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|| SportsShooter.com: Member Message Board
Compressed RAW images
Dan Powers, Photographer
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Appleton | WI | USA | Posted: 2:22 PM on 01.25.07 |
| ->> Someone recently mentioned something to me about compressed RAW images. They are using Nikon. I have Canon. Do you guys know if you can shoot compressed RAW with Canon. If so, what are the biggest advantages and drawbacks compared to the largest jpegs. Thanks...Dan. |
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Howard Curtis Smith, Photographer
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Easton | PA | USA | Posted: 2:34 PM on 01.25.07 |
| ->> I am not positive, but I believe the RAWs that come out of Canon cameras are already compressed. |
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Greg Ferguson, Photographer
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Scottsdale | Az | USA | Posted: 7:29 PM on 01.25.07 |
->> Yes, they are compressed.
Uncompressed RAW or TIFF files are REALLY big and eat cards and drives.
Back when I shot with Nikon, the only real advantage I saw shooting non-compressed images was that the battery would last longer because the CPU wasn't having to do quite as much work. It'd dump the image to the card quickly and be ready to shoot again. With compression enabled it'd have to chew away at the file to shrink it down before writing it so the CPU couldn't sleep as soon.
It's much the same tradeoffs as shooting jpeg or RAW + jpeg thumbnails.
With the current batteries and faster CPUs in the current bodies the delay won't be as bad and the battery life won't suffer as much, but the CF cards will still show a big difference in how many images they can hold. It was pretty drastic when I was shooting with a D1x. |
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Dan Powers, Photographer
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Appleton | WI | USA | Posted: 10:11 PM on 01.25.07 |
| ->> So, can you choose compressed or uncompressed when shooting Canon RAW? And how much extra time does it take to tone RAW vs jpeg? I'm just wondering if our paper should consider shooting RAW instead of jpeg. Also, I have to think transmitting RAW images...especially via a Verizon card...would be a nightmare. Any thoughts? Thanks guys...Dan. |
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Ron Scheffler, Photographer
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Hamilton (Toronto area) | Ontario | Canada | Posted: 2:51 AM on 01.26.07 |
->> Dan:
(Sorry for the length of this post)
No, there is only one option with Canon RAW files, and that's as Howard and Greg mentioned - they are already compressed. But it's a lossless compression (no loss in image quality) which is different than lossy compression of jpegs.
Nikon is different in giving you both options for RAW. IMO, there isn't an image quality benefit to uncompressed RAW, especially for newspaper applications.
As for whether or not to shoot RAW for deadline... that is a more complex consideration. All I can suggest is you experiment with it.
When you work with jpegs, what do you do to them? Is it only caption, crop & transmit, or do you also mess around with them in Photoshop?
If you work on them in Photoshop, then you may find there isn't as much of a difference in working with RAW files. With RAW files, you work in a RAW converter that allows for general, global adjustments, so that once the file is processed, it's generally good enough that you don't need to do more work to it in Photoshop. Unless it needs specific dodging & burning, in other words, localized adjustments. In the RAW converter you can quickly apply any corrections from one file to as many others as you want. This could potentially save you a lot of time compared to working on a stack of individual jpeg files one by one in Photoshop. And some RAW converters are pretty slick, like Apple's Aperture. An advantage of RAW is the ability to easily tweak WB after the fact. Maybe not a big deal during an outdoor event, but under artificial lighting, it lets you judge WB on the computer rather than guessing at the look of shots on the camera's screen. There can also be some latitude in recovering blown highlights, within reason.... and also in digging out more shadow detail, again, within reason. As a Canon user, I find conversions from 1D Mark II N RAW files to be sharper (without any sharpening applied) than the camera produced jpegs, especially at higher ISOs. However, it could be debated whether that added sharpness would actually be visible on newsprint.
One easy summary is to think of RAW like working with a negative. You can go back to it and reprocess it in many different ways for different applications because most RAW converters give you a lot of options for adjusting the look of an image. For example Canon's converter (DPP), lets you adjust the Picture Styles, which is similar to back in the film days when you'd shoot Velvia for high saturation or EPR (Ektachrome 64) for low contrast, neutral color reproduction. RAW files contain a wider range of information than 8-bit jpegs, which allows you that post production flexibility and clean 8-bit output. With a jpeg, everything is locked in at 8-bit to start with, like WB, color style, exposure, saturation, etc. Once you start adjusting a jpeg, you are always degrading its quality.
Here's my take on RAW in deadline situations:
If you are shooting something like a sporting event, then shoot either only jpeg or RAW+jpeg. Download whenever you normally would but only caption & crop the jpegs and ftp them to the paper. If you use Photo Mechanic, it has an ingest option that allows you to download both RAW+jpeg or only one of the two. I find this extremely useful for deadline situations. I will shoot RAW+jpeg but during the event I'll set Photo Mechanic to only download jpegs, vastly speeding up how long it takes for images to get into the computer (which is another consideration - RAW files are much larger and therefore will take a lot longer to download). At some point after the event, I'll download the RAW files and pair them up with the Jpegs, using the IPTC update function in Photo Mechanic to transfer any captions from the jpegs to the RAW files.
The way I look at it is when you're out in the field, your primary responsibility is to get the shot and get it back to the paper as quickly as possible. Therefore, time spent tweaking shots in Photoshop is time taken away from transmitting more images or leaving earlier. Someone in prepress will worry about the nitty gritty reproduction issues.
But, if it's not a deadline situation and there is time to work on images, then by all means. From a prepress point of view, it is always nice to get good files (assuming the photographer knows what he/she is doing). Or, it's good to know that there is a RAW file in the archive to fall back on. If you're out on location with some time to work on the files, I would still convert the RAWs to jpeg for transmission to the paper.
Which leads to another issue: Archiving. How will RAW files be archived? Everything from the shoot, only the RAWs of the edit selects? Or none once final jpegs have been converted from the RAWs? Speaking from experience, there needs to be an understanding with your IT department that if RAW files are going to be archived, that storage demands will triple or quadruple. If that's not reasonable, then you'll be looking at editing the RAW files down to the bare minimum. Not really a big deal since you already edit each shoot anyway, but it may add a couple more steps in the process.
With all that said, and with all the potential benefits RAW can offer, newsprint is pretty forgiving of so-so quality jpegs, unless they are run really large. Having worked in newspaper prepress for years, I've seen a huge range of image quality ordered for publication and it is surprising how OK highly compressed wireservice jpegs can look. Sure, it's nice to get a big super clean file, but if it's only running two or three columns, it won't make a huge difference.
For me, shooting RAW is a matter of control over the interpretation of the look and how the image is processed. In that regard, it can be very useful. So in the end, it really depends on what you are expecting. Are there specific problems you're seeing now with jpegs?
BTW, if I'm ever in GB again for another game, I'll happily spend some time with you after the game to go over any of these issues, though that doesn't help much now...
These links are always good to review:
http://www.sportsshooter.com/news/1301
http://www.sportsshooter.com/news/1199
http://www.sportsshooter.com/news/1182
http://www.sportsshooter.com/news/1081
Vince Laforet discusses using Aperture:
http://www.sportsshooter.com/news/1569 |
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Greg Francis, Photographer
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Rochester | NY | USA | Posted: 9:53 AM on 01.26.07 |
->> Dan,
To give you an idea of the proportions, typical jpg is 2.5mb, typical RAW file (D2x), 11.3 mb.
I shot weddings and corporate work solely in jpg for 3.5 years, then got RAWshooter essentials in 2006. In addition to the ability to change WB, there is a larger latitude for exposure which would help with sports. Like shooting a game on a dark field and underexposing slightly in favor of a higher shutter speed, then adjusting the exposure and contrast in a RAW Converter. Once you prep an image in a RAW converter, you can save quickly as a jpg, in different qualities.
To add to Ron's comments, a good application for RAW is to shoot a game on deadline in RAW + Jpg, prep and transmit the jpg on deadline, then if the Packers make it to the playoffs for example, revisit the RAW file for placement in a broadsheet supplement leading to the playoffs. The RAW file once opened in PS is 60-70mb. |
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Jim Colburn, Photographer, Photo Editor
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Omaha | NE | USA | Posted: 12:46 PM on 01.26.07 |
->> RAW files are, sort of, kind of, LZW (non-lossy) compressed TIFF files with extra stuff in them so even tough they are "compressed" you don't loose any of the information if you uncompress one and then re-compress (save it as another RAW file) it.
If you save a TIFF file in Photoshop you get the option of LZW compression that will reduce the file size by, maybe, 50 percent or more, with no loss of information. It's sort of like the way a Zip file works, a smaller file but with all the info.
JPEG compression, on the other hand, throws away information every time you compress the file so if you did enough compress/decompress JPEG cycles you'd eventually wind up with a JPEG file containing one pixel... |
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Matthew Rosenberg, Photographer
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Charlottesville | VA | United States | Posted: 12:59 PM on 01.26.07 |
->> Just a piggybacked question here. Some people have mentioned so-called lossless JPEGs. I beleive they are talking about saving at level 12 in Photoshop. I was under the impression that any level of JPEG compression is lossy and results in an inferior file. (I am not debating whether that loss is apparent to the end user or not, just strictly the mathematics)
-Matt |
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Dan Powers, Photographer
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Appleton | WI | USA | Posted: 1:14 PM on 01.26.07 |
| ->> Wow...thanks a ton guys. This will give me something to chew on for awhile! I appreciate all of the information...Dan. |
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Bob Ford, Photographer
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Lehighton | Pa | USA | Posted: 1:26 PM on 01.26.07 |
| ->> Dan, I usually shoot RAW, and just convert the photos I'm going to send to jpegs. |
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Jim Colburn, Photographer, Photo Editor
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Omaha | NE | USA | Posted: 10:59 PM on 01.26.07 |
->> "I was under the impression that any level of JPEG compression is lossy"
JPEG is, by definition, is a "lossy" file format. Go for teh LZW TIFF if you need to save space. |
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Mike Braca, Photographer
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Providence | RI | USA | Posted: 1:15 AM on 01.27.07 |
| ->> "Lossless" JPEG usually refers to a file format introduced over 6 years ago as "JPEG 2000" which offers a true lossless compression mode. It is far superior to and intended as a replacement for ordinary JPEG, but it never caught on. Visit http://en.wikipedia.org/wiki/JPEG_2000 for gory details. |
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