The reason I ask, is that the N5 has measurably more contrast than the Epson (max 40k:1 native/400k:1 dynamic vs 8k:1 native/40K:1 dynamic), but in my experience that doesn't always mean a better black level - with both entry level eshift JVCs and the N5, when they're at their shortest throw, that does seem to limit the black level and the contrast range appears to be more at the brighter end, if that makes sense. I've not been able to get to the bottom of why this is, but I suspect that because when the JVC is at it's shortest throw, the F-stop of the lens means it has around 25% less contrast and 25% more lumens, so that will reduce the max contrast potential and raise the black level compared to if it was at its longest throw. If it's also brighter than the other pj, then that will also make a difference. I just felt like it needed an ND filter when I saw them, but I'd have to look further into it. I doubt I'll get the opportunity though.
I see a lot of people on avs being concerned about the throw of the new N5 and N7 because they are already at the closest throw and the new 4K panel gives a slightly less wide 16:9 image, so if they can't move the pj back, they won't be able to fill the screen, so in those cases they will have a similar set up to the one above with a similar outcome.
Just to add, I think that there may also an element of how much better a black level needs to be before it is visibly noticeable - on avs I often see that contrast has to be double (and I assume with the same white level), so if that's the case, the black floor of the JVC may actually be lower, but not by enough in these instances to appear to be any blacker. As we generally are only judging based on what we see then that may make a difference on what we buy.
The way the DI works, I was wondering after if having the manual iris fully open would make a difference to the black level compared to having it fully closed - I think the JVCs attain max contrast with the manual iris fully open and the DI having more range to work with. I need to ask
@jfinnie about that I think as he's been looking more into how it works on his 790 recently.
Similar thing happened at the demo I was at, but the guy with the N5 on preorder went to see an LS10000 right after, and then cancelled his preorder, and now has the LS10000 with a Vertex and UB820.
The mid level eshift pj does have a visibly better black floor than the entry level, and does go darker compared to the 9300 and LS under the above conditions, so I would think the N7 (and N9) should as well.
I think this goes to show that things aren't always as simple and as straightforward as we expect and can throw a spanner in the works