I’ve been trying out Leica’s latest digital camera, the M9. It’s the company’s first digital camera that uses a full 35mm-sized sensor. It’s a rangefinder camera, following the tradition and form of Leica’s renowned film cameras. You view and focus by looking through a small window on the back of the camera. Focusing is done by turning a ring on the lens to merge the double image in the viewfinder’s center spot into one. Framing is accomplished by using one of the three sets of projected frame lines in the viewfinder.

In some ways it’s a throwback compared to digital single-lens reflex cameras that focus automatically and have much more accurate framing. Yet, in spite of that, it’s quickly become the favorite of many professional photographers.

So, if a DSLR has more automation, more features and provides better framing accuracy, what’s the appeal of the Leica?

I asked that question of Ken Rockwell, a professional photographer in La Jolla. Rockwell also writes a popular photo blog (kenrockwell.com) that has hundreds of thousands of visitors per day, likely making him one of the most highly read photographers in the world. He writes great no-nonsense reviews of the equipment he uses, and it’s become one of my favorite sites.

“The reason I shoot an M9 instead of my pro DSLRs while out in the field is precisely not because its image quality is superior; it is because it is small, light, and of paramount importance, because it is simple,” Rockwell said. “It has just what I need. It has none of the B.S. features that my Nikons and Canons have that just get in the way.”

And that’s what I found in my testing. While the Leica takes more effort to compose, and you need to manually set the focus and aperture, it also doesn’t have the myriad of features of a DSLR that can add complexity and isolate you from your subject. The M9 has fewer buttons and options. It doesn’t have multiple metering and exposure modes, no settings for different scenes, nor a world map, a movie mode or other things manufacturers add on to try to win the features war. While those who are attracted by all of these features may think that Leica hasn’t kept up with all of the advancements, others will say the Leica provides a purer form of photography by providing the key essentials and nothing more.

In actual use, the camera worked best for me when I had the time to compose my shots and think about the subject and the lighting before shooting. It was least effective when I tried taking candid images of my young grandsons and their dog, all in constant motion.

The real benefit of the M9 is the quality of the images, the result of Leica’s legendary lenses and a new 18-megapixel CMOS sensor developed for them by Kodak. It’s specially designed to work with Leica’s lenses, which sit closer to the image plane than lenses made for SLR cameras. But I quickly got used to it and felt in control.

The M9 also appeals to many for its smaller size and lighter weight compared to a DSLR. DSLRs can weigh more than 3 pounds depending on the lens, while the Leica and the 28mm f/2.8 lens I used weigh about 1 3/4 pounds and have almost half the bulk.

When I first started shooting, I occasionally forgot to focus and to adjust the aperture when I changed scenes, expecting the camera to do it for me. But I quickly got used to it and felt in control. I never had to think about where the camera was focused because I made that choice.

I shot several hundred images, mostly outdoors, but some indoors using ambient lighting. Scenes ranged from people and suburban landscapes to city skylines. I used the camera at a default of ISO 160, but took some shots up to ISO 800 with very good results. I typically shot with apertures from f/2.8 to f/8 and let the camera self-adjust shutter speed (displayed in the viewfinder). I viewed the results on a 24-inch Mac monitor and magnified details up to 20X. Most shots were well-exposed and had excellent color rendition. I did have to pay more attention to strongly backlit scenes and compensate exposure using the camera’s adjustment feature.

What was most striking about the results was how sharp everything was, particularly tree branches, vegetation and the fine details of buildings. I compared similar scenes taken with a variety of DSLR cameras from past tests and found the M9 images to be noticeably sharper in many cases; some images seemed to pop out of the screen.

After hours of shooting, the camera never weighed me down nor created any discomfort. While substantial and solid in the hand, it carried much like a compact camera, a result of its thinner body and very compact lens. And it slipped easily into a small briefcase, making it much more portable than a DSLR.

The M9 is one the most sturdily constructed cameras. It’s all metal with its enclosure made of magnesium alloy and machined brass, much the same construction Leica has used for years. It’s covered in a rugged, heavily textured leather-like material that makes it easy to grip.

When I asked Rockwell who he thought the audience is, he said that Leica has always been about satisfying two audiences: accomplished pro photographers who use it as a tool, and for those nonprofessionals who take great pride in owning the best equipment, regardless of price. I loved using the camera. It exudes quality in its construction and in the spectacular images it’s capable of taking.

The M9 costs $6,995 for the body and $1,995 for the lens. The M9-P, which has a sapphire glass cover on the LCD display (and other minor differences including no logo), costs $1,000 more. (For comparison, a Nikon DSLR body with full-size sensor costs about $5,700.)