I would suggest a couple of things...first, there is a whole family of limited-light photography. I have posted elsewhere a few examples of night photography, including the night sky, done at an ISO of 4000 or so. No way I could even have started to do that with a D200,l unless I had a powered equatorial mount to allow extremely long exposures (probably three or even four minutes).

The image provided here is certainly at a light level outside photographic norms, certainly for the camera I was using, where I was at the practical ISO limit for the camera. Only the short focal length of the lens made the shot even feasible hand held, given that I did not have image stabilization available. Normal conditions always called for ISO 100 with that camera. This image clearly demonstrates the impact of the loss of two stops of dynamic range from the 8 that would be available at the lower ISO.

My point is really that there is a lot more involved with selecting various levels of camera sensitivity than is recognized. You correctly point out that noise (artifacts) is one of them. But in my experience, loss of dynamic range is usually far more significant to image quality, and, like serious underexposure or overexposure, it is almost always uncorrectable. This is why I am not a supporter of Auto ISO and use it only when photographs are documentary only (and rarely then).

My hope is that others will submit images to the discussion where they have skillfully managed limited lighting, with with modern cameras or with older cameras and explain what they have done and perhaps why. I am especially curious to know what folks have been able to do with some of the advanced Sony cameras. They seem to be well-discussed, but I have never actually seen one at a night sky workshop or group shoot. My question, and I mean this sincerely, is whether they are so good at it that don't even need a workshop to be able to do the night sky. My D850 has a sensor jointly produced by Nikon and Sony. It is very good, but in practice it's only a tiny bit better than my D810.

Shooting in low light- very low light is no longer a problematic issue with today's digital imaging technology.

The concept of shooting in very unfavourable light levels and conditions, as I recall, emerged in the mid to late 1950s in the photojournalism communities. "Press" photographers and photojournalists began to phase out large-format press cameras, flashbulb and strobe usage and transitioned to medium format and 35mm cameras and the use of existing light. Photographers operating in war zones and covering civil unrest, riots, and protests, were workg in unfavourable circumstances, low light, and need to work quickly and maintain low profiles. Photographers wanted a realistic ambience and not the typical effects of on-camer flash.

In that era, the fastest black and white film was Super-XX film, which was introduced at a whopping ASA 100 and later was elevated to 200. The film was not improved but Kpdak decided to discontinue its "safety factor" which tended toward overexposure rather than precise exposure. Tri-X, at ASA 400 was introduced shortly thereafter. The film was extremely grainy nu the DR was somewhat better as per gradations of tone and shadow detail.

Push processing became commonplace but in many situations, shadow detail was sorely lacking, images were excessively contrasty, and coarse grain was everpresent but became acceptable. Special developers such as Acufine, Ethol UFG, Diafina Red and others were formulated to extract more speed with somewhat less grain. The theory was simple. If you want to shoot a" black cat in a coal mine at midnight", get a fast lens, and develop the film in dynamite. Damn the grain, the heck with shadow detail, and as long as the picture tells the story, you're OK!

Oh. let's not forget Kodak Recording Film, originally designed for surreptitious surveillance photography and police evidence gathering. Later reissued as Royal-X-Pan. At ISO 3200 it seemed as the images were printed on coarse sandpaper! Saved you money on buying those costly Mortensen texture screens!

Fast glass? OK- I had a Canon rangefinder camera with an f.95 lens The IQ was nonexistent. Later on, I had a Leica with a Noctolux f/1.0, it was somewhat sharper wide open but virtually no DOP. So, if you want to "have your cake and eat it too" and shoot in the dark, have action-stopping shutter speeds, handhold the camera, get some DOP, the aforementioned dynamite process was the compromise.

High-speed colr films were also problematic in low light. If you were a Kodachrome fan, Super Anscochrome at ASA 200 was like comparing Old Masters paintings to pastel drawings. Many of the Ektachromes had crazy levels of reciprocity law failure, colour crossovers and other unwanted effects in low light. push processing scenarios- let alone colour temperature issues.

Slower and fine grain emulsions with incredible DR were plentiful for photographers that could control their lighting, work in ideal conditions or resort to a tripod and long exposure in low light.

Enter digital! My first digital camera was a Nikon D-300. Not exactly the ideal low-ligt camera but the results in bad light was already superior to film. To make a long story somewhat shorter, nowadays, I can shoot in low light with my trusty Samsung cellphone, in the dead of night, in low light and still get surprisingly decent results. As sensor technology progresses it's getting better all the time.

If you want to assess the limits of your digital camera in really low light, don't use still life as a test case. Shoot an amateur sporting event in a poorly lighted gym. Shoot an act in a dark jazz club. Try an owl in a tree at midnight. The noise will never be as prevalent as grain was. If you do this kind of shooting all the time, it might be time for a camera upgrade. If you generally work in less difficult conditions and have control over lighting or can resort to a longer exposure and tripod use- what's to worry about?

I read this after I wrote it. It rambles some. I've decided to post it anyway. We can sort it out later if necessary. So here goes:

I think maybe I wasn't clear in my intent. While I still have and use my D200 (because I still love the characteristics of the CCD sensor), I now primarily use a D500 and D850. In between, I had a D300, which was, at the time, a huge improvement over the D200, but is far short of the capabilities of either the D850 or the D500. Even so, there are things that the D850 (or D750 or Z6 or whatever camera you might want to list) just won't do. And while technique is important, and while at least some knowledge is important, there are inherent limits in performance that we just can't get past. Handheld photography with a D850 in my backyard at 2 AM with lighting only from our small rechargeable LED landscape light is certainly possible, but it requires use of an ISO level that yields only two or three stops of dynamic range and plenty of grain in the image. That doesn't mean that I've never had occasion to capture such an image, but I do know that it is never going to be a bright, well-saturated art image. Let me add a tripod to the mix and I can do quite a bit better, but there will still be some limitations.

So first...know and understand the limitations. That doesn't mean that you can't devise ways to minimize them, but you do have to understand them. Part of that is knowing, as you indicate, what ISO level you can use with your camera and still get results that are acceptable to you. Once you know that and understand the constraints it implies, then you can begin looking at other adjustments...VR lenses, tripods, supplemental lighting, any number of possibilities.

But the nature of light and the design of our sensors and the interactions that the laws of physics describe for us mean that there is always going to be a limit beyond which a camera can go. That limit will be different for different cameras, but it will always be there. We are also at a point where the difference among the best performing cameras is mostly pretty trivial. But the difference between what we can do with any of the best cameras today is much and what we could do with the best cameras eight or nine years ago i huge. Yes...equipment capability matters. No, the difference does not. At least not really. I mentioned night sky workshops earlier. They have all been interesting. Evn when focusing on what you are trying to do yourself, it is impossible to avoid getting drawn into the difficulties others are experiencing. There are always some for whom the supplemental lighting (for buildings or whatever) that is perfect for you is just not working for them. They need more, with the result that your images gt blown out and you have to reduce your own exposure to less than optimum in order to accommodate them. Was it an equipment limitation? Sometimes. Was it an understanding limitation? Sometimes. Was it an inability or unwillingness to follow instructions? Sometimes.

Most of what we do in photography is really not that complicated at its core. It can be learned. There are a number of ways to learn. The best is partnering with someone who can tell you, explain to you, and show you what to do, then do it all again if necessary. The risk is that because it's not complicated, sometimes it's hard to have the patience to do that repetition thing for someone just learning. And it can be hard to have the patience to keep trying if things don't work just righth the first time.

There have been several replies questioning whether this is really a low light shot and claiming (by folks who have also been there) that this is a bright exhibit, not a dark one. Been thinking about how to best reply, so I apologize for the delay.

To address the second issue first, yes, it is a low light scene. I have an appointment on Wednesday with a friend who has a museum science degree during which I have asked her to share some thoughts and secrets about museum lighting and to show me how it is applied in this exhibit. I'll come back with more specifics after our visit, but will tell you that (with a very few notable exceptions in some very specific cases) there are no bright museum exhibits. This is because the energy in light waves causes degradation to almost everything it touches. Since the "prime directive" in museums is preservation, bright light is a huge no-no. A big area of focus in the museum art, then, is making observers think the exhibit is brightly lighted, when in fact, it is not. So ambient areas tend to be dark, finish colors are carefully chosen, and other choices are made so that it is possible to make exhibits stand out the same as if they were brightly illuminated.

Now...to the first issue. My exposure here was 1/20 second at f/2.8 at ISO 400. If I were to to return and try to duplicate this shot, probably with my D500 this time, I would probably set the ISO at 1200, stay at f/2.8, and set the shutter at 1/60 second, which is the same exposure. If I followed the principles that a lot of you do, and moved away from wide open to, say, f/5.6 in the belief that I could get a sharper image, I would now find myself at an ISO of 4800. That sounds pretty much like a low light exposure to me. If I were shooting a basketball game in a gym with equivalent lighting and wanted a shutter speed of even 1/250, I'd have to go to an ISO of 9600 even if I changed the aperture to f/4 to gain a slight bit of depth of field. So yes, this is a low light situation.

I think what's interesting is that quite often, things are not as they first appear. It is necessary to think through them a little bit to see what is actually going on.

There have been several replies questioning whether this is really a low light shot and claiming (by folks who have also been there) that this is a bright exhibit, not a dark one. Been thinking about how to best reply, so I apologize for the delay.

To address the second issue first, yes, it is a low light scene. I have an appointment on Wednesday with a friend who has a museum science degree during which I have asked her to share some thoughts and secrets about museum lighting and to show me how it is applied in this exhibit. I'll come back with more specifics after our visit, but will tell you that (with a very few notable exceptions in some very specific cases) there are no bright museum exhibits. This is because the energy in light waves causes degradation to almost everything it touches. Since the "prime directive" in museums is preservation, bright light is a huge no-no. A big area of focus in the museum art, then, is making observers think the exhibit is brightly lighted, when in fact, it is not. So ambient areas tend to be dark, finish colors are carefully chosen, and other choices are made so that it is possible to make exhibits stand out the same as if they were brightly illuminated.

Now...to the first issue. My exposure here was 1/20 second at f/2.8 at ISO 400. If I were to to return and try to duplicate this shot, probably with my D500 this time, I would probably set the ISO at 1200, stay at f/2.8, and set the shutter at 1/60 second, which is the same exposure. If I followed the principles that a lot of you do, and moved away from wide open to, say, f/5.6 in the belief that I could get a sharper image, I would now find myself at an ISO of 4800. That sounds pretty much like a low light exposure to me. If I were shooting a basketball game in a gym with equivalent lighting and wanted a shutter speed of even 1/250, I'd have to go to an ISO of 9600 even if I changed the aperture to f/4 to gain a slight bit of depth of field. So yes, this is a low light situation.

I think what's interesting is that quite often, things are not as they first appear. It is necessary to think through them a little bit to see what is actually going on.