Friday, July 28, 2006

My camera has turned into a microscope

Warning: highly detailed images, please exercise patience.
Notice: there are several typographical errors on the images. It is best to ignore all 0.20 markings.

After some optical black magic with the aid of Adrian and Diana's Canon 28-80mm EF lenses, I have been able to turn my Panasonic FZ30 into a microscope capable of resolving details about 760 nm per pixel.

Interestingly, the wavelength of red light is 700 nm, and I can see minor diffraction effects due to the wave nature of propagating light.

Right, let's get to the photographs...

Click here for large size image
The scale is corresponds to a length of 1.0 mm, subdivided into 0.5 mm and 0.2 mm sections.

This is an image of a polymer RM 5 banknote. It is part of the Petronas Twin Towers, where the diagonal line on the left is the bottom of the right supporting-strut of the sky bridge connecting the towers.

The scale is corresponds to a length of 0.1 mm, subdivided into 20 μm (micrometres, microns) sections.

Zooming in to the full sized photo (100% crop), one can actually see the thickness variations on the black-ink film.

The next image is of the holographic strip on a paper RM 50 banknote. The holographic strip includes patterns that look like 4 little squares arranged around the corners of a slightly larger square.

Click here for large size image
The scale is corresponds to a length of 1.0 mm, subdivided into 0.1 mm sections.

The subsequent image is a slight close-up of a corner of those little squares. One can see that the zigzagging band of light around the square array is caused by what appears to be a groove carved into the metallic surface.

There is a typo on the image- the first number on the scale should read 0.1 mm, not 0.2 mm.

The following image is a 100% crop of the full-sized photo. Note the surface textures on the ‘flat’ regions of the holographic surface.

The scale is corresponds to a length of 0.1 mm, subdivided into 10 μm (micrometres, microns) sections.

This is a photograph of the freshly sharpened cutting edge of a kitchen knife.

Click here for large size image

At maximum magnification, the diffraction effects of light are visible, particularly at the knife’s edge. Faint diffraction patterns are visible against the dark background.

A thinly sliced cross section of bak choy (白菜,a vegetable)stem. The visible granular structure appears to be composed of individual cells, although that suspicion cannot be confirmed.

Click here for large size image

This is a 100% crop of the previous image. If the individual particles are indeed cells, then I would suggest that the voids within each cell are the vacuoles (air pocket present in certain plant cells).

Click here for large size image

Put a ruler up to your monitor to measure how long the 0.1 mm sections appears on your monitor. On mine, it is a surprisingly convenient 40 mm, yielding a magnification of 400x. Better than most optical microscopes, I’ll say.

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Anonymous Anonymous said...

not sharp la, how to see properly.No good horrible.

9:55 am, July 28, 2006  
Blogger KY said...

interesting, now take pictures of bugs pls.

11:16 am, July 28, 2006  
Blogger Lao Chen said...

Diffraction effects la- I'm approaching the performance limit of visible light already.

Which is why people use x-ray and electron microscopes- they have much, much shorter wavelengths, thus able to see smaller details.

2 problems: the lenses have been returned.
Intact bugs will not remain on the focusing stage for sufficiently long durations... unless i freeze-kill them.

11:49 am, July 28, 2006  
Blogger 小李飞刀 said...

just out of curiosity, how did magnify the images? Did you use 2 lenses to create a microscope?

8:03 am, July 29, 2006  
Blogger Lao Chen said...

Firstly, something to set things in context. In a regular, unmodified camera, the wideangle lens projects a very large scene (in this case, about 70 degrees across) onto a the film. If the focus is set to infinity, parallel rays will converge to a point on the film. If the film was replaced with a light source (such as a knife), then light from the knife will travel outwards and travel in parallel lines.

In a regular, unmodified camera, a telephoto lens projects a small scene (in my case, 6 degrees across) onto the same film. This is often dubbed 'to zoom in'.

The wideangle lens is arranged (backwards) in front of the telephoto lens. The wideangle lens takes light from the light source, and projects it in a cone of about 70 degrees across. Light from the same point travel in parallel lines.

The telephoto lens is zoomed in as much as possible, so that it only takes a small section of what the reversed, wideangle lens has projected. Focus is set to infinity so that parallel lines converge to a point. The small section is then projected onto the image sensor.

In a handwaving way, one can say that the reversed wideangle lens magnifies the light source, the telephoto lens takes the central portion of this magnified image and magnifies it to fit on the image sensor.


1:07 pm, July 29, 2006  
Anonymous yvy said...

omg yee wei, this is good BUT you're scaring me.

5:20 pm, July 30, 2006  

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