This post is a brief reasoning (my own, mind you) of why you should shoot RAW. A full twenty pages could have been written, but I tried to keep it short and simple. There are also many reasons why you should shoot in RAW mode, and so few reasons why you should shoot in JPEG mode. See the reasons at the end of this post.What is Raw Mode anyway?
When a DSLR takes an exposure, the sensor records the amount of light that has hit each photo site or pixel. This is recorded as a voltage level. The camera's A/D converter (Analog to Digital converter) transforms this analog signal into a digital interpretation. Depending on the camera's circuitry either 12 bit or 14 bit (Pentax K20D) or even 22 bit in the case of the Pentax K10D) of data are recorded. If your DSLR records 12 bit of data then each pixel can deal with with 4,096 brightness levels, if it records14 bit then it can record 16,384 different brightness levels and if it records 22 bit like the K10D, it can record 4.2 million different brightness levels or gradations. What happens after you've taken the photograph depends on whether you have the camera set to save your image to the memory card as RAW files or JPEG. If you've saved the file in RAW mode, you can later convert it to a TIFF file or PSD file in a 16 bit workspace or even JEPG in an 8 bit workspace (With only 256 brightness level or gradation), using a RAW converter software package. Of course, your DSLR can convert to JEPG in-camera, rendering a compressed lossy file.
Shooting and saving in RAW
If you are shooting a RAW image, the camera creates a header file which contains all of the camera settings, including sharpening level, contrast and saturation settings, white balance, and more. The image is not altered by these settings; they are simply attached onto the RAW image data. The RAW data is then saved to your memory card along with the meta-data.
Shooting and saving in JPEG
First, did you know that sensors cannot record colors? A Bayer Matrix/color Filter Array is used in order to record colors. Red, blue, and green filters are placed over each pixel. Half of the pixels are filtered by the green filter and the remaining colors are either red or blue. A proprietary algorithm is used to convert the values recorded by each pixel by comparing each pixel with its neighboring colors. Full color information is consequently derived from this complex process. It’s a wonder that such small “in-camera computer chips” can do this job at all. The in-camera conversion of the RAW file to a JPEG file also applies some Unsharp Masking, contrast, color saturation and save the results to an 8 bit mode file. The brightness level or gradation is now reduced to 256 levels. The resulting JPEG file is compressed to reduce the file size as a lossy file format. To attain this, the in-camera processing has to throw away information, which cannot ever be recuperated.
Differences
RAW file is basically the data that the DSLR sensor recorded along with some additional information added on and non-destructive. A JPEG is a file that has had the camera apply matrix conversion, white balance, contrast, and saturation, and then has had some level of destructive compression added. Also note that each manufacturer decides for you what conversion should be applied to the JPEG file.
Why shoot JPG?
Because you are scared to make the plunge to RAW, like I did. (Once you do, you will forever wonder why you didn’t switch sooner.)
Files are smaller and more can fit on a memory card. (Memory is getting cheaper all the time and this reason is somewhat not valid anymore.)
For many applications, JPEG image quality is more than sufficient (Snapshots, emails, computer screen rendition only) (That may be true, but why not keep your image in a non-destructive RAW file and convert to JPEG as needed, while keeping the original data intact?)
Smaller files are easily transmitted wirelessly and online. (Again, that may be true, but why not keep your image in a non-destructive RAW file and convert to JPEG as needed, while keeping the original data intact?)
Many photographers don't have the time or desire to post-process their files. (This is like saying that you like your food well cooked, but don’t have the time to do so.)
Why shoot RAW?
It holds exactly what the sensor recorded. You are able to extrapolate the best possible image quality, now or in the future. Better image processing software will come along and you will be able to re-process old images in their RAW form with better software.
You can set any color temperature or white balance you want after the fact, with no image degradation.
File color filter array conversion is done on a computer with a fast and powerful microprocessor when compared to the small in-camera processor.
The RAW file is tagged with information as set in the camera by the user, but the actual image data has not been changed. You are free to set parameters based on each image evaluation. You can change your mind now or in the future as the RAW file is non-destructive.
Summary
Every DSLR is actually always shooting in RAW mode. If you choose to save the file as a JPEG, you are committing to the RAW conversion that is built into the DSLR. If you save your image in RAW, you can do the conversion on a more sophisticated platform, and do so time after time. Do you want to do the RAW file conversion now in your DSLR with the manufacturer’s preferences, or later on your powerful computer, the way you like it? Certainly anyone looking for the best possible image quality will want to shoot in RAW mode. Why would you purchase a sophisticated DSLR, such as the Pentax Line of DSLRs, if you don’t intend to use it to its full potential?
Thank you for reading, and have a great Pentax Day.
P.S. You don't have top agree with me, let me know your point-of-view.
8 comments:
Shooting jpg allows you to shoot faster because it takes longer to fill the cameras buffer, thus making the camera ready sooner for the next shot.
This can be important when taking shots of fast moving objects such as flying birds and sporting events.
Tom
Garry Ian Young, Feb 29, 2008; 10:06 p.m.
Hi Yvon. Timely post indeed. When I got my K100D, the fellow that sold me the camera set it on jpeg and said that is all I would need. I presume he was (quite rightly) judging my skill and knowledge as very amateurish.
After a few weeks of jpeg shooting with no post processing whatsoever, I had pretty much committed the camera manual to memory and decided RAW was something I should try. I then got Adobe Lightroom, and started shooting in RAW. Suddenly I got all hung up both on what I could or couldn't and should or shouldn't do in Lightroom, to still legitimately call the image an original creation done by me through the medium of a camera lens.
Additionally I struggled to know what on earth I should be doing in tweaking levels and things, often ending up frustrated by my inability to correctly process images. I switched back to shooting jpegs.
Again a few weeks passed in which time I began to be dissatisfied with about 50% of my shots done in bright mode jpegs. Sometimes the White Balance wasn't spot on, or the saturation was too high for that, but too low for this, etc. But what I did come to see was how much the "in-camera" settings could effect the resultant jpeg. This has given me the confidence to go back to RAW and not be too afraid to tweak the levels and things in Lightroom to better reflect what I saw (or was hoping to see) at the time of shooting.
Your post is encouraging. Thanks.
I am on your side with this Yvon. I see no particular reason to throw away the data.
But, I do have to add some hard drive space to save all these images.
__________________
Albert in the Rockies
Posted: Fri Feb 29th, 2008 10:15 pm
Yvon - I agree with you and have shot virtually everything in RAW the last couple of years. Since they are large files, I basically do a sorting of the images after I get them on the computer and delete all but the keepers. I'm getting more particular all the time.
I spend a lot of time looking at my pictures and use PPL to convert them, since I have the time to play with them one at a time. To me this is part of the enjoyment of photography. Once converted to TIFF's, I do my cropping, resizing and sharpening in post processing, then convert it to a JPG. I always have my original RAW image to fall back on and delete the TIFF's as soon as I'm done with them. I'm one of the old die hards that still uses Irfanview and I have PSP if I need to go further.
I can see Tom's argument for anyone shooting action shots or that shoots a lot of frames at once. I seldom do that, so RAW works for me most of the time. I do shoot JPG if I'm doing HDR, since that is a lot easier and I see the new K20D, now auto brackets 5 shots. I have tried HDR using a RAW image, but have not been as successful with that, partly because the software I use works best with JPG's.
Lately I've been using my tripod and 2 second timer more. This gives me more time to compose my pictures and the 2 second timer engages the mirror lockup before shooting, so the pictures are rock solid. It has made a difference for me. Here again, it's not everyones cup of tea though. I take mostly flower and landscape shots - Bruce
Thanks for Sharing, Yvon. I have a K100D but seldom shoot in raw because its too cumbersome for me especially if I have hundreds of holiday photos to process.
I do try raw once in a while but somehow can't seem to get the settings right, i.e. all my efforts always looks worse than the in-camera settings.
I think it would help if you could include techniques on how to tweak the main settings to get better-than-in-camera images.
cheers
airconvent - Clubsnap.com
charles gravely, Mar 01, 2008; 11:56 a.m.
Cool discussion - here's my experience -
I switched to Raw and I love it!
I think there is a misconception that Raw takes a lot of extra work. That was why I held off for so long. I don't have time to mess with these shots either - imagine having to tweak a hundred photographs or so after every time you go out with your camera - not a chance! I just don't have that kind of time on my hands.
The fact is, you don't have to do anything to them and they are still better than JPEG. Just download the files as normal and you are done. View them, sort them, enjoy them. The difference is, if you find one you like you can then go ahead and make it really great. This has nothing to do with the steep learning curve of photoshop. You don't need photoshop at all (unless you are into localized adjustments).
There are three down-sides to RAW - 1) You have to replace your current photo sorting program with one that handles Raw files. There are a few contenders out there and they are all great. This does cost money. I paid about $300 for Lightroom. 2) They take up loads of space on your hard drive. Of course hard disk space is very cheap now. I will admit, when I switched to raw, I also added two new hard drives to my computer - one just for files and a second one just to have a redundant copy (RAID level 1). This cost me about $250 for 1T of storage - good for loads of photographs and a backup strategy you don't have to think about. 3) If you want to e-mail a photograph to someone, you have to export it to JPEG. Of course this is not really an extra step because even if you started with a JPEG you have to downsample to send to someone anyway. Convert to JPEG and downsample is single step that is done with batches of files in your photo sorting program of choice.
I did say you just download as normal and enjoy your photographs - no extra work. In fact, you do spend more time simply because it is so much fun to tweak the odd shot and add keywords for sorting. This is not because it is necessary but rather you get lured into it.
I started shooting digital (and film) when my daughter was born 8 years ago. Now that I have switched to raw and I am cataloging my old JPEGs in lightroom (about 12,000 shots). I have two regrets - 1) I wish I had organized my files better along the way with keywords etc. 2) I wish they were all raw because the JPEGs are simply stripped down raw files.
I believe the longer you wait to switch to raw, the greater your regret will be later when you realize that all shots up to that point are missing huge chunks of data that you were entitled to. There is no recovery.
I made the jump after viewing Michael Riechman's tutorial on Lightroom. This demonstrates exactly how raw files are handled and clears up many misconceptions about the work involved. Of course it only covers this particular program and there are others that are probably just as good. This is not a criticism because the tutorial is what it says it is - a lightoom tutorial. I believe it's only about $15 and it is unbelievable! It's worth the $15 before sinking $300 into Lightroom. I can't speak highly enough about this tutorial. And by the way, I have no association with Michael Richmann or his company.
Happy shooting Sincerely, Charles
Michael Costello, Mar 01, 2008; 02:42 p.m. (photo.net)
Wonderful post. Thank you Yvon. I have a couple of questions/clarification.
Yvon: You refer to a 16 bit and/or 8 bit workspace. What exactly are you referring to? Version of windows? Type of software?
Charles: You make reference to replacing the current photo sorting program. What are you referring to? I currently store my photos under "My Pictures" in different folders and access them through Photo Shop for any work. Do I require a sort program. If so, what do you recommend? You mention Lightroom however, I really don't have $300.00 to spend at this time.
Thank you very much everyone for the great info. I am committed to starting to shoot RAW and learn some post processing.
Oh, by the way, this post gives me sufficient ammunition to get my wife to change over to shoot raw as well with her camera. I will just say "The Experts", Yvon, Garry, Michael,Cory and Charles say it is so; so it must be true.......Thanks Guys...........:)
Yes! You've convinced me.. it's time I made the move.. so here goes! Thank you for a very instructive post.
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