The 4 things that could improve your Image Quality

Last update:- 22nd January 2024

Introduction

Many social media presenters introduced 2024 with a list of photography essentials. While having good intentions, it's surprising to see how well-known influencers repeat incorrect information.

This inspired me to review the following talking points and introduce a new technique:

1. "Focus" on the subject, and don't let the background or DR distract you.
2. Exposure Triangle - Replace "ISO Sensitivity" with "Image Brightness."
3. Discard all "size and capture" theorists explaining image sensors/cameras.
4. Knowledge and regular practice are +50% of what makes photography fun.

EM1 III w Lumix 35-100mm f2.8 - ISO200 (400), f8, 1/640. ISO400 plus ETTR (+1EV) gave me a +/-2EV brightness variation. See the article.

Imagine you are photographing a blue hour or city scene at night, and it's possible to adjust the image brightness just enough to get more details from street lamps and/or restaurant/shop windows...

How did I take the images below? I used a technique that control the sensor and ISO separately. That means I independently manage my sensor's saturation and the ISO (image brightness).

Figure 1.

1. Focus on your subject, and don't let the background distract you

I am a keen follower of the Danish photographer Thorsten Overgaard. I like his work, enthusiasm for Leica cameras, and passion for photography. Thorsten discusses 4 essentials that could improve your photography in 2024. Many presenters and photographers assume the ISO function on digital cameras is similar to film cameras. Folks, the ISO function does not adjust the sensor's sensitivity.

Watch Thorsten's video for more on his 4 essentials, like focusing on the subject...

2. Remove ISO Sensitivity from the Exposure Triangle

The best way to think of your ISO function is to view it as an in-camera brightness slider. The image sensor and ISO amplifier are separate components. The sensor's sensitivity is measured and adjusted at the factory. This is a once-off and permanent adjustment that prepares the image sensor for use with digital cameras. The ISO function simply amplifies the image signal from the sensor...

Study this article for more details.

Why is the "Digital Exposure Triangle" different? It allows us to improve our tonal (image) data. The ISO "sensitivity" theory limits our ability to manage the sensor's saturation. This and a lower Dynamic Range are why "experts" say ETTR isn't safe at higher ISOs. This article focuses on the benefits of having a saturated sensor and using the ISO as a brightness slider (image signal amplifier).

EM5 II & 7-14mm f2.8 lens - ISO800, f2.8, 1/250. The Advanced Raw File was converted in WS. The new ISO technique will benefit this photo...

The information below applies to all digital cameras:

1. The Shutter and Aperture are responsible for exposing the sensor.
2. The ISO function only amplifies the image signal from the sensor.
3. This doesn't mean the ISO is not part of the camera's exposure calc.

Consider this when you set your camera's exposure with the Digital Exposure Triangle:

• Reflected light (Shutter Speed and Aperture) controls the sensor's saturation level.
• More reflected light saturates the sensor. This improves the SNR, which decreases noise.
• Less reflected light decreases the Saturation/SNR. A smaller SNR increases visible noise.
• Study the Photons to Electrons conversion graph in one of my previous articles - link.

This brief summary explains why ALL digital cameras have visible noise at lower SNR values...

EM1 MKI & 12mm f2 lens - ISO1250, f2.0, 1/25. The Enhanced Raw File was converted in WS. These scenes benefit from the ISO technique.

3. Avoid any "size and capture" theorists explaining digital cameras

The left photo in Figure 1 is the JPEG from the EM5 II, and the one on the right is the converted and adjusted raw file. They're an expression of knowing your camera and Workspace. They are NOT the result of AI, computational photography, a LUT, or advanced image editing. Photographers in Group A will typically complain about the EM5's small sensor and its low dynamic range, and those in Group (image) B will discuss new ideas to improve their knowledge and technique?

Olympus EM5 II & 12-200mm f3.5-6.3 Lens - ISO200, f7.1, 1/500. The new ISO technique lets us control any highlights in the above scene.

4. Knowledge and practice are +50% of what makes photography fun

How did I create Image B (Figure 1)? I separately optimized the sensor from my ISO. Image quality is a function of sensor saturation, and image brightness is a function of the ISO, Gamma Curve (camera and WS), and Workspace (Exposure Compensation). The EM5 II is known for its image quality and the sensor's smaller noise floor. The DxOMark "Low-Light ISO" rating gives us a safe range to tweak our highlights in the camera and Workspace (WS). (1 to 2 stops are all we need)

This new technique consists of a few basic steps. The Image brightness can be adjusted in the camera or Workspace while the sensor is saturated. We can also use Gradation, Highlights/Shadows, and/or the WS Tone Curve to tweak the Enhanced Raw File's Gamma Curve in the camera or Workspace.

Olympus E620 w 12-60mm f2.8 Lens - ISO100, f8.0, 1Sec. 3 AE bracketed raw files were converted and edited (HDR) in Photoshop.

Are there other ways to create Photo B? Absolutely. I used this method to show the camera's sensor and ISO function. Some will say the EM5 II is ISO Invariant. Folks, the "size and capture" theory and "ISO Invariance" are marketing theories. Those pushing them can't clearly explain the origins of image noise (SNR), the sensor's noise floor, or why only "some" sensors are "ISO Invariant."

Here are the steps I used to create Image B:

1. Image A. The sensor was exposed (f4.0 and 1/25) at its base ISO200 (Auto Exposure).
2. The DxOMark "Low Light" Sports rating showed I could safely vary the ISO with +/- 2EV.
3. That meant the camera's "highlight" exposure settings should be f4 and 1/100 at ISO800.
4. I manually used ISO200, f4, and 1/80th shutter speed @ 20% ETTR (+/- 2EV highlights).
5. ISO200 gave me control over any clipping highlights with the camera and Workspace.
6. I applied my final ISO (brightness) adjustments via the Enhanced Raw File & Workspace.
7. With regular practice, it's also possible to edit the Gamma & brightness in the camera.

Olympus E410 w 14-42mm lens - ISO400, f13, 13 Sec. The highlights and general IQ of the E-410 will benefit from this ISO technique.

It takes time to visualize and create new techniques. It improves our experience in problem-solving, Olympus Cameras, and Workspace. For example, the concept of ALL sensors having a noise floor is part of this technique. It's only possible to control any clipping highlights with an optimally exposed sensor. I experienced no increase in noise for Photo B (ISO200, -2EV image) or the image below.

Here is another method to create Photo B (Fig. 1). Olympus cameras automatically vary the sensor's saturation level with AE Bracketing. That means the camera doesn't change the ISO in AE bracketing mode. Use ISO800 and the "2f 1.0EV" bracketing option to take 2 photos. Manually take another image at ISO200 (-2EV) and the 20% ETTR aperture and shutter values. Do your final Gamma Curve and image brightness adjustments in the camera or Workspace.

Olympus EM5 II w 7-14mm f2.8 lens - ISO64, f7.1, 1/125. ISO64 helped me to up the SNR and saturate the sensor.

Conclusion

Modern digital cameras and mobile phones are great products with excellent Image Quality. While AI re-uses (copies) almost anything someone else puts on the web, the difference is those who step away from reckless marketing theories, master their digital cameras, and practice frequently.

This article showed the value of knowing your digital camera. It enabled me to control the clipping highlights while managing the sensor's SNR independently. This ISO technique is designed to benefit from the DxOMark "Acceptable Image Quality" rating, meaning I will have a minimum Color Depth of 18, a DR of 9EV, and an SNR of 30db (no ETTR) at ISO800. My ability to prioritize and select/edit older RAW files benefited from my ISO, Sensor Saturation, and SNR (visible image noise) knowledge...

One final example of timing, compositions, and complex exposures.

Alex Nail is a great landscape photographer. He took a group of photographers into the Drakensberg mountains. The vegetation in this mountainous region brought back memories of my Heimat, South Africa. Image quality is not only a function of your camera because all digital cameras have unique strengths and weaknesses. The joy of photography is mastering your camera's limitations...