• Fusion imaging,  X-Ray

    Spider conch X-ray fusion photo

    A friend gave me a shell of a spider conch to make more fusion images. The scientific name of the spider conch is lambis lambis and it is a sea snail. There is a nice Wikipedia article on it.

    The hard shell with a lot of radiopaque lime made me doubt the success of my X-rays. On top, my first attempt at a HighKey image wasn’t really convincing. Only the combination of a normal photography for the color, a HighKey image for a transparency effect together with the X-ray image resulted in nice image.

    Fusion image spider conch X-ray and photo seen from the bottom © Julian Köpke
    Fusion image spider conch (lambis lambis) X-ray and photo seen from above © Julian Köpke

    The X-ray image appear less lively, but full of formal power. The orientation of the animal is conveyed by the photographically reproduced color. There are only minimal hints wich orientation the X-ray has.

    These are the corresponding X-ray images:

    Spider conch (lambis lambis) © Julian Köpke
    Spider conch (lambis lambis) © Julian Köpke
  • General

    X-ray Odyssey

    How to communicate an erratic process in terms of an image ? The Iliadic greek were pirates of the Mediterranean with fast vessels, invading mainland from the seas, enslaving people, robbing stocks and much more.

    The writing down of the Ilias was between 678 and 662 B.C., a time of Assyrian dominance and cultural superiority.

    With three different Nautilus shells I bought last September on Crete I did this composition on my big X-ray sensor with 35cm x 43 cm and 170µm per pixel resolution. Two energy levels were necessary to get a high resolution image of the core of the Nautilus shells.

     

    Odyssey © Julian Köpke

    To overcome the look-and-feel of a medical X-ray it is a logical idea to invert the light. Black becomes white and vice versa. White means shining through of X-rays, black means opacity. It’s like a dream !

    Odyssey (light inversion) © Julian Köpke
  • X-Ray

    Nautilus and Flowers

    How to prepare a X-ray session ? What flowers suit to a Nautilus shell ? Where does color come in ? 

    I went to my gorgeous florist to have a look what offer she can make during wintertime. My phantasy were spinning around something ethereal or unrealistic. I bought some flowers with respect to their shape. 

    The Anthuria caught my eye immediately. The Tulip was still closed and got more and more yellow within hours.

    All these compositions shown here were made with dual energy X-ray. The lowest energy of the tube is 40kV, which yields with 4 mAs a quite good insight of flowers. For the center of the Nautilus shell, 70kV and 2.5 mAs is more appropriate.

    My first composition was a Nautilus taking off a bouquet of flowers. This reminded me of Renaissance engravings full of symbols. I do not feel depressed. The representation as a X-ray positive jsut shows the bouquet.

    Miraculous flowers and nautilus shell © Julian Köpke
    Miraculous flowers © Julian Köpke

    A more grounded composition is the second with a Nautilus shell moving towards the roots of my bouquet. Hopefully, the plants will survive. The positive representation always needs some extra editing. By just inverting the Blacks and the Whites the Nautilus would be too dark. Our reception cannot be just inverted and feels alright.

    Flowers and Nautilus © Julian Köpke
    Flowers and Nautilus © Julian Köpke

    With the look-and-feel of old engravings in mind the third composition ist between surreal and a still. It took me some time to mask out the flaws of an original X-ray to get a true black background. Masking can be done iteratively and easily combined with Photoshop. („That’s what Photoshop is made for  !“).

    Some colorizing was done to overcome missing photographic shots. There was simply no time in my X-ray unit to do both at a time.

    Nautilus shell as a vase or a vessel („Hansekogge“ or cog) © Julian Köpke
    Positive representation of Nautilus shell as a vase or a vessel („Hansekogge“ or cog) © Julian Köpke
    Coloured Nautilus shell as a vase or a vessel („Hansekogge“ or cog) © Julian Köpke
    Coloured positive representation of a Nautilus shell as a vase or a vessel („Hansekogge“ or cog) © Julian Köpke

    My fourth composition is called „The Argonauts“. The Nautilus shell serves as Argo, the legendary fast ship, with its crew, called Argonauts. The colored version is more convenient for our eyes. As before the X-ray positive looks more ethereal. 

    A Nautilus with flowers as Argonauts © Julian Köpke
    A Nautilus with flowers Argonauts © Julian Köpke
    X-Ray positive of a Nautilus with flowers as Argonauts © Julian Köpke
    Colored X-ray positive of a Nautilus with flowers as Argonauts © Julian Köpke
  • FAQ: X-ray Imaging of Nautilus shells

    X-rays were initially used for research in atomic physics and medical diagnostics and therapy. Their ability to reveal structures inside an object even with an opaque surface was the driving feature of scientific and technical development of X-rays. Nowadays, beside its proven medical usefulness, X-rays are used to examine technical structures and there are telescopes to map X-rays from our Galaxy and the universe. Every radiological technician who starts in its profession learns to do X-rays of common structures like flowers, animals or teddy bears.

    In the digital era, X-ray images are obtained using sensors, while film was used historically. The sensors in the medical radiological field have dimensions such as 24cm x 30cm or 43cm x 43cm. The corresponding spatial resolution for these sensors is between 70µm and 140µm.  A typical high-end camera used by a professional or advanced amateur photographer might have a pixel resolution between 4 and 8 µm. Therefore, photographers might well wonder if there is any precise imaging possible with such pixel size. Let’s look at this a little more closely.

    X-rays, like visible light, can be characterized by their energy or wavelength. Shorter wavelengths correspond to higher energy. The capability to penetrate an opaque structure increases with energy. If you think of a photon as a particle, smaller particles with higher energies penetrate an object more easily. An overview of this relationship is given in the table shown here:

    To make this more clear, here is a series of X-Ray  images with increasing energy. The first image was obtained with 40 kV which corresponds to a wavelength of 0.031nm. Our eyes are only able to see wavelengths between 400nm (blue) and 750 nm (red). Therefore, photons with a wavelength at 40 kV cannot be seen with the naked eye. The peripheral parts of the Nautilus shell are clearly depicted. A photographer would classify the circle at the center of the shell as „blown out“. In fact, they are not blown out. The radiation is not able to resolve the structure, because the wavelength of the X-rays is too long in this case to penetrate the shell.

    40kV 10mAs 0.031nm

     Let’s go to shorter wavelengths (implying higher energies). Using 50 kV or a wavelength of 0.024nm gives more structure to the central parts. The photographic impression of a „blown out“ center is reduced. However, looking at the peripheral parts of the Nautilus there is a loss of intensity and a more grayish impression. It is conceivable that this might be regarded as an overall acceptable but subtle effect.

    50kV 2mAs 0.024nm

     To take this further, we can go up to 60 kV or down to 0.0207nm. The center is now close to perfectly „exposed“ with some detail apparent, although some smaller structures are still not resolved. The intensity loss at the peripheral parts increases and is now pronounced. A photographer would clearly regard the periphery as „underexposed“.

    60kV 2mAs 0.0207nm

    The last example of this direction of higher energy and shorter wavelengths is 70 kV or a wavelength of 0.0177nm. The photons wavelength is  now 57% compared to 40 kV. You may think of this as „smaller“ photons. The result is a clearly depicted core with a complete loss of peripheral structure. A photographer would have every reason to be worried about „underexposure“ and loss of detail everywhere but the center.

    70kV 10mAs 0.0177nm

    What we’ve seen here is that the capability of X-rays to penetrate an object and to go through an object is dependent on energy levels. With shorter wavelengths X-rays go through an object without disturbance but our sensor is „blown out“ at the peripheral parts of the Nautilus shell. Using 70 kV the central parts are much better resolved, but the periphery is too dark. The energy to use for any X-ray image therefore often depends on the primary goal of which portion of the subject is most important to capture.

    If combined, the four exposures shown provide a beautiful, nearly weightless image:

    Nautilus X-Ray Energy Compressed © Julian Köpke
  • Lightbox

    Mediterranean creatures on a lightbox

    Today I put some tests on my cretean purchases from last September to evaluate their potential of being subject to fusion imaging. I bought three Nautilus shells and two sea snails, holding them in the store against the sun to check their transparency. My untidy studio accommodated these precious stones under quite a bunch of something.

    The best representation is with a black background, i.e. with inverted L-channel in Lab colors. With a black background a soft shining light appears in the objects.

    This snail has a shape a triangle and resembles a bear claw or an Apollo capsule in the late Sixties. The translucency is very little.

    Cretean Snail © Julian Köpke
    Cretean Snail © Julian Köpke

    The following snail has a classic shape. With the black background it resembles a galaxy in outer space.

    Mediterranean Snail II © Julian Köpke
    Mediterranean Snail II © Julian Köpke

    My first attempt with the Nautilus shells led me to a copper-like color representation with a single shot image. Lab colors is the key to this color and light distribution. Very attractive is the fact of two shells turning right and one left. Why did I wait so long to make this image ? Why do we miss important opportunities ?

    Three Nautilus shells with light inverison © Julian Köpke
    Three Nautilus shells with light inverison © Julian Köpke