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#1 |
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![]() ![]() [align=justify]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. [/align] [align=justify]What is Raw Mode anyway?[/align] [align=justify]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.[/align] [align=justify]Shooting and saving in RAW[/align]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 [align=justify]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.[/align] [align=justify]Differences[/align] [align=justify]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. [/align] [align=justify]Why shoot JPG?[/align] [align=justify]Because you are scared to make the plunge to RAW, like I did. [size=(Once you do, you will forever wonder why you didn't switch sooner.)][/align] [align=justify]Files are smaller and more can fit on a memory card. [size=(Memory is getting cheaper all the time and this reason is somewhat not valid anymore.)][/align] [align=justify]For many applications, JPEG image quality is more than sufficient (Snapshots, emails, computer screen rendition only) [size=(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?)][/align] [align=justify]Smaller files are easily transmitted wirelessly and online. [size=(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?)][/align] [align=justify]Many photographers don't have the time or desire to post-process their files. [size=(This is like saying that you like your food well cooked, but don't have the time to do so.)][/align] [align=justify]Why shoot RAW?[/align] [align=justify]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. [/align] [align=justify]You can set any color temperature or white balance you want after the fact, with no image degradation.[/align] [align=justify]File color filter array conversion is done on a computer with a fast and powerful microprocessor when compared to the small in-camera processor.[/align] [align=justify]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.[/align] [align=justify]Summary[/align] [align=justify]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? [/align] [align=justify]Thank you for reading, and have a great Pentax Day. [/align]Yvon Bourque [align=justify]pentaxdslrs.blogspot [align=justify][/align] [align=justify]P.S. You don't have top agree with me, let me know your point-of-view.[/align] [/align] |
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#2 |
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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 |
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#3 |
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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 moreparticular all the time.
I spend a lot of time looking at my pictures and use PPL to convert them, since I have the timeto 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 timerengages 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 |
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#4 |
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There is no argument that RAW is better for ultimate image quality, however you discount jpeg unfairly. As Tom pointed out the smaller size and greater camera speed with jpeg is extremely useful to sports photographers, photojournalists and anyone on a very tight deadline. The trick is just to get your metering and white balance right.
I now shoot almost exclusively RAW however when I had my old computer I used jpegs becuase processing time was an issue. I have shot two weddings (very successfully I might add) in jpeg since the use of flash and outdoor locations made white balance easy and I could have their pictures ready much more quickly. Nothing wrong with stating an opinion but perhaps a little more diplomatically next time. Ira |
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#5 | ||||
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Monza76 wrote:
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#6 | ||
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Pentax Socal wrote:
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#7 |
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I never said RAW was not the best way to go for the best quality, but shooting RAW with fast action makes your chances better that when the shot you really wanted comes up, you will be waiting for the buffer to fill instead of getting the shot.
There is nothing wrong with jpg if your camera does a good job with WB, as Ira said even weddings can be done just fine with jpg. I shot a couple of weddings using jpg and 400 of the shots came out just fine at each wedding and I was able to shoot the candids at a faster rate to get just the expression I wanted. At the moment I am shooting a DS which does a great job with WB, so I really don't feel at a disadvantage using jpg instead of RAW. Now my K10D was not that reliable in jpg and had a bigger buffer, so I shot quite a bit in RAW with that camera. Now a different camera such as Canon or Nikon with a bigger buffer than Pentax and faster focusing makes RAW a better choice instead of jpg. Even with those cameras you are still stuck with some major PP time in RAW that is not there with jpg. Tom |
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#8 |
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Nice post... You can find lots of stuff supporting .JPG in the main forms though. some basic points,
-if you get the right exposure, .jpg will save time (= money-right ) and space. -If you are doing landscapes raw probably better. Shooting sports or people .jpg probably fine. If you like to tinker on the pc shot to shot ( I know there is batch processing...but isn't that what the k10d is really doing - with your adjusted setting- when you shootjpg ) then raw. if you want to shoot more and post process less, shot jpg check the ken rockwell site for a greataticel on this but -ALSO LOOK HERE FOR A GREAT COMPARISON OF RAW CONVERTERS... SHOOTING RAW IS NOT THE END, CHOOSING THE RIGHT CONVERTER MAKES A BBIIGG DIFFERENCE. http://www.ok1000pentax.com/2007/03/...onverters.html bob After looking again at this article I may just put it in its own post. |
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