Self-advising to buy a camera: DSLR or compact

This hub belongs to a series of hubs pre-titled "Self-advising to buy a camera" talking about the advantages of taking decisions when buying a digital camera, and what we need to succed in the choice: knowledge and good information.

In this hub I talk about the first dilema: what kind of digital camera do you need? from compact to DSLR, with all the hybrid types in between?

DSLR stands for Digital Single Lens Reflex. Reflex means that the body has a mirror that reflects the image to the viewfinder and when the picture is taken, the mirror lift up to let the image light reach the sensor (or to the film in the case of analog cameras).

Some new so-called DSLR cameras, like micro four-thirds format, or those equiped with pellicle mirror, are mirrorless or have a mirror that don't lift up at shotting. I think that you have to consider the benefits of a reflex camera system and distinguish whether these differences versus the reflex behaviour change the quality of the images or the characteristics and features of the camera. And when you look deeper inside into the analysis of the benefits of DSLR versus compact cameras, you realize that the benefits of DSLR cameras are not in the R letter neither in the SL letters. Nowadays, the main benefits strike in other points:

• the interchangeable lens system, that allows choosing the best lens for every situation, and to upgrade to better lenses when the budget improves.
• the far bigger image sensor, that allows more light to flow to the sensor and a bigger dot (pixel) in respect to compact digital cameras with much smaller sensors.
• the bigger body that allows better ergonomy.
• the bigger space for the dials and options.
• an independent top LCD display to show the settings, only for semi-pro reflex cameras. The begginer models become smaller and there is neither place nor budget for such a usefull display.
• a viewfinder benefits the ergonomy because you move your eyes and your head with the camera, because you can see the exact picture before to press the shutter, and because you see the scene before shotting in every light condition, even in very shiny environments.
• an optional RAW mode that keeps the picture as the image sensor has captured it, without compresion nor post-processing.

In the shake of compact cameras, it's to say that exist some models having RAW formats or HDR capabilities. But when a so-called reflex take characteristics of compact, is losing weight and ergonomy, lacking of mirror, optical viewfinder, some dials and the independent settings display, reserved only for the semi-pro reflex cameras, but the bigger image sensor and the interchangeable lens are still there.

Image sensors are a very important component of digital cameras. Actually, image sensors make the difference between a fim camera and a digital camera. In the times of analog cameras, sensors didn't exist. The mechanism of the light going through mirrors and lenses was roughly the same, but at the end of the "tunnel" the light encountered a film emulsioned with photosensitive material instead of the digital image sensor of digital cameras.

Attending their size and form factor (always a rectangle), sensors take different names:

• Medium format, for very exclusive professional cameras, with a sensor size 48 mm x 36 mm.
• Full frame, with a sensor as big as a 35 mm negative. They use to be exclusively professional cameras, ranging more than $2.000.
• APS-H and APS-C, aprox. a 60% the size of a Full Frame. The common size in entry-level and semi-pro DSLR.
• Four Thirds. A format used almost exclusivelly by Olympus in traditional DSLRs, and in the micro Four Thirds cameras, mirrorless cameras, by Olympus, Panasonic and Samsung, but with interchangeable smaller than usual lenses.
• 1/7" to 2/5" are sizes reserved to compact cameras.

The image sensor incorporates a processor, a very important component that has a lot to do with the speed that images are taken, stored in the memory card and processed. The more definition a sensor has, the more power is needed in the processor to store and process the so big amount of resultant dots.

Bigger image sensor is directly related with shallower depth of field. Taking pictures where the target is perfectly focused and everything else is out of field (blurred) is only achieved with a big image sensor camera, starting at four thirds format and up to full frame, that is, with a DSLR.

Fashion photography, portrait and professional studio photography with models, a modality of photography that requires shallow depths of field most of the time, and big amounts of light across the lens to get sharp details and true color images, usually demands full frame cameras.

Actually there is a relation between the size of the sensor and the price of the camera: the bigger the sensor, the bigger the budget has to be.

The resolution of a digital camera are properties of the image sensor and the screen display. The important one, when taking pictures is the sensor resolution. It indicates the amount of independent dots in matrix disposition, each one having its own independent color, that conforms a picture. Let's imagine a sensor as a grid of points that are independent enough to capture the small portion of light that corresponds to its zone.

There is a mathematical relation between the number of dots of the sensor and the size of each individual dot. Since it is a question of light, it's to be assumed that the bigger the dot is, the bigger the ability to capture light and thus the performance of the sensor to get images close to reality, with true colors even in low light conditions.

Resolutions are to be measured in Mega pixels (dots). When multipliying the number of rows by the columns of the sensor it results in the number of pixels. When dividing the number of pixels by 1.000.000 (actually 1.048.576), you get the Mega pixels. At the first ages of digital cameras, resolutions were around 1 Mega pixels. Today market cameras are equiped with image sensor resolutions between 10 and 18 Mega pixels.

Increasing the resolution of the sensor, while keeping its size is the current practice in camera manufacturers. Technical advances enables better and better processors enhancing the quality of the sensors. Actually there exist less more sensor than camera manufacturers, so it's to be expected that all the contemporary sensors behave similarly, and better that its ancestors. But there is an issue to keep on mind. A big sensor with a low resolution get better images than a small sensor with a big resolution, because, remember, it's a question of light.

Budget is a major issue. Compact cameras start at about $50 while a budget DSLR with a 18-50mm zoom lens kit costs starting $430, where compact cameras have their maximum price.

Nevertheless, although it's clear enough that DSLR take better pictures, in worst conditions, there are some features and conditionants, budget aside, that will make you prefer a compact camera over a DSLR.

1. The size. Compact cameras are very small and light compared to DSLR. Compact cameras easily fit in every pocket, making them the perfect travel companion.
2. High-zoom and ultra-zoom bridge cameras raises versatility of a compact to levels of a DSLR equiped with double kit lenses: a 28-50mm and a 50-300mm zoom lenses, that will need an special bag to be carried alongside the camera, and good shoulders, because the set will easily weight more than 1 Kg.
3. The value. As compact cameras has less value, losing them will not suppose the death of anybody. That makes you feel safer with a terrenal compact camera than with an expensive DSLR that you have to carry all the time and keep an eye on constantly.

But if you are a perfectionist, a lover of creative photography and like the pictures well focused with blurred backgrounds then you need a DSLR camera.

What if you believe that you need a small camera to travel and to take everywhere, but you enjoy creative photography and, most important, don't want to renounce to anything? The answer is clear: buy a hi-zoom (10x optical zoom) compact camera and a budget DSLR, for the price of a non-budget DSLR. You just have to lower the expectatives of your preferred DSLR one step down.

If your budget is less than $400, then you know that a DSLR is not a camera for you. And for less than $40, you will not find even a compact point-and-shot camera. Let's settle down a starting point. The cheapest models in the market are: