Hi, I'm going to try to explain as better I can whats the problem that exactly I have. I want to use a graphic card to a biomedical image processing application. I want to take profit of the performance operating with images. But for the moment I only want to simulate...not really implement into my graphic card, so I use Devyce REF. I thought that if you use this kind of device, I don't have to be worry about if backbuffer really suports my formats, I I thouthg in any case, for create render target, i should not have any problem if I create like R5B6G5 or L16, neither using HAL or REF. CAn you confirm that? My purpose is not to appear the transoformations on the screen. Is to get the data like "values of pixels" in a matrix, so I 'm not going never to render into the screen. In the simple program I develop I have two problems. One is creating my device. I would like not have to create a window, but when I put null in the window parameter of D3DPresentParametes, my program fails creating the device. And second, I would like to be able to get my data from my rendertarget, in L16 or L8. So I would like to be able to create a RenderTarget, first as Devyce Ref, to know if my program works, and after, I will buy a graphic card compatible with my program. The problem is that my program works when I create it as R5G6B5 but it fails (in creating render instruction)as soon as i change to L16, using both HAL and REF. After my program changes the render target from my backbuffer to my render targer, I render, after I block, and I get the data...! But this fdata is going to appear in R5G6B5, i f i'm not able to create the render target as L16... Can you told me whats wrong exactly to try to understand what's going on, and what knowledge I have is not true. Thanks, Jesus