Thông Báo

**Hiệp Khách** · 02-10-2015, 01:55 PM

Cuối cùng, ảnh định dạng RAW là cái gì?

**FBI Bụi** · 02-10-2015, 11:32 PM

Ô cơ , cho ngừ Mẽo bít nói tiếng Việt như sư phọ () đọc bài viết bằng tiếng Mẽo thì chét dễ hiểu hơn

10 Reasons Why You Should Be Shooting RAW

by Rob Lim

You’ve probably heard over and over that you should be shooting in RAW. But do you know why it’s so important? And what it really means for your images? Let’s sort it out!

First off, what is RAW? RAW is a file format that captures all image data recorded by the sensor when you take a photo. When shooting in a format like JPEG image information is compressed and lost. Because no information is compressed with RAW you’re able to produce higher quality images, as well as correct problem images that would be unrecoverable if shot in the JPEG format.

And happily many many cameras these days shoot RAW, including point and shoots! So even if you’re using a little camera, you might still be able to take advantage of the RAW file format (just check your camera manual to see!).
So, the benefits of RAW. Let’s list ‘em out:

1. Get the Highest Level of Quality

This is one of the biggest benefits. When you shoot in RAW you record all of the data from the sensor. This gives the highest quality files. And when it comes to your awesome images, you want high quality.
Look at it this way: all cameras technically shoot RAW. Yes, it’s true.

The difference when you shoot in JPEG format is that the camera does it’s own processing to convert the RAW information into a JPEG.

However, your camera is nowhere near as smart as your brain, nor is it as powerful as your computer. When you shoot RAW, you’re able to do that processing yourself. You can make the decisions on how the image should look, and produce way better results.

2. Record Greater Levels of Brightness

Levels of brightness are the number of steps from black to white in an image. The more you have, the smoother the transitions of tones. Smooth is good.

JPEG records 256 levels of brightness, and RAW records between 4,096 to 16,384 levels! This is described with the term “bit”. JPEG captures in 8bit, and RAW is either 12bit or 14bit. That’s what that bit business means!

The effect this has on your images is huge. Those additional steps of brightness let you make more adjustments (expoosure, blacks, fill light, recovery, contrast, brightness) to your image without a significant reduction of quality, because there’s more levels to work with!

It’s also easier to avoid or correct posterization in your images when you shoot in RAW. Posterization is the banding that you often see in bright skies, which really doesn’t look good in prints!

3. Easily Correct Dramatically Over/Under Exposed Images

Obviously you want to get the best exposure in camera, but sometimes things move fast (especially with weddings!) and you wind up with a dramatically over or under exposed image.

With RAW you have additional information in the file, so it’s much easier to correct the image without a drastic reduction in quality. You can also recover more blown highlights and clipped shadows. Good stuff.

4. Easily Adjust White Balance

When you shoot JPEG the white balance is applied to the image. You can’t just easily choose another option. With RAW the white balance is still recorded, but because you have way more data, it’s easy to adjust.

Great white balance and colour are essential to an awesome image, and shooting RAW lets you make the adjustments easier and faster, with better results.

5. Get Better Detail

When you shoot RAW you have access to sharpening and noise algorithms in a program like Lightroom that are way more powerful than those found in your camera.

Plus, these sharpening and noise algorithms are always improving, so in the future you’ll be able to re-visit your RAW files and take advantage of these improvements. And jetpacks.

6. Enjoy Non-Destructive Editing

When you make adjustments to a RAW file, you’re not actually doing anything to the original data. What you’re doing is creating a set of instructions for how the JPEG or TIFF (another file format) version should be saved.

The awesomness of this is that you never ever have to worry about ruining an image, accidentally saving over, or being unable to go back and make changes. You can always reset your adjustments, and start over again.

JPEG files lose quality every time you open them, make adjustments, and save again. True story. It’s what is known as a “lossy” file format. So if you’re making edits to JPEGs you always have to be duplicating the image and saving out a new version if you don’t want to lose file quality. Hassle.

7. Get Better Prints

Because of the finer gradation of tones and colours you’ll get better prints from RAW files. Even though more and more people are shooting digital, great prints are as important as ever (maybe even more so, due to their relative rarity!)
You’ll also get less banding, which is really yucky on a print.

8. Select Colour Space on Output

Colour space is a bit of a complex topic, but here’s a quick tip. With RAW you can choose from any colour space when you are exporting it out, so you can adjust depending on the situation!

Is the image going on to the web? Then output in the sRGB colour space to ensure maximum compatibility among web browsers.

Are the files heading to a client? Save it in the common Adobe RGB (1998) colour space.

Do you want the widest colour space possible? Use ProPhoto RGB.

Basically there are different colour spaces that work best for different situations, and when you shoot RAW you can export a single image in multiple spaces! Sweet!

9. Have an Efficient Workflow

It’s easier to work through large batches of images when you’re using a workflow centric program like Lightroom or Aperture. They’re designed to easily process groups of RAW images. Photoshop is not meant for that kind of thing, it’s built to handle one image at a time.
In order to take full advantage of all the benefits of Lightroom and Aperture you should be shooting RAW!

10. It’s the Pro Option

Professionals should be providing their clients with the highest quality possible. Issues like banding and blown highlights are big deals when you’re offering your clients printed products. Achieving proper colour balance, and choosing the right colour space for the situation are critical as well.

By shooting RAW you take control, and are able to manage these problems to create the best results possible.

Now that some point and shoots are capable of shooting RAW, hobbyists and amateurs can also take advantage of this pro level option, and get better files and prints! Good deal.

Downsides and Solutions

Now, there are always pros and cons to every option, and RAW does have a few downsides. We’ll chat about those, as well as some potential soluations!

Need To Be Processed

A common argument against shooting RAW is that because the files need to be processed, it takes more time to shoot RAW than JPEG. If you don’t do any processing to your JPEGs that might be true.

However, most photographers do some level of processing to their JPEGs so already the argument is getting flimsy.

Then, when you add in the fact that adjustments like white balancing, and recovering highlights and shadows are way faster with RAW files, and it actually begins to looks like processing RAW can be faster than JPEG!!

Then, with RAW, you can easily export to JPEG, as well as convert to various sizes (like web res) at the same time. If you really wanted you could even shoot RAW + JPEG simultaneously!

RAW gives you way more options, and can be processed just as fast, if not faster, than JPEG.

Takes Up More Space

Since RAW files have more uncompressed information they can be 2-3 times larger than JPEG files. This is definitely a concern for many shooters, especially those who create a lot of images.

But over the past few years, the cost of hard drives has really dropped, and they’re incredibly affordable!

Let’s consider a 3TB hard drive.

A 3TB drive costs about $129
If a large JPEG file is about 8MB, you’ll fit 375,000 images on the drive, at $0.000344/image
If a RAW file is about 30MB, you’ll fit 100,000 images on the drive, at $0.00129/image

Obviously you can store fewer RAW files, but the number of images that you can cheaply store is so large for both formats that it’s not really an issue! It’s also probably a good idea to not place so many images on a single hard drive. Don’t put all your photographic eggs in one basket!

Memory cards are the same deal. They’re constantly dropping in price. Remember when a 2GB card was over $200?? Nowadays you can hardly even buy one that small, and 4GB is as cheap as $15. Madness!

Yes, RAW files are bigger and take up more space. But that’s because they’re of higher quality. Go with high quality for the extra $0.00121/image.

Slows The Camera Down

RAW files are larger than JPEGs, so they’ll fill up the buffer of your camera faster. The camera will still shoot the same frames per second, regardless of whether it is RAW or JPEG, but you may have to wait for the camera to write to the memory card if the buffer fills up.

If shooting fast sequences if critical for you, and you want to shoot RAW, you can purchase faster memory cards, or a more expensive camera with a larger buffer.

In A Proprietary Format

RAW files are often recorded in a proprietary format, which means that the camera manufacturers haven’t officially disclosed how the raw data can be converted. Companies like Adobe either need to license software to decode the RAW files or reverse engineer how the files should be converted. (For Canon cameras the RAW format looks like .CR2 and for Nikon it’s .NEF).

The problem here is that you can’t be certain that in 5, 10 or 20 years you’ll be able to easily open that RAW file if you don’t have the proper software to decode it!

A new open source RAW format has been developed in order to overcome this obstacle. It was developed by Adobe and is known as DNG (Digital Negative). Using a program like Lightroom, you can convert your proprietary RAW files into the open source DNG format. It’s an extra step, but it will ensure your files are readable far into the future!

Already the Leica M9 shoots in the DNG format, so look for more camera manufacturers to support this open source format in the future!

Wrap It UP!

Hopefully this look at RAW and it’s benefits has cleared things up a bit! Suggestions that RAW takes too long, or is too much work, don’t really hold water anymore.

These days, it’s super duper easy (and fast!) to process RAW files, and you’ll be able to get the absolute best quality out of those images that you put so much time, effort and love into!

Ô cơ , còn muốn set up RAW trong máy ra sao thì mỗi máy có setting riêng , phải mò vào đó coi á ... lấy cái Cannon & Nikon ra làm thí dụ :

**Hiệp Khách** · 04-10-2015, 09:43 AM

feel better now

. Nói thật, tiếng Việt dịch cho vấn đề kỹ thuật sao giống dao ta búa lớn quá. Có lẽ người dịch chỉ là biết tiếng Anh chứ không hiểu gì kỹ thuật. Ví dụ như lò microwave thì dịch là lò Vi ba ? Sóng microwave dịch là siêu vi sóng? vậy mili-wave dịch sao đây? đâu phải cứ micro là siêu hay vi đâu chòy. Software dịch là phần mềm? hardware dịch là phần cứng, còn firmware dịch sao đây?

**puppyz** · 05-10-2015, 12:48 PM

Nguyên Văn Bài Viết Của Hiệp Khách View Post

feel better now

. Nói thật, tiếng Việt dịch cho vấn đề kỹ thuật sao giống dao ta búa lớn quá. Có lẽ người dịch chỉ là biết tiếng Anh chứ không hiểu gì kỹ thuật. Ví dụ như lò microwave thì dịch là lò Vi ba ? Sóng microwave dịch là siêu vi sóng? vậy mili-wave dịch sao đây? đâu phải cứ micro là siêu hay vi đâu chòy. Software dịch là phần mềm? hardware dịch là phần cứng, còn firmware dịch sao đây?

cứng hơn phần mềm nhưng mềm hơn phần cứng ... sao bác cứ bức xúc làm chi ... chỉ lo khi phải dzìa VN làm thui hà ... he he he vậy chứ cái đơn nào cũng có độc lập tự do hạnh phúc bự thù lù nhưng nói lạng quạng thử coi nhẹ ăn mắm tôm mạnh đi gở lịch

**puppyz** · 05-10-2015, 12:57 PM

Cho dân pro thôi chứ dân tay ngang nội sắm software để convert từ RAW qua mấy dạng thông thường là đủ chết

Thông Báo

10 Lý Do Bạn Nên Chụp Ảnh Định Dạng RAW

10 Lý Do Bạn Nên Chụp Ảnh Định Dạng RAW

Comment

Comment

Comment

Comment

Comment