Zbrush seems to have a rather limited amount of rendering controls. So I was wondering what do people use to get the best images. For instance what other programs are out there to use and are there any hidden ways in zbrush to get higher quality images.
Hi wickednick, for all I know there are many render settings.
I don´t know what you mean by “rather limited” .
I think it would be really helpful if you´d include more infos/details.
For example which render options/controls you already know.
Rather limited – that´s a matter of opinion. 
I´d say there are quite a few.
Don´t forget the “AAHalf” button for a good result:
“The best possible antialiasing is produced by working on a canvas that is twice the final size. After rendering, press the Zoom:AA Half button to display the image at half size using optimal antialiasing. When displayed in this mode, the image will be exported at half size with antialiasing intact. AA Half Size can be used for any of the render modes”
For more infos please see here:
http://www.pixologic.com/docs/index.php/Antialiasing
I´m still busy with learning how to render – but I believe you get great results if you know how to use all the different render-settings.
Fog, Shadow, Depth, Reflections (…and a lot of others )
You can adjust each of these functions as desired.
You can also adjust for example the direction-,color, and intensity of the light.
Here are some infos about rendering and the Render-Palette:
http://www.pixologic.com/docs/index.php/Rendering_The_Big_Picture
http://www.pixologic.com/docs/index.php/Render_Palette
Here some about lighting and the Light-Palette:
http://www.pixologic.com/docs/index.php/Lighting
http://www.pixologic.com/docs/index.php/Light_Palette
And for example of lighting check out Martin Beyer´s making-of:
http://www.zbrushcentral.com/zbc/showthread.php?t=069499
I also recommend to learn more about materials.
By the way – there are also many MatCap materials in Pixologic´s Download-Center if you need some.
http://www.pixologic.com/zbrush/downloadcenter/library/
Infos about the materials:
http://www.pixologic.com/docs/index.php/Materials
http://www.pixologic.com/docs/index.php/Material_Palette
You can change for example the gloss, transparency, noise and many many other things.
Each of the materials has its own Modifier-settings.
Hope that helps and I hope it´s all correct.
Now it´s up to you to combine all these things as desired.
You´ll see – there are rather endless possibilities.
well i hate to agree but zbrush is a little bit limited rendering wise. on the other hand i think zbrush is really good at rendering really polygon heavy objects.
you can get some real nice renders with a decent matcap and have the lighting tweeked, and of course a lil bit of photoshop.
look thru the forums theres some great tutorials that deal with lighting and rendering