Well, I didn't think the D3 could be improved. I was wrong, it can.
Jim from Brightscreen sent a Proscreen (big 13mm microprism-only, the same design Guy and I tested on the 5D and the R9/DMR all that time ago). No other marks in the finder at all.
It is perfect. I want to mention here that on other threads people have been asking about the focus confirmation light (D300). Folk need to know that the AF lightpath and the AF confirmation light is one system; the finder and screen a separate system. I have had the personal experience (S5 Pro) where the focus confirmation pathway was spot on, and the MF pathway so far out of spec it was unusable—so much so that the body was replaced.
There is no guarantee that the systems are in sync. You just hope they are if you want to use MF.
The D3, being a pro camera, is like the 1Ds series: AF and MF pathways are more likely to be accurate. So this morning, I removed the standard MF screen in the D3 and put the Proscreen in. Adjusted the dioptre (something I do every day before shooting; the eye changes daily) and put the incredible Zeiss 100/2 macro on the body.
Perfect; that's all I can say. And on checking the focus on lines of type, I can say that on my D3, AF and MF pathways are perfectly in sync. And the bottom line is that the Proscreen makes a HUGE difference to ease of manual focussing: you can see focus being pulled across the parts of any letter in individual lines of type. It's incredible, frankly, and the standard screen definitely cannot do this. I mention this because my standard approach to portraits is to pull focus along the bottom eyelid on the closest eye—with this screen you can put that critical focus plane where you want.
As well, in the short time I have played with this, I can see that the AF will be improved, too. Why? Because I can SEE when AF is, in fact, in focus. I missed a few shots last week because the Pilates studio was dim (I was using strobes, but focussing by natural light, for the models' benefit) and there are a number of occasions the AF missed, even though it looked fine in the finder. I think the Proscreen will help in this regard, because it is so damn obvious when you are out of focus, even in the dim light of my studio here.
The Proscreen gives a completely open finder, you can see the AF points as easily as with the standard screen, and there is no comparison re. MF: the new screen is so much better in this regard.
I will ask Jim if he has D300 screens—if he does, I will get one for my D300 too. One of the advantages of the D300 finder and AF points is that in the D300, the AF points cover almost all the finder area, and the second advantage is that you can choose the "Rule of Thirds" lines as a Menu option. I have mine on all the time—I wish the D3 had these too, for the interiors I will shoot this year with the new TS 24.
Jim did mention that he will be making similar lines on a Brightscreen, but I would prefer to have the lines switchable—I would want it off for some of my work, I think.
On reading the other posts from the D300 owners, a Proscreen might be just what some of you are looking for, MF-wise. I only hope that the mirrorbox specs and QC are as good as the D3. Cheers to all, KL