Photography Step By Step

When buying a digital camera one of the factors that you will be looking at is the power of the zoom function. People who are not very experienced in this field are starting to be a little mislead because manufacturers are often claiming a zoom function called digital zoom, or they add this zoom to the optical zoom so the total zoom to be greater. This is not so fair on the consumer as you will understand from this lesson.

Optical zoom is the real zoom. This function of a camera uses the lens to draw the image closer. When using optical zoom quality remains the same and the full resolution of the camera can be used on the zoomed image. The motion of the front lens moving outwards on a camera is the lens achieving a greater level of zoom.

Digital zoom is not a true form of a zoom function. The image doesn’t actually come any closer because the optics in the camera stay the same. The way the digital zoom works is the same as it does on your PC. The idea behind digital zoom is that it takes a portion of the image and expand that image to the full size of the image so the section you are looking at becomes bigger, not closer. The image does look closer because it has been expanded however all that has happened is that the image quality has been reduced.

Here is an example of optical and digital zoom:

So the digital zoom is the same as the zoom you can do on any software of digital image manipulation and it is also done with loss of quality. In conclusion the only zoom that is really important when you choose a digital camera is the optical zoom, the digital zoom if just for marketing purpose and in my opinion it’s useless.

To define optical zoom, first I’ll have to briefly explain you what is focal length (or focal distance). If you look on the lenses of any decent camera you’ll see written there something like this: 5.8 – 34.8mm (or any other pair of values like that). This is the focal length specification and it is a characteristic of the lenses. I will not enter into physical theory of lenses and stuff like that, the main thing you have to understand about focal length is that if you are at the same distance from the subject, with the same camera (it is important, because the sensor is part of equation), the smaller the focal length is the further the subject will appear in the final picture.
Here is an example:
- focal length 18mm:

- same distance from the object, but focal length 55mm:

As you can see, the bigger the focal length is, the larger the object will appear in the picture, but the angle of visibility will be smaller.

Now that you have an idea about focal length, lets talk about optical zoom. This specification of cameras will always be seen just on point and shoot digital cameras, but it’s also applicable on DSLRs lenses. You will find it as a value like 3X, 5X, 10X or something like that. These numbers are obtained by dividing the biggest focal length of the lenses to the smallest. For example, if you have a lens with focal length 18 – 55mm, the optical zoom will be 55 / 18 which is approximately equal with 3, so 3X. In other words the optical zoom is the number of times the subject will be magnified compared to the subject dimension at the minimum focal length of the lenses. So in the example above the object has been magnified 3 times.

In the next lesson we will talk about the difference between optical and digital zoom.

Now you have an idea about the differences between point and shoot digital cameras and DSLRs and you know which one is best for you. The next step is to actually buy the camera. In the next few lessons I will explain to you a couple of very important technical aspects that are essentials in choosing the right camera from the vast number of models that exists on the market today.

In every camera’s specifications you will find the number of megapixels that it has. But what is a megapixel? A megapixel means 1 million pixels. A pixel is a single point in a graphic image. All graphic images are made up of thousands of tiny points. If your camera is 5 megapixels, it means that any pictures it takes will consist of 5 million of these pixels (on its highest quality setting). Generally, 5 megapixels is enough to print good quality 8x10s. But just because one camera has a certain amount of megapixels doesn’t mean that it will take better pictures with one with a lower amount. There are many factors which affect this, including build quality, type of camera, etc.

If you’re just planning on printing small prints of your photos, or viewing your photos on a computer, you can do this with a lower number of megapixels. But if you want to print quality 8x10s, you will need a bigger number of them. For a quality print, you’d want to start with a photography which contains at least 240 DPI (or dots per inch), 300 DPI would be even better, but 240 is enough. So, for a 4×6 print at 200 DPI, we would need an image size of 960×1440 pixels or better. For a 5×7, we would need 1200×1680, and for an 8×10 we would need 1920×2400 or greater. Now, most 5 megapixel cameras produce an image of around 2592×1944, which when printed at 240dpi comes out to a 10.8″ x 8.1″ print. So, with a 5 megapixel camera you could print 8x10s but only is you are not cropping your image.

Why isn’t more megapixels always better? Camera companies keep increasing the number of megapixels and now even some point and shoot cameras have well over 10 megapixels. But does this mean that they will take pictures of better quality than older models with lower number of megapixels? The answer is no. By continuously increasing the number of megapixels which cameras can output, the camera companies are not paying as much attention to quality as they should. Just because you are cramming more pixels into a photo doesn’t mean that the pixels are sharp enough for there to be any discernible increase in image quality. So, while your pictures may be getting larger, they might not even be sharp enough to be printed at this larger size, merely because there was an increase in pixels, but not an increase in quality. In theory, more megapixels would mean a nicer photo, but in actuality it may just mean a terrible photo composed of more dots.

Once you get past 4 megapixels or so, the resolution stops mattering as much, and optical quality comes more into play. This is why a 8 megapixel DSLR camera will take better pictures than a 10 or 12 megapixel point and shoot digital. Another fact worth mentioning is that DSLRs have larger sensors than a typical point and shoot. These larger sensors produce much less noise than their point and shoot rivals, leading to a much cleaner shot.

Some camera manufacturers have released cameras with the DSLR label that technically are not. I’ll define DSLR’s as cameras that have removable lenses, that have a reflex mirror which allows live optical viewing through the lens taking the image. DSLR’s use a mirror that allows you to see the image you’re about to shoot through the view finder – when you take the shot the mirror flips up allowing the image sensor to capture the image.

Here I will present the strengths and weaknesses of these cameras. To do that I need to use some terms that may be new to you, but I’ll explain all of them in later lessons.

Strengths:

Image Quality – due to the larger size of image sensors in DSLRs which allows for larger pixel sizes, DSLRs are able to be used at a faster ISO which will lead to faster shutter speeds and less grain.

Speed – DSLR’s are fast pieces of machinery when it comes to things like start up, focusing and shutter speed.

Large ISO range – this varies between cameras but generally DSLRs offer a wide array of ISO settings which makes them very flexible in shooting in different conditions.

Adaptability – DSLR’s ability to change lenses opens up a world of possibilities for photographers. DSLRs can be fitted with many high quality lenses ranging from wide angle to super long focal lengths. Add to this a large range of other accessories (flashes, filters etc) and a DSLR can be adapted to many different situations. When it comes to lenses the diversity in quality of lenses is great. Image quality is impacted greatly by the quality of the lens you use.

Optical Viewfinder – due to the reflex mirror DSLR’s are very much a what you see is what you get operation.

Manual Controls – a DSLR is designed in such a way that it is assumed that the photographer using it will want to control their own settings. While they do come with good auto modes the manual controls are generally built in in such a way that they are at the photographers finger tips as they are shooting.

Quality Optics – in general the lenses that you’ll find on a DSLR are superior to a point and shoot camera. DSLR lenses are larger and many of them have many hours of time put into their manufacture.

Weaknesses:

Price – while they are coming down in price DSLR’s are generally more expensive than point and shoot digital cameras. Also consider that you might want to upgrade your lens or you may wish to add more lenses later and that this adds to the cost of a DSLR.

Size and Weight – DSLRs are heavy and sizable and when you add a lens or two to your kit bag you can end up with quite the load!

Maintenance – every time you change lenses you run the risk of letting dust into your camera. Dust on an image sensor is a real annoyance as it will leave your images looking blotchy. Cleaning your image sensor is not a job for the faint hearted. Many new DSLRs are being released with self cleaning sensors.

Complexity – while DSLRs are designed for manual use this means you need to know how to use the tools that they give you and the learning curve can be quite steep.

Here I will present the major strengths and weaknesses of these cameras.

Strengths:
- Size and Weight – to be able to slip a camera in a pocket is a wonderful thing. These days point and shoot cameras are in general slim and light – to the point of not even knowing you’ve got them with you. This is wonderful for parties, travel and all manner of situations.
- Auto Mode – the quality of images varies greatly, but in general they shoot quite well in auto mode. Manufacturers presume that this style of camera will be generally used in auto mode (or one of the preset modes) and as a result they come pretty well optimized for this type of shooting.
- Quiet Operation – with the new cameras there are frequently situations when you don’t even notice you’ve took the shot.
- Price – in general point and shoot digital cameras are cheaper.
- LCD Framing – many digital camera users prefer to frame their shots using LCDs. Point and Shoots always come with this ability and some even come with movable screens that enable users to take shots from different angles and still see what they’re shooting.

Weaknesses:
- Image Quality – point and shoots digital cameras generally have small image sensors which means that the quality that they produce is lower. If you’re not planning on using your images for major enlargements or in professional applications, the quality of point and shoot cameras is more than enough for the average user.
- Reliance upon LCD – most point and shoot digital camera rely upon their LCD for framing. While some enjoy this others don’t. Most point and shoot cameras have view finders but they are generally small that they are useless.
- Smaller ISO range – this is changing slowly, but in general ISO ranges are more limited in point and shoot cameras.
- Speed – point and shoot digital cameras are notorious for their slowness, particularly their time between pressing the shutter and when the image is taken.
- Manual Controls Limited – many point and shoot cameras do have the ability to play with a full array of manual settings, but quite often the manual controls are hidden in menu systems and are not as accessible as on a DSLR.
- Less Adaptable – point and shoot cameras are generally not very adaptable. What you buy when you get them is what you are stuck with. Some do have lens adapters but generally people don’t go for these accessories.

In the next lesson we will talk about DSLR cameras.