Sound Advice: Negatives outweigh benefits of full-frame digital SLR cameras

Q: What do you think of full-frame digital SLRs? Are they worth the extra cost?

A: A full-frame digital SLR has a sensor the size of a frame of 35-millimeter film, which is 24 by 36mm. This refers to the physical dimensions, not resolution. You can have a full-frame sensor with 12 megapixels or a full-frame sensor with more than 36 megapixels. There are mirrorless full-frame cameras, as well, for example, Leica M cameras or Sony's new A7 series.

The other typical sensor sizes are the smaller APS-C, which is ubiquitous in consumer SLRs, and Micro Four Thirds (or just Four Thirds), which is slightly smaller than APS-C.

A bigger sensor will provide better dynamic range (ratio of light to dark captured by the camera), as well as lower noise in low-light situations. All other things being equal, bigger sensors are better for image quality.

There also are operational advantages. The viewfinder is much larger than an APS-C SLR, and you have more control over depth of field. If you want a really soft background for a portrait, it's easy to achieve with a full frame. There are no focal-length multipliers, so a 50mm lens behaves like a 50mm lens, not a 75mm lens.

You can get fully professional quality with smaller sensors, but if you are taking up wedding photography, shoot in low light often or have professional aspirations, full frame might be a good choice. It also is suitable for those who demand the highest resolution and image quality regardless of price, as long as you don't mind the weight and bulk of the equipment.

There are notable negatives. To me, the benefits of full frame are outweighed by the drawbacks, especially for consumer photographers.

Full-frame cameras make gigantic digital files. You will fill up memory cards and computer hard-drive space quickly.

The cameras, as well as suitable lenses for them, tend to be large and heavy. Sony's new A7 is an exception, but there aren't many lenses available for it yet.

I have fully embraced the Olympus/Panasonic Micro Four Thirds system and use it for almost all of my shooting now. I'm picky, and I'm fully satisfied. I just got back from Europe, and everyone who looks at the pictures on my iPad is simply floored by the technical excellence. I know I could make huge enlargements, and they would look great.

I have to admit that I wouldn't mind owning a full-frame SLR and might buy a used one to play with. It would be a nostalgia trip for me. I grew up using 35mm SLR cameras, and most people don't know what they're missing when they look in the tiny viewfinder of a typical APS-C digital SLR, or when they have to juggle their lenses because a 28mm wide-angle lens behaves like a 42mm normal lens.

If you want to give full frame a try without spending big bucks, look for a used Canon 5D. It can be had for $500 to $600. That's probably what I'll do if I decide to try the format.