Bmp is not supported for output. Of course you can easily convert from PNG to BMP if you want, but there is usually no reason for doing that. For input Lux supports almost all bitmap formats, and probably BMP, but, again, that is a format that should be avoided. The backdrop in Studio is not support. If you want a backdrop you need to place a plane with your choice of bitmap for texture.

My images never go beyond HD format, 1920x1080, but that's just me. Others have made larger images. The limit that you have is based on the memory available and the time to render the image.

Cheers 

Paolo

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