November « 2008 « Yiuphotography.com

Raw or Jpeg? A Quick Guide to Image File Formats

Post by fotolistic on November 10th, 2008 In Category : DSLR Photography 101

Raw or Jpeg
If you are reading this article, chances are you’re currently shooting your photos using a Jpeg format (extension .jpg). At the same time, you may also be interested in knowing what Raw file can offer. Before starting a conversation on the pros and cons of using Raw and Jpeg (and the creative implications it has on the field of digital photography), let’s firstly, try to understand how your digital camera captures and turns an image into one of these files.

Shooting in Raw
Digital images are recorded as binary data by the camera’s imaging sensor. The binary data is recorded via a two step process. Firstly, the camera’s imaging sensor records the black and white value of the image (also known as brightness). The color value of the image (also refers to as hue) is then translated by a series of color filters (red, green, and blue) at the top of the sensor. (Please see the example below.)

The merging of these two sets of data creates what we call a Raw file. If you shoot in this format, both sets of data (untampered and unaltered by your camera) will be stored directly to your memory card as a 12 bits-per-color Raw image file. However, this Raw image file isn’t really a “usable picture” just yet. One way to better understand how Raw works is to use the following visualization: Imagine that Raw file is like film negative which after exposed to light, will require further processing, i.e: developing the film in a darkroom. In the case of a Raw file, you would need to use external software (such as Photoshop with a Raw file processing plug-in, Apple’s Aperture, Adobe Lightroom, or the native software from your cameras’ manufacturer), to render a Raw file, to a usable image. Raw file formats are not standardized and vary, depending on the camera manufacturer. In other words, each manufacturer has its own unique version of a Raw format. Furthermore, your camera does comes with the matching CD software to process those files. Undoubtedly, problems arise for the photographer when s(he) lacks the proper software to open a particular Raw file and have to go through the trouble of tracking down the right program that will open it.

Advantages of Raw files:

Disadvantages of Raw files:

You get everything straight from the imagining sensor with nothing wasted.
In terms of data, 100% loss-less; unaltered. Great for post-processing usage. With its 12 to 14 bit-per-color image file, this will give you a much higher range of tolerance while performing any kind of heavy duty color, contrast, sharpness, and detail adjustment.
Since no white balance correction has been applied to the Raw file by your camera, you can correct the white balance spectrum anyway you like. This is especially valuable when photographing under difficult lighting condition and the photo comes out too yellow, red, or green.
Because Raw files carry a wider range of data, details that may be lost in the shadow or highlight area (due to overexposure or underexposure) can be easily recovered with just a slight tweak of the contrast of the image.

Not ready to use straight-out-of-the-camera, requires further processing before it can be a usable image.
Not print-ready. A Raw file has to be properly processed into a useable image before it can be printed.
File format is not universal. Raw files requires compatible software for processing such as Adobe Photoshop with Camera Raw Plug-in, Adobe Lightroom, Apple Aperture, or Microsoft Raw Image Thumbnailer or whatever native software (included with a camera’s purchase) capable of opening these files.
Because Raw files are uncompressed, file size is much larger compared to that of a Jpeg file. Hence, you cannot fit as many photos on your memory card and will require extra hard disk space on your computer for extended storage.
Not as sharp and low in contrast compared to a Jpeg file (that is, if no additional processing was apply to the Raw file)
You need to have some understanding of color theory and how to process your photo using the the software applications mentioned above in order to bring out the very best quality in your Raw file.

Shooting in Jpeg
Technically speaking, all Jpeg images created by your camera were once Raw image data, or a Raw file. What happens is, your digital camera has its own image processing firmware built-in. To create a Jpeg file, your camera takes the Raw data of your image and process it by applying white balance, tonal curve, saturation, sharpness, and a compression or resizing ratio. All of which is based on the image processing or enhancing option that you set under your camera’s menu. It will then throw away any extra data that is beyond the range of what is required to display your image at its most optimal quality — physically turns your 12 bits image file into an 8 bits. Lastly, it will brand this image with a new identity, *.jpg. All of these operations take place right before your image shows up in your camera’s preview LCD panel. You now have a Jpeg image file that is portable in file size. Furthermore, Jpg files are universal (in computer language) so any imaging software or web browser can read it.

Advantages of Jpeg files:

Disadvantages of Jpeg files:

Universal format, readable by any image software or web browser.
No additional processing require for printing and sharing of your Jpeg file. It is ready to use straight-out-of-the-camera.
It is a compressed file, very portable in size. Usually 1/5 to 1/3 from what the cameras mega pixel number is. It achieves its compression by eliminating any extra data that it doesn’t need beyond what it requires to display the photos at its optimal quality.
With its smaller file size, you get more photos per memory card if you shoot in Jpeg compare to that of the Raw file. Great for those who favors quantity. (Please read How many photos can my memory card hold? for more information about image capacity)
White balance, contrast, tonal curve, saturation, and sharpness had already been applied to your image by your camera. Therefore it is sharper, higher in contrast, and much more vivid in color compared to an unprocessed Raw file.

Only 8-bit per color, you are getting just the amount of information that it needs.
Not so great for post-processing usage. Because it is only an 8 bit image file, it has a much lower range of tolerance for heavy duty image adjustment.
The ability to adjust the white balance correction and color contrast is very narrow. Usually leave your image with an unsightly compression artifact.
It carries much less data, it is much more difficult to recover details loss in the shadow or highlight area due to overexposure or underexposure.
Highly destructive, which means any kind of editing you do to an Jpeg image will cause it to throw away additional image data. Even the simple task of just opening and saving it.

Raw Vs. Jpeg: Side by Side Comparison
In the end, all that really matters is the quality of the photo.

Here is a section cropped from the flower image above; zoomed in at 100%, pixel to pixel. The (straight-out-of-the-camera) Raw file, Frame A, is low in contrast, less vibrance, and lacking in sharpness compared to the (straight-out-of-the-camera) Jpeg file, Frame B. The reason for the difference in quality is because the camera automatically processes the Jpeg file before it stores the image in the memory card.

Now let’s compare Frame B and C, the processed Raw image. After a few minutes of fiddling with the plain Raw image using Aperture (my photo processing software of choice from Apple), the resulting post-processed Raw file held up much better in contrast, tonal curve, and sharpness. More significantly, the processing of a Raw file is not as destructive as that of a Jpeg. If you look closely at Frame B, the underside of the flower bud has a grid-like, compression artifact— a series of little squares grouped together to define detail within that area. This phenomenon proves that the Jpeg file had evidently undergone the processes of compression and interpolation through an act as simple as opening and re-saving the image. While this is a way to reduce the Jpeg’s file size, the unfortunate side effect of this process causes information loss.

The primary reason why some may prefer to shoot in Jpeg rather than in Raw is that Raw files always require that extra investment of time and effort. Even though the original Raw image has a less-than-impressive quality than that of the Jpeg, Raw files have more potential to become stunning, higher quality photos if you are willing to put in a little more work.

So which format to use?
As we discussed earlier, both formats have their advantages and disadvantages, especially in terms of usage and convenience. If you are the artsy-fartsy type like myself then, Raw is certainly the way to go. You get to tweak the photo anyway you like. Envisioning in your mind how you might want your captured image to look, not how the cameras’ firmware thinks it should look. However, I must say, it is not for everyone. For you to be shooting in Raw, you must have at least intermediate to advanced knowledge and experience in using the image editing software applications mentioned above. However, if your primary goal is to take decent and properly exposed photographs with acceptable color and contrast, in addition to being share/print-friendly, well then, just stick with shooting in Jpeg.

To further help you figure out if Raw is right for you, I compiled a series of neurotic questions to assist you in this monumental decision. Please answer the following five questions:
1) Do you favor quality over quantity?
2) Would you mind being in front the computer longer than usual?
3) Would you like to spend more time processing photos? What about inspecting and tweaking each and every photograph to perfection?
4) Do you know how to use Photoshop on your own?
5) Do you have an (almost) unlimited amount of storage space and a very large memory card for your camera?

If you’ve answered “yes” to most of these questions, then Raw is the right choice for you! Even if you answered “no” to a few, there is certainly no harm in shooting in Raw for experimental purposes, right? Take some risks and see how far you can go with it.

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There’s a texture for every mood…

Post by fotolistic on November 8th, 2008 In Category : DSLR Photography 101, Other, Photography

Photographers often use the post-production process to achieve a more artistic and rustic/antique quality in their photographs by utilizing Photoshop filters, actions, and even texture layers. While Photoshop filters and action sets can easily be applied and created within the software itself, natural looking texture are usually more convincing they are taken from a “real” photograph instead of a software-rendered image.

However, usable textures of high quality are usually very hard to find online. So I basically, went out and took my own texture photos. Among the 20 to 30 photographs taken, the following eight textures seem to work the best for me. Once applied to photographs, I also simplify the overall color and details of these photos to enhance its effectiveness.

A lot of photographers and photoshoppers who regularly visit my site asked about textures and I thought I’d put some up for you, these are downloadable, by the way. You’re welcome.

Click on each image below to enlarge in new window

Please note, in order to effectively blend these textures into your photographs, the use of Photoshop layers, layer mask and layer blending mode are highly recommended. Not all textures will work for every photograph. You should definitely take the time to test on and play around with a few of them before deciding which will work for a particular picture. You may be able to create variations of a textured image by applying more than one texture to your photograph. Another good technique is to use a small section or pieces of texture instead of using the entire texture image. Just look for interesting patterns within the whole and you’re bound to find something that works best. One effective way to create a unique effect is to apply a white texture onto your photography instead of using a black one. The use of these textures, in combination with the advance editing tools available on Photoshop, can potentially produce an endless array of artistic possibilities.

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{ Posts for November, 2008 }

Raw or Jpeg? A Quick Guide to Image File Formats

There’s a texture for every mood…