Sainte-Chapelle, the radiant Gothic chapel in the middle of Paris, has been a "bucket list" photo destination of mine for years. It's hidden within the Palais de Justice and underneath the shadow of its more famous, larger cousin: Notre Dame.
Gothic cathedrals are famous for their heavy stone structures and foreboding decorations. The purpose of all that masonry is to provide support for enormous windows. Nowhere is this more evident than Sainte-Chapelle: it seems the entire structure is made of garishly-saturated stained glass.
Now, I find many of the most interesting Sainte-Chapelle photographs were taken when just light enough outside to illuminate the windows, but dark enough to necessitate the interior chandeliers to be lit. Given you are not allowed to bring a tripod into the chapel, that means that most of the work I've seen of the chapel either lacks dynamic range, detail, or is butchered by overly-aggressive post-processing.
Years ago, during my last visit to Paris, I had missed the opportunity to tour the chapel. Knowing I had a few free hours in Paris upcoming, I immediately prioritized bringing a camera to the chapel and I decided to rent a new Sony A7r III for two purposes: to compare it to my standby D800, and to see if the in-body image stabilization (IBIS) that the camera boasts was truly able to offer multiple stops of stabilization.
I received a Sony A7r III (I'm sure I was the first person to use this particular camera) and a Novoflex Nikon G to Sony FE adapter on a Thursday and by Saturday I had shoved it along with a tripod and my D800 and associated lenses into a duffel and was on my way to the airport.
The first visit I made was during the daytime hours on a Sunday, the place was relatively empty and the sunlight was both intense and direct. It shone through the glass and cast shades of purple and blue throughout the chapel. Though the photographs (and more importantly, the experience of visiting) were beautiful - I had a different image in my mind.
Under these well-lit conditions, there was little difference between the Nikon and the Sony - chalk that up to the ability to stop down and still achieve a low ISO with either camera. The Nikon was far more pleasant to use (perhaps a function of familiarity), however, and therefore I ended up taking more images and ended with a better set.
When the skies opened up a day later and stormy weather began to roll over Paris, I had a short window of time available before meetings and I decided to try again. I trudged through the rain to wait in line once more. This time, I was rewarded with near perfect lighting conditions - the thunderstorm had created precisely the atmosphere I was seeking.
Inside the chapel, I worked to capture most angles with both cameras - I wasn't interested in a scientific comparison, but in a real-world test of image quality in the field. This is about comparing the in-the-moment experiences and qualitative impressions of both systems captured while using both heavily under time pressure and in difficult lighting.
Another long flight back and I sat in front of the computer to compare results. A couple of conclusions:
1) On overall image quality, and particularly dynamic range, the Nikon D800, for being many years old, can still hold its own against the latest and greatest offerings.
2) For those of us accustomed to DSLRs - the OVF and ergnomics are superior to the more compact, mirrorless options. This is purely subjective and, as advantages go, short-lived. Photographers who buy into mirrorless will feel the opposite way once their muscle memory is accustomed to their cameras. Kudos to Sony for making something I could rent and learn and use effectively in a weekend - but it's tiny and cramped and all a bit, well... unsubstantial.
3) Nikon owners don't have automatic adapters yet (or at least I didn't) and therefore are still reliant on manual focusing and manual aperture control - if you're thinking of switching you can use your Nikkor lenses, but don't expect to enjoy it.
4) 42MP is a truly marginal improvement over 36MP - if you're a D800 user lusting after more resolution, you're either eyeing the D850 or (more accurately) a 100MP back or future camera to see another step-change the likes of which you experienced moving to the D800
5) The Sony A7r III produces truly amazing images - on par or better with the best DSLRs. This bit is obvious and has been shown over and over again in qualitative and quantitative tests.
6) The Sony's IBIS gave me at least 1-2 stops improvement over the Nikon - producing sharp images at ~1/8 of a second and below. When you consider that IBIS systems in general degrade image quality (the sensor is moving, after all) and that 42 megapixels is a brutal judge of sharpness - that I could reliably shoot below 1/10th of a second and produce sharp images is truly remarkable. The top image is 6 frames shot handheld and stitched - all of them were taken in quick succession and have no issues with blur or hand shake. Amazing.
7) The Sony's dynamic range and therefore the ability to draw out shadows and pull back highlights in post was at least as good as the D800 - an awesome parlor trick for those of us who grew up on film and early digital no matter how old.
8) I have no idea if the A7r III has a focusing advantage or even how it operates with an autofocus lens.
9) It's not that much smaller. If you're trekking through the back-country then the size matters, but the much-touted smaller form factor comes with as many costs as benefits. I have a Leica Q, so maybe that disqualifies me from commenting on size (as I already have a camera that solves for the size/quality maximum) - but if you're a DSLR user, I wouldn't buy this for the size advantage. After all, a good lens (and you'll need one to benefit from that sensor) isn't going to clock in any smaller on the Sony than the Nikon
10) There are a mix of Nikon and Sony images on this page - you can't tell them apart unless you look at the EXIF - and both are years ahead of mobile image quality. As good as it is, the iPhone photo below (shot in RAW and processed with Adobe Lightroom Mobile) is clearly inferior to the "big camera" images. Mobile cameras were, at one point, "catching up" with DSLR image quality, but we've now entered into a time where that gap is opening again.
11) None of these images were possible anywhere near this quality 10 years ago. This is the bit that's exciting - despite diminishing returns - digital tech is still opening up new frontiers in what you can capture. That goes double for the "low quality" iPhone image - if I'd brought film with me, the iPhone would blow it out of the water.
Was the image quality noticeably better under tougher conditions with the Sony? Yes. Would I switch to Sony mirrorless? Not yet. Would I rent again for a situation like this? Yes - I may even leave the DSLR home next time and save a little carry-on room for a warmer jacket.
This technology is real - Nikon and Canon (who may have fallen permanently behind) need to continue to over-deliver on their DSLRs - the D850 probably keeps me in the Nikon fold if I need to replace my 800 in the coming years.