was mounted on the full-size camera, it was same to the lens was focused to very close. = Close-up or Macro shot.

But the focal length of the lens can be extended by the diverging lens. = So, I tried it with a diverging lens which came from a Nikon Zoom lens = It worked well !

Somewhat similar to the situation of “Twisted lens” we are discovering the “inconvenient truth” of the optics. They may not be a residents of the holly land. (I’m talking about the optical effect — utilising its effect while making precise lens-shifting mechanism etc and make usable / reliable products is far beyond the ordinary man’s capability.)

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