Every camera stores sensor image data in a file for further use. The sensor image data are just grey values of different intensities in every pixel. A single pixel doesn’t show color. Our sensor image data contain a black and white world. How sad.
How do we get color images with a sensor that maps only grey values between white and black ?
All the colors we know can be derived from a combination of a specific value of Red, a specific value of Green and a specific value of Blue. If we know the shares of Red, Green and Blue in a color we know the color.
Our camera sensor measures the shares of Red, Green and Blue with small lenses in front of each pixel on the sensor that act as filters for Red, Green or Blue. The complete sample of these filter lenses is called a color filter array or „CFA“. The distribution of Red, Green and Blue filter lenses on the sensor is completely known only to the manufacturer.
The file that contains the sensor image data is called a RAW file. Beside the sensor image data at the beginning of a RAW file are informations about the complete file content. I found a nice Wikipedia article pointing this out. A RAW files contains also exposure data and information about the camera lens.
A software converting the sensor image data of a RAW file into pleasing colorful images is called a RAW converter. A well known and popular RAW converter is Adobe Camera RAW (ACR). A Phase One Raw file can be straight forward converted by ACR to a 16-bit TIFF. No further postproduction has been applied (see left image below).
A RAW conversion of the same file with the Phase One manufacturer’s own RAW converter Capture One to a 16-bit TIFF shows different color and brightness (see right image below). There was no setting of temperature, hue and saturation to make the images identical.
One RAW file was converted to two different TIFF. The difference between the TIFF can easily be obtained in Photoshop with the difference layer mode. The difference is an image in itself. With a sensitive gradient applied the following image is obtained:
The difference TIFF (Capture One) – TIFF (ACR) is derived pixel by pixel. The converted TIFF using Capture One contains more green, more magenta and more yellow in the darker values. The impact on the final result is unclear at the moment.
With my new glasses in my pocket I gazed the nearby market place on Saturday. I was captivated by six red callas whose price I could knock down to 10€ for all of them.
With my Zeiss 50mm Macro lens and no tripod I was trying to get nice shapes late in the evening. The following images have been processed using Lab color to enhance contrast and colors.
Just normal light of our living room let me to a nice coloring and interesting shapes. The blossom next to the lower right corner is a Siamese twin on a double stalk.
There are many stops put to a CT-scan, especially when dealing with women in reproductive age. We are always very careful before exposing any patient to radiation.
This middle-aged patient with repeatedly nausea and discomfort opposing pregnancy very strict and claiming menstruation 28 days ago underwent some medical examinations including gastroscopy and, eventually, a CT-scan.
We were prepared for a tumor when scanning the abdomen. We were amazed to find a baby despite many questions about patient’s history before the exam. Maybe, some obesity covered the situation with a veil.
You can see the bones of the upper and lower extremities, as well as the skull and some parts of the spine. The ossification of knees, feet and hands will take place the next ten years after birth.
It appears to be discussion-worthy if it’s a boy. Our methods didn’t lead us further on this.
To me the rotated, inverted and cropped image resembles to cave paintings. These paintings are assumed to be some kind of religious art, reflecting astonishment and grandeur of lost civilizations.
Certain is, the baby touches its right ear, as it was amazed by itself or reflecting its life. What else than human life is this ?
I like organ music. And I like the architecture of an organ. It’s always a composition of different metals and woods.
Today my favorite organ player gave us nice preludes as a present during the service.
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.
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 !
We went up to Cape Perpetua before our breakfast. I’d been there before after the eclipse in 2017 with Christa and friends. That year the sky was full of smoke.
Today the sun was shielded by some haze coming from the Pacific Ocean. I wasn’t clear in mind about going there a second time. The impressive view of Heceta Head lighthouse the day before hadn’t left me.
Black and white gives more meaning and feeling than faded colors. But it’s already long time ago and far, far away.
My new homepage is brought more and more into line. I’m pretty happy about the seamless integration of my astrophotographies as a top menu link in the new design. To be more precise technically: astrophotographies reside as a subdomain now. Painting with light became the leading website.
Using a new CMS it’s a bit fuzzying to get things under control. It’ll take some time …