The main reason imho: being able to zoom into a large field of view, and not getting pixelated details when doing so.
I know you prefer displaying the image as a whole thanks to your carefully chosen 4K setup, but some (including me) will rather display with what they have - probably some HD or Retina display, no more - and will happily zoom into the image to inspect details.
Let's preface my comments and questions in the context that this is an Electronically Assisted Astronomy Forum. Also, that I am personally curious to know the answers as this has troubled me for a while...
I can see how having a larger sensor and higher resolution camera might benefit Astrophotography where, during post-processing, on (say) a 3860 x 2160 (UHD) display monitor, much of your huge image is typically hidden beyond visible screen dimensions. You might then focus on a Region of Interest (ROI) within view and crop a portion of your massive 6062 x 4042 pixel original image to the available 3860 x 2160 and/or Zoom to fill a 4k UHD display. Super stuff! All makes sense for AP.
But is having a large sensor and higher resolution camera of tangible practical benefit to those that pursue EAA in the context of near live observing where viewing is limited by a lesser display/monitor? I wonder....?
I deliberately pair a 16 megapixel resolution camera with a 4K UHD graphics card and 4K UHD display because I don't see the merit of so much resolution being output to a limited, far more common, 1080p HD laptop screen. Because of interlacing to fit the screen limits, many of the lhe lovely higher pixel count would simply be lost on the lower resolution screen. So if you use a 24 megapixel camera won't the benefit of a higher number of pixels similarly be liimited unless you upgrade to a matching graphics card and 8K display?
The counter argument will, of course, be to use Region of Interest (ROI). But how much of an advantage is that for EAA, and does ROI and Zoom in (say) Sharpcap work in the same manner as in a photo-processing application? I am not convinced that it does....
My Atik Horizon has a 4/3" sensor and 4644 x 3506 pixels, but pixel size of 3.8 um x 3.8 um.
The ASI2400 has a much larger sensor, 6062 x 4042, but somewhat surprisingly, has a larger pixel size of 5.94 um x 5.94 um. This begs some interesting questions for EAA...
Surely if squeezing a larger FOV into a common screen dimension then DSO objects will appear smaller? Surely a larger FOV demands more Zoom than a smaller FOV? That is certainly my experience with Hyperstar.
However, note that the ASI2400mc pixels are almost double the size of those of my Atik Horizon. How does that benefit Zoom? Surely the camera having the smaller pixels will offer the greater Zoom potential as for each degree of sky more pixels will have been captured? So might a larger sensor and larger pixels offer no advantage for near live viewing unless you increment graphics and display capabilities to mirror the camera?
Sharpcap typically fills my screen at my normal resolution. But when I use ROI in Sharpcap, it simply crops to produce a smaller area than my original. It doesn't work like (say) Corel Photo-paint where an original image might have its perimeters outside visible screen display. Instead it fits to available screen When I apply Zoom, all remains constrained by original pixel size. As my camera might use a thousand pixels to capture an objects diameter and the ASI2400 might use merely 600 pixels of larger size, how can the latter be superior when applying Zoom? Surely, the ASI2400 camera's apparent higher resolution advantage is simply a product of the larger sensor. It is not a greater physical advantage and the larger FOV might even be a disadvantage if your software/monitor is designed to fit your original image to available screen. Or am I missing something?
As I said, I can see the benefit of having a full frame 24 megapixel resolution camera for Astrophotography where post processing is applied in a photo-processing Application. But is there any advantage for EAA within regular EAA software unless you have an 8K monitor? I really don't know, hence thought I should ask these thought provoking questions so that those more expert in camera technology might explain.