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Thread: Raw to JPG

  1. #1
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    Raw to JPG

    This is my first time posting I do not know if this is the right place for this question.
    I just started shooting in Raw. When I process a photo in PPE8 I then save it as a JPG it is smaller in size example from raw at say 5GB it save it to JPG 975KB. Is this the way it is supposed to size the photo?

  2. #2

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    Re: Raw to JPG

    Yep JPG is a compressed file format and its size will depend on the compression (or quality) that you save it in, always smaller than the RAW file you started with. Your RAW files are usually 12 bit giving you a possible range of 4000 shades per channel of red, green and blue. JPG files are 8 bit giving you a possible range of 250 shades per channel so converting to JPG can be a bit of a compromise and some information may be lost or re-interpreted so yes they're smaller. Start 'messing' with a JPG in PPE or Photoshop and you'll find that images start to posterize (loose their smooth tonal ranges) pretty quickly. JPGs are one of a few image file formats and are universally used by web browsers and simple image viewers, not many programs apart from image processors can display a RAW file.
    Also apply edits to a RAW file and you won't change it (you will change another file associated with it which contains the processes you went through to edit it) this is a good thing as your RAW file is essentially your 'negative'. Apply edits to a JPG and you will change the file itself and the possibility exists that each time you edit a JPG it will degrade as it is compressed using this lossy algorithm (you loose data which is not a good thing). Try saving a JPG at quality 2 or 3 and comparing it with the same image compressed at quality 12 (highest quality and largest file size) and you'll get what I mean and be thankful that you still have your RAW file.
    Other image formats to work with include TIFF which don't use 'lossy' compression and can be edited without loss of data and are also significantly less prone to posterization, they are a larger file size but a lot of programs (not the web) recognise them and if your image processing software can work in 16 bit (JPGs are only 8 bit and contain a fraction of the tonality) they are a good way to go for image processing because of the greater range of tonality that you can preserve.
    I convert RAW to DNG (Adobe digital negative) for various reasons and convert to TIFF for processing and printing. If I post to the web or email a photo I convert to JPG, that's about the only thing I use them for.
    Good luck with RAW you'll find you can do so much more with or to your photos.

  3. #3

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    Re: Raw to JPG

    I can't really add anything to Paul's comprehensive answer.

    The only other suggestion I could make about file formats is that if you are short on space, you could try one of the alternative formats which partially compress an image without any loss of data. Such as PNG which is widely used nowadays; or a compressed Tiff, but some software will not recognise these.

    However, if space isn't a problem, use Tiff or one of the other non compressed formats.

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    Re: Raw to JPG

    Hi Leona,

    Welcome to CiC - it's great to have you with us

    Not a lot to add to the above except to say that JPEGs are designed to be small so that they download and display faster on the internet.

    In the world of photography, you'll want to keep 3 copies of each file ...

    1. The original RAW file (or a DNG equivalent)

    2. A full resolution version, saved will lossless compression (eg PSD for Photoshop, or TIFF from other programs), and

    3. A down-sampled JPEG version, for uploading to online photo albums etc.

    Does this help?

  5. #5
    rob marshall

    Re: Raw to JPG

    Quote Originally Posted by leona View Post
    This is my first time posting I do not know if this is the right place for this question.
    I just started shooting in Raw. When I process a photo in PPE8 I then save it as a JPG it is smaller in size example from raw at say 5GB it save it to JPG 975KB. Is this the way it is supposed to size the photo?
    Hi Leona

    A RAW file is normally about 10-20MB, not GB (a MB is a million bytes, a gigabyte is a billion bytes). keep your RAW files, but only the ones that are good shots and you may want again. The output file really ought to be a TIFF or PSD file from Photoshop to avoid too much data quality loss which you get when you save to JPEG. Your TIFF/PSD will be about 5-25MB depending on the camera used, the amount of cropping, how much colour detail is in the shot, and various other things.

  6. #6
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    Re: Raw to JPG

    Just want to thank everyone, and to say the replies have been very helpful. My camera is a Canon 50D. I haven't posted any photos as yet as I need to practice much more to take as nice a photo as I have seen on this site.

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    Re: Raw to JPG

    In many ways, Leona, it is the imperfect photos which are the most interesting.

    Advice on improvements to shooting settings or alternative editing techniques always receives sympathetic responses and is often able to help many other struggling photographers.

  8. #8
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    Re: Raw to JPG

    Great comment. I am a total newbie, haven't a clue on what RAW files are.
    Now I know what you have written up.

    I have only freebie download software, Ifranview, and Photoscape.

    What would I use to edit RAW files.

    Camera: Nikon D70s

  9. #9
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    Re: Raw to JPG

    A good freebie download for RAW processing is Rawtherapee - rawtherapee.com

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    Re: Raw to JPG

    Quote Originally Posted by rob marshall View Post
    keep your RAW files, but only the ones that are good shots and you may want again.
    I'd suggest "being careful" with doing that, until one has the experience to judge what really is a clunker. RAW files contain a LOT of safety margin - so much so that a shot that one may initially discard as for example being "too dark" or "wrong colour" may well be something that can be recovered once ones RAW conversion skills improve.

    Personally, I convert my RAW files to the DNG format and keep pretty much all of them and over the years they're still fitting in around 1/2TB.

  11. #11
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    Re: Raw to JPG

    Quote Originally Posted by Colin Southern View Post
    Hi Leona,

    Welcome to CiC - it's great to have you with us

    Not a lot to add to the above except to say that JPEGs are designed to be small so that they download and display faster on the internet.

    In the world of photography, you'll want to keep 3 copies of each file ...

    1. The original RAW file (or a DNG equivalent)

    2. A full resolution version, saved will lossless compression (eg PSD for Photoshop, or TIFF from other programs), and

    3. A down-sampled JPEG version, for uploading to online photo albums etc.

    Does this help?
    Dear Colin,

    I have been doing the same PNG, PSD, JPEG (1-7 MB) and a JPEG for the web (aroung 200KB). I am about
    to start printing as a next step for the first time. What would be your workflow from then on eg psd to
    print? or JPEG to print?? Ive been told by my printer she wants files in JPEG not PSD at 300dpi. Does that
    mean I am losing info quality in the process??

    Thanks

    Nasseem

  12. #12
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    Re: Raw to JPG

    Dear Leona,

    I also use a 50D. First of all welcome to CIC. I have only been active since January this year really so I
    know what you are going through. Just a few points to remember:

    1. Try and shoot with RAW (15MB) not RAW 1 (7MB) or RAW 2 (5 MB) so your images can be post
    processed a lot more and in RAW without loss of information (a lossless form of editing).

    2. Your JPEGS will now be larger than 975KB but anything up to 5-7MB? These are reasonably sized photos and when converted to 300dpi are large enough for good quality prints up to 8x12 inches. Thats what I am experiencing at present. In fact I am going to print some photos in the next few days for my first paying customer. I hope I dont disappoint. Ill let you know if that does not prove to be right.

    I hope that Colin or Dave or Rob would correct me if I am wrong. Good shooting remember the
    more you click that button the faster you will learn and soon you will be teaching the new CIC generation RAW.

    Nasseem

  13. #13

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    Re: Raw to JPG

    Quote Originally Posted by maloufn View Post
    I hope that Colin or Dave or Rob would correct me if I am wrong.
    You're wrong!

    (Just kidding - I love saying that )

    Seiously, forget this mythical "300dpi". At the end of the day, the file you have in your hand will be "X" number of pixels wide and "Y" number of pixels high. When you divide the width and height of the image your intending to print into these pixel dimensions, you come out with a "figure" that may be close to 300 - or it may be close to 700 - or it may be close to 100; it's really just an indication of what the quality is likely to be.

    If you go below 100 then the loss of detail will start to become obvious if you look closely. Above 180 then generally it'll look pretty good. The difference between 180 and 300 is "difficult" to detect ... I'm not saying it can't be seen, but most people wouldn't notice it unless they were looking for it.

    The reason I say "forget about it" is that generally there's very little you can do about it - if you need to make a very large print and the resolution ends up being 75 ppi, then there's nothing you can do to get it any higher - so "75 it is". If it ends up being a lot more than 300 you could down-sample the image, but why bother? So in reality "it is what it is".

    The single most important thing to remember though is to CONVERT YOUR IMAGES TO sRGB BEFORE GETTING THEM PRINTED. In Photoshop simply click Image -> Mode -> Convert to profile (not assign profile), and make sure that the destination profile is set to sRGB (or sRGB and a whole bunch of numbers).

    Hope this helps

    PS: I might add that we're talking ppi here, not dpi (people often get the two confused). Most printers print at a fixed dpi (mine is 1280) ... the printer driver will up-sample the image to what it needs automatically.

  14. #14
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    Re: Raw to JPG

    So Colin are you saying 100 dpi or more is fine?

    Thanks for reminding me about sRGB before printing. I must check my photos to be printed.

    THanks Nasseem

  15. #15
    rob marshall

    Re: Raw to JPG

    Quote Originally Posted by Colin Southern View Post
    The single most important thing to remember though is to CONVERT YOUR IMAGES TO sRGB BEFORE GETTING THEM PRINTED. In Photoshop simply click Image -> Mode -> Convert to profile (not assign profile), and make sure that the destination profile is set to sRGB (or sRGB and a whole bunch of numbers).
    here's what Ken has to say about it... http://www.kenrockwell.com/tech/adobe-rgb.htm

    I keep forgetting to do that. I don't have that option, Colin. This is what I get in CS5

    Raw to JPG

    I have to go to EDIT/ASSIGN PROFILE. Like this.

    Raw to JPG

  16. #16

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    Re: Raw to JPG

    Quote Originally Posted by maloufn View Post
    So Colin are you saying 100 dpi or more is fine?

    Thanks for reminding me about sRGB before printing. I must check my photos to be printed.

    THanks Nasseem
    Yes - and no (just to be confusing).

    Generally, the bigger the photo, the greater the viewing distance - and the greater the viewing distance, the less our eyes can resolve. So if you print something at 100 ppi (ppi, not dpi) then it might be 3 feet wide and 2 feet high - so you'd probably view it from about 5 feet back - at which 100ppi would look fine. On the other hand, if you crop the living daylights out of a shot so it's 100ppi but only 6 inches by 4 inches then you'd naturally hold it a lot closer and 100 is a little borderline.

    The texture that you're printing onto also makes a difference; canvas (which I print onto a lot) is quite coarse, so I can get away with lower ppi settings.

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    Re: Raw to JPG

    Quote Originally Posted by rob marshall View Post
    I have to go to EDIT/ASSIGN PROFILE. Like this.
    Sorry Rob - temp insanity at my end -- Edit -> Convert to profile is what I meant (NOT assign profile though - that'll muck things up).

  18. #18
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    Re: Raw to JPG

    I thought it was all clear. Now you have introduced a few more variables (viewing distance and paper/ texture you are printing on) to think about.

    No wonder I have black circles under my eyes!!!

    Thanks Colin

  19. #19
    rob marshall

    Re: Raw to JPG

    Quote Originally Posted by Colin Southern View Post
    Sorry Rob - temp insanity at my end -- Edit -> Convert to profile is what I meant (NOT assign profile though - that'll muck things up).
    Colin

    When I print I get this panel

    Raw to JPG

    The pull down for profiles includes sRGB as you can see, but I normally use the one near the bottom which is my personalized profile from Permajet (the one that was created from a spectromized print) Surely that equates to sRGB?

    Also, if you do it this way (at print time) does it leave the embedded profile as it is in the file in case you need it for other purposes?

    Raw to JPG

  20. #20

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    Re: Raw to JPG

    Quote Originally Posted by rob marshall View Post
    When I print I get this panel
    Hi Rob,

    That works OK for those of us who do our own printing, but off the street print shops can invariably only handle sRGB. So if you leave a lovely portrait set to ProPhoto, it doesn't get the benefit of the Rob or Colin custom profile - it just gets treated as sRGB with terrible results.

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