“There are other factors influencing viewfinder brightness, such as the design of the reflex mirror. In all current phase-detection AF SLRs, a percentage of the incoming light passes through the mirror and is diverted downwards to the autofocus detection mechanism. In the EOS system the ratio of reflection to transmission is usually around 60:40. You may want to check with some of the other manufacturers to see what their specifications are in this area, but I would guess they are probably similar. However, this factor is the main reason why AF SLRs in general are perceived to have dimmer viewfinders than manual focus SLRs with their full-reflection mirrors.
“Moving from generalities to specifics, the EOS 20D and 30D APS-C viewfinders are just as bright as the full-frame EOS 5D viewfinder when the lens is the same, but the size of the viewfinder image overall is much larger on the 5D. Some people may perceive the 5D viewfinder to be brighter for this reason, but it’s not. It’s just bigger because of the full-frame format.” Thanks, Chuck, that’s a lot of valuable information. One of the key terms in the foregoing would be “perceive,” as in some people perceiving the full-frame image as brighter, simply because it’s larger. This raises another suggestion about demonstrating the camera—be sure there’s a bright area for the customer to aim at when evaluating the viewfinder image. Pointing the camera out the store window at night is probably not a great idea.
It would take sensitive instruments and a lab setting to determine which cameras, exactly, have the brightest viewfinder, which have the dimmest, and which fall where on the continuum between. For the mathematically inclined, this might make an interesting intellectual exercise, but it might also be splitting hairs. Some cameras’ viewfinders are noticeably brighter, others noticeably dimmer, a point we’ve given in several of our in-depth reviews.
But the dimmest is still pretty bright—certainly bright enough for clear and easy viewing in even the low levels of light yours truly loves taking pictures in.
Probably the dimmest of the viewfinders we’ve used is in the Olympus Evolt E-330, which, as we described two issues back, siphons some of its light out of the viewfinder path and redirects it to the Live View imager pickup. This constitutes a trade-off in light management, and it’s one we approve of. Yes, the viewfinder image is a little dimmer, but in exchange you get the live feed to the LCD screen.
The subject should become more of a discussion as time passes. The Olympus E-330 is the first camera with the Live View, but by the time you read this, it shouldn’t be the only. Panasonic’s own Four Thirds DSLR, practically the twin of the Olympus, should be shipping. And we’ve received preliminary, albeit secret, information on a third well-known make that will offer the same feature, to be announced at photokina.
So, for reasons of optics, electronics, or perceptions, there’s a lot to say about viewfinder brightness. Thanks to our reader Tracy, we know what it is.
Whatever Happened To…
Another reader, Joshua Shapiro, wrote a few months ago to inquire after one of our favorite products, the Foveon imager. That is, he asks:
“Two years later, how keen are you on the Sigma/Foveon system? Is it still competitive?”
Two years is a long time in digital photography, and except for the Sigma, there are no camera models on the market that are quite so venerable. Foveon’s claim was that their imager with 3-million three-sensor sites gave performance equivalent to a conventional sensor in the 7+ megapixel range, but today there are 8MP cameras selling for under $1,000. Not only have there been increases in pixel count, there have been dramatic improvements in processing speeds, noise reduction, and other valuable characteristics of camera performance generally. So we’d say that the SD10 (which is the SD9 with a slight upgrade, hence closer to four years old) does not have a strong competitive position today.
Neither does a Nikon D1X or a Canon 10D, cameras that were contemporary with the first Sigmas. We do think the basic premise and technology of the Foveon imager has great promise, but a new model is overdue.
At this writing, there are no stated plans for a new Sigma/Foveon camera, and the prospect for a new model is dim even at photokina. Foveon apparently has disbanded its marketing department, and its sales department doesn’t return calls. On the surface, this looks grim. But an explanation given by one of the ex-marketing guys, when we caught up with him, was that Foveon really needed to sell its product to manufacturers, not the public, for which a marketing department is not really required. Our understanding is that the company has been devoting its attentions to imagers for products like camera phones, more than DSLRs.
Canon and Nikon both claim authorship of their imaging sensors, and most of the others are made by the “giants”—Kodak, Matsushita, Sony—undoubtedly with fairly elaborate contracts with the camera makers. It could not be an easy market for an upstart like Foveon to crack. Indeed, it took an equally new and independent camera line like Sigma’s to give the new imager its foothold.
Both the Sigma camera and the Foveon imager it contained were excellent performers in their time. If that dynamic combination were to revive with a larger number of pixels—say, 10 million sites with three sensors each—it would probably prove an excellent performer in its own time. Yours truly maintains faith in the principle, and we’ll see what the future brings.