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.
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:
It feels like very long ago. Harold and I were taking the shots and X-rays of new compositions last week of April this year. Our first try was an orchid with two stems. The transparency effect is very much augmented using an X-ray. A stem behind petals doesn’t show easily in HDR light box photography.
With a Phase One camera at my disposal a strong crop of the composition shows the tenderness of our orchid much better. With a resolution still sufficient.
Since 1905 there is an X-ray meeting in Germany. It was the 100th time this year. Nowadays the convention takes place every year.
Besides the scientific news the convention offers the opportunity of caring for personal contacts. It is part of the beautiful things of the convention to meet old acquaintances and to exchange with them.
Leipzig fair is a great environment for this event. An agreeable tiredness affects me at the end of the day after many positive conversations. I left the celebration with relief.
Clematis is a reliably blossoming flower in our garden. Every year we look forward to her blooms for many weeks. Photographing flowers means sacrificing beautiful little things. It took me some time to go there.
With growing experience I feel less pain to sacrifice a bloom for artistic purposes. It relieves me a little, that I have the blooms swum after my photo and X-ray sessions in a soup-plate filled with water which is in the kitchen. Many people like the floating blooms in a soup-plate, if they are in a break.
The HDR series of my composition with three clematis gave me a hard time. Although a tripod is indispensable and always used, a small pixel shift between exposures was perceivable. After fixing this, light, color and structure was processed for an HDR image.
The X-ray of the three clematis was performed as mammography due to the size of my composition. The fusion image can be understood as a texturized HDR by means of a radiograph. But there is no unique solution to all compositions. The best solution has to be found out individually.
After all, the clematis look as light as a feather in this image. It was worth it.
First flowers in spring show up. With much support from my colleagues I’m able to do some fusion images. We all would like to have another calendar.
Preparing the lightbox, the X-ray machines, my camera and picking out the data is a bunch of hassle.
My personal favorite is the blue cornflower. It looks like a print of an old botanic book:
The next day I turned my attention to our white and blue Aquilegias. No chance to process the raw data yesterday. Eventually, there was a chance today, after quite a bit of tedious work at my desk:
Fusion imaging is a method full of surprise. My red calla lilies revealed an effect I had forgotten completely. There must be a gradient in every X-ray exposure.
Preparing a fusion image composition with my 6 red calla lilies I found a troublesome gradient in the X-ray.
The cause for the gradient is a weakening of X-ray radiation at its origin in the X-ray tube. A closer look at the phenomenon can be found in my FAQ. This effect of variable recording of photons phycisists call „anode heel effect“.
As part of my creative process I rotated the composition shown above by 180 degrees and exposed it a second time with the same parameters. Note that post-production as well was done equally for both X-ray exposures !
Sometimes reality falls behind our expectations. With 6 red calla lilies I felt well prepared to do some new X-rays and HDR images for image fusion. But my X-ray system surprisingly raised a barrier. The main computer stopped doing his job.
Many thoughts ran through my brain. Will we be able to examine patients the next day ? How fast the supplier will be able to react ? Will the company find a cause of this disturbance ? How many days will my calla lilies be alive ?
I found a work-around by thinking over the interacting hardware. Doing some steps and with a newly restarted system I was able to create 7 different compositions without further disruption of which I show here No. 4.
With X-rays emerges a more impressive illusion of transparency than a plain HDR would have been able to produce. Even when using a lightbox.
Similar to a lightbox it produces better results when laying a petal or a complete blossom over the top of the stalk of another one.
On top of the longest stalk is a twin blossom !
You never know if the inversion in Lab colors leads to an attractive result. It’s always worth looking at Lab color transformations. In this case the black background yields vivid colors.
A couple of days ago I went to see a friend who knows my weakness for X-ray examinations. He gave me a mammoth tusk. At first glance I doubted if there would be any possibility to produce an image because of the estimated high density of this stone age tooth.
So I decided to try a CT scan. I had some butterflies in my tummy and feared an artistic disaster. Indeed, the first slices emerging from our scanner weren’t much convincing. As a first step of postproduction My technician and I decided to do a volume rendering of the 0.75mm slices. We got a surprisingly good result that showed interesting details of the inner structure of this biological remnant.
A tusk is a tooth of the upper jaw of the mammoth (or elephant). A major blood vessel branching off while running to the tip can easily be seen. The caves on right hand side are assumed to stabilize this life long weapon of a mammoth.
This tusk has been stone age ivory and consists mostly of calcium phosphate and calcium carbonate.
As there is no restriction to trading of mammoth ivory there is an increasing amount of siberian stone age ivory emerging to the market.
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.
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.
Fusion imaging is beauty made of composite X-ray images and HDR images on a light box. The primary question is what energy fits best for flowers. To my experience 40 kV is often suitable. But: the proof of the pudding is in the eating.
Mammography systems start e.g. from 20 kV and reach 39 kV. The sensor is up to 24cm x 30cm. Conventional systems start from 40 kV and reach 125 kV. The sensor is up to 43cm x 43cm what makes them more attractive to floral compositions.
The higher resolution and the lower energies of a mammography will suit better for transparent objects. But the spatial limit of a composition (which is 24cm x 30cm) might put hard restrictions on the artist.
Floral compositions have more creative space with a bigger sensor. But the X-ray tube starts with 40 kV and this might lead to overexposure of tender structures.
Thus I performed today more than ten compositions to study this relation.
After four exposure of three tulips I found this composition with four dense blossoms attractive to go further. The composition might somehow resemble to a sketch of three angels. The image is nice due to very soft edges of their „wings“, technically blown out portions in the image. The inner structure of the nearly closed blossoms is well resolved. The stalks serve as „body“. There is no advantage with higher energies.
The same composition was done immediately after the X-ray as a bracketing series on a lightbox. After returning I processed a manual HDR, the colors not to warm.
The final fusion image is a composite of the preceding two images. Compared to the lightbox photo, the hidden stalks reappear naturally, the inner petals are outlined like a sketch.