Focusing screens for your DSLR
I’m often asked, particularly with Zeiss ZF and ZE lenses, whether there is a split-prism focusing screen for various Nikon and Canon DSLRs.
Canon and Nikon do not offer a split-prism focusing screen for their DSLRs, but KatzEyeOptics.com does for some cameras (but not all). There is a split-prism screen for the D700 for example, but not for any Canon 1 series or 5D* cameras; they are all for the smaller-sensor models. At least not at present.
Nikon and Canon both offer alternative focusing screens for some models. In general Nikon offers few choices (if any) and Canon has more. If you want to try a different screen, my preference is either a super-matte variety or a grid screen (for composition).
I have good success with the standard screens on Nikon and Canon.
When feasible, stick to Live View, which is most accurate of all. Get a Hoodman Hood Loupe 
for Live View focusing. When you install a different screen there is often some other compromise made; whether it’s an overall win will depend on your own usage.
Update — reader reports
Reader Murray O reports “I had Katz Eye place one in my D700 (I sent it in; well worth the nominal fee for the quick turn around time); what was lost was spot metering. Otherwise, it works like a charm.”
Reader Chris D reports “I use brightscreen for my d3 and have a katzeye for my d2x. Katzeye does not offer a screen for the d3/x. I like both although I think I will try the diagonal split screen. The horizontal one is just not critical enough for me”
Reader Sten R reports sanding a Canon screen to fit Nikon: “I bought the a split prism screen from Brightscreen (large split prism version). The split and prism area is huge and very convenient for the purpose of getting things in focus, but the drawback is that it totally messes up the spot- and to a certain degree the CW- metering. A modified Canon EC-B works much better (although spot metering is affected a little with this too). When verifying achieved focus using the matte area, subjects pop into focus much easier with the Canon screen compared to the two Nikon screens available for the D3.”.
Reader Mihai B reports getting a split-prism screen for Canon at FocusingScreen.com.
