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Old Feb 29, 2008, 8:55 PM   #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.
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[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]
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Old Feb 29, 2008, 9:26 PM   #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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Old Mar 1, 2008, 1:15 AM   #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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Old Mar 1, 2008, 7:49 AM   #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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Old Mar 1, 2008, 8:30 PM   #5
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Monza76 wrote:
Quote:
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
Quote:
Actually, I thought I was diplomatic and never intended to insult anyone's intelligence. Less than a decade ago, Nikon was introducing the D1 at nearly $6,000. with a whooping 2.7 megapixels and a speed of 4.7 frame per second (At 2.7MP mind you. The K20D does 21FPS @ 1.6MP and 3fps @14.6MP) Every Professional photographer on the planet thought it was wonderful. Today's point and shoot cameras at $200.00 can do better than that. The point is if that was great for Pros shooting sports just as they are today, why does one really need 9fps shooting. I always thought that a 300 to 500MM with a large aperture was what was needed. If sport photography requires faster action than that, mayve a quality video camera is what's required. Anyway, let's travel back 9 years and see what the wonderful Nikon D1 general specs were.
Quote:
About a year ago (in early 1999), Nikon announced their first all-digital professional SLR, the D1. At the time, the specifications and projected price point (2.7 megapixels and a list price of $5850 for the body) rocked the pro camera world, and left many wondering whether Nikon could actually do it. Well, it's now a year later, and Nikon's production is finally starting to catch up with demand. (At least to the point that they were willing to spring loose an evaluation unit for our testing.) Did Nikon hit the mark? We think the answer is a resounding "yes": The D1 looks, works, and feels like a Nikon SLR in every respect, and the image quality matches its performance in other areas. But we're getting ahead of ourselves: Read on for all our findings about this remarkable camera.

The all-Nikon, all-digital studio!
Nikon announced two other products at the same time as the D1, which combine with it to bring new capabilities to studio photographers. The first is an exceptional tilt/shift macro lens, the PC (for perspective correction) Micro Nikkor 85mm 1:2.8 D. This amazing lens provides greater tilt and shift capabilities than any other lens currently on the market for the 35mm format. The result is to convey to the D1 (and other Nikon SLRs) many of the perspective and depth-of-field controls traditionally associated with large-format view cameras. The second announcement was a special version of their SB-28 speedlight, the SB-28DX. This new unit was designed specifically to work with the D1 in TTL (through the lens) metering mode. The SB-28DX is also impressive because it offers the capability to combine multiple speedlights into a single system, all controlled by the camera through its TTL flash metering.

The net result is a remarkably capable digital photography system for studio work, all available from a single manufacturer. The small size of the SB-28DX units makes them ideal for location work as well. For product photography, the tilt/shift capabilities of the new PC Micro Nikkor mean you can finally gain control over the perspective distortions typical in tabletop photography setups. (Caused by the need to tilt the camera down on the subject, causing converging parallels.) Likewise, the tilt capability can drastically increase or decrease the effective depth of field, making it a cinch to get all of the product into focus. We saw these related developments as so significant that we imposed upon Nikon to lend us not only the D1, but one of the first units of the PC Micro Nikkor released for review anywhere, as well as a pair of SB-28DX speedlights, and the miscellaneous cabling and adapters necessary to tie them together into an integrated system with the D1. The results were very impressive, and are detailed in separate "All-Nikon All-Digital Studio" report. (Sorry, that report's not quite ready yet, but coming soon!)


Highlights

  • 2.7 megapixel, 23.7 x 15.6 mm, 12 bit RGB CCD delivering 2000 x 1312 pixel images.

    [/*]
  • Single-lens reflex digital camera with interchangeable lenses (Supports essentially all standard Nikon F mount lenses).

    [/*]
  • Variable ISO (200, 400, 800 and 1600, 3200 and 6400 in "sensitivity up" modes).

    [/*]
  • TTL optical viewfinder with detailed information display.

    [/*]
  • 2 inch, low temperature polysilicon TFT LCD with 114,000 pixels.

    [/*]
  • Program, Shutter Priority, Aperture Priority and Manual exposure modes.

    [/*]
  • Continuous Shooting mode capturing up to 21 images at up to 4.5 frames per second.

    [/*]
  • Variable white balance with Auto, Preset, Incandescent, Fluorescent, Direct Sunlight, Flash, Overcast and Shade

    [/*]
  • Plus/Minus fine adjustment (arbitrary units) on white balance settings.

    [/*]
  • TTL autofocus with Single-Area or Dynamic-Area options.

    [/*]
  • Topside hot shoe for external flash connection of Nikon Speedlight SB-28DX flash as well as a second flash sync socket.

    [/*]
  • TTL Matrix flash exposure, independent of ambient-light exposure computation

    [/*]
  • Front-Curtain Sync, Red-Eye Reduction, Red-Eye Reduction with Slow-Sync, Slow Sync and Rear-Curtain Sync flash sync modes. (With compatible external speedlight.)

    [/*]
  • 3D Color Matrix, Center-Weighted and Spot metering options.

    [/*]
  • Adjustable exposure compensation from -5 to +5 EV(!) in 1/3 EV increments in all exposure modes.

    [/*]
  • Shutter speeds from 30 to 1/16,000 seconds in 1/3 increments, and a Bulb setting for longer exposures.

    [/*]
  • Self-timer with a duration from two to 20 seconds.

    [/*]
  • Secondary shutter release with lock for vertical-format shooting.

    [/*]
  • Image storage on CompactFlash Type I or II.

    [/*]
  • JPEG, uncompressed TIFF (RGB-TIFF and YCbCr-TIFF) and RAW data file formats.

    [/*]
  • DPOF (Digital Print Order Format) compliant. [/*]
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Old Mar 1, 2008, 8:44 PM   #6
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Pentax Socal wrote:
Quote:
Less than a decade ago, Nikon was introducing the D1 at nearly $6,000. with a whooping 2.7 megapixels and a speed of 4.7 frame per second (At 2.7MP¬* mind you. The K20D does 21FPS @ 1.6MP and 3fps @14.6MP)¬* Every Professional photographer on the planet thought it was wonderful. Today's point and shoot cameras at $200.00 can do better than that.
Not really. The P&S of $200 nowaday may have more MP count, but they are still not approaching D1 in terms of image quality given the right lens. The more expensive P&S like Canon G7 just maybe a different story.

Quote:
The point is if that was great for Pros shooting sports just as they are today, why does one really need 9fps shooting.
Not really. 9 FPS is needed for wildlife, fast sport & bird in flight pictures. Also what is hidden behind 9FPS is the more important predictive focus tracking/locking.

Daniel
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Old Mar 1, 2008, 10:11 PM   #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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Old Mar 2, 2008, 10:17 AM   #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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