Buying a new digital camera
Buying a new digital camera can be a very overwhelming endeavor. Technology is in a constant state of change and there seems to be new camera announcements every month! There is a way to ensure that you purchase the right camera for your needs however. Understand the technology. Not all of it of course, but just enough to make the right decisions. This article will cover the features of digital cameras that are most important for you to understand.
To begin with me will discuss the similarities between film and digital cameras. Basically a camera is a light airtight box that allows exposure of a light-sensitive material through the use of a shutter and an aperture. This process is the same with either a digital or film camera.
Lenses focus the image and control how the photo will look (wide or telephoto); both film and digital cameras have lenses. The lens is also one of the most important factors in determining overall photo quality; the better the lens quality, the sharper and more clear your image. In film or digital photography- poor lenses=poor image quality.
Both types of cameras also use shutters to maintain the duration of the exposure. Both film and digital cameras need an aperture to control how much light hits the sensor during the period that the shutter is open. Very large apertures (2.8 or 4) will let in a lot of light, while small apertures (16 or 22) will let in very little light.
Focusing will always be a necessary step in creating sharp photographs regardless of whether you are using film or digital cameras. Manual and auto focusing can be found on both types of cameras. So what are the differences between the two? The main difference is the way in which the cameras record light. The traditional camera uses film while the digital camera has a sensor and a processor. Understanding the way the sensor and processor work is the key to knowing digital cameras.
So what are the differences? The main difference is the way in which it records light. The traditional camera has film and the digital camera has a sensor and a processor. Understanding the sensor and processor is the key to knowing digital cameras.
Film Advance, Lag and Response Time The digital sensor records light much like film. Once the light strikes film however, it is “exposed” and the camera must advance the film to the next frame to continue the process. With digital, the information that was captured during exposure is passed on to the processor and the sensor is freed up to record another image. The amount of time it takes for the sensor to “dump” its information and be ready to record again is called Advance Time. The digital camera’s speed is also influenced by how many images it can store in the buffer before the camera needs a time out to process them. A typical statistic could be “23 full-res(resolution) JPEGs or 6 RAW images at 5 fps”(Canon 20D). This means the camera will shoot 5 frames per second until the buffer fills up. The buffer will become full at 6 exposures if you are shooting RAW and 23 if you are shooting the highest quality JPEG.
ISO In traditional (film) photography ISO (or ASA) was the indication of how sensitive a film was to light. It was measured in numbers (you’ve probably seen them on films - 100, 200, 400, 800 etc). The lower the number the lower the sensitivity of the film and the finer the grain in the shots you’re taking.
In Digital Photography ISO measures the sensitivity of the image sensor. The same principles apply as in film photography - the lower the number the less sensitive your camera is to light and the finer the grain. Higher ISO settings are generally used in darker situations to get faster shutter speeds (for example an indoor sports event when you want to freeze the action in lower light) - however the cost is noisier shots.
This increased sensitivity does have its drawbacks however. With film you get an excess of grain, with digital you get what is called noise. The grain of film, in most cases is considered acceptable and in some cases even desired. Noise, however does not have the same allure. Unlike different emulsions of film, the sensor really only has one sensitivity. To manage an increased ISO, or during very long exposures, the camera must send more power to the sensor, which results in the appearance of small specks or dots of white or color. A blotchy look can also be created from the higher ISO’s or long exposures. Most of the noise will generally manifest itself in the darker areas of your image. This is an important point to pay attention to if your photography requires higher ISO settings, nighttime or long exposures. In higher end cameras, manufacturers have spent the money to reduce the noise problem, but it still may present itself on the lower cost models. Look to reviews for how much noise individual cameras will produce.
In today’s world almost all digital cameras have very high resolutions. Even the less costly cameras all come with resolutions sufficient enough to make good 8×10-11×14 prints. Higher resolution is basically a selling point to manufacturers. Higher resolution is good but what is even better is a larger sensor size. The bigger the better. Sensor size is a much better measure of the camera’s final image quality. In film cameras, a 35mm is better than an APS camera because the size of the image on the film is bigger. There is no different with digital cameras.
Please remember, it is very common to see cameras that are equal in resolution but have different sensor sizes. In cases such as these it is a better idea to go for the larger sensor. Now you may be wondering, “how do you know how much resolution you do need?” It’s simple really. You need to ask yourself how large of a print you want to eventually make. 3 and 4 Megapixel cameras are plenty sufficient for everything up to 8×10. If you need to create larger prints you will want to move up to the 5 and 6 Megapixel cameras.
White Balance The processors ability to create “correct” color in your pictures is referred to as white balance. The sensor in the digital camera always captures “raw” images at which point the onboard processor processes it and then sends it to the memory card.
The human eye is an amazing thing. What is even more amazing is that it is excellent at ignoring color casts. When we are indoors under typical house lighting the color is quite orange/yellow while office lighting (fluorescent) is very green. Our eyes are able to ignore this, but film and digital cameras faithfully record all color nuances. When using film photography it is often necessary to put filters on your camera or to purchase film that is balanced for the particular lighting (color) that you are using. With digital photography we can easily change the white balance. All digital cameras come with a good variety of choices for correcting typical lighting situations with white balance. They also generally include an auto setting as well which is useful if you do not know what kind of light you are working under. Typically the more expensive cameras will also include the ability to custom balance to any color light!
So if your light is Then the color is Choose this White Balance for good color Daylight Neutral (”white) Daylight Late Afternoon/Sunset Warm (yellow/orange) Daylight Early Morning Warm (yellow/orange) Daylight Cloudy Cool (blue) Cloudy/Overcast Open Shade Very Cool (blue) Open shade Unknown Light source ??? Auto Tungsten/Incandescent Very yellow/orange Tungsten/Incandescent Fluorescent Green Fluorescent
Choose a digital camera that is right for you Hopefully by now you recognize that understanding how the sensor works will enable us to make some intelligent choices regarding resolution and camera speed. We also know that white balance is a fairly uniform feature across the entire line of cameras, negating any serious consideration in this arena. So you might be wondering what other features exist that may influence your camera purchase?
Lenses Lenses play a major part in creating high image quality, along with the sensor and processor. Luckily in todays marketplace we are at a place in time where most lenses are of a very high quality. So we now know that speed and length are the qualities that you should look at. Speed refers to the fastest -stop of the lens. 2.8 is faster than 3.5, which is faster than 4. A faster lens allows you to shoot in lower light conditions without raising your ISO. It also allows you to achieve a shallow depth of field, which should result in a blurred back or foreground.
Buying a new digital camera
Focal length is the next consideration. Do you like to shoot with wide-angle lenses? Long telephoto lenses? Do you enjoy shooting up close with macro lenses? Digital cameras come with all of the same lens options that your film camera does. It is just a matter of choosing the camera with the qualities that you want. By looking at magazines or stepping on to the web and going to dpreview.com you can easily find the specifications that describe all of the options.
Two sets of specs are commonly given when you begin to look into focal length . The first set is generally the actual focal length of the lens. For example, 7mm-28mm. This example would be an extreme wide angle on a film camera. The digital camera however, has a smaller sensor area than the film camera which makes the 7mm lens look more like a 35mm lens. So the second set of numbers on this lens would be 35mm-136mm. This is typically considered the 35mm equivalent. It is these numbers you should pay attention to when researching different cameras for focal range as they will be more recognizable to you.
Many amateur digital cameras do not provide a wide spectrum of wide angle lens choices. Most will commonly go down to 35mm or even 28mm but rarely can you find a 24mm or wider due to the difficulties in building such a small focal length lenses. So if you enjoy wide angle photography you many want to think about moving up to a digital SLR.
When it comes to long telephoto lenses the digital cameras have a big advantage to film cameras! Their smaller sensor size turns even moderate telephotos into very long lenses. For example a real 57mm focal length behaves like a 370mm! This is a real advantage to people who like to shoot “long”. Please note, beware of cameras which claim their longest focal length as Digital Zoom. You should always avoid Digital Zoom. For these purposes we are concerned only with real or actual focal lengths.
The last lens specification to consider prior to purchasing is the focusing distance. If you like, or need, to shoot macro, look for a lens that has the ability to focus very close. They will usually be signified by a “macro mode” or be called “close focusing”.
Shooting your digital camera in the field Shooting your digital camera should be the fun part. Do not let all of the bells and whistles confuse you out in the field. There are many choices and they can be a bit overwhelming. Here a are three of the most important things you should always check before you start photographing.
ISO- If you are outdoors or in areas where you have plenty of light keep the ISO set to a low (100 or 50). Raise the ISO only when you need to prevent camera shake. Typically most digital cameras will provide great images all the way up to 400 ISO. If you need to go higher than 400 ISO, you must know that you may run the risk of introducing a visible amount of noise to your photos. Take some time and play with your digital camera to figure out which ISO produces unacceptable noise levels.
Jpeg vs. Raw- This is an easy choice. Shoot RAW if you want to work on every image in your computer. The RAW format is very flexible and easily allows you to correct for errors in exposure and color cast without degrading your image quality. You will want to use the Jpeg mode if you do not have the time or desire to work on every image. Jpeg mode uses a minimum amount of image compression which provides extremely high quality pictures.
Image Size- Many cameras will come with multiple resolutions. Your choices may look like this: 2304×1728, 1600×1200, 1280×960, 640×480. Simply put, always choose the highest resolution. In this case that would be 2304×1728. This will supply you with the highest quality images possible.
Digital Camera Accessories To say that there are a lot of accessories for the digital camera would be an extreme understatement! It can boggle the mind with all of the different options, cases, cards and storage units. There are however, only a very few accessories that are absolute necessities.
Compact Flash-The first is the type of storage that your camera uses. I prefer cameras the use Compact Flash. This medium seems to be the best all around Flash Card. Sturdy, durable, not too small to lose or to big to be bulky. It also comes in very large capacities-up to 8 gigabytes! My recommendation is to have a least two cards in case one becomes damaged or lost. Your total amount of storage will be determined on how much you want to spend on your cards (cameras rarely ship with a card that is adequate for most photographic purposes). Having two 512Mb cards seems to be adequate for most shooting situations, unless you are very trigger happy. Having 4 of these cards or two 1 GB cards will ensure that you will never be without storage.
Portable Storage-If you have enough Flash Card storage, you will probably not need a portable storage unit. This theory dependent on moving your photographs from the cards to your computer on a regular basis. For instance, if you are on vacation and will not have access to your computer for long periods of time you may want to consider a portable storage unit. The most basic form of a portable storage unit is one that allows you to plug your card into the unit, and download your images to it. You can then put the card back into your camera, reformat it to remove the existing photos, and continue shooting. When you return home you can simply hook the storage unit to your computer and move the images. Typically these units come with enough storage space for many days of shooting. A good purchase would be a unit with at least 10Gb of storage.
Storage and transfer are the most basic functions which all of the models will perform. At this point they can get really fancy. There are units that will automatically create Cds from your cards, which produces an immediate archive of your images. Others come with an LCD screen that allows you to preview your photos right on the storage device. Advanced features will even allow you to organize your images into folders and albums. Prior to purchasing one of these units you may want to think about the length of time you will be away from your computer as you may not need one with these advanced features.
Extra Batteries / Charger Digital cameras go through batteries at an alarming rate. You will definitely need to have back up batteries. Given that you will go through so many batteries, rechargeable batteries are the intelligent choice. Most digital cameras come with a proprietary battery with a charger. This is helpful as it allows a stronger battery. If this is your situation, it is a good idea to purchase extra batteries when you buy your camera. If your camera is powered by common AA batteries, you would be wise to buy a couple sets of rechargeable batteries.
Bulb blower- this is a must if you are considering purchasing an interchangeable lens SLR. Often when you change the lens on these cameras dust is introduced into the camera body. Ultimately the dust will migrate to your sensor and manifest itself as small blurry splotches on your final image. A few seconds with the blower bulb will save you hours on the computer cleaning up your photographs!
