A novice photographer asks: “Does the camera body have any effect on image quality? Can I get a top-quality image with a consumer-level camera, or should I spend big bucks on a Pro camera?
Lens and Film Stock
Back in the days of film the two most important things with regard to image quality was the “glass” and the emulsion, i.e. lens and film stock. The main purpose of the camera body was to serve as a light-tight box with an accurate timed shutter. Some other camera features were important like maximum shutter sync speed. But all the bells and whistles that Nikon and Canon added to camera bodies had negligible effect on image quality.
For image quality, size matters. Larger format films have more detail than miniature formats. Medium format cameras like the Hasselblad 6×6 or Mamiya 6×7 which used 120 film have more detail than 35mm formats because the area is bigger. A single 35mm frame is about 1.5 square inches of film. Hasselblad ’s 2-1/4 format exposes about 5 square inches of film. And 4×5 view cameras expose a gigantic 20 square inches of film.
Choice of film stock also matters. Slower speed film stocks have smaller grain and are capable of holding more detail. As time went by film emulsions improved to the point where higher speed films like ISO 200 and ISO 400 produced excellent images. I usually shot with 100 speed chrome film because it was fast enough but still had fine grain. Then there was ISO 50 Velvia from Fuji that had almost no grain.
What about lenses. With regard to image quality, primes lens are superior to zoom lenses. And better quality lenses will cost more. There is also a “sweet spot” with regards to aperture. Most lenses are best stopped down a couple of stops from the largest aperture. So for a fast f/2.8 lens maybe f/5.6 or f/8 is best. Really small apertures like f/22 might introduce diffraction effects that can degrade the image.
Digital Image Sensor
With digital photography, there is no film. The image sensor takes the place of the film to expose the image. But not all image sensors are created equal. Two kinds of sensors are CCD and CMOS. CCD sensors are an older imaging technology. CMOS is newer and superior.
Just like with film, sensor size matters. Bigger image sensors, provide more detail. Images sensors in older and less expensive cameras are cropped. Newer and more expensive cameras from Canon and Nikon now have full frame sensors which are the same size as a 35mm film frame (about 24mmx36mm). Medium format sensors for Hasselblad are even bigger (60mmx60mm), but the cost is much higher.
Larger image sensors can either provide greater linear pixel dimensions (more pixels), or larger pixel sites. Larger pixels provides a greater dynamic range which means more f-stops of exposure. This allows for wider exposure latitude, approaching that of negative film. If it was me I would opt for larger pixels over more pixels. I’d rather have a smaller picture with highlight separation and shadow detail, than a larger picture with blown highlights and blocked shadows.
Here is a link from dpreview.com with a very good explanation and nice illustrations about Sensor Sizes. Observe how tiny the sensors are in some of the point-and-shoot cameras compared to 35mm film. I read somewhere recently that some of the newer P&S cameras are packing even more pixels into smaller sensors. This is to reduce cost, but can not be good for image quality. Bigger sensors are better.
My Final Answer
So the answer is: if shooting on film, the choice of camera body is not so important in determining image quality. Image quality is all about the lens and the emulsion.
But if shooting digital, camera bodies with larger and better digital sensors are capable of producing higher quality images. And the lens is still important.
