# Rendering to offscreen buffer of a different size than render window
**URL:** https://discourse.vtk.org/t/rendering-to-offscreen-buffer-of-a-different-size-than-render-window/10836
**Category:** Support
**Created:** [February 28, 2023, 10:00pm UTC](https://discourse.vtk.org/t/rendering-to-offscreen-buffer-of-a-different-size-than-render-window/10836 "2023-02-28T22:00:35Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@tchen87](https://discourse.vtk.org/u/tchen87)
#### Post date: [February 28, 2023, 10:00pm UTC](https://discourse.vtk.org/t/rendering-to-offscreen-buffer-of-a-different-size-than-render-window/10836/1 "2023-02-28T22:00:35Z")
I have an odd stereo rendering pipeline where I need to pass left and right images rendered at 2K to a weaver object, and then display the weaver output at 4K. Thus I want my final render window to be 4K in size, but I want to utilize offscreen rendering to create two 2K images.
Currently it seems like the offscreen buffer is always the same size as the render window. If I want my offscreen buffers to be rendered correct at 2K, I have to set the size of my render window to 2K. But then I end up only being able to see a quarter of the final image that I want. Similarly, if I keep my render window at 4K, I have not figured out how to properly render my left/right images at 2K rather than 4K.
Is there a way to define the size of the render output besides setting the size of the render window?
Thank you
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### Author:  [@tchen87](https://discourse.vtk.org/u/tchen87)
#### Post date: [March 10, 2023, 6:19pm UTC](https://discourse.vtk.org/t/rendering-to-offscreen-buffer-of-a-different-size-than-render-window/10836/2 "2023-03-10T18:19:42Z")
Just wanted to bump this topic up and see if anyone has any thoughts.