Rendering reflections and bumps looks different when rendering in different output sizes.

[ricky.corderoR5PJS]

Hi Im having an issue.

I am setting up some product renderings to be rendered at very large sizes however when I prep all my materials and render at a lower output size they look one way but then when I render them at the much larger size they look different. The reflections from lights the details from bumps all look different.

Is there a way I can see what my rendering will look like at a smaller size before I render for 7+ hours only to have it look completely different?

Im using 3ds Max 2020 with Vray 5

[CAMedeck]

It would really help if we knew what the difference in the renders was explained better, bonus points for image attachments.

My initial reaction is that when rendering at a higher resolution, the maps used in the Bump slots are not being downsized by the software, and more of the detail in them is being read by the renderer.  But I'm not sure about the reflections, and why they would look different at a higher resolution.

I'm also curious about what the pixel size is of your low res and high res images.

[RobH2]

You can do a 'Region' render to see just a small area at your full resolution. You might have to render one or two locations. In IPR you can drag to render a small area.