gdanmitchell wrote:
About the idea that, say, “24MP is enough” — it is complicated:
1. It may be more than enough for many purposes. Few people print or otherwise view their photographs at sizes where 24MP would be insufficient. (Someone I know once “tricked” a group of very talented — and in two cases well-known and highly-regarded — photographers with a 12” x 18” print sourced from an iPhone!)
Yes printing is less common these days, and our 4k screens only display 8MP. 60+MP screens are a very long way off.
gdanmitchell wrote:
Many of us recall when 24MP was out beyond the far fringe of what we thought was possible. My first FF body had “only” 12MP… and it seemed amazing! I could make some pretty big prints that looked great with those images. In fact, I still can, and they look good now, too.
Yes the sensor size mattered more than the number of pixels even at "only" 12MP.
gdanmitchell wrote:
For some photographers, at least, there are still potential benefits from higher resolutions sensors. Potentially greater detail even at large reproduction sizes is one of them, but there are others, too. Areas of low contrast and subtle transitions may be smoother. the “grain size” of any noise will be smaller and potentially less visible. Greater cropping may be possible. Moire may be less likely to appear.
“Greater cropping” and “greater detail at large reproduction sizes” are basically the same thing to me. From my testing, zooms at f/2.8 only give me about 10% more cropping power. Primes stopped down to f/2.8 or slower may be able to extract more than that. We really should be using primes when greater cropping and large reproduction sizes are important.
With the A7RVI, the “areas of low contrast and subtle transitions may be smoother” part is definitely true. However, I think that has more to do with DGO and how Sony is using the stacked sensor to improve image quality. The A7R VI shows a considerable improvement in these areas even over the A7RV, despite the difference in megapixels being fairly modest.
“Moire may be less likely to appear” is also true. But with modern noise reduction, I think “noise will be smaller and potentially less visible” is basically a non-issue with a 24 MP sensor.
gdanmitchell wrote:
The subject matters, too. The extra detail may be useful in a highly detail shot, say of certain kinds of landscape or architecture, for example. This may be less the case in other types of photographs — perhaps in certain kinds of portraits or in some photographs of active subjects such as sports and some wildlife.
Whenever the subject allows you to shoot with primes stopped down past f/2.8 at base ISO, to me that’s where the advantage of the higher megapixel count becomes much more apparent
gdanmitchell wrote:
The manner of shooting makes a difference. There’s an argument that when you shoot handheld you are limiting the potential level of detail you’ll record since the camera will never be perfectly vibration/movement free, so you are less likely to take advantage of the higher potential detail resolution at the sensor compared to shooting with a perfectly stable tripod-based camera.
I’m not sure about this one. I think when shooting handheld, the shutter speed just needs to be high enough. The camera doesn’t need to be completely vibration-free. What matters is the magnitude of the movement during the exposure relative to the pixel pitch.
gdanmitchell wrote:
Finally, something else has changed. Back when I had the 12MP FF camera, I had to give up other kinds of performance to get it. That camera’s dynamic range was limited, it produced significant noise if I raised the ISO much at all, frame rates were quite low, and so forth. We are now at a point where we don’t give up all that much to get the higher resolution. For example, the new Sony A7r6, from all reports, while not quite equaling the lower resolution cameras optimized for speed, comes quite close… and a camera like the A1ii which is optimized for speed gives us resolution that less than a decade ago was available in only one FF camera. ...Show more →
Relative to the A9iii you do give up a lot.
the A9 III’s global shutter
better low-light AF
120 fps
1/80,000s flash sync
Oversampled 4K
Uncropped 4K120.
No EVF resolution drop
This is a lot to give up just to print 10% larger. You cant even go up one paper size:
Arguably, there are better primes than the 20/1.8 G used in the video, but I strongly suspect to actually print one paper size larger with an R-series camera compared to a 33 MP A7V/A7IV, you may well be limited to just a handful of the very very best primes.