RAW vs JPEG

17 May

 

OK, so you handed over a large chunk of money for a great DSLR. No doubt, within a week, you have been told

“You should be shooting in RAW”

Like me, you probably looked at the person with a blankness associated with a politician asked to actually provide an answer to the question.

Then. like me, you got home, jumped online, checked your manual and even tried out shooting in RAW. So what happened?

Shooting in JPEG

OK, so shooting in JPEG is quite a simple thing to consider. You take the photo, the software (or firmware to those so inclined) quickly does some magical calculations and creates an image, based on what information it gets form the CMOS and what it has been programmed to do with that information. The information from the CMOS, can and does change based on the shot itself (lighting,) and the setting used at the time.

From this you get an image which may have some colour loss.

The major actor in this case is the Discrete Cosine Transformation (or DCT) which breaks the image up into blocks (usually 8×8 pixels) and determines what can be “safely” thrown away because it is less perceivable (the higher the compression ration and lower the quality of the JPEG, the more is thrown away during this phase). And when the image is put back together a row of 24 pixels that had 24 different tones might now only have 4 or 5. That information is forever lost, as the raw data from the sensor isn’t recorded in a Raw file.

In the end you have an image that is far better than your old point-and-shoot cameras. If you are using burst shots, then JPEG will allow more as there is little to no processing time.

A JPEG File is:

• a standard format readable by any image program on the market or available open source.
• exactly 8-bits per color (12-bits per location).
• compressed (by looking for redundancy in the data like a ZIP file or stripping out what human can’t perceive like a MP3).
• fairly small in file size (an 8 megapixel camera will produce JPEG between 1 and 3 MB’s in size).
• lower in dynamic range.
• higher in contrast.
• sharper.
• immediately suitable for printing, sharing, or posting on the Web.
• not in need of correction most of the time (75% in my experience).
• able to be manipulated, though not without losing data each time an edit is made – even if it’s just to rotate the image (the opposite of lossless).
• processed by your camera.

Shooting in RAW

If you are shooting in RAW, then you get some real benefits. You get what you shoot. Everything. It is as simple as that. There are however some really good points for this, and some not so good points against this.

Whilst most modern camera have some software inbuilt to allow for basic processing or RAW images, the majority of your processing will be on your computer. Why? Simple, your computer has much more power to do this quickly and efficiently.

This is both a pro and a con. On the pro side, you have absolute control over the final image, using all of the information taken in when the image was first taken. On the con side, you have to create the image. I liken it to similar to processing film. The benefit is you can get it wrong and simply start again, changing white balance, colour, shadows and the like.

You will need some software for this, there are some good Freeware versions out there, and some excellent versions you pay for, sometimes quite expensive.

As stated above, the camera in processing a JPEG will lose some data that is considered ‘unnecessary’, so you don’t get the ‘full picture’, so to speak, in RAW you do get it, and are able to manipulate it.

A Raw File is:

• not an image file per se (it will require special software to view, though this software is easy to get).
• typically a proprietary format (with the exception of Adobe’s DNG format that isn’t widely used yet).
• at least 8 bits per color – red, green, and blue (12-bits per X,Y location), though most DSLRs record 12-bit color (36-bits per location).
• uncompressed (an 8 megapixel camera will produce a 8 MB Raw file).
• the complete (lossless) data from the camera’s sensor.
• higher in dynamic range (ability to display highlights and shadows).
• lower in contrast (flatter, washed out looking).
• not as sharp.
• not suitable for printing directly from the camera or without post processing.
• read only (all changes are saved in an XMP “sidecar” file or to a JPEG or other image format).
• sometimes admissable in a court as evidence (as opposed to a changeable image format).
• waiting to be processed by your computer.

Comparisons

From the two shots below, you can see what post processing in RAW can do to save an otherwise poorly lit shot.

Picasa_Before

Before Picasa

Picasa_GettingLucky

After Picasa

OK, the first image has a real washed out, lacking in colour look, you might associate with some cheap point-and-shoot camera. The second photo shows the corrections made and the vibrant colours that were achieve, post production.

Now this was apparently done using Picasa, a FREE app, from Google. To me, yes it works, but the skin tone on the girls almost makes them appear like they all have jaundice. I am guessing it is a result of the process of adding yellows to bring out the green grass, but it also effects the other areas.

I understand that some of the ‘better’ options, Adobe Photoshop or Lightroom or even Capture NX2, allow almost pin point accuracy in making these changes, but I personally cannot see a great benefit considering the time one would spend ‘getting it right’.

For me, more time spent ‘getting it right’ with the camera would have resulted in a better shot to start with. But that is just my view.

So the verdict?

I will not seek a war here. I personally find the simplicity of using JPEG at this point of my experience better. I do little to no post-production, as I go from the view, I either go the shot or didn’t. There are those who prefer to ‘enhance’ their shots, and complain of limitations if the image is in JPEG.

I have tried RAW and found it an interesting option. I expect later I may use RAW occasionally, and maybe more, as I will demand more of my images as I become more self-critical of my shots. I may even go into post production eventually, who knows.

When considering post production however, I think from my limited experience, pretty much anything you can do in RAW, I can mimic in JPEG. Software these days does more than simply lighten/darken, heckI think I can pretty much change any layer of any photo at the layer level using such Freeware as Gimp 2. So for me, at this point shooting in RAW, seems to simply create more work to get to my image.

Try RAW, it can make some interesting differences, but the resulting image may not be as sharp as the comparable JPEG. You could try shooting RAW + JPEG, as a lot of cameras now allow. This gives you the best of both worlds. You get that JAPEG for the sharpness, and also the RAW data saved, should you decide to play with the image later.

I have heard many say, all professionals shoot only in RAW. I think that is a bit of a bold statement. I suspect they shoot in RAW + JPEG, and some even simply use the power of the camera and shoot in JPEG itself.

It is a matter of personal choice. I will not and honestly cannot say which it ‘correct, better or right’, but I can say, both work in the way they are intended, so go forth and use whatever suits your needs and preferences.

Yes, shooting in RAW can save an otherwise lost photo, but to me personally, that ‘lost’ photo is not of such great importance that I would spend hours tinkering with it, at least not at this stage. For me, JPEG provide a clear, sharp image, which I can apply, if I choose, some basic ‘enhancing to’.

Remember, I am no expert, just someone learning photography. This is my opinion, based on my experience, you may have a different one, that is fine, I accept that.

One Final Note

One thing I did not mention in this was the size of the resulting file, whether it be RAW or JPEG. Some may ask why? Simple, these days we are not limited as we were not too long ago by the very small sizes of memory cards. Where we thought we were doing well having 32 Mb of memory, while the professionals were lucky and had 512 Mb. I use a 16Gb SD Card. I recently found a bargain price of $30 for an 8Gb CF Card, which I bought for a friend who I knew was getting by with a 16Mb card. With many Gigabytes of space, the concern of a 3-4Mb JPEG vs 10-12 Mb RAW, is not worth the hassle. Just in case you were wondering.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: