ISO and Sensor Sensitivity

FujiFulm X-H1 ISO dial

Changing ISO in digital imaging does not change the sensitivity of the sensor. That is impossible. 

To the chagrin of many, probably due to the language used and the analogy to film, one can not change the sensitivity of a sensor. ISO adjusts the gain applied to the signal that comes off the sensor—this happens after the image is captured. In other words, if the base ISO of one’s sensor is 200, all images are captured at 200 and when ISO is adjusted, to 400 as an example, additional gain is applied. The variation is that of a dual ISO sensor but, in short, that means that were is a second amplifier in the system/camera.

One might argue that using ISO terms in digital imagery was a mistake because of how it related to film. It confuses the actual technical nature of the device to the nature of silver halide. If one were to shoot with a film camera, ISO 200 film is twice the sensitivity to light as ISO 100. But that can not happen with a sensor. The light that hits the sensor is the light that is recorded—it is what it is. However, should one need a faster shutter in lower light, the signal will be boosted using the ISO adjustment on one’s camera but to reiterate, it does not change the sensitivity of the camera’s sensor but amplifies the signal from the sensor before it reaching the analog to digital converter.

Sony EX-1 gain switch

Interestingly enough, cinema cameras frequently do not have an ISO control but a gain control. My old workhorse Sony EX-1, pictured here, does not have an ISO control—gain is low, medium, high that I custom set to 0dB, 3dB, or 6dB (decibels of gain).

While decibels is frequently associated with audio gain, dB can be applied to any signal in electronics.

If I can really throw a wrench in one’s understanding of digital photography, ISO isn't even part of the exposure triangle. “Heretic!” they all scream. But that is for another article.

While one can imagine ISO as being a change in sensitivity of the sensor in a camera, the very fact is, it is both incorrect and inaccurate and gives a false impression of what is actually taking place when shooting with a digital camera.

Edit: I originally stated that my Sony EX-1 gain settings were 3dB, 6dB, and 9dB but, upon checking, they were set to 0, 3, 6.

Spectacle of Specs — Motorola RAZR 2019

With the announcement of the new Motorola RAZR 2019, I think it would be a challenge to argue it isn’t cool. The RAZR of yesterday is a legendary phone. Motorola is no stranger to making some important advancements in mobile phone technology. Going back even further, the StarTAC was a super cool, Star Trek, communication device that change the mobile world. 

This new RAZR is really slick—the hinge was four years in the making to ensure that it doesn’t (hopefully) have the same fate as the Samsung Galaxy Fold. The external display allows for one to engage the device for quick responses to messages, see notifications, use the primary camera, control music, and more. The design is glass, stainless steel, resin material, and has splash resistances. When unfolded it is flat and beautiful. When it is closed, it is compact and slick. 

However, with all the coolness, 2004 retroness, technology, thiness, and more, people are complaining about the tech specs.

While I’m not here to really discuss the choices of Motorola, I’m discussing technical specifications as a whole and how, mostly, they do not matter.

Consider this: In 2000, were people checking there email on computers? And in 2010? And will we be checking email on computers in 2020?

The correct answer is ‘yes.’ And that is the point. Overall, how we use our devices, hasn’t really changed. Let’s consider iPhone in 2010. It was the year of iPhone 4, Instagram, and people started to really use their iPhone as a camera. In fact, I took a whole trip to London and left behind my Nikon D700 just to see how far I could push my iPhone 4 camera. While it was no match for iPhone devices of today or my Nikon D700 of 2009, I have photos from London that I love.

I took those photos, edited them and posted them to Instagram, and did so while abroad, on various networks in the U.K.

Today, iPhone 11 Pro is a very sophisticated mobile computer with three cameras, OLED XDR display, and (mine) has eight times the storage of iPhone 4, LTE, and so much more. But in the end, I use it very much the same way as before.

The Motorola RAZR has an “old” processor and camera sensor, small battery, and 128GB of storage. But who cares? This device isn’t designed for the power user. To make it highly portable and foldable, it would make sense to put a smaller battery. But to save on power, they put in a “slower” processor. 

Let’s discuss two scenarios:

1. Motorola makes the RAZR thicker with a bigger battery and a more powerful processor. Audience: “it is too heavy, bulky, and doesn’t fit the RAZR heritage."

2. Motorola makes the RAZR thinner, smaller battery, and compensates with a slower processor. Audience: “it isn’t as fast as other new Android devices."

Consider every device you own and how much engineering and other decisions go into them. Specs are one facet of any device and the perspective of good or bad is very much relative. Everything is a tradeoff. 

Images courtesy of Motorola