Last updated: 8th April 2026
The positive memories of filming with VHS inspired my priorities while preparing the next update to my filming series with Olympus cameras. My goal was to prepare the final look of my images and video footage in the camera. That meant more advanced color and exposure techniques. I decided to use two Olympus E-M5 II cameras, as the unique film look of these cameras supported my VHS theme. It's also easier to set the look and feel of the recordings in the camera. I came across an interesting video from a YouTuber, Duade Paton, which encouraged me to prepare this short article in support of future articles. It's a good idea to watch his video before you study this interesting subject.
PS: My next article in my filming series will be out soon...
Olympus E-M10 II with the M.Zuiko 17mm f1.8 lens. ISO200, f4.5, 1/400. What do we learn from the histogram?
Basic guidelines to optimize your exposure mix
The histogram in the above image suggests an optimum exposure mix. The best way to confirm that is to evaluate the histogram with the camera's exposure mix. The goal is to check the saturation and the SNR levels of the sensor. For example, the histogram and native ISO indicated a saturated sensor. The exposure mix produced excellent image quality with a wide depth of field at f4.5. The 4th exposure variable (late afternoon sun) was ideal for this scene and the "painting with light" effect.
Summarizing the exposure mix and histogram of the above image:
- Histogram: A native ISO with no clipping and the histogram to the right.
- Native ISO: The sensor was saturated (with a high SNR) at the native ISO.
- Scene Luminance: The late afternoon sun and "painting with light" effect.
- Aperture: The right focus point and f4.5 created an optimum depth of field.
- Image sharpness: A shutter speed of 1/400th worked well for sharp results.
Tip: LV (Light Values or scene luminance) - See the Duade Paton video.
Figure 1.
The above image signal flow diagram is a high-level overview of the digital imaging process. It was created as a practical guide for photographers seeking an alternative to the oversimplified "bigger is better" or "capture more light" theory. The goal is to simplify managing technical aspects like image quality, dynamic range, and image noise. The image signal flow diagram highlights:
- 4 critical aspects of the digital imaging process (lens, sensor, processor, and Workspace).
- the 3 variables exposing the image sensor (reflected light, aperture, and shutter speed).
- the sensor and why the photons to electrons graph is critical for managing the sensor.
- the exposure formula and the 4 variables we manage in the digital imaging process.
- the role of the TruePic image processor and managing the digital imaging process.
- the link between the image processor, the exposure calculation, and Workspace.
The question photographers fail to ask is, what causes noise, and how do we manage it? The answer is the photons-to-electrons graph. As the bucket-filling-with-water example has been used to promote the "size and capture" theory, it failed to explain critical aspects like image noise, sensor saturation, and SNR. Duade Paton added the role of "Light Values" in managing the exposure mix, noise (SNR), and ISO amplification. My suggestion is to add the following to his bucket presentation:
- A layer of sand at the bottom of the bucket to represent the sensor's noise floor.
- Explain SNR and the effects of ISO amplification and lower light values on noise.
- Sensor saturation and the link to SNR, "filling the bucket," or exposing the sensor.
PS: Saturating the sensor (filling the bucket) is not something magical linked to the size of the sensor...
Figure 2.
Many photographers never learned that lower SNR values cause more visible noise. The sensor's noise floor is always present; we just don't see it at higher SNR values. In other words, the layer of sand in the bucket is more visible with less water. The alternative for low-light conditions is saturating the sensor (filling the bucket) at the camera's native ISO, wider apertures, or longer exposure times. One could also plan lower SNR values with more noise when upping the ISO and shutter speed.
It should be clear that the ISO function does not generate noise. One can, therefore, consider the ISO function as an image signal amplifier (Fig. 1) or a creative/control element. For example, it's possible to manage highlight clipping when finalizing your exposure mix. For instance, set your nighttime city exposure mix, dial back the ISO (1 to 2 stops), and correct it with the exposure compensation slider in Workspace. What is the difference between exposure compensation and a tonal adjustment?
The information in this article enables us to explain and manage dynamic range in a similar way as we do with noise. We can also explain dual ISO with the above illustration. Dual ISO is another example of the FF collective withholding information because sales have priority over knowledge.
PS: Visible noise simply means the sand (noise floor) becomes more visible with a partially filled bucket.
Olympus E-M5 II with the amazing M.Zuiko 7-14mm f2.8 lens. ISO500, f3.2, 1/10 sec. I converted the enhanced Raw file in Workspace.
How to use the histogram
Always consider the ISO value as another variable in the camera's exposure formula. ISO amplification is the difference between a partially exposed sensor and an 18% gray exposure or saturated sensor. The camera uses 18% gray exposures to accurately replicate the ambient light and color.
Photographers were never "given" the opportunity to optimize the camera's sensor or manage specifics like sensor saturation, SNR, noise, dynamic range, or the exposure mix. The reason is social media distractions, like the histogram displays only 8-bit JPEG data, and ISO 100 on Olympus cameras differs from ISO 100 on other cameras, or we shouldn't trust the histogram because it's inaccurate. These distractions are totally irrelevant when you start applying the histogram. Why?
A more productive option is to practice the basic principles discussed in this article. For example, I always think in terms of f-stops (1 EV steps) while preparing my camera for a challenging shot. It's a real benefit to develop a feel for doubling or halving your exposure values. The most effective way to use the histogram is to use the image signal flowchart in figure 1 and manual mode on the camera to have the histogram and Live View highlight specific information. See the examples below...
Example 1 - Ambient light
I am always surprised at the level of ignorance or cognitive dissonance when people boast about using ISO 25600 on social media. For example, ISO 25600 means 7 stops of amplification, whereas the above images illustrate a 3 EV delta. The left image was amplified by 3 stops, or ISO 800, and the image to the right shows how much reflected light was reaching (exposing) the sensor at ISO 800.
The histogram measures the brightness of the pixels in the image. The horizontal axis represents the brightness levels from pure black on the left to pure white on the right (0-255 tonal range), and the vertical axis shows the number of pixels at each brightness point on the horizontal axis.
How did I measure the reflected light exposing the sensor? Start by setting your exposure in auto or aperture mode. Change to manual exposure mode and apply the autoexposure values. The histogram will display the reflected light exposing the sensor as you turn the ISO back to its native value. That means the histogram is measuring the reflected light passing through the aperture and shutter onto the sensor. The flow diagram in Figure 1 helps us to identify and target specific phases in the imaging process, and manual mode helps us to display them in Live View and the histogram.
For example, the goal with ETTR is to saturate the sensor. That means more reflected light reaching the sensor. One option is fixing the ISO and adjusting the shutter, aperture, and scene luminance. Use the histogram to follow the reflected light reaching the sensor. The final example is clipping. For example, it's possible to clip your highlights with ISO amplification, which means the sensor is not clipping. Use the histogram to establish which exposure variable causes clipping.
Olympus E-30 with the Zuiko 50-200mm f2.8 lens. ISO100, f5.6, 4" (An ambient light example)
The above image shows it's possible to saturate the sensor in low light. It's incorrect to link noise to low light because longer exposure times saturate the sensor. It simply means the bucket doesn't have to be filled instantly because the sensor is designed to also saturate over longer periods. Higher ISOs and shutter speeds are, therefore, application-specific. It is critical to consider the reflected light reaching the sensor when selecting your aperture and shutter speed mix. Unnecessary safety margins result in less light reaching the sensor, higher ISOs, and more visible noise (lower SNRs).
Example 2 - Ambient light with +2EV illumination
The above example is exciting because I upped the scene luminance (4th exposure variable) with 2 EV. I used a similar method for the image with the cuckoo clock. I used a powerful LED light in the above example and selective lighting (painting with light) for the cuckoo clock photo. Selectively using or applying the time of day is another way of managing the scene luminance creatively.
Photographers often need higher shutter speeds in normal daylight conditions. Modern cameras are more efficient at lower saturation and SNR values, which makes higher ISOs of up to +3 stops "normal" in such conditions. Study the inserted 200% cropped gray card in these photos. We can also manage the SNR to selectively add noise to the monotone (B&W) or monochrome picture modes.
I never consider social media talking points like noise, DR, diffraction, or image quality when I am out photographing with my Olympus cameras. I also don't use personalized ISO guides for my cameras. A basic understanding and the knowledge shared in this article are enough to benefit our results with any digital camera. For example, I only use Workspace and Affinity to process my images. Why would anyone prefer unfriendly MFT raw converters over Olympus colors and Workspace?
Olympus E-30 with the Zuiko 50-200mm f2.8 lens. ISO100, f5.6, 1" (Another ambient light example)
It's a rewarding experience to study and discover Olympus and OM System cameras plus Workspace. The histogram is only a tiny example of the creative and supportive features the Olympus engineering team created. For example, the creative color strategy, unique tonal adjustments, computational photography, IBIS, and photographers getting access to the camera's TruePic image processor and Workspace are something unique and special about these MFT cameras.
Here is a list of things we can explain with this knowledge:
- Knowing that the ISO can be a cause of clipping is huge.
- Test the sensor and select the SNR points you are happy to use.
- It is now possible to explain HDR photography with this knowledge.
- The goal with ETTR is to manage and improve sensor saturation and SNR.
- It is now possible to manage the amount of noise in your black & white shots.
- 18% gray exposures and calibrating the WB in WS insure consistent image colors.
- This article reviews a new exposure technique to control the DR in night photography.
- The unique histogram and the Live View functionality of Olympus cameras and Workspace.
E-M5 with the M.Zuiko 12mm f2.0 lens. ISO12800, f9, 1/150. Monotone Picture Mode.
I took the above image with the Olympus E-M5 MKI. I selected the MKI because it has a larger noise floor than newer cameras. The histogram plus Live View confirmed that the sensor received almost no reflected light. It wouldn't surprise me if the exposure level of the sensor were almost at its Absolute Sensitivity Threshold (Fig. 1). Do you think one would see more noise at ISO 24600?
The next image was taken with the E-P7 and the monochrome function. My E-P7 review received more views than any of my other articles. In fact, the daily views tripled when the rumor surfaced that OM System might release an E-P8 in 2026. The monochrome function (Pen F, E-P7, and OM-3) is absolutely brilliant. It's, therefore, frustrating to see social media statements like "My favorite monochrome profile..." I'd rather see people experiment and manage their own monochrome results. The enhanced raw format and Workspace are great options to tweak your monochrome raw files.
E-P7 with the M.Zuiko 12mm f2.0 lens. ISO1000, f4.0, 1/20. Monochrome Picture Mode.
In summary, always plan and apply all 4 exposure variables controlling the camera's 18% gray exposure mix and practice using the histogram to follow the scene luminance exposing the sensor. The image signal flowchart and photons-to-electrons graph are basic tools to help us master key variables like sensor saturation, SNR, and the ISO (image signal amplification). While the ISO is part of the exposure formula, it does not directly control the reflected light to the sensor. Other key elements impacting the digital imaging process are the lens, sensor, TruePic processor, and Workspace.
Should we trust those promoting the idea that physical size is a reliable measure for the efficiency of electronic parts? Should we take advice from those saying the ISO function was designed to adjust the sensor's sensitivity or larger sensors have more image quality, dynamic range, and less noise?
Someone who recently changed to an OM System camera solution made an interesting comment. The person explained that one of the aspects sparking his interest in MFT cameras was the knowledge and general creativity one immediately recognizes in Olympus and OM System communities.
Best
Siegfried
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