Camera Construction - Photography Honor
Here are answers to the basic questions you might have when attempting to earn or teach the Photography AY Honor.

excerpted from

A photograph is made when light enters the camera and exposes the light sensitive chemicals on the film inside, leaving an image on the film. There are four main components on every 35mm SLR camera that control the exposure of the film to light: the shutter speed settings, the film speed settings, the aperture (f-stop) settings, and the focus. Other features on your camera may include; a mirror lockup button, a hot shoe for your flash, and a self timing mechanism. Your camera may have more or less features than those listed, so I would suggest you get out your camera's operator's manual and see what features you have. The digram below shows some of the basic features of a 35mm SLR camera, and the list below that details each feature. Be sure you use your camera's operators manual to locate all the features, since these features vary somewhat from model to model.



Copyright©1997 C.E. Vest

Film speed settings.

Most 35mm SLR cameras have a dial to set the film speed. These numbers will generally range between 25, and 3200. Somewhere on your film speed dial, will be the letters ASA, or ISO that designates it as a film speed settings dial. Since film is available in so many speeds, be sure you check your film speed settings when changing film in your camera. If you have an automatic camera, then this should be done automatically for you.

Shutter Speed

The amount of time you choose on the shutter speed setting will determine how long light exposes the film in your camera. Shutter speed dials are located somewhere near the top of the camera body in general, and will have a list of numbers that range from B to 1000. The B, or Bulb, setting will leave the shutter open for as long as you hold the shutter button down. This can be useful for taking photos of fire works, and other low light situations requiring long exposures (though you will need a tripod to avoid camera shake). The other numbers designate how many fractions of a second the shutter will stay open. 1/125 means the shutter will stay open for 1, 125th of a second. You also need to check to see what your shutter syncronization setting is. Some cameras will only work properly with a flash if the shutter sync speed is set. On many cameras, this is 1/60 of a second. However, check your operators manuel to make sure. Some cameras will sync at any speed.

Aperture or f-stop

The aperture is the opening in the lens that controls how much light gets to the film. By opening or closing (stopping down) the aperture, you control exposure. The numbers on the aperture control will be numbered as follows: 16,11,8,5.6,4,2.8,1.8. The higher the number, the smaller the opening, and less light is admitted. lower numbers mean larger openings, and more light. Some automatic models give you the option to control aperture, and shutter speed, or both. Otherwise, this is another feature that automatic cameras can take care of for you.

The Focusing Ring.

All 35mm SLR lenses have them, even automatic ones. You should be able to easily find the focusing ring located on the camera lens. Practice looking through your viewfinder and focusing on objects far and near. If your camera has an auto focus feature, you may want to do this anyway; It is a skill everyone who take pictures needs. In my personal experience, I never use an auto focus lens. This is not to say that I don't highly recommend them; I do. Auto focusing is especially good for people with vision correction problems. However, if the need ever arises that you can't use that feature for some reason, your focusing skills should be at-the-ready.

Hot Shoe, or Flash Mount

Your camera should have a small device on the top that will enable you to attach a flash unit. These come in two types: a hot shoe that is directly connected to the cameras electronics, and a regular flash mount that is not connected to the cameras electronics. With a hot shoe, there are electrical contacts that work with the electrical contacts on the bottom of the flash unit. When you press the shutter, a small electrical charge is sent to the hot shoe, causing the flash to fire at the right second.

If you only have a regular flash mount, then you will need to connect your flash unit to the camera with an inexpensive, and readily available PC sync cord (nothing to do with computers). There should be a small plug like a headphone jack ( but much smaller), somewhere on the camera body that enables you to plug the cord in and connect it to your flash. Be sure you buy a flash that will accept a PC connection, and the proper sync cord for your camera, or this won't work.

Mirror Lockup button

Your camera may or may not have this feature, but if it does, then you will find it handy for slow film photography. Essentially, this device locks the mirror in your camera into the up position. When you look through the viewfinder of a 35mm SLR camera, the image you see is being projected there by a prism shaped mirror. This mirror sits in front of the shutter, and when you press the shutter button, it must flip up and out of the way to allow light to strike the film while the shutter is open. Usually, this is not a problem. However, on occasion when using extra slow film, and shutter speeds, the small amount of movement produced by the mirror flipping up and down may be enough to cause a slight blur in the picture. Most amateur photographers never have to worry about that. However, as you hone your skills and experiment with different techniques, you may want to consider doing this.

The only drawback to locking the mirror up is that once you do so, you can no longer see through the viewfinder because the mirror is out of position. You will have to set your photo up, then lock the mirror up before shooting.

Film rewind knob.

I know, you all know how to rewind your film. Or, hopefully you do. If not check your operators manual. There should be two operations involved in rewinding your film if you have a manual camera: The rewind release, and the rewind knob. There is always a knob, or button, or some sort of device that locks the rewind knob in place. You will have to unlock it before your rewind knob will work. If you have an automatic camera, the whole operation may be done for you. Never, never open your camera until you have completely rewound your film.

If you suspect that your film has come off the spool ( this does happen occasionally) go into a completely dark room. One with absolutely no light at all such as a windowless bathroom. Be sure you are in total darkness. Let your eyes adjust to make sure there is no light before you open your camera. Carefully, and gently remove the film, and return it to the plastic outer canister the film originally came in. Make sure the lid is on tight before you switch on any lights, and tape the lid securely down.

Self Timer Switch

Many manual 35mm SLR cameras will have a self-timer switch on the front of the camra body. Check your operators manual to find out where yours is. You usually get around 15 seconds after you set the timer to get in the picture, and you will need a tripod to hold the camera. The best way to take a picture of yourself is with other people. Arrange everyone in the picture while looking through the viewfinder, and use someone to stand in your place. Look through the camera, be sure everything is ready, set the timer, and then run, and jump into your spot. If you don't have time for all that, or you are alone, just make sure that you focus the camera at the distance you will be from it by focusing on the ground where you will be standing.

Shutter Button

You probably know where this is on your camera. Most cameras have them on the top right side of the camera. This button opens the shutter for the amount of time you have specified on the shutter speed setting. Using the shutter realease button can cause you to move your camera slightly when you press it. To avoid this, take a deep breath, hold it in, release it about halfway, hold, press the shutter button, and let the rest out. Those of you who hunt, or practice shooting firearms will be familiar with this method. It helps keep you steady, and will improve your pictures. Practice makes perfect on this one, so make it a habit.