ISO invariance is one of the most talked-about topics in photography today, yet most people don’t really understand what it is. That isn’t a surprise; ISO invariance can be very technical and counter-intuitive, and it doesn’t fit well with many photographers’ general understanding of ISO. However, ISO invariance is an important topic, especially since many cameras today are close to being ISO invariant. If you want to maximize your camera’s dynamic range and avoid using “useless” ISO values, this topic is directly relevant to your photos. So, what is ISO invariance, and how can you use it to your advantage in your own photography?
For landscape photography, most of the time, you’ll end up using your camera’s base ISO. That’s the power of a tripod; it lets you set long enough shutter speeds to capture a bright photo, even in dark environments at low ISO values. However, settings like this do not work for all images. Sometimes, depending upon the landscape, you’ll need to raise your ISO in order to capture a successful photograph. This article dives into the most common of those situations.
Although the megapixel race has been going on since digital cameras had been invented, the last few years in particular have seen a huge increase in resolution – we have seen everything from 41 megapixel camera phones to now 50.6 megapixel full-frame DSLR cameras. It seems like we have already reached the theoretical maximum for handling noise at high ISOs with the current generation sensor technology, so the manufacturers are now focusing their efforts in packing more resolution, while keeping sensor sizes the same in order to lure more customers to upgrade to the latest and greatest. In this article, I will try to explain some basic terminology in regards to resolution and hopefully help our readers in understanding camera resolution better.
The subject of sensor crop factors and equivalence has become rather controversial between photographers, sparking heated debates on photography sites and forums. So much has been posted on this topic, that it almost feels redundant to write about it again. Sadly, with all the great and not-so-great information out there on equivalence, many photographers are only left more puzzled and confused. Thanks to so many different formats available today, including 1″/CX, Micro Four Thirds, APS-C, 35mm/Full Frame, Medium Format (in different sizes), photographers are comparing these systems by calculating their equivalent focal lengths, apertures, depth of field, camera to subject distances, hyperfocal distances and other technical jargon, to prove the inferiority or the superiority of one system over another. In this article, I want to bring up some of these points and express my subjective opinion on the matter. Recognizing that this topic is one of the never-ending debates with strong arguments from all sides, I do realize that some of our readers may disagree with my statements and arguments. So if you do disagree with what I say, please provide your opinion in a civilized manner in the comments section below.
I apologize for not being able to post the ISO comparisons in the Nikon D750 review earlier today. Unfortunately, the comparisons took a long time, because I had to retest everything several times. My first copy of the D610 had strange exposure issues, making it hard to properly compare it with the D750, so I had to find another one. Just in case, I also got a D600, a D4 and a D4s from Tom Redd (thanks Tom!) to add to the comparison. Since the D4 produced very similar result as my Nikon Df, I did not bother with uploading D4 crops.
After I received the Nikon D810 in the morning today, I thought about posting an article on the ISO performance of the camera and how it stacks up against the Nikon D800E. After Adobe announced the release of the Camera RAW 8.6 RC, I thought about using the Adobe converter for the Nikon D810 RAW files instead of Nikon’s software like Capture NX-D or ViewNX. Well, that was a really bad call on my side, because I ended up wasting the whole day trying to figure out why the performance of the D810 was coming out so bad when compared to the D800E. I ran many different tests and each one of them showed the same thing – the D800E was surpassing the D810 at every ISO above 3200. Whether it was with retaining colors and dynamic range, to plain noise – the D800E was just killing the D810 in every case. Although the D810 images were coming out about a stop brighter (with the exact same exposure settings and even custom white balance set at 4700K), I even tried to equalize the brightness both in cameras and post, only to see variations of the same problem. Nothing made sense and I simply could not believe that Nikon would release a camera that was inferior than its predecessor in image quality. That really did not make sense, but that’s what I was seeing!
After I posted my last article comparing the high ISO performance of the Nikon D4s vs D4, a number of our readers requested that I provide a similar comparison with other cameras such as the Nikon D600/D610, D800 and Df. Instead of posting multiple articles that show these comparisons, I decided to put it all into a single article, so that our readers could look at the side by side comparisons, or download the files to their computers for closer examination. Before you start comparing the below images, however, I would like to point out that the images are just provided as a reference, and only represent one side of the camera performance – high ISO in low-light, indoor conditions. Each camera comes with its own set of features, strengths and weaknesses, so please do not draw conclusions from these shots. Please note that ISO performance might vary in different lighting conditions. My recommendation would be to read the comment exchange I had with Brad Hill of Natural Art Images in the previous Nikon D4s vs D4 comparison article, where we discuss the topic of comparing sensor performance in detail.
I have been working on testing the performance of the new Nikon D4s to compare it to the D4 and see what advancements in sensor technology and image processing pipeline Nikon delivered in the latest revision of the top-of-the-line camera. Designed for sports, news and wildlife photographers that often have challenging light conditions and demanding environments, the high-end camera line is supposed to feed the never-ending thirst for more pixels and better low-light performance. Does the Nikon D4s deliver better image quality than its predecessor? While we know that the resolution of both cameras stayed the same, the big question is whether Nikon was able to enhance the existing 16.2 MP sensor and perhaps use better software algorithms to decrease noise – and that’s what we are here to find out today.
I guess today is a “blow your mind” Friday, because we have a guest post here by Iliah Borg, the person behind the RawDigger software that is used to analyze RAW images. I had a chance to engage in a conversation with Iliah when discussing the noise performance of the Nikon Df, where he not only proved me wrong on my assumption that the Df had exactly the same sensor as the D4 (turns out that they are similar, but not exactly the same), but also shared some incredible information about testing procedures, data analysis and other crazy, mind-boggling stuff! The learning curve with photography never ends, especially when you get into the whole sensor and image processing pipeline side of it. I must warn our readers though – the below article is very technical and is not intended for beginners! Hope you enjoy it! Nasim.