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#1 OFFLINE   Ralph2

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Posted 04 April 2003 - 12:36 AM

HelloSoon to enter the world of digital cameras. Have shortlisted to a Canon A70, but in looking at the specs note that the only format the camera will save in is JPG. So, how important is this? JPG is considered a lossy compression, so right off the bat am I loosing quality? :D I "think" it is important to have the option to save in a raw or TIFF mode but ...... Anyone with any opinions / advice? ThanksRalph :D

#2 OFFLINE   eksimba

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Posted 04 April 2003 - 11:55 AM

Do you think you'll ever use the tiff format? If not, it's no big deal. I've been using a 3megapixel camera as my main source of personal snapshots for quite a while now, and I've never needed anything other than the standard jpg it provides, even though I can take pictures in raw format if I'd like.I find that even for printing decent sized snapshops (4" x 6", maybe even 8" x 10") the jpg format works great.-eric

#3 OFFLINE   carlcroom

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Posted 04 April 2003 - 12:44 PM

Hi Ralph2I  started  the digital division of a large  professional photo lab in Memphis a few years ago. Growing with digital through the last couple of years, we get this same question from a lot of our customers.From our experience, camera resolution and the image processing algorithms  used are far more important than whether the file is saved as a JPG or RAW or TIF. Part of the confusion comes from calling JPG a lossy format.  It does lose picture information. However, it loses information  ONLY when changes are made to the file then saved again as a JPG. The situation is similar to making photocopies. If you take a high quality original and copy it , the copy never looks quite as sharp and crisp as the original. But as long as you use the original to copy from, all the copies will be identical.IF, however, you copy one of the copies, those copies look much, much worse.The same process works with digital images saved as JPG. You take a picture with your digital camera  and it saves it as a JPG. You then transfer the JPG to your hard drive by dragging it from the camera folder  to your computer. The JPG that resides on your hard drive is EXACTLY the original image. It is a bit for bit copy of the file.  Bit for bit copying will never result in reduced image quality.If you use Photoshop or other program  to open the JPG from your camera , then save the image to your hard drive , you have now made a copy of a copy. Why? Because, the JPG format  is a lossy format  that compresses files by removing ( reducing ) information.  By doing the FILE - SAVE  from within a program , you have compressed an already compressed file.As an aside, if you open the JPG in Photoshop or whatever, print it on your inkjet, then CLOSE ( not SAVE ) the image, you have done nothing to the original file.Lastly, if you have images that you know that you will do correction work on , open the JPG in something like Photoshop and SAVE a copy as a TIF. Do all your corrections on this TIF and leave the original JPG untouched.Sorry this was so wordy, but I hope I answered your concerns.BTW, the Canon cameras take excellent pix. Likewise the Olympus 4000 & 5000 series.For more professionally geared photographers, the Olympus e-20 and Fuji S-1 / S-2  are unbeatable for picture quality.

#4 OFFLINE   Ralph2

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Posted 04 April 2003 - 01:52 PM

Thank you Eric, I am not sure...... but would prefer to buy a camara that did not limit my options.Thank you Carl, Your wordy explanation was exactly what I wanted to hear. Your comparison of photocopies makes a lot of sense. Will check out the specs of the two you mentioned as well. At this point of my "expertise" I am giving too much weight to the cosmetics of the camera and appreciate your recomendationsBest regardsRalph

#5 OFFLINE   zox

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Posted 04 April 2003 - 01:56 PM

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Part of the confusion comes from calling JPG a lossy format. It does lose picture information. However, it loses information ONLY when changes are made to the file then saved again as a JPG.
I disagree since even if it is the first time, you loose some information.JPEG is lossy image file format, period.More you resave it as JPEG, more you loose every time.IMHO RAW is much better.Saving RAW gives you solid original base and you avoid camera processing of image.If you really care about final result, camera can not match software for image processing on computer.If you don't care that much, JPEG will be fine as long as you don't resave it again and again as carlcroom pointed.

#6 OFFLINE   eksimba

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Posted 04 April 2003 - 02:52 PM

zox, on Apr 4 2003, 10:56 AM, said:

I disagree since even if it is the first time, you loose some information.JPEG is lossy image file format, period.More you resave it as JPEG, more you loose every time.IMHO RAW is much better.Saving RAW gives you solid original base and you avoid camera processing of image.If you really care about final result, camera can not match software for image processing on computer.If you don't care that much, JPEG will be fine as long as you don't resave it again and again as carlcroom pointed.
This is true. Even the original JPEG will have lost image data as compared to an original RAW image. However, to the naked eye, the original JPEG is almost exactly the same quality as the original RAW image. I think JPEG only works perfectly fine, as long as you always keep the original untouched JPEG around just in case you want to edit the image again. It's not so good to edit a previously edited JPEG, because you will continue to lose image quality with each iteration.

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IMHO RAW is much better.
Better for what? Printing high-quality prints? Yes. Web pages? No way. Email? No. Storage space? Nope. Professional portfolio? Absolutely.All things considered, there are a few special circumstances which may lead you to choosing a camera which allows you to save in RAW format. For all other uses (which for me comprise 99%), JPEGs of a high enough resolution (3 MegaPixel minimum) are perfectly good.- eric

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Posted 04 April 2003 - 02:55 PM

In my personal opinion, JPEG is not the future.. JPEG2 is not the future either.. GIFF is out of question... But PNG has a great potentials...Be prepared that in the next generaton of Windows, PNG will play an important role in there  :)

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Posted 04 April 2003 - 02:56 PM

zox, on Apr 4 2003, 12:56 PM, said:

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Part of the confusion comes from calling JPG a lossy format. It does lose picture information. However, it loses information ONLY when changes are made to the file then saved again as a JPG.
I disagree since even if it is the first time, you loose some information.JPEG is lossy image file format, period.More you resave it as JPEG, more you loose every time.IMHO RAW is much better.Saving RAW gives you solid original base and you avoid camera processing of image.If you really care about final result, camera can not match software for image processing on computer.If you don't care that much, JPEG will be fine as long as you don't resave it again and again as carlcroom pointed.
raw is a bad choice because it takes too much memory. Anything that can be compressed to save space is good choice.

#9 OFFLINE   teacher

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Posted 04 April 2003 - 11:06 PM

Oh me, oh my..... such opinions.  I always explained to my students that if you saved a lot you needed to switch out of jpeg.  My antique digital camera (oh it is three or four years old) saves them in jpeg that are large enough I can change to Tiff for paper copies, etc. and go back to jpeg for the final copy for web or computer.  I would be more concerned about what software I had to edit the photos and the options it gives.  I know Photoshop (my favorite) lets me change sizes and do so many things like editing balances to get more out of my photos.  I would also be more concenered about what it uses for a disk.  I don't care for ones that use floppy disks (do they still exist) because that limits too much.  I have a ton of scandisks and I keep a reader hooked to my computer so I can pop them in and out.  It is handy to have extras, particularly when traveling overseas or away from home.Now if I just had a decent digital camera that would let me crop pictures and then save them to film (read this as an art major somewhere in the family) or slide without costing an arm and leg to convert--all of this, of course, before I ever save it anywhere. I can dream can't I?
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#10 OFFLINE   zox

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Posted 05 April 2003 - 12:03 AM

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raw is a bad choice because it takes too much memory. Anything that can be compressed to save space is good choice.
True only if you are concerned with how many images you can fit onto media, but if the quality is you are after then it doesn't matter as long as you have high quality, right?To be honest with you, I am using JPEG from my digital camera most of the time and I am satisfied. Only couple of times have I used RAW file format and it was mostly for testing, and yes there is a difference on high end devices (printers).

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In my personal opinion, JPEG is not the future.. JPEG2 is not the future either.. GIFF is out of question... But PNG has a great potentials...Be prepared that in the next generaton of Windows, PNG will play an important role in there
It was about time someone started noticing PNG.It has been around since 1995 and been endorsed from W3C from 1996 as standard for web.I would just point out that these image file formats do not directly compete, but complement each other.They are all part of present and future and I don't think you can single one to be future because of aforementioned reason.They are different with different targets and capabillities.

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Now if I just had a decent digital camera that would let me crop pictures and then save them to film (read this as an art major somewhere in the family) or slide without costing an arm and leg to convert--all of this, of course, before I ever save it anywhere.I can dream can't I?
Yes you can dream indeed, but again, to be honest I am soo happy that we are finally getting rid of film :unsure:.




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