Super-camera - justified for building interiors?

Going on from https://support.capturingreality.com/hc/en-us/community/posts/115001659992-photos-for-building-interiors, am thinking to hire some photo equipment for experiments to decide the optimum for inhabited-room interior photography for RC.

As an alternative to strong diffuse flash lighting, small aperture and low ISO, someone has suggested the following and I would appreciate expert comment on tech suitability for RC (let alone the cost of the equipment!):

"we discussed the need to hire a better camera - one that will overcome the following issues that you encountered, namely:

  1. Wider FOV required
  2. Low light performance issues

I know we discussed lighting rigs (flashes and such), however these will not be required with a Sony A7S camera. The camera is capable of capturing sharp images at ISO 204,800, which is incredible.

https://petapixel.com/2015/07/04/this-is-how-good-the-sony-a7s-is-with-low-light-and-high-iso/

Although the camera has a relatively low pixel count at 12MP, it is optimised for video and low light photography. If you do not think that you need such incredible low light performance, you could consider hiring a Sony A72, which still has *very good* low light capability and offers a higher pixel count at 25MP.

With regards to hiring a lens, I recommend hiring a Sony G Master lens. This lens is extremely bright and sharp, at f2.8 throughout the range.

Please consider the following issues:

Depth of field. 

You want as much of your subject in focus as possible, this means you should usually stop down to between f/8 and f/16. Each lens will have a different point where diffraction sets in and the higher f-stop will start to reduce overall sharpness, rather than increase it. Most common lenses can be looked up on a website like DPReview.com to find the best f-stop for your lens. 

FOV

Generally a lens with a low amount distortion will perform better than something like a fish eye lens that has a large amount of barrel distortion. We are trialing a 16-35mm lens, so I would recommend experimenting at both extremes. In an ideal world, we would be shooting at 50mm as this has the least distortion, but I don’t think this will be practical.

As for settings, f/8, ISO 400, shutter speed 1/30 Is a good starting point. I have never used a camera with such incredible low light performance, but I imagine that one could simply increase the ISO to 800 and still keep the shutter speed at 1/30 with no problems. I recommend shooting in aperture priority mode and letting the camera take care of shutter speed and ISO speed.

Does this sound like sense?

Hello, Tom, thanks for your questions…

I’m sure the camera you’re considering is quite good, but the main difficulty for any image-based reconstruction with low light images remains sensor noise. That is, taking at face value that the camera can give sharp focus at ultra-high ISOs, what does the noise look like in RAW? I suspect you won’t be happy with the results of feature search from such images, because there is no way around the laws of physics in terms of light gathering unless the lens and sensor are enormous.

The sample images on the page you link show less noise than the straw man cases they compare to, but I don’t think you’d like to search for features with their result, especially in comparison to what you could achieve with soft box lighting.

Naturally your caveat is ‘inhabited room’, which I take it comes with some compromises.  If you get some results from such a camera, I’m sure the forum would love to see them!

I’ve had pretty good results at iso 800 on d810.

iso noise is less bad than motion blur. but i wouldn’t go much higher, even with a a7s.

if you have time though, using a tripod will give better results. just much slower to take the photos.

also if you shoot wide open on a bright lens, it will also have less of the scene in focus. which is also an issue.

I’ve also had good results with 14mm on the wide end (might be possible to go 11-12mm too). fisheye I’ve had mixed results, but its not really supported at all now. so i would stay away until it is.