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Old Mar 26, 2005, 5:31 AM   #1
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Hi,

Most cameras (that are not that expensive) only deliver pictures in jpeg, and I wonder how that affects what I can do with the photos in the end?

Since I want to be able to resize and also do some other editing in Photoshop I wonder if I "need" a camera that also can manage formats like tiff or raw?

I know that jpeg is a format that uses a destroying compression algorithm and that tiff preserves image quality better, but how important is it...or rather "when" does it matter? Please explain for me.

Best regards
/Anna
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Old Mar 26, 2005, 7:23 AM   #2
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It depends on the kind of work you want to do. If you're only wanting to make generally good photos with least amount of sweat, use your camera's top JPEG mode. You will still be able to engage in a certain degree of post-production tweaking in Photoshop, Paintshop Pro or other software, but what you can do is relatively limited.
If you enjoy the digital darkroom, however, and want to be able to have ultimate control over your image, use RAW.

No one, though, can give you a complete answer in the space of a forum like this, so you might want to read a few basic articles about what's involved. Here are some starters:

http://www.luminous-landscape.com/tu...aw-files.shtml
http://www.luminous-landscape.com/es...awtruth1.shtml
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Old Mar 26, 2005, 9:15 AM   #3
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A lot depends on the camera's best compression. Cameras with a true SHQ JPG can be worked with as well as TIFF and I defy anyone to tell the difference. I've downloaded true SHQ images and recompressed them 20 times in Photoshop at best quality – and yes I was careful to not just be compressing the original 20 times. Starting with a true SHQ and decompressing and recompressing 20 times still wasn't producing artifacts.

TIFF is a useless mode for a digital camera to output in IMO. I always save after editing in either TIFF or PSD, but that is dealing with a fast processor, gobs of RAM and a large fast HD.

Some cameras don't have a true SHQ or even a high quality JPG. Someone on another thread was complaining that his Kodak was taking shots as low as 700k in 5Mp best quality. Looking at Steve's samples the best quality 5Mp images were averaging just over 1 Mb. That isn't too good and there is nothing you can do to improve it. Fuji is as bad with their super CCDs unless you interpolate up to a ridiculous large image.

There are a lot of advantages to RAW and you can't go wrong working in raw if your camera buffers it properly. But if your camera is putting out a high quality JPG you are going to be able to work with the image without problem – just save it in an uncompressed format after you alter it unless you are saving for the web.


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Old Mar 26, 2005, 6:32 PM   #4
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Years ago, I remember a similar discussion about the differences between TIF and JPEG. The result was the there was really little or no difference between a first JEPG save and a TIFF. Someone took a JPEG and an identical TIFF and split them apart and made a third shot..half JPEG and half TIFF but no one could tell which was which.

The major advantage of TIFF is that as an uncompressed format it will survive an edit/save cycle better than a JPEG but, of course you can take a JPEG directly from the camera and save a TIFF.

I have never found a use for RAW format..but then I have only been using digital since 1998!
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Old Mar 26, 2005, 10:04 PM   #5
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RAW is the most useful of all three file types, at least in terms of versatility. This is the absolute closest thing you can get to (film negatives)with a digital camera. RAW is an image format that takes the data directly from the sensor and compresses it in a lossless manner. This makes things much nicer if you need to adjust white balance, etc after the shot has been taken.

JPEG is a nice quick format to work with, and typically takes up significantly less storage space than a RAW file will. I rarely ever shoot in JPEG (even highest quality JPEG) just due to the fact that it's still compressed, and if you want to play with it much in the computer in post processing, it won't respond as well since it's dropped some data in the compression process.

TIFF is basically worthless, since it produces a huge file (bigger than a RAW file), and tends to take forever for most cameras to process. Once on the computer it's handy to save things as after editing, etc, but I don't think it's worth the time it takes to capture a photograph with it, especially when RAW is more versatile and offers smaller file sizes than the TIFF.

As to whether you "need" to be able to use a certain file type to get the results you want, unfortunately that is a question you need to answer for yourself. It's one of those things you discover very quickly if you're unable to achieve the effect you want with the file type you're using. I'm sure most people are happy with JPEGS taken at high quality, but I like the extra measure of insurance I get when using RAW (or even RAW + JPEG if your camera happens to support it). RAW's can be processed a little more before image quality becomes unacceptable, whereas if you start to tweak a JPEG file too much it degrades quickly due to the lossy compression... This of course is simply my opinion and doesn't necessarily represent the opinion of anyone else living, dead or inbetween.
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Old Mar 26, 2005, 10:57 PM   #6
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For those of you that are not aware of it, Mike Chaneywrites a monthly article that you can find under the Tech Corner menu choiceon this site's main page.

The October 2004 article was titled JPEG Images: Counting Your Losses

Mike included samples of what happens (and doesn't happen) to JPEG images that have been resaved at different quality levels, and discusses file types and image compression.

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Old Mar 27, 2005, 2:02 AM   #7
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Ok, thanks for explaining. Concluding from your answers Raw seems to be the best format if I want to be able edit the photos a little bit more. But how come there are so few cameras supporting Raw´s, at least among those ones that are not to expensive (app. < $450)? Does anyone know some camera that are not that expensiveand supports both raw and jpeg?




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Old Mar 27, 2005, 7:54 AM   #8
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serrander wrote:
Quote:
Ok, thanks for explaining. Concluding from your answers Raw seems to be the best format if I want to be able edit the photos a little bit more. But how come there are so few cameras supporting Raw´s, at least among those ones that are not to expensive (app. < $450)? Does anyone know some camera that are not that expensiveand supports both raw and jpeg?

When you think about it, all digital cameras have a stage of image processing that contains a RAW image. It's just being processed, then converted to JPEG before being written to the memory card.

In fact, users have discovered "hidden" RAW modes in some entry level models from Nikon, Casio, Konica-Minolta, and others.

I have a little Konica KD-510z with a hidden RAW mode. Heck, it even has hidden modes for things like focus bracketing. ;-)

Do I useit's RAW mode Very, veryrarely! Why not? Speed of operation, limited benefits to RAW, post processing requirements, memory card space.

For one thing, most consumer models have a very limited buffer size (RAM to store images being written to the memory card). Processors in the camera and the speed of writes to the media also tend to be much slower than in DSLR models.

So, with my Konica, if I take a photo in the hidden RAW mode, I have to wait on the camera to flush the image tomedia (which takesabout 4 times as long as a JPEG file would take). The camera is not usable during this time, since there is little to no buffer space, and the camera is not designed to allow both camera operation and writes to the media concurrently.

I have spent alot of time exploring the benefits of RAW with this model, and concluded that it's just not worth the effort for me to use it.

Since this camera's image processing algorithms are very good, I have to spend a considerable amount of time to get the images looking anywhere near as good as the JPEG Files, using more than one software tool. My initial conclusion (with LOTS of test images)was that it was only useful (to me), if I was in a high contrast lighting situation where I mayoverexpose highlights (which is something I try to avoid to begin with). I did not find white balance to be an issue (in fact, I found it more difficult to get accurate white balance shooting in RAW, versus correcting the JPEG images when necessary with my camera model).

Also, keep in mind that RAW is not a standard. It's proprietary to a manufacturer. So, you have to find a tool to convert the RAW files into other usable image formats. There are a number of such tools on the market. But, most third party tools are a result of reverse engineeering the proprietary RAW formats, and the results you get can vary considerably.

Now, I'm speculating here... But, I think a big part of the problem (lack of RAW support in entry level models) iscost related.

I can imagine the phone calls and complaints to a manufacturer's customer service department wanting to know why their camera was so slow shooting in RAW, not to mention the software support needed for RAW conversion utilities. So, this is going to increase a manufacturer's cost.

Now, technology is advancing, with faster processors, more buffer space, faster interfaces to media, etc., in lower priced cameras. But, because the RAW files must be converted to a standard format for things like display and printing, most consumers probablywouldn't want to bother with it. So, why would a manufacturer want to increase their costs to add it (or unlock it), if their is no demand in entry level models?

To answer your question... yes, you can find lower priced models with RAW modes (not necessarily supported by the manufacturer, though). Dave Coffin (the author of dcraw) has a list of models with RAW ability on his web page at http://www.cybercom.net/~dcoffin/dcraw/

Many commercial software packages with RAW support are based (at least in part) on Dave Coffin's work.

Some of the lower priced Fuji and Canon models have RAW modes that are actually supported by their manufacturers.

But, I'd make sure to investigate things like speed of operation before going this route. ;-) Unless you're shooting still life or landscapes, you may find that it's more trouble than it's worth (since most entry models don't have very fast cycle times shooting in RAW, and/or they are unable to buffer multiple RAW images).

I don't know which models under $450.00 have anything close to acceptable performance shooting RAW (of course, what is acceptable depends on the conditions you're shooting in).... But, for most uses, I suspect that one with acceptable performance in this price range would be difficult to find -- for now.

Added:

Looking through current pricing, it appears that some of the Canon models may warrant investigation. For example, the new S70 can apparently buffer 5 RAW images, and I'm seeing vendors like B&H selling it for under $450.00 now. You may also want to take a look a some of the Fuji models. However, you may need to go with third party software to get acceptable results (as many users seem to find the manfacturer supplied RAW conversion software to be lacking).


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Old Mar 27, 2005, 11:05 AM   #9
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IMO raw is heads and shoulders above any other format if you are serious about post-processing. I would shoot only in raw with a camera that properly buffers raw shots so you don't miss shots waiting for the write. And that is Catch 22 for cheap cameras as JimC pointed out. My 3 year old Minolta D7i requires a 10 second wait before you can take another shot if you shoot raw. I found I missed so many shots waiting for the write that I use raw only in static situations. Had I waited for the 7Hi I could shoot mostly in raw because they added a decent buffer.

It is possible to put decent buffers in relatively small cameras. The Oly C60 will actually buffer 6Mp TIFF files, which is incredible. After 3 shots you have to wait the full 30 seconds per shot, so there are limits. But they left the great buffer off of the 7Mp C7000, which has raw mode. Without the buffer raw is of limited utility. Everything seems to be a compromise when companies cut corners to keep the prices low. I would have bought a C7000 had they kept the buffer from the C60, but I guess their marketing research felt people like me are rare enough that it wasn't worth the cost.

But with a decent buffer raw is great. Some advantages:

Most higher end cameras process internally at 12 bits and sometimes 14 bits. If the camera writes to TIFF or JPG it reduces that to 8 bits. You can extract a 16 bit file from raw that preserves the extra bit depth. Now that Photoshop works better with 16 bit, most pros are working in the higher bit depth.

You can adjust things like sharpening, saturation, contrast and white balance in the software just as if you were adjusting it in the camera. So when you are shooting you need concern yourself only with proper composition, focus and exposure. All of the other modes are really null – the raw image comes out the same regardless of those settings. The settings just tell the camera how to convert to a JPG or TIFF. You have finer adjustments plus time and a large sharp screen to get the image just right. It is silly to be messing with white balance while you are shooting when you can get it exactly right in the software.

It isn't the same as adjusting a TIFF or JPG in an image editor. Contrast reduces your dynamic range. Setting any contrast moves the white and black points toward each other. When the camera writes to TIFF or JPG everything outside those points is lost. Many cameras do a touch of contrast even at the lowest settings.

Sharpening adds artifacts. Those artifacts are sometimes compounded in post processing, so the pro's advice is to always sharpen last. Even the lowest setting in most cameras give a little sharpening, which you don't want.

I always shoot flat with minimum sharpening and contrast with all of my cameras. I have a Photoshop action to bring them up to decent viewing and run it in batch, also keeping the originals for any post processing I have to do. So it isn't that much hassle to run a similar batch for raw. It just takes longer.

The only downside I see to raw in a camera with a decent buffer is that you need a fast processor and plenty of RAM or the conversion is like watching the grass grow.

Imaging Resource has a page like this for every camera they test. If you are interested in raw it is worth checking the cycle times to make sure they are buffered properly. This is an example of a current camera with a poor buffer that would limit use of raw: http://www.imaging-resource.com/PRODS/CP8800/CP88A7.HTM

My little S4 has a hidden raw mode. As much as I like raw I haven't even bothered to set it up. Cycle times and limitations make it not worth the effort, although some people do it.


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Old Apr 11, 2005, 11:21 AM   #10
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Quote:

Also, keep in mind that RAW is not a standard. It's proprietary to a manufacturer. So, you have to find a tool to convert the RAW files into other usable image formats. There are a number of such tools on the market. But, most third party tools are a result of reverse engineeering the proprietary RAW formats, and the results you get can vary considerably.

What's the results like with Adobe's new DNG format?
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