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Minolta Dimage 7 Minolta unleashes the first 5-megapixel camera, with a tack-sharp 7x zoom lens, and amazingly sensitive electronic viewfinder! Select a topic Reference: Datasheet Dimage 7 Sample Images --------------------------------- 1. Intro and Highlights 2. Executive Overview 3. Design 4. Viewfinder 5. Optics 6. Exposure & Flash 7. Shutter Lag & Cycle Time Tests 8. Operation & User Interface 9. Camera Modes & Menus 10. Image Storage & Interface 11. Video, Power, Software 12. Test Results & Conclusion --------------------------------- Print-Friendly Review Version Additional Resources and Other Links Reader Comments on Dimage 7 Review --------------------------------- Digital Camera Comparometer (TM) --------------------------------- <-- Digital Cameras (Home) <-- Digital Camera Reviews Index <<Design :(Previous) | (Next): Optics>> Page 4:Viewfinder Review First Posted: 5/23/2001

Viewfinder
The viewfinder is one of the most interesting aspects of the Dimage 7. It employs a "Digital Hyper Viewfinder" as well as an LCD monitor for composing shots. The Digital Hyper Viewfinder display would generically be called an "Electronic Viewfinder" (EVF), and is essentially a miniaturized version of the LCD monitor, complete with image information display.

We confess that we've never been big fans of EVFs, for a variety of reasons. For one, resolution is often considerably less than the rear-panel LCD, and it doesn't remotely compare to the view through a purely optical viewfinder. A bigger concern though, is that most EVF displays are woefully inadequate for low-light shooting. The high refresh rate required to provide a "live" view of the subject means that the CCD just can't capture enough light in each frame to make the EVF display usable. Time and again, we've seen EVF-equipped digicams that are capable of taking pictures in conditions far darker than those that can be viewed in the EVF itself. Without a low-light capable viewfinder, you're reduced to guessing where your subject is in the viewfinder.

Prior to receiving our evaluation sample, Minolta hinted that the Dimage 7's EVF would be something special. If anything, they understated their case. The EVF on the Dimage 7 works down to incredibly low light levels, and has very high resolution under normal lighting. The spec sheet indicates that the EVF uses a reflective ferroelectric LCD display, with a visual resolution "equivalent to 220,000 pixels". We're not sure how the "equivalent" resolution is computed, but there's no question that the resolution is quite high. The ferroelectric technology is also a new one on us, but apparently has been around since the 1980s. We don't pretend to understand how it works, but the bottom line appears to be that ferroelectric LCDs not only switch states faster (potentially providing faster refresh rates), but they are also somehow able to represent a full range of color at *every pixel,* compared to the purely red, green, or blue coloration available with conventional LCDs. This was evident in looking at the Dimage's EVF display, which appeared remarkably smooth, with none of the red / green / blue pointillist appearance of conventional micro displays. Whatever the technology, the Dimage 7's EVF is unusually clear and sharp, and is also dramatically more light-sensitive than conventional designs we've seen. (Note though, that at low light levels it switches to a monochrome mode to improve sensitivity.)

Another neat feature of the Digital Hyper Viewfinder is its auto-switching capability. On the right side of the eyepiece, there are infrared sensors inset behind a pair of vertical windows. (You can see the windows slot to the right of the objective in the viewfinder eyepiece photo above.) By placing the Display Mode control in the "A" position (see photo inset right), the IR sensors detect your eye as it approaches the viewfinder, automatically turn off the rear panel LCD, and activate the EVF. If you bring the camera back down again, the process is reversed, and the LCD panel comes back on. Very handy! (As you can see, there are also settings for activating the EVF or LCD only.)

For added convenience, the electronic viewfinder eyepiece tilts upward 90 degrees, offering a range of viewing angles. A Diopter Control sliding switch adjusts the viewfinder to accommodate eyeglass wearers, in arbitrary units from —5 to +0.5. (This covers a wider range of eyesight than we're accustomed to seeing in eyepiece adjustments. It handled our 20:200 vision with no trouble at all.)

We did find a couple of quibbles with the EVF though, and some users have complained about its characteristics quite a bit. Here's what the issues appear to be. (Both from our own observations and reports from users.):

1. Eyepiece optics. - Several users have written to complain of blurriness in the viewfinder, which seemed strange to us and prompted us to take a closer look. We're not sure how to characterize it, but it did seem that we sometimes got a slightly blurry view in the eyepiece. We think this might be a "curvature of field" problem, where not all of the field of view is sharply focused at the same time. We confess that we couldn't get a consistent "look" though, as sometimes everything seemed perfectly sharp, while at other times, there was a distinct blurring around the edges. (All this with no change to the diopter adjustment.) It might have something to do with eye position, but we never did nail it down. 90+% of the time, everything looked OK, and those times it didn't, it seemed like a little fidgeting and squinting ended up with it looking right again. A bit of a mystery, but we do see what some users were referring to.
   
   
2. The "cracked glass" effect. This is evidently a consequence of the ferroelectric LCD's square, firmly abutting pixels: If you have a subject in view with lots of very fine, sharply-contrasting detail, the viewfinder image gets a "crackled" look to it. It seems that these artifacts result from the fact that, while the square, smoothly tiled LCD pixels give a very smooth appearance, the image can change very abruptly from one to the next. On a conventional LCD, with the R, G, and B pixels spread across a bit of an area, your eye tends to smooth over inter-pixel transitions. With the ferroelectric LCD though, adjacent pixels can change brightness very abruptly, causing this "crackled" pattern.
   
   
3. Blown highlights. - In extended use, the biggest complaint we personally had about the EVF was that it was very hard to judge what was going on in the highlights. In landscape shots where we cared about cloud detail for instance, it was very hard to compose the sky portion of the image, because the bright areas tended to wash out to a featureless expanse of white. This is somewhat due to the tendency of the camera itself to drop highlight detail, but we lay some of the blame on the EVF system for it.

Overall, after living with it a bit more in the production unit we received to test, we still like the Dimage 7's EVF better than others we've tried, but are still of the opinion that optical viewfinders are to be preferred if they're available. (As we see more long-ratio zoom lenses on digicams though, expect to see more and more EVFs along with them. - It's just too difficult to create a 10x zoom ratio optical viewfinder that's lightweight, accurate, and affordable.) We think the bottom line on the Dimage 7's EVF will be a matter of personal preference: It's hard to hear ourselves saying this (being such internet mavens), but prospective purchasers should probably make an effort to get a hands-on look at the camera and play with the EVF, before making a purchase decision.

The rear-panel 1.8-inch, TFT color LCD monitor is comprised of about 122,000 pixels, and offers a very bright, clear image display. Like the electronic viewfinder, the LCD monitor displays a range of exposure and camera information in both Record and Playback modes, which is activated by the i+ button on the Display Mode dial. While shooting with the Dimage 7 outdoors, we observed that the LCD seemed to be much less prone to washing out in direct sunlight than the LCD's we've tested on most other cameras.

In Playback mode, the Dimage 7 displays a fair amount of image information, which is again controlled by the i+ button on the Display Mode dial. A histogram feature is also available, for checking on the tonal range of the captured image.