NEW: I have reached a point where I completely distrust those promoting the idea that physical size is a reliable measure for sensor efficiency...
Showing posts with label Camera Technique. Show all posts
Showing posts with label Camera Technique. Show all posts

Apr 7, 2026

The histogram and digital imaging process...

Last updated: 16th April 2026 (Application examples and technical updates)

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 image and video footage in the camera, which meant more advanced color and exposure techniques. I decided to use two Olympus E-M5 II cameras for their unique film look. The color creator, tonal adjustments, and other settings make it easy to set the look and feel of my videos. I also came across a video from the 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: The 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 on the histogram and exposure


The histogram in the above image suggests an optimum exposure mix. The best way to confirm that is to analyze the histogram with the exposure mix. The goal is to evaluate the sensor's saturation level and SNR. The histogram plus the native ISO indicated a saturated sensor. This exposure mix produced excellent image quality with a wide depth of field at f4.5. The 4th exposure variable (late afternoon sun) was also ideal for the scene and the "painting with light" effect. This analysis would have looked different at higher ISOs, even though the histograms might have looked the same.



Summarizing the exposure mix and histogram in 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 its native ISO.
  • Scene Luminance: The late afternoon sun and "painting with light" effect.
  • Aperture: The right focus point at f4.5 - The MFT depth of field advantage.
  • Image sharpness: A shutter speed of 1/400th worked well for sharp results.

It's impractical to evaluate image quality at higher ISOs with only the histogram. The alternative is to add sensor saturation and SNR to the mix with a personalized set of guidelines. The info in this article will help you identify and document "acceptable image quality" SNR values for your camera's sensor and ISO-to-SNR ratios. The reason is each camera and sensor has a unique noise floor.

Tip: LV (Light Values or scene luminance) - Discussed in the Duade Paton video.


Figure 1.


The above image signal flow diagram represents a high-level overview of the digital imaging process. It was created as a basic 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 finalizing the digital imaging process.
  • the link between the image processor, the exposure controller, and Workspace.

The question photographers fail to ask is, what causes noise, and how do we manage it? The answer is to familiarize yourself with the graph below. While the "water bucket" example worked well to explain the "size and capture" theory, it couldn't explain technical 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 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 magically linked to sensor size...


Figure 2.


Many photographers don't know that lower SNR values are the reason for visible noise. The sensor's noise floor is always present; we just don't see it at higher SNRs. In other words, the layer of sand in the bucket is more visible with less water. An alternative approach to having lower SNRs is to saturate the sensor (filling the bucket) at the camera's native ISO, wider apertures, and longer exposures. One could also accept more noise when upping the ISO and shutter speed (lowering the SNR).

It is important to master concepts like 18% gray exposures, tonal or gamma adjustments, and color. The information in this article enables us to explain and manage dynamic range in a similar way as we do with noise. For example, we can explain dual ISO with this knowledge. Marketers unfortunately withhold information because repetitive sales lines have priority over basic knowledge. 

PS. Visible noise simply means the sand is 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. 


More about the exposure mix and the histogram


Always remind yourself that the ISO function is another variable in the camera's exposure formula. ISO amplification is the difference between a partially exposed sensor and an 18% gray saturated sensor. The camera needs 18% gray exposures to accurately replicate ambient light and color.

Photographers were never "given" the chance to monitor the camera's sensor or manage variables like sensor saturation, noise, or dynamic range. The reason is the "bigger is better" narrative and social media distractions, like the histogram displays 8-bit JPEG data, ISO 100 on Olympus cameras differs from ISO 100 on others, or we shouldn't trust the histogram because it's inaccurate. These distractions are totally irrelevant when you start applying Live View and the histogram. Why?

A practical way to apply the exposure principles reviewed in this article is to think in terms of f-stops (1 EV steps) while preparing the exposure mix for challenging scenarios. For example, one can double the reflected light exposing the sensor when reducing the ISO by 1 stop. It's crucial to master the digital imaging process (Fig. 1) and the ability to manage the image sensor. Manual exposure mode is the most effective way to monitor specific variables with the histogram and Live View.

Tip: I get the best view when studying the examples below on my 27' iMac...


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 reached (exposed) the sensor at ISO 800.

The histogram shows the brightness of the pixels. That means all 4 exposure variables. The horizontal axis is the brightness levels from pure black on the left to pure white on the right (0-255 tonal range), and the vertical axis is 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 now measuring 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 monitor the reflected light reaching the sensor. The next example is clipping. For example, it's possible to clip highlights with ISO amplification, which means the sensor is not clipping. Use the histogram to establish which of the 4 exposure variables are causing clipping.

PS. See the exposure formula for why I say 4 exposure "variables" and not only the 3 in the exposure-triangle.


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 need to be filled instantly because the sensor is designed to also saturate over longer periods. Higher ISOs, shutter speeds, and noise are, therefore, application-specific. It is critical to consider the reflected light reaching the sensor when setting your aperture and shutter speed mix. Random safety margins results in less light reaching the sensor, lower SNR values, or more visible noise. 


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 with the cuckoo clock image. For example, I used a powerful LED light in the above example and selective lighting (painting with light) with the cuckoo clock. Selectively using or applying the time of day is another example of "managing" your scene luminance.

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 possible in these conditions. Study the inserted 200% cropped gray cards in the photos. If needed, the AI noise filter of Workspace works from ISO 800 upwards. We can also manage the image look by selectively adding noise to monotone (B&W) or monochrome photos. See the example further down.

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 my results with any digital camera. For example, I only use Workspace and Affinity to process my images. Why would anyone prefer MFT unfriendly raw converters over Olympus colors and Workspace?

PS. I can make any camera's ISO test look worse than another with equavilent camera settings... How?


Olympus E-30 with the Zuiko 50-200mm f2.8 lens. ISO100, f5.6, 1" (Another ambient light example)


Here is a list of things we can explain with this article:

- 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.


Examples of applying the information in this article 


It should be clear that the ISO does not generate noise. One can, therefore, consider the ISO function as an image signal amplifier (Fig. 1) or a creative/control option. For example, it's possible to manage highlight clipping by upping the ISO by up to 1 EV while setting the exposure mix in manual mode and dialing the ISO back prior to taking the image. The next step is finalizing the exposure in Workspace with exposure compensation and the tonal curve. One could also use auto ISO in manual mode with cameras like the OM-3 and the E-M1 III. This means a constantly saturated sensor while using exposure compensation to offset the ISO and Workspace to correct or set the final brightness.

The above technique came to mind as I studied the digital imaging process, the exposure formula, the ISO function, and sensor saturation. I hardly ever apply the technique as described because I get good results controlling the sensor (exposure mix) and ISO separately. I did lower the ISO with a two-thirds stop and corrected it in Workspace for the artist with the golden body paint below...

Tip: Click on the photo collection below and click again for a large view of each.

Pen E-P7 - I used the know-how in this article to set my ISO range (ISO1250 - 3200). Workspace - The Color Creator & basic tonal tweaks.


It's important to keep in mind that modern sensors are so efficient that we don't need this knowledge for stunning results. The purpose of this article is a good understanding of the digital imaging process and the know-how to plan, solve, and optimize challenging and more complex applications.

The following Pen E-P7 images are examples of complex scenes. They were all taken in fast-changing low light, changing colors, and fast-moving scenes. I started by taking a few test images to evaluate different exposure mix variations. I tried aperture mode with various combinations of exposure shifts, exposure compensation, and fixed ISOs to "manage" the exposure mix of my Pen E-P7.

The color creator is perfect for LED lighting and illuminated colors. My circus and X-mas photos were photographed in an environment dominated by illuminated colors, which complicates WB readings and colors like red in the camera and post-processing. The color creator behaves differently between reflected and illuminated colors. It's an excellent option for illuminated color applications.

Tip: Using auto ISO plus Exp. Comp with a constantly saturated sensor (M-mode). See P66 in the OM-3 manual.


Olympus Pen E-P7 with the M.Zuiko 45mm f1.8 lens. ISO2500, f1.8, 1/1000. I converted the RAW file in Workspace.


What makes Workspace special? The camera's TruePic imaging environment is part of Workspace and the enhanced RAW file. That means we can tweak our camera settings and finalize our exposure and tonal settings in Workspace and on a large PC screen. For example, we don't have the powerful tone curve function or the extended color options of the Workspace color adjust function in the camera. Workspace lets us do more in a replica of the camera's TruePic imaging environment.

It's exciting to study Olympus/OM System cameras and Workspace. For example, the histogram is only a tiny part of the creative and innovative features the Olympus Engineering team created over many years. For instance, it's unique for older MFT cameras to have access to the latest processing of the creative color strategy and advanced tonal and computational options from Olympus. Photographers also get access to the cameras' TruePic image processor via PC-RAW mode and Workspace.

PS. Fuji Raw Studio does not offer the same benefits for older cameras without the camera being connected to the PC.



The E-M5 & E-P7 Monotone/Monochrome with noise...

E-M5 with the M.Zuiko 12mm f2.0 lens. ISO12800, f9, 1/150. Monotone Picture Mode.


I took the above image with my Olympus E-M5. I selected the MKI because it has a larger noise floor than more recent cameras. The E-M5 histogram and Live View showed that the sensor received almost no reflected light at ISO 12800. It wouldn't surprise me if the sensor's actual exposure level were at the Absolute Sensitivity Threshold (Fig. 2). Will ISO 24600 increase the visible noise?

The next image was taken with the E-P7 in monochrome mode. My E-P7 review received more views than any of my other articles. 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 also frustrating to see social media statements like "My favorite monochrome profile..." I'd rather see people experiment and manage their own monochrome look. Workspace and the enhanced raw format are perfect for tweaking and practicing your monochrome photography skills.

I couldn't confirm it, but read Olympus studied analog prints to create the realistically looking "noise patterns" of the Pen F, E-P7, and OM-3 monochrome function. I used the 2nd option below.

PS. Which of the older Olympus cameras have the best looking monotone noise?


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.


OM System OM-3 with the tiny M.Zuiko 9-18mm f4 - 5.6 lens. I converted the RAW file in Workspace - AUTO Gradation.


Folks, it should be clear why we only see some references speculating about the information in this article. The complete "bigger is better" commercial theory will fail as people learn more about digital photography. For example, I only use the "low" noise filter in Workspace and Olympus cameras. Noise and dynamic range have become nonissues to the experienced photographer, which explains why not all Olympus and OM System cameras have access to the Workspace AI noise filter. 

Someone who recently changed to an OM System cameras made an interesting comment. The person said that one of the main aspects sparking his interest in MFT cameras was the knowledge and general creativity associated with Olympus and OM System photographers/communities.

Best

Siegfried

PS. I took these circus photos last weekend with a tiny kit consisting of the E-P7, the 17mm f2.8, and 45mm f1.8 lenses. Most MFT photographers don't appreciate the significance of the 2-stop depth of field advantage we have with Micro Four Thirds. For example, I took most of these images at f1.8 with the right focus points. That means I applied the 2-stop DOF and ISO/SNR (lower noise) MFT advantage with my E-P7. The Olympus cluster-autofocus function again proved to be a winner...


Olympus E-P7 with the M.Zuiko 45mm f1.8 lens. ISO1600. f4, 1/250. I converted the RAW file in Workspace - Color Creator.


An action shot with the E-P7 and M.Zuiko 45mm f1.8 lens. ISO3200. f1.8, 1/640. RAW converted in Workspace.


E-P7 with the M.Zuiko 17mm f2.8 lens - ISO1600, f2.8, 1/400. Raw converted in Workspace - Color Creator.


Pen E-P7 with the M.Zuiko 45mm f1.8 lens. ISO1600, f1.8, 1/200.


Olympus PEN E-P7 with the M.Zuiko 17mm f2.8 lens. Click and download to see my camera/editing settings in Workspace...


Click and download to see my camera/editing settings (Exif data) in Workspace...


Jan 17, 2026

Are full-frame cameras better than M43 cameras?

Last updated:- 7th February 2026

A personal experience with M43 cameras changes everything. Full-frame marketers prefer to prevent that with theories like "bigger is better." For example, why should I buy an OM-5 II or the OM-3 if they are inferior to full-frame cameras? It has become almost normal for respected influencers to suggest that M43 cameras have inferior image quality. There are also several videos suggesting that the high-resolution function is inferior to 40 MP or higher FF cameras. Why would people think OM Workspace is inferior to the commercial RAW converters from Adobe and DxO? Shouldn't the logical alternative be to convert your high-resolution RAW files with Workspace or the TruePic X image processor, especially with the new and improved PC-RAW mode of the OM-3, OM-1 Mk I/II, and Workspace?


The E-M5 III (OM-5) with the M.Zuiko 12-45mm f4 pro, 17mm f1.8, and 75mm f1.8 lenses is an excellent day or low-light option.

It's concerning that we don't have basic guidelines to "manage" modern digital cameras. The guidelines we do have are an outdated analog exposure triangle and the "bigger is better" theory. It should be normal to have a digital exposure triangle supporting technical aspects like sensor saturation and ISO amplification. The analog exposure triangle, "size and capture," and "ISO sensitivity" guides disregard the differences between the technical and optical aspects of digital cameras. Modern photographers will benefit from practical guides like the digital exposure triangle and an image-signal flow diagram. For example, it should be normal for modern photographers to manage optical controls like DOF and technical controls like sensor saturation and image signal amplification (ISO) in 2026.

Goto my Page Menu or open this link for the full article.

Dec 10, 2025

Olympus EM-5 III, Workspace, and AI noise reduction

Last update: 14th December 2025

My wife and I visited the X-mas show on the island of Mainau in Lake Constance, Germany. The island of Mainau is known for its seasonal flower presentations and the X-mas show in December. Expecting cloudy and low-light conditions, I decided to take my E-M5 III and my favorite 25mm f1.4 lens. I knew many people would be visiting the X-mas show, which meant less time to frame my images, handheld photography, and higher ISO values. I recently sold my M.Zuiko 17mm f1.2 pro lens and kept my Leica 25mm f1.4. The Leica has simply proven to be a more exciting and versatile lens.

I converted my RAW files in Workspace and prepped some of the posted images with Affinity. The photos in this article showcase the older 20MP sensor's ability to capture enough data for high-quality results across the sensor's linear operating range. Low-light photography is a joy with a combination like the EM-5 III, the Leica 25mm f1.4 lens, the Enhanced Raw Format, and the Workspace AI noise filter. One could get even better results when adding the OM System OM-3 to this mix.

Note: I added an example of changing my camera settings in Workspace.


Christmas reminds me of the birth of Christ and X-MAS of something totally different...

The E-M5 III is known for its image quality, pro-level sensor, and tiny noise floor. The depth-of-field (DOF) benefit of M43 cameras supported my decision to use f1.4 in these low-light conditions. I also knew the E-M5 III cluster AF option will optimize the DOF by selecting the right autofocus point. The AI noise filter from Workspace is perfect for ISO 800, 1600, 3200, or 6400 if needed.

The bright LEDs and overpowering colors of the event made it difficult to duplicate what we saw with my standard camera configuration. I knew it's possible to review my camera settings in Workspace and the enhanced raw format. I also knew I could use the EP-7's color functions on my enhanced raw files. See my articles on Olympus cameras, the TruePic image processor, and Workspace.




I highlighted several critical aspects about modern image sensors in 2025. The most significant aspect is the sensor's optical versus technical characteristics and the photons-to-electrons conversion graph. The latter help us to master aspects such as sensor saturation, SNR, and the linear nature of recording reflected light. I will focus more on this linear aspect of sensors, the gamma or tonal curve, and color in 2026. For example, modern pro-level sensors perform well across this linear range.

Photographers learned to appreciate the human aspects of photography in 2025. The introduction to AI highlighted concerns about photography know-how when substituting knowledge for sensor size, AI masking, and AI autofocusing. A critical aspect for review is the difference between computational or AI features and statements from web services like ChatGPT and xAI. The mix of theoretical, political, and commercial platforms serving as AI data sources highlighted critical discrepancies when receiving information from xAI or ChatGPT. For instance, AI will claim that bigger sensors are better when referencing data sources such as DPReview, or the camera's optical and technical design criteria guide the camera and sensor's operating efficiencies when referencing theoretical sources.




My personal highlight for 2025 is Affinity and learning more about the innovative RAW conversion and editing initiatives of the previous imaging business. Workspace became one of my preferred options while testing and studying Olympus cameras. See my articles for more about creative color, the M43 digital sensor format, color basics, the gamma (tonal) curve, sensor saturation, and SNR. Workspace is a reference to the groundbreaking solutions initiated by the previous imaging business.




Another highlight of 2025 is OM System's ongoing commitment to photography and the M43 segment by introducing exciting new products. My personal favorite is the OM System OM-3. The new OM-3 has quickly become a worthy replacement for my older Pen F. I am looking forward to writing more about Workspace and cameras like the OM-3, the E-M1 III, the E-M5 III, the E-P7, older cameras like the E-M5 II, and Olympus DSLRs like the E-3, the E-30, the E-620, the E-500, and the E-450.

PS. I think we should acknowledge and support this commitment to the M43 segment more in 2026...


Global color adjustments like WB or the Color Creator works better for LED and reflected "color" presentations like these. Why?




The color control we have with Olympus (OM System) cameras and Workspace surprised me. Reflected light and WB are normal variables for camera manufacturers. WB is typically expressed as sunlight, shadow, clouds, and artificial light. The EM-5 did not know how to interpret the extreme color shifts of the colored light sources at Mainau. The Color Creator is not only unique in "normal" lighting but also for colored light sources like large concerts, laser shows, and LED presentations...






The images in this article show what's possible when we ignore "independent" social media influencers repeating the same scripted lines or those simply repeating similar "bigger is better" lines. Take the time to learn more about Olympus and OM System cameras, Workspace, and how they could benefit your photography and image editing. It shouldn't be a surprise that modern M43 cameras capture high-quality RAW data. Some just make it much easier to create excellent JPEG images.

Folks, I like to wish you a blessed Christmas season and only the best for 2026.

Siegfried























An example of the extreme color effects at Mainau. Workspace gives us tremendous control.






























Olympus E-M5 III with the 25mm f1.4 Leica lens. ISO3200, f1.4, 1/5th. I converted this night scene (Enhanced RAW file) in Workspace.

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