How high can the resolution be set under render options and still make an impact on the render Thanks in advance

The resolution doesn't make any difference! (Until you go to print the image) The width and height are the numbers to change. H:)

yes in a way but wanting to know how high you can set the resolution I've set at resolutions of 300, 600, 1200 I see a difference between 300 and 600 and it appears there is a difference at 1200 but wanted to find out if its just my vision or can poser support values this high or higher

Right Unless you print it out you cannot possibly see much more on your monitor than about 100 pixels per inch. The degfault most people use is 72 dpi but some of the betters screens must be getting close to 100 dpi

The "pixels per inch" does not affect the image you see on the screen. This value is stored in some image formats as a guide for the printer drivers. For instance... you render an image at 200x200 pixels, 100 pixels/inch. You see it on screen as a 200x200 pixel image period. the size of the pixels on your screen is defined by your video card and video settings. Printing this image would give a physical image 2inches x 2inches square. Render the same image at 200x200 pixels, 1000DPI. The image is exactly the same on screen. 200x200 pixels. When ytou print this image, it will only be 1/5th of an inch along each side. Tiny. I don't think there is a limit to the DPI setting (Digital Pixels per Inch) within Poser, but I believe there is a maximum x/y size in pixels. 4000x4000 I believe. H:)