Last updated:- 4th November 2024
Introduction.
Considering image quality, which is more important, the photographer or the camera? Forum experts claim most photographers think the sensor is more important. Another myth promoted on forums is a general need for high-resolution sensors and more Dynamic Range (DR). It's sometimes good to remind ourselves why we do photography or select a specific camera or format. This article summarizes my takeaways after spending time with the DPReview M43 forum. These takeaways are best described as the contrasts between real-life photography and the talking points pushed by marketers.
Landscapes with dramatic clouds and deep foreground shadows are known for having a higher dynamic range. The light reflecting from the clouds and deeper shadows increases the ambient DR, which adds to the complexity of photographing and editing these scenes. The Olympus Bracketing and Auto HDR (High Dynamic Range) functions are two ways of capturing and managing High DR scenes.
This article reviews the more practical aspects of photography like light, exposure techniques, and image editing. I prefer a more hands-on photography style. I will discuss the following:
- The Micro Four Thirds (M43) sensor format and a short history.
- The Technical versus Optical characteristics of digital cameras.
- Why is the social media discussion of dynamic range sales talk?
- More advanced exposure techniques versus the sensor do it all.
- Why were ETTR and HDR techniques more popular before 2012?
- The image sensor versus the image processor and post-processing.
- What does it mean to study light conditions or paint with light?
- Does the photographer manage the scene's dynamic range and how?
- A short video discussing image editing, dramatic clouds, and Workspace.
- Features like Stacking, Auto HDR, Bracketing, Composite, and others.
All digital cameras have technical limitations, such as a limited dynamic range, rolling shutter (sensor readout speeds), image noise, and others. Acknowledging these limitations, the Olympus engineering team created innovative functions like stacking, composite, and computational photography.
The M43 format is a true digital design. The goal was to optimize the image signal path from the lens to the sensor's image circle, the lens flange design, and the pixel entry angle. Live MOS sensors have bigger photon-sensitive pixel areas and are more efficient than Standard CMOS sensors.
Have you wondered why a 4:3 ratio versus the 3:2 ratio? The 4:3 ratio fills the sensor's image circle more efficiently than the 3:2 ratio. This means it enabled Olympus to optimize their Zuiko lenses and the average photon entry angle (efficiency) of M43 image sensors. It's interesting to study the M43 format. Olympus considered every efficiency variable while designing a new digital format.
Could this improve our Image Quality? Photographers can't control the efficient use of the sensor's image circle. The IQ improvements of the 4:3 ratio versus the 3:2 ratio are typically smaller than 1%. This example is only interesting to manufacturers because many such improvements make a huge difference. Most Full-frame promotions or "fact statements" fall into this 1% category.
What are the benefits of using Zuiko (Olympus) M43 lenses? Study this information.
Complex digital camera parts like image processors, image sensors, IBIS, and computational options like Auto HDR features did not replace the need for experience, photography skills, advanced lighting skills, and camera knowledge. They also didn't replace the need for tripods, a fill-in flash, lens filters, diffusers, reflectors, remote shutter controls, or any other photography accessory.
Experienced photographers value the significance of the above features and options. Forum "experts" push photographers to rely on "modern" image sensors, not knowledge and experience.
Advanced landscape and street photographers carefully select their locations, equipment, weather, quality of light, and sunrise/sunset times. Extraordinary images require planning and a series of short 3-minute photo sessions in perfect lighting windows. For example, the lighting could be ideal until the next cloud covers the sun. Capturing those special moments and great scenes plus post-processing can take days and hours. It's not a case of large sensors and randomly point-and-shoot photos.
Advanced photography means you know your camera, editing, and how to apply good lighting. The various "tree" images illustrate the concept of painting with light. I prefer to select the best dynamic range between the highlights, mid-tones, and shadows with the right time of day, clouds (diffused light), and the sun's position (incident light). The EM1 III image benefited from the afternoon sun, rich colors, and increased mid-tone and shadow information (reflected light) onto the sensor.
The above tree selection shows knowledge and experience are as critical as the camera. For example, older cameras like the Olympus EM5 and Stylus 1s have excellent image quality in good light. Studio photography is another example of photographers managing the ambient light. The above trees show the potential when reading a scene and matching the light to the photo, camera, and editing.
What about the camera's dynamic range? Camera reviewers and forum "experts" push oversimplified theories like "bigger is better". For example, they will say the EM5 II in the above example has less dynamic range than the EM10 IV. Does it mean the EM5 II has too little dynamic range to capture more shadow details or did I select the worst time of day? The Photons to Electrons graph (Figure 1) shows we can manage the digital camera's dynamic range by controlling the reflected light to the sensor. In addition, Olympus cameras have several options to tweak the tonal response curve.
This means we as photographers determine the sensor's Saturation and SNR. This is huge. The first question one should ask forum "experts," is how do I manage it and will it improve my IQ?
The images in this article were taken with my EM1 III, EM5 II, EM10 IV, and EP-7.
Technical and Optical Characteristics.
Why Technical and Optical characteristics? Modern marketing programs and simplified commercial theories are designed to support sales. The most effective way to learn more about digital cameras is to start with the differences between Optical and Technical characteristics:
- Optical characteristics like FOV, DOF, and lenses are linked to the sensor image circle.
- Technical characteristics like DR, SNR, and Noise are linked to sensor type and design.
The camera's optical characteristics are linked to the sensor's diagonal measurement. The Lens Image Circle has to cover the complete image sensor. This explains why the 25mm M43 lens is the same as a 50mm full-frame lens, why the Field of View (FOV) of M43 lenses is smaller than full-frame (FF) lenses, and why it's possible to design physically smaller M43 lenses than FF lenses.
Technical info helps photographers because it gives more details about the design and type of sensor, camera features, and image processors. Contrary to social media FF promotions, sensor size doesn't guarantee better image quality. An experienced EM1 III photographer will capture similar IQ in the same light conditions as most forum "experts" with FF cameras. For example, technical information helps us to master the technical limitations of image sensors. Technical details are valuable when reviewing and analyzing digital cameras and image sensors. The key is acknowledging the technical limitations of digital cameras and that cameras benefit from experienced photographers.
Do large sensors have better color? The theory behind color is simple. The camera removes the color information from the reflected light with an RGB filter covering the sensor, which means the sensor captures a Black-and-White image. The Image Processor uses the RGB filter values, WB measurement, and the sensor's B&W image information to recalculate the final color information in 8, 12, or 16 bits. The quality of light and the camera's Image Processor is responsible for Color Rendering.
The practical side of Optical and Technical knowledge. Social media experts rely on the size of the sensor. The value proposition of the "bigger is better" theory is little image noise, more color, higher dynamic range, and image quality. Experienced photographers adjust the camera's technical and optical features (camera settings, lens, framing, plus options) to match the scene, time of day, and lighting. The benefits are technical and optical control with more creative freedom.
Does technical information improve my photography? Technical papers and the following Photons to Electrons graph explain that the sensor's Noise Floor consists of Read Noise (Temporal and Dark) and Shot Noise. Social media experts focus only on Shot Noise because the "size and capture" theory says larger sensors capture more light with "less" noise. Wouldn't the shot noise increase with more light? (Fig. 1) A better way is to control any visible noise (noise floor) with the sensor's SNR and Saturation. The Photons to Electrons graph gives a theoretical overview of the image sensor.
See this link for a recent paper discussing image sensors.
Photons to Electrons Graph. Each photographer should study Figure 1. Did you know that the typical grainy effect is caused by Temporal image noise? The sensor's noise floor (Dark and Temporal noise) is active when we turn on the camera. The sensor only produces an image signal once the reflected light exceeds the sensor's AST (Absolute Sensitivity Threshold). I added the histogram to the above graph to help people visualize the visible shadow noise with smaller SNR values.
The Average Scene Luminance in the exposure formula is proportional to Reflected/Incident Light, time of day, and weather conditions (quality of light). That's why Pro photographers work with light. The role of the Aperture and Shutter when Exposing the sensor is critical. Photographers use these external and camera variables to manage the sensor's Saturation and SNR.
A short summary of the camera's Exposure Variables are:
- The Aperture and Shutter Speed expose the image sensor
- The ISO setting amplifies (brightens) weaker image signals
- Flashes and Diffusers control the Average Scene Luminance
- The time of day and the sun change the scene's Luminance
- Different materials and colors influence Reflected Light
The Image Signal Path is the final part of this Technical and Optical summary. The next illustration gives us a basic overview of what happens in the camera. This is a helicopter view of the image signal path inside digital cameras. The illustration was designed to assist digital photographers with enough information and know-how to master the image sensor's Saturation and SNR performance.
This flow diagram is the key to mastering Workspace and the Enhanced Raw Format.
See this video discussing more advanced exposure techniques.
What did we learn from this article?
Final thoughts.
