What is RAW?

[Flyflicker]

I recently got a Rebel XT, the 8.1mpg... And I was reading through here, admiring some of the pictures when someone mentioned that his pictures are much better in RAW. Now I saw it as an option for quality but I don't understand what it is and the advantages and disadvantages. Can someone please help in explaining these to me.

Thanks

 

[saltycreefer]

Raw is a WWE show on monday night.

 

[BlueCorn]

RAW is the unprocessed pixel data that your sensor captures on every shot. To get an image from it the data has to be converted. If you choose JPG, the camera converts the raw data and spits out a jpg. When you shoot in "RAW" mode, you use a program external to the camera to convert the data into an image file.

The beauty of it is that things like white balance setting are a function of that conversion. Aquarium photography's biggest challenge is getting the camera to set WB correctly under the lights that we use. In RAW, you can control that after the shot. You can also do a much wider range of exposure correction without loosing pixel data.

If you do a lot of lightness/contrast adjustments to a jpg and then look at the histogram in photoshop it looks like a comb. That's depicting data that's lost forever. With RAW you can make those adjustments without destroying the image.

 

[gregr]

Basically raw files are picture files consisting of the raw data right from the sensor, with no processing applied. When you shoot in jpeg mode the camera compresses the file and applies color adjustments, sharpening etc. (depending on your settings). That is the most basic difference. Working with raw files adds steps to your workflow-- that is the downside. The additional steps involve converting the raw file to a jpeg or tiff file (the two most common image formats). The upsides are big- you can make your white balance adjustments during that conversion process, plus you can make other exposure and color adjustments if you want to. But for aquarium photography the big deal is being able to adjust the white balance on your computer, after the picture has been taken.
Your camera came with raw conversion software, plus Photoshop and other programs can convert raw files.

 

[gregr]

No fair- he types too fast :lol:

 

[BlueCorn]

:lol:

 

[Ebn]

WB is still affected in RAW, but it isn't as significant.

In addition to the comments above, the big difference is gonna be in compression. JPEG files (non-RAW) are 8 bits whereas RAW files are 12 bits+. There's a ton of info that's lost/stripped between conversion.

 

[Flyflicker]

So is it better to shoot in RAW?... given the extra space and conversion later that needs to be done. Does the picture turn out that much better?

 

[jeffbrig]

It depends somewhat on the camera, but even with my XT, I see a big difference in fine detail between a .jpg taken directly from the camera vs. a raw file that was converted to .jpg using photoshop.

The best thing is, most cameras will let you store raw + jpg for the same shot. Try it and see the difference for yourself.

 

[Flyflicker]

Will the rebel XT allow you to store both?

 

[jeffbrig]

Yep!

 

[Flyflicker]

Sweet!
But you are making me do something that I hate doing... I can't believe that I will actually have to read the manual!

 

[Rosseau]

I read the manual for my D-SLR, (XTi) I couldn't believe myself....

What is photography doing to the manly men inside of us?

 

[Flyflicker]

After looking over my manual I noticed that in order to have RAW+jpeg I have to manually do a whole lot more than point and shoot. Yea, I have to say that the manly man inside of me is curled up in the fetal position sucking his thumb crying for his mommy.

 

[jeffbrig]

Ah, didn't think about that....I've been shooting in full manual since I got my XT. You're right, a lot of the camera's features (and potential ) are locked out if you use the automatic modes.