Canon Eos Rebel T2i Internal Memory

Photography Masterclass

Photography Masterclass Online Course

Get Instant Access

However, reduced image quality can sometimes be beneficial if you're shooting sequences of photos rapidly, as the T2i is able to hold more of them in its internal memory buffer before transferring to the memory card. Using the RAW+L or RAW settings, the largest burst you can expect will be 3 to 6 shots. Eschew RAW and go for JPEG Fine at maximum resolution, and you might get more than 34 photos in a single burst. Canon says that with a JPEG Medium setting, bursts of up to 1120 shots are feasible. (I've never checked this out, because I don't have the patience or inclination to fire off 1120 pictures at one time.) For most sports and other applications, you'd probably rather have better, sharper pictures than longer periods of continuous shooting, so the JPEG Fine setting will work best.

JPEG vs. RAW

You'll sometimes be told that RAW files are the "unprocessed" image information your camera produces, before it's been modified. That's nonsense. RAW files are no more unprocessed than your camera film is after it's been through the chemicals to produce a negative or transparency. A lot can happen in the developer that can affect the quality of a film image—positively and negatively—and, similarly, your digital image undergoes a significant amount of processing before it is saved as a RAW file. Canon even applies a name (Digic 4) to the digital image processing (DIP) chip used to perform this magic in the Rebel T2i.

Choose your resolution, JPEG compression, and file format from this screen. The figure in brackets on the top line shows the number of exposures remaining on the memory card at the resolution you have selected.

A RAW file is more similar to a film camera's processed negative. It contains all the information, captured in 14-bit channels per color (and stored in a 16-bit space), with no compression, no sharpening, no application of any special filters or other settings you might have specified when you took the picture. Those settings are stored with the RAW file so they can be applied when the image is converted to a form compatible with your favorite image editor. However, using RAW conversion software such as Adobe Camera Raw or Canon's Digital Photo Professional, you can override those settings and apply settings of your own. You can select essentially the same changes there that you might have specified in your camera's picture taking options.

RAW exists because sometimes we want to have access to all the information captured by the camera, before the camera's internal logic has processed it and converted the image to a standard file format. RAW doesn't save as much space as JPEG. What it does do is preserve all the information captured by your camera after it's been converted from analog to digital form.

So, why don't we always use RAW? Although some photographers do save only in RAW format, it's more common to use either RAW plus the JPEG option or just shoot JPEG and eschew RAW altogether. While RAW is overwhelmingly helpful when an image needs to be fine-tuned, in other situations working with a RAW file can slow you down significantly. RAW images take longer to store on the memory card, and require more post-processing effort, whether you elect to go with the default settings in force when the picture was taken, or make minor adjustments.

As a result, those who depend on speedy access to images or who shoot large numbers of photos at once may prefer JPEG over RAW. Wedding photographers, for example, might expose several thousand photos during a bridal affair and offer hundreds to clients as electronic proofs for inclusion in an album. Wedding shooters take the time to make sure that their in-camera settings are correct, minimizing the need to post process photos after the event. Given that their JPEGs are so good, there is little need to get bogged down shooting RAW. Sports photographers also avoid RAW files for similar reasons.

JPEG was invented as a more compact file format that can store most of the information in a digital image, but in a much smaller size. JPEG predates most digital SLRs and was initially used to squeeze down files for transmission over slow dialup connections. Even if you were using an early dSLR with 1.3-megapixel files for news photography, you didn't want to send them back to the office over a modem at 1,200 bps.

But, as I noted, JPEG provides smaller files by compressing the information in a way that loses some image data. JPEG remains a viable alternative because it offers several different quality levels. At the highest quality Fine level, you might not be able to tell the difference between the original RAW file and the JPEG version, even though the RAW file occupies, by Canon's estimate, 24.5MB on your memory card, while the highest quality JPEG takes up only 6.4MB of space. You've squeezed the image by two-thirds without losing much visual information at all. If you don't mind losing some quality, you can use more aggressive Standard compression with JPEG to cut the size in half again, to 3.2MB.

In my case, I shoot virtually everything at RAW+L. Most of the time, I'm not concerned about filling up my memory cards, as I usually have a minimum of three 8GB memory cards with me. If I know I may fill up all those cards, I have a tiny battery-operated personal storage device that can copy an 8GB card in about 15 minutes. As I mentioned earlier, when shooting sports I'll shift to JPEG FINE (with no RAW file) to squeeze a little extra speed out of my T2i's continuous shooting mode, and to reduce the need to wade through eight photo bursts taken in RAW format. On my last trip to Europe, I took only RAW photos (rather than shooting both RAW and JPEG), to fit more images onto my 60GB personal storage device, shown in Figure 3.3, as I planned on doing at least some post-processing on many of the images for a travel book I was working on.

Figure 3.3

If RAW storage space is a concern, consider a portable storage device like this one.

Figure 3.3

If RAW storage space is a concern, consider a portable storage device like this one.

Was this article helpful?

0 0
Get Paid to Take Digital Photos

Get Paid to Take Digital Photos

Reasonable care has been taken to ensure that the information presented in this book is  accurate. However, the reader should understand that the information provided does not constitute legal, medical or professional advice of any kind.

Get My Free Ebook


Post a comment