Life is a series of moments that leaves us with memories, both splintered and whole.
If you are just joining us, the PRELUDE & SYLLABUS section is the logical starting point for the series.
Welcome to Digital Photography #101
by Virtual Studio Photography (VSPHO)
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Now we ask: How does this compare to DIGITAL IMAGING?
This comparison fairs well with Audio CD technology. In 1982 the CD was born, just 93 years after the first vinyl record was pressed for the Gramophone in 1889.
The audio purest of vinyl albums love the seamless musical reproduction and even the "pops" of the imperfections in the vinyl. But the initial reproduction of music stored in a digital/mathematical system was reproduced in a non-esthetically pleasing way. In its infancy, the CD was like listening to amplified AM radio with a lot of Bass and Treble, but no soul, no depth.
With each new generation in the critical Digital to Analog stage of audio reproduction, the sound imagining quality improved dramatically. Now with CD digital audio reproduction, even when listening on less than an audiophile sound system, it can be breath taking.
Just as musical reproduction has advanced since the gramophone, equally the art of digital visual reproduction has evolved to an unparalleled refinement.
The initial Digital Imaging Cameras released after their birth in 1979 by Eastman Kodak were primitive at best. Like the CD, it took several years of refinement to produce Digital Cameras that rival and even surpass the best 35mm cameras in picture quality.
The image resolution, spatial resolution, high dynamic range capability and over all esthetics of a high quality digital image is second to none. The convenience, speed, photographic agility and unlimited configurations of the Digital Camera Spectrum was unimaginable before 1979.
As we outlined in Part 1, 35mm Film still has a drawback in Resolution when Faster Film Speeds are required. So we will do the comparison with 35mm Film Speed ISO 100 for fairness to 35mm film.
For many years, ISO 100 has been the industry standard for compromise in Film Speed for general use with high enough resolution for image enlargement capability.
What we are really comparing in Resolution is how many "DOTS to Dye Clouds" Per Inch (see Part 1) are available to compose a picture. By measuring the DOTS PER INCH when printed, we can compare the Resolution of any size picture to each other.
If we have a 4 x 6 printed picture with 240 Dots Per Inch (240 DPI is the industry standard resolution for magazine publications), we would simply Multiply 4 x 6 = 24 to get the Total Square Inches.
We also need to convert our 240 DPI into how many DOTS we need for each Square Inch to print. 240 x 240 = 57600 DOTS Per Square Inch when printed. Just to clarify, when it is still on our Computer Monitor, it is the same exact calculation, but measured in PIXELS.
Then we would Multiply the 24 (square inches) by the 240 DPI resolution (57600 DOTS/PIXELS per Square Inch) to see the Total Amount of DOT/PIXELS we need for a 4 x 6 image.
24 x 57600 = approx. 1.38 Million Dot/Pixels to make a high resolution 4×6 inch color print at 240 DPI. NOTE: The highest resolution commercial grade, professional color printer is FUJI at 350 DPI. These are the big floor standing printers you see at your local photo stores. They make prints from Digital Images or from the negatives of 35mm film.
As we outlined in Part 1, Dye Clouds are not perfectly sized dots, they vary in size and shape to a small degree. So the average sized Dye Cloud in a high quality ISO 100 film is around 10 microns.
I am going to do the math and just give you the outcome in inches to keep this simple. (Advanced photographers may want to do the math.)
That is 2540 (or more) Dye Clouds Per Inch, this is around 6 ~ 9 mega-pixels for the entire 24mm x 36mm film image. For many years, you could have fit many Dye Clouds into a single PIXEL. Many consumer level cameras were only .31 mega-pixels. When Digital Cameras got up to 1 & 2 mega-pixels, they were considered high-resolution for Digital.
But now in comparison with technical advancements, new consumer level cameras starting at $3000 (not $40,000 professional digital cameras) have a Resolution of over 36 Million PIXELS. That is up to SIX TIMES (600%) the resolution of 35mm ISO 100 film. Even ISO 25 film (the finest resolution ever made in 35mm film) has an average Dye Cloud size of 4.9 microns.
You can now fit up to 6 Physical Pixels into one Dye Cloud of ISO 100 film.
Now we look at the DynamicRange. This is the ability to produce images with Light Intensity that varies from the darkest part of our image to the lightest part.
The Dynamic Range of Human Eye can rectify about 6.5 f-stops of light. That is called the Static Contrast Ratio. That means that at any given time, whatever the "current size" of the Iris, the Human Eye can see detail within that range of Contrast. If the Light Intensity changes, so does the size of the Iris.
The overall Dynamic Range of the Human Eye is called the Dynamic Contrast Ratio. So overall, a young healthy Human Eye can rectify around 20 f-stops across the entire visual light spectrum with the adjustment of the Iris.
Traditionally, 35mm film was able to shot an image of around 6 f-stops of Light Contrast with the proper exposure. That is close to the same Static Contrast Ratio as the human eye. Most Digital Camera Sensors are at a 5 f-stop light range but are closing fast to the 6 f-stop capability.
However, the big difference now becomes the ability to widen the Dynamic Range in post production (the Digital Dark Room) to more than a 10 f-stop range. This is called HighDynamicRange.
With 35mm film you could try some tricks like a half and half Neutral Density Filter (covered in another section) on the top to reduce the light level from the sky to try and control the Dynamic Range. This of course could also look unnatural.
With Digital Technology, any picture can be shot with multiple exposures with a function call "Bracketing." This is available on 35mm Cameras also, but you can not easily mesh the two diversely contrasting film negatives into one wide dynamic range picture easily, if at all.
In a quality digital photo editor, meshing two highly contrasting images is a learned talent, but once mastered becomes an easy task.
The Dynamic Range of Digital Imaging is quickly evolving.
The last thing I am going to cover here is the COLOR DEPTH. With 35mm film, the Color Depth is infinite. Because the film is covered with a color filter, the intensity of each color is directly proportional to the amount of light that strikes any given Dye Cloud.
In the next section, ISO Sensitivity I will explain in more detail about the technical aspect of the Depth Chart.
In a nut shell, when a Digital Image is captured, a number is assigned to each individual Pixel as to the intensity of the color for that Pixel. In the old days (five or six years ago), memory and hard-drive space was more expensive, a need to save space.
With Digital Technology getting less expensive everyday, storage is no longer an issue.
Your camera has settings pertaining to resolution and picture quality. (RAW format is the best of everything, more in another section on RAW format.) When you set the Quality to the "best" setting, you are utilizing the best Color Depth of the camera.
This is incorporated with the Dynamic Range settings know as the Grey Scale or "Shades of Gray." (Graduated Levels from the Blackest Black to the Brightest White.)
In the highest setting, a good DSLR Camera records information in a "Bit Depth" of 14. That is 2 to the 14 power of graduated levels on the grey scale, or 16384 Shades of Grey.
That also means 16384 Shades of any Color. Example: Say Red being dark to almost Black to a Red being a very Light Pink almost White with 16384 shades of Red in between. The to Human Eye, that is virtually infinite.
But Professional Digital Cameras already utilize 16 Bit Depth, the gradient levels jump to a Grey Scale of 65,535 Shades of Grey. This may become standard for consumer level cameras as professional level cameras continue to advance.
Here is an example of three Bit Depths. If you click on the link, you may compare a 3 bit 8 color depth, a 4 bit 16 color depth and an 8 bit 256 color depth.
Hold the CNTL key and hit + or – to control the image size.
Click HERE for PICTURE: Then hit the "back arrow" at top left of page to return. If the picture comes up BLACK, just hit the screen REFRESH icon. Round Arrow upper left of screen.
I will also clarify, when you set-up your computer monitor to the highest color setting, it is listed as 24 bit or TRUE COLOR (16 million colors). That is not a direct comparison to Digital Cameras. That is an industry standard of an 8 bit dynamic range across three color channels (RGB). So the direct comparison to Digital Cameras is an 8 bit Color Depth.
Likewise, Computer Monitors do not have the same capability of resolution as enlarged prints. The newest Monitor Standards like the QSZGA have a total PIXEL capacity of almost 5.3 mega-pixels. But our comparisons for now are in reference to printed pictures. Plus, to get a print or film negative to a digital image, you have to scan it. That defeats the purpose of the comparison in the first place.
From my perspective, when Printing a well shot, high resolution image from a quality Digital Camera, it will meet or exceed any 35mm film image, even in the arena of overall esthetics.
Here is a simple piece of art dedicated to Joseph Niepce. We can use Digital Technology to create an artistic silhouette in honor of the first photographic picture. (The technique is the purest form of Posterization utilizing a 1 bit color depth.)
Hold the CNTL key and hit + or – to control the image size.
Click HERE for PICTURE: Then hit the "back arrow" at top left of page to return. If the picture comes up BLACK, just hit the screen REFRESH icon. Round Arrow upper left of screen.
When you add the limitless capabilities of editing in a professional photo editor (known as the "DIGITAL DARK ROOM"), the Digital Imaging World has come of age!
In the NEXT section, we will apply this Digital Technology to the Third Parameter of the EXPOSURE, the ISO Sensitivity.
Virtual Studio Photography (VSPHO)
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