With DSLR (Digital Single Lens Reflex) cameras saturating the market since the onset of digital photography, knowing the difference between SLR and DSLR cameras may seem irrelevant. However, being educated on the basic principles of photography is crucial to any aspiring photographer, so any old-school or new-school knowledge is still important.
While they seem obsolete and are often more costly than their digital counterparts (because of the use of photographic film, developing, and printing) SLR (Single Lens Reflex) cameras still offer a bevy of unique advantages as compared to DSLR cameras. Why? Because there are nuances between film and digital images that need to be explored.
Additionally, if you are dead serious about honing your photography skills, or if you plan to become a professional photographer at some point, learning how to use both SLR and DSLR cameras is a must, and knowing the difference between SLR and DSLR cameras is even more essential.
What Is an SLR Camera?
A Single Lens Reflex (SLR) camera makes use of a reflex mirror which allows the viewer to see an optical image through the viewfinder.
The reflex mirror is slanted at a 45-degree angle and is located between the lens and the shutter. Translucent glass and a prism above the mirror enable the image to be reflected and projected onto the viewfinder.
The image from the reflex mirror bounces onto the translucent glass, which then mirrors it to the prism. The prism receives an inverted image and then flips it in order to project the right-side image to the viewfinder.
Once you see the image through the eyepiece, you can adjust the focus and overall composition of the image you want to capture before taking the photograph. This capability for precision is why professional photographers use SLR cameras.
The action starts when you press on the shutter button. The camera flips the mirror up and out of the way so the image is directed towards the now exposed film. This is why the viewfinder goes blank the moment you press on the shutter button.
How Does an SLR Camera Make Use of Photographic Film?
An SLR camera makes use of photographic film; usually 35 mm. Images captured by an SLR camera are recorded on photographic film which contain microscopic and light-sensitive silver halide crystals. The resolution, sensitivity, and contrast capabilities of a photographic film are dependent on the size and attributes of these silver halide crystals.
When the shutter button is pressed, it allows the photographic film to be exposed for a very short time, producing a latent but invisible image in the emulsion of the film, depending on the light absorbed by each of the halide crystals.
When the photographic film is developed through the use of chemicals, the latent image becomes visible as a negative image which then can be printed into a positive image (or a photograph). The use of photographic film is the most significant difference between SLR and DSLR cameras.
How to Operate an SLR Camera
Because an SLR camera uses photographic film, using one requires more steps than a DSLR camera. Features such as the rewind release and rewind crank can be a little unnerving to use, but getting the hang of it shouldn't be too difficult.
Let's discuss some of an SLR camera's unique features (as a film camera) so as to help familiarize you with its functions.
The Shutter Speed ?Dial
The shutter speed dial sets how much time the film is exposed to light. Depending on how old your SLR camera is, the increments may vary. For cameras from the 1960s onwards, the increments can be seen as 1/500, 1/250, 1/125 and so forth. For earlier cameras, the values may seem arbitrary.
The ISO Dial or Button Press
The ISO (sometimes marked ASA) indicates the speed of the film you are using. Because films vary in speed, setting this properly is necessary. However, some SLR cameras (especially newer ones) are able to read the film speed from electrical contacts found on the film cartridge. DX-capable cameras have electrical contacts in the film chamber, which means it sets the film speed automatically so you don't have to do so.
The Rewind Release
This is used to rewind the film after you've used up all the shots in your film. While shooting, the film is locked to move forward. The rewind release unlocks this mechanism. The button is usually found on the base of the camera, but some cameras might have it at a different location.
The Rewind Crank
Usually found on the lefthand side, the rewind crank allows you to wind the film back into its canister. A flip-out lever allows you to turn more easily. There are cameras though that do this task either automatically or by just pressing a button. These are just some parts of an SLR camera that you need to familiarize yourself with. There are also some helpful things to know about operating one of these cameras.
General Usage Tips:
The first and most basic thing you need to know is to never load film under direct sunlight. If you're using a manual-focus SLR camera, turn your focusing ring until you find the sharpest image on your viewfinder.
Fully manual cameras require manually setting of both the aperture and shutter speed. A match-needle meter in the viewfinder will show whether your image is overexposed or underexposed. Press the shutter halfway to do some metering.
Set your aperture, shutter speed, or both until the needle rests at the halfway mark (more or less). If you're using negative film, keep in mind that it has a higher tolerance for overexposure, so going slightly above the halfway mark wouldn't make much of an impact to your shots.
What Is a DSLR Camera?
A Digital Single Lens Reflex (DSLR) camera operates on the same general principle as an SLR camera, except that a DSLR camera uses a digital imaging sensor to record images. Captured images (and videos) are stored in a memory card, which is capable of storing thousands of pictures as opposed to only a very few images that can be captured by photographic film.
Unlike images captured on photographic film, images (or videos) taken by a DSLR camera can be instantly viewed after you've taken them. You can also delete or erase images that are unsatisfactory, manipulate or edit images with a DSLR camera's other features, or directly transfer the digital images to a computer for further manipulation/editing with more professional software (such as Adobe Photoshop).
A highly useful add-on feature to newer DSLR cameras is the ability to capture videos, which an SLR camera is incapable of doing. Just like the SLR camera, a DSLR camera makes use of interchangeable lenses. A DSLR camera uses autofocus in order to allow a more accurate calculation of optimal lens position.
The Difference Between SLR and DSLR Cameras
As we've previously discussed, the primary difference between SLR and DSLR cameras is that the former uses photographic film while the latter uses digital imaging sensors and a memory card to store captured images.
A DSLR camera also offers the convenience of live previews, so there is less guesswork and wastage compared to an SLR camera where you have to wait for the film to be developed in order to tell if the shots are good or not.
However, while a DSLR camera presents a lot of convenient features, an SLR camera still provides the look of film grain, a better contrast, and more crisp photographs.
The results will greatly depend on how you utilize light and on your keen sense of composition when it comes to capturing images.
If you take photography seriously, honing your skills in all aspects of the craft and educating yourself on the nuances and details to tell the difference between SLR and DSLR cameras will give you a better idea of how to use both effectively.
While the difference between SLR and DSLR cameras is profound, these cameras are not at all that different in certain respects. Whichever camera you prefer to use, remember that they are just tools. You are still the photographer, and the camera only does what you want it to do. A painter is not defined by the type of paint he uses: it's how the painter uses the paint that makes artwork unique. The same principle applies to photography.
Knowing the difference between SLR and DSLR cameras should not deter you from using them both. Instead, their unique characteristics should encourage you to experiment with each to know what their individual strengths and weaknesses are so that you can use this knowledge to your advantage.
The best way to achieve this informed knowledge is to go out there, take plenty of pictures, and enjoy the experience!+