Katzeye Focusing Screen (for D7000) Review
Background
This is a review for the Katzeye focusing screens. I have a few very nice old manual focus lenses (including a Tamron 300/2.8 SP IF, Nikkor 50/1.4 AIS and 105/2.5 Type K AI'd), and being able to use them with proper metering was a major consideration in choosing the D7000 over other similar cameras (the EOS Canons require you to do stop down metering, and lower Nikon bodies don't support metering at all). The OEM focus screen didn't quite cut it for me, and I found that I could not judge focus accurately. The electronic rangefinder helped a bit, but was difficult to judge accurate focus, plus it was down in the bottom of the viewfinder, and moving your eyes back and forth from the subject proved too slow for me).
I had heard of Katzeye screens for a while, and had considered them for use with my Olympus cameras, but up to this point I had always had lower end 'consumer' (I hate that word) bodies which only cost a few hundred dollars; putting a $100 focusing screen in a body which I didn't plan on using for more than a couple years didn't seem right to me. Plus, the cheaper Olympus viewfinders are quite small and dark, which makes manual focusing (even with aids) difficult at best.
However, with the purchase of the D7000 body, I felt that I had a camera which I would stay with for years. The usability and feel of this body was much better than the lower Olympus bodies (comparable to the E-30, which I had for a short time before switching). This was a body which I could customize!
Having decided that I wanted a focusing screen, I now had a choice. There are a few different types: the Katzeyes are the most pricey, but have consistently good reviews. Then there are Hoada screens and Focusing Screen.com, which are about 70% of the cost of Katzeye. Finally there are the Chinese screens on eBay for about $20.
The eBay screens were not considered. While monetarily cheap, I would say it is a safe bet to assume they are functionally cheap as well.
Hoada screens have a very uninformative web site. While Internet reviews seem to speak highly of them, I could not see on their website whether the D7000 was even supported, let alone what options were available for it.
Focusing Screen.com was a very close second. They have a very nice website, and offer different types of screens other than the traditional horizontal split with micro prism ring; plus, they have pictures of how the different screens look when installed! In the end I decided against them solely due to their location -- they are based in Taiwan, so shipping would be fairly lengthy. Plus, in the event that I needed support, I figured that the language barrier may be a problem.
So I decided to go with Katzeye. The total cost ended up being about $130 including shipping to Canada; by size, it was probably the most expensive piece of glass I have ever bought (and that is coming from someone who wore glasses for a number of years!)
(Before we go any further, and since an entire page of text is boring at best, I will give you a sneak peek of what is possible with manual focus and a Katzeye screen: this was taken using my Tamron 300/2.8:)
(Nikon D7000, Tamron 300/2.8 @ f/4.0; 1/3000s, ISO 560)
Installation
Installation was not too difficult, although it is not for the faint of heart. Katzeye provides you with a small tool which looks like a flatheat screwdriver with a chip taken out of the blade; this lets you carefully remove the wire clamp from the focusing screen to release the old one, and then reattach it to the new one. They have instructions customized for your camera, which I found to be well written and accurate.
In the end it took me a couple of trys to get it just right. The OEM shim was persistently sticking to the old screen, and it was difficult to get it in place without touching either the old or the new screens. During the process I actually got a spec of dust inside the screen; it is at the bottom edge of the screen, though, and is not objectionable so I ended up just leaving it instead of trying to get it out and possibly make things worse.
Results
I am very happy with how this has turned out. The screen makes focusing with old lenses not just possible, but actually easy! I am still not nearly as fast as a good AF system, but the accuracy seems to be just fine, and I am sure that with more practice I will continue to speed up.
The overall screen brightness is good for f/2.8 and faster lenses. My 18-105 gets a bit darker than before at the long end (although I knew that going into it), but even at f/5.6 it is still usable. Their claim of the split screen not blacking out as early as before is true (when compared to my FM2 which is almost unfocus-able at f/5.6), but I would definitely not want to try focusing manually at that f-stop unless I was in very good light.
On their website they list usable f-stops for the Katzeye Plus (which is included by default on all screens; this is different from the Optibright treatment, which costs extra). The chart indicates that 'minimal attention [is] required' down to f/9.0, and that 'careful attention [is] required' down to f/22, but that you can still see both sides of the screen. While technically this may be true, I would have to disagree with the implications of their assertion; while you may be able to see both halves of the split screen at level 4 at f/22, there is no way you could even come close to focusing accurately at that aperture IMHO. Personally f/5.6 is about the darkest that I would want to focus with and expect even somewhat accurate results. Using a f/8 mirror lens or something would IMHO be very difficult; it may be possible if you are outside during daylight shooting a high contrast subject. (My own experiences are obtained from un-structured testing under poor working conditions: indoors, with subjects without much contrast. Under optimal conditions you can probably get by with a smaller aperture. For myself, though, I don't consider manual focusing to be reliable unless I can do it in a wide range of conditions.)
From my experience, Katzeye Optics does accurately describe the microprism collar: they estimate f/4 for the usable aperture when using the collor for focusing, and I would agree with that assertion (f/3.5 would be a bit more usable, but with a good subject f/4 should be usable).
(Nikon D7000, Tamron 300/2.8 @ f/2.8; 1/500s, ISO 800)
Update (December 24 2010)
After a few weeks of shooting I found that the accuracy was not quite on; when the screen reported perfect focus using the split screen, the resulting pictures were very slightly backfocused. This was only visible at close distances and f/1.4, and (I thought) only affected my 50/1.4 lens; the 105/2.5 and 300/2.8 seemed to be OK. However, I thought I would email Rachel anyway to see what (if anything) could be done. Even though it was Christmas Eve, she replied very quickly with instructions on how to test for this condition in a controlled fashion. Sure enough there was a slight back focus; to my surprise it was also there on the other lenses, not just the 50/1.4 (I just had not noticed before since their smaller apertures gave me a bit more DOF to work with).
Reporting these findings back to Rachel, she sent further detailed instructions on how to adjust the focus. By following those instructions I seem to have completely eliminated the focus error. This is exactly the reason why I decided to go with Katzeye over the cheaper screens: while the product itself may be 30% more, the support which Katzeye provides is top notch.
Conclusion
If you are someone who wants to use manual focus lenses on your digital camera, I would highly recommend Katzeye Optics. Their products are top notch, but more important than that, they go above and beyond the call of duty in their support to guarantee customer satisfaction. If you have had previous experience with split screen focusing aids on film cameras, so much the better. Manual focusing is a different experience than relying on autofocus, and while it may not be for everyone, I feel that it can provide an accuracy that rivals the best AF system, while keeping you in control of your exposures more than you otherwise would be.