31st August 2006
This evening, a rather tatty looking yellow jiffy bag was propped up against the door of my apartment when I got home. With a sinking feeling, I noted that it had a quite clear boot print right in the middle of it. Indeed, UPS seemed up to its usual standard of care with respect to handling anything marked fragile, but I digress.
The package contained, astonishingly in perfect condition, the Beattie Intenscreen replacement ground glass I ordered a few weeks ago for my Bronica ETRS. It was packaged inside a plastic clamshell case lined with foam, inside which a pretty velvet pouch contained a pristine ground glass screen wrapped in tissue. I read the accompanying instructions, detached the finder from the ETRS body, then stared blankly at the innards for a while. I read the instructions again, then realised that things weren't making sense because the old screen, beaten up and scratched beyond recognition, wasn't even actually clipped in properly. It came out easily enough, and was replaced with the Beattie screen by the simple expedient of inserting a small metal tab on the screen into a slot in the camera, then gently lowering the screen into place, locking it by moving a silver pin to engage with the rear clip. After a quick dust off, I reassembled the camera, and, wow, what a difference!
Like much of my equipment, I bought the ETRS cheaply on eBay. It was in otherwise beaten-up-but-OK condition, other than the old ground glass which looked like someone had taken a chisel to it. After a couple of failed attempts to buy a replacement Bronica screen on eBay (why is it that people outbid me at sufficiently stupid prices that they could have bought an entire body, lens and finder?), I folded and decided to take Richard Chang's advice and buy one of the new fangled high brightness screens that are becoming increasingly popular these days. I ordered the diagonal split prism version with 1cm-spaced grid lines, on the basis that a 37mm square sensor will fill nearly all of the central 4x4 squares, hopefully making it rather easier to compose on the ground glass.
The first impression I had on looking through the finder was, wow, is this really the same camera? The image is now considerably brighter, with my 250mm now looking about as bright as my 75mm f/5.6, and the 75mm f2.8 looked as bright as a good standard lens on an old 35mm film SLR. The image appears to be significantly sharper, and the diagonal split image in the centre is extremely bright and precise. I should probably mention, for the benefit of anyone who came to photoraphy post the autofocus revolution, that a split image rangefinder prism is an absolute godsend for manual focussing. Basically, it splits the image, shifting each half in opposite directions if (and only if) you aren't in sharp focus. When you're dead on, the images line up perfectly - it is much easier to see this than it is to focus purely on the ground glass. The difference was particularly visible with the tilt lens, where the effect of adjusting the tilt was much easier to see (and therefore set correctly) in the viewfinder.
I tried each of my lenses in turn, and all worked extremely well. The split image remained usable across the whole range of focal lengths, including with my tilt/shift lens up to a fairly extreme amount of tilt, a considerable improvement on the original equipment screen. It was odd to be able to use the depth of field preview at surprisingly small apertures and still be able to see a usable image, even though I was only playing around in my not particularly well lit living room.
One issue that Beattie warn about is that these screens can throw off TTL metering, which usually operates by measuring light scattered by the ground glass screen. I haven't yet made an A/B comparison between the screens, but I'll probably just calibrate it against the digital back's ISO setting and figure out an appropriate offset.
To sum up, a bit pricey, but very well recommended. If a suitable screen is available for your camera, I'd heartily recommend giving one of these things a try.
Update: 27th September 2006
I've now had chance to use this screen with three different finders. It works well with all of them: a standard ETRS prism, an AE-II metering prism and a waist level finder. My favourite option is actually the waist level finder -- for some reason, I like the mirror-flipped image, and tend to get better results in terms of composition. I know a lot of people talk about this effect from view cameras, and have experienced it myself, but it also seems to work for the right-way-up-but-mirrored thing you get when using a waist-level finder on a medium format body. With the focus magnifier folded away, it's really rather nice for composition, the screen is bright enough that this is possible even on a very bright day. For accurate focussing, popping up the magnifier lens and putting my eye up to the finder results in a huge, bright image that makes focusing extremely easy, rather easier than with one or other of the prisms. My main reason for getting the waist level finder was actually an attempt to get the weight of my gear down, but I'm very happy that it also has had some other benefits too.