Questions about Raw in the 20D

[triangle]

At the risk of sounding stupid, I am going to ask these questions. I have read several times about shooting in RAW mode and have been advised to try it. Now to my few questions.

I noticed that when I shoot Large Jpeg that my images are around 3Mb, which is really close to what I was getting with the DRebel. But when I shoot RAW, I am getting the 8.3Mb per photo.

So my 1st question is this - Is the only way of getting the full 8.3Mb the camera is capable of is to use RAW?

2nd Question - If that is the case, if I were to crop into a RAW photo will that give me still greater file size than I would have shooting in jpeg? (Depending on the size of the crop of course) What I mean is say I eliminate 1/2 of the actual shot of a RAW image, than convert that cropped image to Jpeg. Will that end result be a possible 4Mb file?

If the above questions are true, than I think the light bulb is coming on as to why shooting in RAW has some advantages. So here is my last question.

3rd Question - I shoot alot of photos at games (200-300) and post them for parents/family members to purchase. Therefore it is speculation shots, not sure sales. I am noticing that working with the RAW images take alot more time to work with. So when do you find it more of an advantage to use RAW? Another words worth the time and effort to work with the photos. Or will I get faster at processing the photos maybe?

[tim]

1) Nope. JPG Image compression knocks the file size down, but you still have full resolution and a great quality JPG. JPG is compressed with lossy compression, RAW is exactly what came off the sensor.
2) You can't change your RAW file, if you crop it you have to save it as something (eg TIFF, JPG) otherwise your changes will be lost. Some image editors like CS2 save your RAW crop settings, but they're stored in a seperate file.
3) If you can get the images right in the camera JPG is a much faster workflow and just as good a quality picture. If you need to tweak exposure, levels, white ballance, etc frequently, RAW will give you a better picture. I'm pretty quick at RAW processing now, but if I could get it right in the camera 99% of the time then i'd go for JPG.

You should buy this book (http://www.amazon.com/exec/obidos/tg/detail/-/032127878X/qid=1113466778/sr=8-1/ref=sr_8_xs_ap_i1_xgl14/002-3047575-5896047?v=glance&s=books&n=507846) if you want to understand RAW, it's a great book.

hth

[triangle]

Thanks for the quick reply Tim. I am going to look over that book.

One other question, when and why would you shoot RAW + Jpeg? That must really eat up some memory.

[MikeCaine]

A RAW file is like an digital version of a negative. You have to process it to get the final picture. The final file size depends on how you process it, or rather, what you process it into. It could be a compressed JPG, it could be a TIFF. You might find that your finished file is 100KB or 24MB depending on what file format you use and what, if any, compression you use.

If you want speculation shots I'd shoot RAW + JPG, possibly small fine size. That way you can get a quick photo to show parents and have the RAW file to develop the shot from if needed

[triangle]

If you want speculation shots I'd shoot RAW + JPG, possibly small fine size. That way you can get a quick photo to show parents and have the RAW file to develop the shot from if needed


:) You must have entered this answer while I was typing. Thanks.

[MikeCaine]

It might even be worth switching from Parameter 2 (the default) to Paramater 1 which would give the JPG a little extra contrast, sharpness and saturation so they pop out a bit more. You'd still have full control of how you process the RAW at a later stage

[GyRob]

i think Parameter 2 is very flat 1 is better or do a test and set your own to your taste.
Rob

[topaz]

triangle, I'll also add, in case it helps, that megapixels are not at all the same as megabytes. You can't tell, from looking at a file's size, exactly how many pixels are in the image. The number of bytes required for an image depends on the file format (JPG, RAW, etc.), the quality parameters, and the contents of the image itself.

So on a 20D, you're getting the full 8.3 megapixels whenever you use RAW or "L" size JPG settings, regardless of the file size.

[thanhda]

I understood more about RAW after reading this short chapter abour RAW file processing from outbackphoto.com:

http://www.outbackphoto.com/handbook/rawfileprocessing.html

There are alot of great articles in that website.

[Nightcrawler]

You will also notice that some of the RAW files will be much smaller as in 5-6MB. That is because there is more redundancy in the picture that was taken. Such as a clear blue sky. So, not all RAW files are 8.2MB.

[triangle]

triangle, I'll also add, in case it helps, that megapixels are not at all the same as megabytes. You can't tell, from looking at a file's size, exactly how many pixels are in the image. The number of bytes required for an image depends on the file format (JPG, RAW, etc.), the quality parameters, and the contents of the image itself.

So on a 20D, you're getting the full 8.3 megapixels whenever you use RAW or "L" size JPG settings, regardless of the file size.


:oops: I should have known better, I equated them to be the same when I saw the RAW at the 8.2. Thanks for the heads up.

[triangle]

I understood more about RAW after reading this short chapter abour RAW file processing from outbackphoto.com:

http://www.outbackphoto.com/handbook/rawfileprocessing.html

There are alot of great articles in that website.


Thanks for the link.


You will also notice that some of the RAW files will be much smaller as in 5-6MB. That is because there is more redundancy in the picture that was taken. Such as a clear blue sky. So, not all RAW files are 8.2MB.

That makes sense, thanks.

[Nightcrawler]

No problemo. You can equate the type of compression that takes place in the RAW files to the type of compression in a ZIP file. Both are lossless and thrive on redundancy.

[Rob612]

One other question, when and why would you shoot RAW + Jpeg? That must really eat up some memory.

Always. I've found that for my purposes shooting RAW+JPEG works fine. I do not care about memory because I have plenty of CFs in various size.

I mainly use Jpeg for a quick look, for web exhibition and anything else that I need to do fast (i.e. sharing pics here on POTN).

If I got something that needs to be PP (and it happens a lot) then I'll take the RAW and do whats needed. Sure enough, if I'm shooting a party with friends, I do not bother to elaborate the RAW unless there is a real keepen in the bunch, I just keep them as a negative.

[Jon]

RAW+JPEG when there's time for the camera to write it out. JPEG only when I'm in an active setting (steeplechase, air show, anywhere things may be changing rapidly and I can't afford to wait for the buffer to clear). If possible, I'll use the JPEG, relying on the RAW only for odd lighting situations or other cases where serioous post-processing comes into play (gotta love being able to extract 16-bit TIFFs).

[aam1234]

I have a question, and it's been answered before but would like a confirmation / clarify my understanding.

What advantage(s) does a jpeg coming from RAW has compared to a straight jpeg.

Thanks

[kenyc]

I have a question, and it's been answered before but would like a confirmation / clarify my understanding.

What advantage(s) does a jpeg coming from RAW has compared to a straight jpeg.

Thanks

jpgs all come from RAW, it's just that the camera has a build in pre-set jpg algorithm that does the conversion when you take the picture. If you convert it yourself, you can control the parameters of the conversion.

KAC

[tim]

I have a question, and it's been answered before but would like a confirmation / clarify my understanding.

What advantage(s) does a jpeg coming from RAW has compared to a straight jpeg.

Thanks

If you get the exposure or white ballance wrong then you can fix it in RAW before JPG conversion.

[aam1234]

Thank you guys. Maybe I should have been more specific, sorry about that.

You often hear about the 12 bit RAW vs. 8 bits jpeg. So was wondering if these extra bits can be translated into a better jpeg (coming from raw).

Thanks again.

[tim]

RAW lets you pull more detail out of the shadows. Sometimes you might need to merge exposures (or the same exposure at EC -2, 0, +2) to get the benefits of it. For example, in this photo (http://www.wildphotography.co.nz/gallery/JJ/Grounds/pages/JJ046B.htm) I used something like +1 to expose the house correctly, -2 to expose the bright clouds correctly, and blended the exposures to get this one. It's not perfect but it's better than what it would've been otherwise.

[lostdoggy]

Thank you guys. Maybe I should have been more specific, sorry about that.

You often hear about the 12 bit RAW vs. 8 bits jpeg. So was wondering if these extra bits can be translated into a better jpeg (coming from raw).

Thanks again.

I think that others have made this point. Converting from RAW to JPEG is like using negative to make a print. Shooting in JPEG is like shooting Polariods. Once its done is pretty much done. The RAW file gives you a second chance to make it right if you mess up the first ime. The other point is when ever you take a JPEG and open it for Manipulation and save it again in JPEG there will some lost from the compression.

[aam1234]

Thanks lostdoggy,

According to what you said there doesn't seem to be any "extra bits" advantage to jpeg coming from raw, only correcting "mistakes". Hope I understood you correctly.

Thanks

[tim]

According to what you said there doesn't seem to be any "extra bits" advantage to jpeg coming from raw, only correcting "mistakes". Hope I understood you correctly.

That's not correct. "Correcting mistakes" is one thing you can do, but you also get more dynamic range, which with proper techniques means you can get light and dark objects in the same image. I had one shot I did at a wedding that was too dark because the flash hadn't recharged in time: it was virtually black, with only the reflector of a motorcycle visible. At EC+3 or +3.5 and after a bit of noise reduction the image was quite usable. If anyone's interested I can show the before and after images.

[aam1234]

Thanks Tim, now all clear.

Would be nice if you can show the before/after of that photo.

[tim]

Here you go. First, the original, unprocessed RAW file, straight conversion to JPG. The reason it's dark is either a) The reflective headlight (less likely IMHO), or b) Flash wasn't fully charged for the shot yet.

http://mrwild.co.nz/unprotected/potn/before.jpg


This is the same photo after using exposure compensation +4, and run thru noise ninja.
http://mrwild.co.nz/unprotected/potn/after1.jpg


And cropped.
http://mrwild.co.nz/unprotected/potn/after2.jpg

It's not going to win any awards, but you can see how much difference makes. Try and do the same thing with a jpg and you'd not get much out of it.

[aam1234]

Thanks Tim. That is a big difference.