- D300
With image sensors getting cheaper and more powerful, most serious amateur and semi-pro shooters are opting for the versatile Digital SLR, merrily leaving their film cameras behind. This guide is geared toward people that are already familiar with an SLR photography, but are unfamiliar with the digital process.
Shooting with a DSLR is just like shooting with a film camera. All of the common mechanical functions are there, right where you would expect them to be. And, while there aren’t any chemicals to deal with, each image still has to be processed before it can be shared with the universe.
THE SENSOR
CCD chip
In film photography, a chemically treated segment of plastic is exposed to light for a predetermined period of time, permanently embedding an image onto the film. The film is then processed to create negatives, which in turn are processed into photographs or slides. The concept is the same for digital photography, except instead of a segment of film being exposed to light, a CCD (charged coupling device) is exposed and the light is converted into electrical signals that are recognized by the camera’s processor, the files are then stored on a solid state memory device such as a CF card. Each pixel on the sensor captures red, blue, and green information.
Having millions of pixels means sharp images, it also means that the images can be edited very precisely without loss of quality, bringing photography out of the darkroom and onto the desktop.
Sensor Conversion
The CCD frame is smaller than the 35mm frame by a factor of 1.5. Since almost all SLR lenses were designed to work with a 35mm image area, the focal lengths on your lenses are affected by a factor of 1.5. For example, a 12mm lens at it’s widest focal length has a digital conversion of 18mm (12mm x 1.5). That means that a fair amount of the light collected by the lens is not being used, a trade off between film and digital. But on the bright side, your longer focal lengths are helped by the sensor conversion, a 400mm lens has a 600mm focal length. Good news for bird watchers!
Film frame compared to CCD
There are full-frame image sensors on the market, but they are considerably more expensive than a standard CCD. Achieving true wide angle photography is still not possible with the digital conversion law in effect, but from my experience a 18mm on the D300 looks a lot better than an 18mm on film camera.
ISO/Film Speed
The sensitivity of the CCD can be adjusted to accommodate lighting situations, much the same as choosing an appropriate film speed on a film camera. And like film, the faster the film is, the more grain or “noise” the image will have. Noise is generally bad in digital photography, grain can be added digitally during editing, so it is important to use the slowest ISO possible. ISO 200, 400, 640 prove to be almost entirely noiseless on my D300, while there is noticeable (but not bad) noise at 800 and 1000. ISO levels over 1000 should expect a fair amount of noise.
Lenses
Any common mount SLR lens will work with a DSLR. For example, a Nikon len
s from 1982 will work on a Nikon DSLR built today, but the functionality will be limited. Autofocus may be the most you can hope for with your old lenses. The difference between lenses made today and pre-digital lenses is the ability for the lens to communicate with the camera. CPU lenses have circuitry that gathers information from the scene, including depth of field, white balance readings, light readings, ISO readings, etc. A CPU lens combined with a modern DSLR provides enormous flexibility when it comes to exposure, focus, and color correction. It is likely that your DSLR came with a CPU lens, but if you have old glass be prepared to work a little harder.
Image Quality
Because finding a pleasing composition and getting a good exposure isn’t enough to think about while shooting, a new facet has been added to your game. Producing a high quality digital file is every bit as important as composition and exposure, it takes all three components for things to be just right. Think about it, how many pictures get rejected because they were underexposed? Or how many killer shots were ruined by poor composition? The same goes for the image file. You would no sooner deliver a blurry image to a customer than you would deliver a sub-par image file.
Workflow
The time period from when you depress the shutter to when you post the images online for your family is called a ‘workflow’. Having an efficient workflow is critical to providing high quality files on a consistent basis, once the workflow is second nature to you, you will be able to focus entirely on shooting. The key to a successful workflow is being well organized, time spent setting up now is time very well spent. See my detailed workflow for Aperture 2. Here are the basics of a general workflow:
- Shoot only RAW (uncompressed) photos. You should completely forget about the other resolution settings on your camera. You wouldn’t drive a Ferrari only in second gear, right? So why limit the information gathered by your camera? Memory cards are cheap, and having only a small JPG original of the best shot you have ever taken is EXTREMELY frustrating. Save all of your images, even the bad ones.
- Have plenty of external storage space. You will be generating a lot of data, you will need a safe place to keep it away from your main machine. Spending an hour juggling disk space on your main drive when you just want to work on your photos is a very quick way not to work on your photos. Keep only your active photo library on the internal drive, move older libraries to the external drives. I create a new library every two weeks, moving the previous to its archive drive.
- Use a dependable image management software package like Aperture 2
(for Mac only) or Adobe Photoshop Lightroom 2
. These applications are designed to manage the large amount of data generated by high resolution cameras. One of the biggest benefits of these apps is that they keep your original files untouched. Any adjustments made to the photos are made on a version of the original, you will be able to export the version in any size, resolution, format directly from the program. Using a good image management software is the most critical part of developing a smart workflow, I cannot overstate the value.
Histogram
Histogram Examples
White Balance
Every light source emits a certain ‘temperature’ of light. Florescent and Incandescent light sources emit a blue, cooler, tint. Sunlight, flash bulbs, studio lights are all “white” light and are generally much warmer. The white balance meter in your camera will assign a temperature to each image automatically, using the most intense light source in the scene to set the temp. In my experience, white balance is an area where DSLR’s really need improvement. Very often, the auto white balance is not correct, rendering the image too warm or too cool. This can be very frustrating when shooting mixed lighting conditions, such as a typical photo of a kitchen and dining area. There are florescent light bars in the kitchen, incandescent bulbs in the recessed ceiling cans, and natural light coming through windows. I used an Expodisc to achieve accurate white balance in the image below.
Example of mixed lighting conditions.
In order to achieve natural looking results you might need to adjust the white balance in Aperture 2 or LR.
Powerful Tool
The DSLR takes photography to the next level. It can take a dedicated amateur and turn them into a paid professional, and turn an established professional into a master. But, like any tool, it only works if you use it correctly.
Two more bits of advice: shoot only in manual mode, and carefully read the owners manual.
Happy shooting!
