Advanced Digital Cameras: Beyond the Basics

RAW Vs. JPEG

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The debate about which format to use among RAW and JPEG seems to be one of the most controversial topics in the digital photography field. The arguments around this topic seem to have no ending sometimes as each person has his own opinion in selecting a certain format. In fact, even though the RAW format has obvious strengths in creating the good image quality, JPEG also has its own advantages.

Let’s clarify the differences between these two formats here.

What is the RAW format defined?

The RAW image format refers to the image file that have not been compressed or processed after it’s shot by the image sensor of a camera. For this file format, the in-camera processing is just at the minimal level. This digital format is equivalent to a film negative that has been exposed but not processed.

When a photo is shot, the amount of light which has stroked every pixel has been simply recorded by an imaging chip inside the camera (this chip is either CMOS or CCD) (so, the more the number of megapixels is, the larger amount of information is recorded). The recording number is either 14 or 12 bits of data at this step, based on the type of your model. If the photo is shot in the RAW format and you convert this photo into a .PSD or TIFF file, the exported result is 16 bits. This means that the above 14 or 12 bits are spread over the entire 16-bit workspace. Meanwhile, you just have the result of 8 bits with the JPEG format.

Professional photographers often like to take the best advantage of the RAW format as a way to make sure that their shooting results have not been processed by any in-camera software because these photographers prefer to perform the editing in the post production by themselves.

How a file in the RAW format is saved

When a file in the RAW format is saved, there is attached metadata with your photo. Importantly, this file includes all of the camera configurations, for example, the white balance, the color temperature as well as the sharpening level. There will be a header file for this data that the cameras attach with the photo in the RAW format. The above settings won’t change any aspects of your photo. The whole combined file will be saved into the camera memory card. Sometimes, you can find these files compressed in some cameras but others may not, but the image quality is not affected as there is just the minimal compression.

The software for editing photos will read the metadata of a file in the RAW format to display the photo, but not change any metadata.  Later, you can use the software to control the settings manually and check the effect on the files under the RAW format.

How a file in the JPEG format is saved

When a file in the JPEG format is saved, you will find that all of the data which a RAW image file keeps separately in a header file would be saved as part of the JPEG image file (and will be unchangeable).

The JPEG configurations will be automatically set by the camera, and the settings have been limited in several cases. For example, there is only between one and three configuration levels of sharpening, such as “unsharp masking,” at which the edges between the dark and light areas are found and the contrast between these two areas is enhanced. As the sharpening capabilities are limited, you may find clear halos surrounding the edges with high sharpening levels. Therefore, if you set too low sharpening levels, you may have insufficient sharpening.

Also, keep in mind that the image sensor itself cannot record the colors. The colors are recorded thanks to an imaging chip which is known as a Color Filter Array or Bayer Matrix. Based on the layman’s terminology, there are three layers for the green, blue and red colors which have been placed on every pixel, and the information on the colors are defined by comparing between the recording values of every pixel and its surroundings.

The drawback of saving a JPEG file is that the original quality of higher number of bits (12 or 14 bits) is often converted into a lower number (8 bits). With the eight-bit mode, the camera is only able to record 256 shades of color for one pixel (in comparison to 4,096 shades recorded with the RAW’s capability). Consequently, a large amount of potential date on the colors disappears. And the important thing here is that with the JPEG format, the file data will be compressed, so you have the images of smaller sizes. Obviously, a certain number of data is not recorded. If the data are just compressed in a low level (for example, 2:1), the number of lost data is just little. But when the compressing levels are higher, a large number of data is obviously lost.

Why is the JPEG format still commonly used?

The main strength of the JPEG file is that it is possible to save a larger number of JPEG images into the camera memory card thanks to the compressions to create files of smaller sizes. It is also easier to transfer these types of images on the Internet that is preferred by a lot of photographers at the amateur level. In addition, there is also a need for a large buffering zone for shooting images in the RAW format fast and continuously, while the JPEG enables you to have the camera fired quickly. One important thing for amateur photographers is that the JPEG files do not require the post-processing (Certainly, it takes you more time to process RAW image files)

Additionally, many generic converting softwares included in the camera don’t let you have many configurations for adjustments. The price of advanced editing software is not cheap at all. There are two major programs for processing images, including Adobe Bridge and Capture One (these two programs are in the Photoshop). The lowest price point of these has been about $70.

The comparison between the RAW and JPEG format: Conclusion

Not only the number of recorded data with RAW images is higher, but there is also a need for a more complex platform for converting these types of images. The full photo quality will be not affected by saving the converted images into TIFFs. With JPEG images, you’ll have more exposure of image settings around the image quality (for example, color saturation, white balance or the overall contrast). Due to this reason, keep the above-mentioned aspects within the limited range, or you may find the deterioration of photo quality become clearer.

If you are considering which format for the greatest possible photo quality, it is obviously the RAW format. However, the JPEG does meet your needs well in a lot of circumstances. If you just want to shoot quick shots of your family photos, the JPEG will be very nice. The image quality of this format is also good for the prints at the sizes that are lower or equal to A4 sizes.

In conclusion, depending on your shooting purposes, the In the RAW or JPEG format has its own advantages.

Auto Focus Vs. Manual Focus

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If you are a photographer who have just transferred from a point and shoot camera into a DSLR, certainly you should learn about a certain number of photography aspects right before you want to be able to use your DSLR camera successfully. Among these aspects, the manual focus is among the ones that may get you the most confused. It is much more complicated than the auto focus mode.

The following tips shall help you better understand the differences between the manual focus and the auto focus mode.

Auto focus refers to a mode in which the camera sets the best focus for photos, using image sensors that are specialized for measuring the focus of the scene. In this mode, you don’t have to set anything as the camera has done all for you.

Auto Focus Vs Manual Focus

Auto Focus Vs Manual Focus

Even though you won’t have to worry much about the shutter lag with DSLR cameras as it is just at the minimal level, the quality of the auto focus system shall decide the amount of shutter lag of your DSLR camera.  When you select this mode, you should have your camera pre-focused on the shooting scene to reduce the shutter lag. Just hold down the shutter button halfway and keep this button still in that position until the auto focus has locked onto the targeted subject. Then, hold down the shutter button completely to shoot the photo. By this way, you can minimize the shutter lag.

The manual focus refers to the mode in which you use your palm of the left hand to cup the zoom lens. Then, have the focus ring on the lens slightly twisted until you have the sharp focus onto the subject.

When you use the manual focus, you can find it easier to define whether you have the sharp focus on the shooting screen through the viewfinder which is better than the LCD screen in this case. If the shooting conditions are outdoors in bright sunlight, you can hold the viewfinder against the eye for avoiding the glare on the camera LCD because with the glare, it will be harder to define the focus sharpness.

To check which focus mode you are using, hold down the Info button on your At times, you can have the focus mode set on the camera interchangeable lens. To do this, just slide the switch to select between the manual focus and auto focus.

There are some various auto focus modes, based on which DSLR camera you’re using, such as: AF-S, AF-C or AF-A. AF-S (short for single-servo) is proper for shooting still subjects in which you see the focus lock when you press the shutter button halfway. AF-C (short for continuous-servo) should be used for shooting moving objects using the continually-adjusted auto focus. With the AF-A (short for auto-servo), the camera itself will select one of the above two auto focus modes, depending on the scene.

You tend to encounter some problems with the performance of the auto-focus when the colors of the background and the subject are not much different, when one half of the subject is in bright sunlight and the other half is in shadow and when there is one object between the camera and the subject. In the listed situations, you should use the manual focus.

When you select the auto focus mode, the focus of the camera is often on the targeted subject in the frame center. However, you can change the focus points in almost all DSLR models. This can easily be done by determining the auto focus area  and retargeting the focus point with the arrow keys.

If there is a switch for selecting between the auto focus mode and manual focus mode, you often see the A (auto focus) and M (manual focus) labels on your camera. However, you can see the inclusion of an M/A mode. This can be understood as the auto focus that supports the manual focus overriding option.

You can find out which focus mode you’re using as well as other camera configurations on the LCD screen.

White Balance Modes on DSLR Cameras

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There are various color temperatures of the light during the whole day. And the white balance refers to the process in which the color casts created by various color temperatures are removed. Our human eye is far better in the color processing, and it is possible to find what should be in the white color with the human eye. But a camera needs some helps.

Temperatures of Colors

As I discussed earlier, you will have different color temperatures for different time periods of a day. The measurement unit of light is kelvins, and 5000 k (as short for kelvins) is needed to create the neutral light. As I listed below, you will understand the various temperatures given by different types of light.

  • From 1000 to 2000k: You have candlelight
  • From 2500 to 3500k:  The light is tungsten (Normal household bulb)
  • From 3000 to 4000k: You have the light of sunrise/sunset (as the skies are clear)
  • From 4000 to 5000k:  The light is fluorescent
  • From 5000 to 5500k: You have the light of electronic flash
  • From 5000 to 6500k: You have the daylight (as the skies are clear and there is sun overhead)
  • From 6500 to 8000k: You have overcast skies (Moderate)
  • From 9000 to 10000k: You have heavily overcast skies or shade

White Balance Modes

If you see my list of symbols, perhaps you will realize the white balance modes for your DLSR camera. The first three symbols allow for a range of color temperatures. You will have the color temperature set accurately in all the trickiest lighting conditions with Auto White Balance (AWB), which is more and more improved nowadays. In the Custom White Balance, you can set your own white balance through using a gray card (18% gray is offered for the shot, which sits between the true white and true black. This mode is commonly selected by advanced photographers in a studio environment at which they need the absolute white background.

With the Kelvin configuration, you are able to adjust the color temperature as you want. Thanks to this option, the result will be very accurate because the kelvins can be tweaked in small increments.

The other symbols represent various color temperatures listed above. You should keep in mind that there is an orange cast on your images when you select the tungsten light and a green tinge with the fluorescent light.

How should you use the White Balance mode?

As I said, the AWB can be useful in many situations. Especially when the light is from an external source (for example, a flashgun), this mode does bring helps, because the neutral light produced by this shall often remove any color casts. There may be a problem caused by several subjects for the AWB – especially in the warm or cool condition. These subjects can be misunderstood as a cast over a photo and can subsequently be adjusted by AWB. Therefore, for example, if a subject has the over excessive warmth, a blueish tinge will be casted over the image so that the camera can balance this out. Obviously, the color cast will become very funny in this case.

The mixed lighting also makes the AWB confusing (for example, a photo with the combination of artificial and ambient light). In general, the best way to adjust the white balance is through manual setting, which brings a warm tone to the subject that are lit with ambient light. Warm tones seem to be more appealing to the human eye than tones that bring you the cold as well as sterile cool feelings.

In summary

The white balance is a very useful feature found in DSLRs and you will not have to correct color casts with filters of high prices. The white balance setting brings the images accurate changes and super precise color temperature readings. Finding out thoroughly about the various modes shall also be useful for correcting any mistakes that may be caused by the AWB.

Aperture In DSLR Camera

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Aperture refers to the amount of light which come through the lens of a camera to strike the image sensor. There is an iris within the lenses of DSLR cameras, which is often opened and closed to put the limitation on the light amount that reaches the image sensor. The f-stops is the measurement of the aperture. The aperture of a DSLR camera brings you the two features: the light amount coming through the camera lens and the level of depth of field.

The Range of F-Stops

There is a wide variety of F-stop numbers, especially on the lenses of DSLRs. However, the maximum and minimum number of f-stops shall base on the camera lens quality. The image quality can be lower when the aperture is small (you will understand this term in my explanations later in the article) and based on the design and quality, the minimum level of aperture is limited in some lenses. The common lens range is from f3.5 to f22, but the range of f-stops in a variety of lens can be: f1.2, f1.4, f1.8, f2, f2.8, f3.5, f4, f4.5, f5.6, f6.3, f8, f9, f11, f13, f16, f22, f32, f45.

Usually DSLR cameras has a larger number of f-stops than film models.

Aperture and Depth of Field

First, let’s start with the most basic feature of the aperture: the capability to control the camera depth of field.

Depth of field (DOF) refers to level of your photo in focus around the subject, which means that the targeted subject will be sharp and the foreground as well as the background becomes blurry when the depth of field is small. The higher the DOF is, the less focused the main subject is, so the entire photos will be sharp throughout the depth.

A small DOF will be useful for shooting some certain kinds of subjects, for example jewelry or creatures and a large DOF will be more proper for shooting photos on landscapes. There is no rule for setting the right DOF, as it just depends on your own purpose of shooting certain subjects.

To understand the f-stops, just keep in mind that a small DOF is shown by a small number. For instance, f1.4 refers to a small number and the DOF will be small. Meanwhile, the large number is to show a large DOF. For instance, f22 is an example for this case and the DOF will be large.

Aperture and Exposure

Photographers are often confused about this.

When the aperture is small, the relevant f-stop is represented by a higher number. Therefore, f22 refers to a small aperture while f1.4 refers to a large one. Photographers often easily get confused because the whole mechanism seems to be back to front! Just keep in mind that with the f1.4, you will have the iris of the lenses widely opened that allow a huge amount of light to come into the image sensor, so this aperture is large.

In addition, there is another way to remember the relation of f-stops and the aperture. In fact, the aperture refers to an equation in which the aperture diameter divides the focal length of the lens. For instance, your lens has the measurement of 50mm and you have the widely opened iris, there is likely a hole with the diameter measurement of 25mm. Therefore, the result is 2 when you have 50mm divided by 25mm. In this case, the f-stop is f2. If you have the smaller aperture (3mm, for instance), the f-stop will be f16 when 50mm is divided by 3.

Adjusting the aperture setting is known as “stopping down” (if the aperture is set smaller) or “opening up” (when the aperture is set higher).

Aperture’s Relationship to Shutter Speed and ISO

Because one of the functions of the aperture is to control how much light will pass through the camera lens to hit the image sensor, the photo exposure will be affected by the aperture setting. Meanwhile, the Shutter speed refers to the duration that the camera opens the shutter button, which also affects the exposure.

Consequently, in addition to determining the DOF through the aperture configuration, you should also pay attention to the amount of light that come through the camera lens. If you need a small DOF and select the f2.8 number, for instance, you will also need to increase the shutter speed to a pretty fast level to make sure that the camera does not open the shutter for long, which results in overexposed images. A slow number of shutter speed (for example, 1/1000) enables you to shoot very fast moving subjects while a high number of shutter speed (for example, 30 seconds) will be suitable for shooting photos in low light, such as in the night time. You should decide the exposure based on how much light is currently available. If you are primarily concerned about the DOF, the shutter speed shall be adjusted accordingly.

The ISO setting also has the relation with the aperture setting as it brings more light when needed. A higher number of the ISO (found with a higher number) will be very useful for shooting under low light conditions while you don’t have to change the shutter speed or aperture. However, don’t forget that your images may have more noise when the ISO is higher and you may easily encounter photo deterioration. To understand that, the ISO should be considered as the final way.

Camera Debate: Viewfinder Vs. LCD for Framing Photos

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LCD screens are nice, right? It’s likely that these LCD screens are better for newer DSLR models launched into the market. And you will see the whole shooting frame that is captured by the camera sensor in the LCD, which is different from the operating way of the optical viewfinder. With optical viewfinders, you will see just 90-95% of the photos, even you’re using an advanced DSLR. A tiny percentage on the very edges of the photo will be lost.

Therefore, you will need to consider using the LCD screen or the viewfinder for framing an image with your DSLR model.

Although the LCDs are very nice, photographers who have a lot of experiences (not except me) will like to frame photos with the viewfinder. Below, I’ll clarify the reasons for this:

  • It’s easier to keep your hands steady with the viewfinder. It will be very challenging to hold the camera at your arm’s length while you are seeing the LCD screen and steady your camera while you’re attempting to zoom more closely on a subject. The images may be caused blur when you use the LCD in this manner. Digital SLRs aren’t the lightest of beasts and the viewfinder will be very much easier for you to shoot crisp and sharp photos when you have to press the camera up to your eye in using it. By using the viewfinder, it is better for supporting and steadying your lens and the entire camera with your hands.
  • There are certain problems with the LCD under the bright light. Obviously, this problem is the most significant for LCDs. Due to the glare appearing on LCDs under the bright light, you almost cannot see LCDs in these situations. Of course, this depends on the LCD quality but this problem is pretty common. Moreover, under the bright sunlight, the crystals included in the LCDs tend to “flare”, which increase the trouble in using LCDs under this type of condition.
  • The viewfinder helps save the power. In terms of the battery life, viewfinders help you save the power better than the LCD screens. When you are shooting outside and cannot have your battery recharged convenient, you will highly appreciate the strong battery power.
  • In terms of the human eye. When the day’s going to pass by, as smart as digital models are, the LCD resolve less detail than the human eye. Therefore, the view of your photos will be more accurate and sharper when you use the viewfinder.
  • LCD screen may not give you the exact overview of your images. Whether your LCDs are very good or not, you will probably not have the exactly precise overview of the photos that you have just shot. For the majority of LCDs, you’ll find your photos overexposed by as much as one full stop. It is recommended that you should find out thoroughly the technical aspects on photography so that you can make sure about the correct settings and proper exposure for your photos. Don’t just depend on the LCD to decide the image quality.
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