• flowers,  Lightbox,  Macro

    Last hot summer days

    The last hot summer days are noticeably less hot. Autumn shows up on my rose hips, which are still fed by the water of a vase. Over the course of the days her leaf green became increasingly discolored in autumn. I don’t want to believe it.

    Delicate rose hips before autumn starts © Julian Köpke
  • flowers,  Lightbox

    Staying at home

    Light is subject to permanent change. The transformations of light accompany us always. In the course of the day, we immerse ourselves in the light of various sources and their shaping unnoticed. In a photograph, too, the imperceptible shaping of light is our companion.

    The light in a photograph and its impression is shaped or transformed by postproduction. The changeability of the light by postproduction helps an image to its final expression. 

    What light do we see in our dreams ? What light do we see when pre-visualizing an image ? What light do we see when we get the idea to a photograph ? The latter light we experience like „a flash within a long night“. It is only after the completion of the work that relaxation may take place.

    Inner light in a red rose © Julian Köpke

    Having learned how to do focus stacking on my PhaseOne camera, I made two series of 20 macro images with a rose on a lightbox, the box switched on and off for the two series. Combining the two light situations made this image possible.

    You may find more roses here.

  • flowers

    A rose is a rose is a rose

    Just photograph a rose and show its beauty – how wonderful that would be. Is the light right ? Do false shadows emerge ? Is the structure correctly reproduced ?

    Again and again I have to go through our garden and look at the flowers. Yesterday was it again. The sun had just set and the full moon should have decreased a little later.

    I tried it with all f-stops the camera and lens gave to me. To my surprise the aperture 32 at ISO 50 with 45s exposure speed was my favorite. Only at the edge the picture had to be darkened and desaturated. Post-processing can be as simple as that.

    Rose during Golden Hour © Julian Köpke
  • Travel

    A rose is a rose is a rose

    Recovering from a strenuous afternoon where I was exposed to an increasingly deep dementia I sat in my hotel to have a light meal. Nerve-racking music all over the room. A beautiful sunset with warm colors and flattering light after a grey and rainy day.

    A rose is a rose is a rose © Julian Köpke

    Dementia shows a person deprived of many intellectual capabilities. There is still the capability of a relation left, weak and vulnerable. There is no understanding left for us. Speechlessness counts the most.

  • X-Ray

    Effect of photon energy on X-ray images

    I assume that everyone has had at some point the experience where less was more. Especially when dealing with computer based image postproduction. Software makes handy wonderful, or better: powerful, filters. Experienced artists know that only a pinch of something or homeopathy is a key to better results.

    The same holds true in X-ray production. A maximum of energy does not provide better images. Let’s look closer at this point.

    What is the influence of energy to X-ray images ?

    Higher energies in X-rays mean shorter wavelengths and a higher resolution. Therefore it might seem reasonable to increase the energy in our X-ray tubes always to the maximum to produce incredible images based on a maximum resolution.

    With four images below I show the influence of increased energy levels on X-ray images of a single rose. The applied energy levels are 40kV, 60kV, 90kV and 109kV. The steps of postproduction were the same in every image. Slight differences are owed to best contrast in each exposure.

    Surprisingly to the novice we get an increasing loss of contrast (or less available contrast) in each image with higher energies. This effect of loosing contrast can easily be seen in this series of four X-rays and is highest at 109kV.

    Rose digital X-ray photo at 40kV © Julian Köpke
    Rose digital X-ray photo at 90kV © Julian Köpke
    Rose digital X-ray photo at 60kV © Julian Köpke
    Rose digital X-ray photo at 109kV © Julian Köpke

    The explanation for less available contrast with higher energies is the following physical effect: the more photons have shorter wavelengths the more photons run unaffected through the object down onto the sensor. With all photons running through without any hindrance the sensor would show a homogenous gray value.

    Every structure looses contrast when turning to higher energies. The optimum for a structure is found by experience and varies significantly.

    In the medical field the applied energy strongly depends on the purpose of the examination and the structural demands to be diagnosed.

    The above demonstrated meaningless low contrast for our single rose at 109kV doesn’t hold true at all in radiology. Radiologists use frequently 125kV for a chest film to get reproducibly valuable contrast in most patients.