Ok. I’m done with modelling and I’m close to my final render. full scene with lots of stuffon a table and a window in the background. 1080p isn’t cutting it but I went 5x on both (9600x5400) and took like 20 minutes to do the whole thing on my rtx 3070. But it’s really clear with almost no grain. Then again it’s like 370MB with 16 bit color and no compression.
So what render resolution so you like to use for such open space renders like my table scene?
Most likely you do not require that many pixels. You need less than that even if you were printing at 300 dpi on a 36" x 24" sheet of paper. If it is grain you want to get rid of, play with denoising. You also probably won’t make use of 16bit colours, and definitely should use .jpeg with compression, unless you plan to manipulate your blender output in another software. At the end of the day, the quality of your images is limited by the way you present them. Always use the bare minimum that gets the job done.
Hum, it’s a weird question 
My computer screen is 1920x1080 8bit monitor. Sometime having a bigger picture is great to zoom and see the details. 16bits is overkill unless you want to tweak the image latter.
The best is too choose a format that’s easily visible on most computers.
The image should stay interesting even at a low resolution. if you look at the top bar gallery on this site, most image are still good even when scaled down a lot. But of course, you want to look them fullscreen , and even sometime zoom on it to see the details.
Like this image :
The image is good and well balanced because even at that size or even lower , we can still understand the image very clearly. There are good contrasts, framing, shapes reads.
Now of course, having it fullscreen will help to get more details, and zooming into would probably reveal other things.
is png worse than jpeg?
Both jpeg and png can be lossless, but with png you can have transparent pixels (alpha channel). JPEG offers much more efficient image compression. If your image doesn’t need post processing outside blender and doesn’t require transparency , use jpeg for its portability.
I recommend that you select a render-size that is based on the resolution or the capabilities of your “best” target device. Maybe a little larger but really not much … just enough so that the post-production processes “always sample down." Render the final image in “OpenEXR.” This image has had no compression or anything-else applied to it, and it exists in a pure-linear color space. This is your “master.” This is your "data file.”
Next, create one or more blend-files which produce your actual deliverable(s), each one working from this pristine master, and each one as-necessary built for a particular target [device]. In this stage (and, only this stage) you will consider things like compression, gamma, and so on. Sometimes you feel like your image just got butchered by the compression process … and/or that online services like YouTube just made it even worse … and yet the final image still “looks pretty good.”