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Thread: PS raw and Printing questions.

  1. #1

    Default PS raw and Printing questions.

    Hi guys.

    I am quite new at raw processing in photoshop. while i was playing around with the raw settings in the first window of PS, i noticed i can actually increase or decrease the resolution. why is it so? i thought the maximum resolution i can get should 6MP(my digi cam resolution)?

    secondly, i am sending some photos for priniting in S8R size. however, there's this particular photo that is only 2.7MP due to cropping. after reading some internet reccommendation tables, i noticed the closest 3MP is only fairly good on S8R. anyone printed 2.7MP photos on S8R before? i would like some first hand views as i had read enough "rough" tables the internet has given.

    thanks!

  2. #2
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    Default Re: PS raw and Printing questions.

    Quote Originally Posted by satay16 View Post
    Hi guys.

    I am quite new at raw processing in photoshop. while i was playing around with the raw settings in the first window of PS, i noticed i can actually increase or decrease the resolution. why is it so? i thought the maximum resolution i can get should 6MP(my digi cam resolution)?

    secondly, i am sending some photos for priniting in S8R size. however, there's this particular photo that is only 2.7MP due to cropping. after reading some internet reccommendation tables, i noticed the closest 3MP is only fairly good on S8R. anyone printed 2.7MP photos on S8R before? i would like some first hand views as i had read enough "rough" tables the internet has given.

    thanks!
    I think the different resolution just mean that during processing, the software will automatically resize it.
    as for 2.7MP, if your image are of high quality and sharp with loads of details, S8R shouldn't be that much of a problem.

  3. #3

    Default Re: PS raw and Printing questions.

    There is often the confusion in the word resolution. From wikipedia:

    "The term resolution is often used as a pixel count in digital imaging, even though American, Japanese, and international standards specify that it should not be so used, at least in the digital camera field."
    The amount of information in a digital image is measured by its pixel count, one meaning of "resolution", albeit not recommended.

    The other meaning of resolution is the ppi or pixels per inch. This I think is what you saw in Adobe RAW and it is something you can change. But you cannot increase the inherent information content in the picture.

    So if you have an image that is 3000 by 2000 pixels, and if you set the resolution to 200dpi, what it means is that the image will be sized as a 15 by 10 inch image to display its maximal content. If you set it to 300 dpi, then it will be sized as a 10 by 6.7 inch image.

    Of course you can set your resolution or ppi to 300 and yet resize your image to S8R which is about 12 by 8 inches, beyond the maximum 10 by 6.7 inches. All it means then is that Photoshop just interpolate between pixels to generate the missing pixels, using algorithms such as bicubic interpolation and others.

    I rather think, as recommended, picture content or information in pixel counts, eg 8MP, and think resolution only as something relevant only when you are talking about media or presentation of the picture information. Picture content is always constant, but you can show more or less of this in your specific display medium. As an analogy, a concept is language independent, only when you have to say the concept, then you need words which are not language independent. Resolution is something characteristic about a display medium and not about your picture.

    So for example I display images on the web at 72 dpi and at reduced sizes, but print them from 200 dpi upwards depending on the print size that I need.
    Last edited by espion; 6th March 2007 at 10:05 PM.

  4. #4

    Default Re: PS raw and Printing questions.

    so if lets say the photo shop prints my photos at 300dpi (is it? correct me if wrong or right), i can just set my pics to 300dpi, fit a 12 by 8 crop, and the print will turn out the same as one that is 100000dpi?

  5. #5

    Default Re: PS raw and Printing questions.

    Quote Originally Posted by satay16 View Post
    so if lets say the photo shop prints my photos at 300dpi (is it? correct me if wrong or right), i can just set my pics to 300dpi, fit a 12 by 8 crop, and the print will turn out the same as one that is 100000dpi?
    The answer must definitely be no, and do you see that you are using "resolution" in two different senses here.

  6. #6

    Default Re: PS raw and Printing questions.

    Quote Originally Posted by espion View Post
    The answer must definitely be no, and do you see that you are using "resolution" in two different senses here.
    hmmm, but i thought no matter what, if the printing dpi of my print shop is 300dpi, it doesn't matter what resolution the softcopy is as long as it is more than 300dpi right?

  7. #7

    Default Re: PS raw and Printing questions.

    Quote Originally Posted by satay16 View Post
    hmmm, but i thought no matter what, if the printing dpi of my print shop is 300dpi, it doesn't matter what resolution the softcopy is as long as it is more than 300dpi right?
    OK but you are yet talking about a different thing. You are saying that if the maximal resolution of your printer - at home or shop - is 300 dpi then it is OK if your source image is equal or more than that. Thats true. This is so as the printer will resample/downsample to 300 dpi, and anything more will be thrown away, the reverse of interpolation where artificial data is created.

    But that's not how you should think.

    Let's suppose you capture an image at 3000 by 2000 pixels, or 6MP, and you want to print up to S8R which is 12 by 8 and your printer highest resolution is 300 dpi.

    So to print all the data in S8R you need only 250 dpi. Anything more will be fictitious data, created by interpolation, ie to print S8R at 300 dpi, your image have to be 3600 by 2400 pixels. The additional pixels need to be algorithmically inserted into the picture.

    (But interpolation is essential in digital photography. Artificial data is generated in the very sensor itself. So what is reality then?)

    If you however do not want such "artificial" data then the max you can go at 300 dpi is 10 by 6.7 inch, or if you still want S8R, then your initial image must be captured at anything above 8MP.

  8. #8

    Default Re: PS raw and Printing questions.

    Quote Originally Posted by espion View Post
    OK but you are yet talking about a different thing. You are saying that if the maximal resolution of your printer - at home or shop - is 300 dpi then it is OK if your source image is equal or more than that. Thats true. This is so as the printer will resample/downsample to 300 dpi, and anything more will be thrown away, the reverse of interpolation where artificial data is created.

    But that's not how you should think.

    Let's suppose you capture an image at 3000 by 2000 pixels, or 6MP, and you want to print up to S8R which is 12 by 8 and your printer highest resolution is 300 dpi.

    So to print all the data in S8R you need only 250 dpi. Anything more will be fictitious data, created by interpolation, ie to print S8R at 300 dpi, your image have to be 3600 by 2400 pixels. The additional pixels need to be algorithmically inserted into the picture.

    (But interpolation is essential in digital photography. Artificial data is generated in the very sensor itself. So what is reality then?)

    If you however do not want such "artificial" data then the max you can go at 300 dpi is 10 by 6.7 inch, or if you still want S8R, then your initial image must be captured at anything above 8MP.

    WOAH.... my cam only got 6.1MP . guess i have to step down the print size then.

    thanks for the long post btw.

  9. #9

    Default Re: PS raw and Printing questions.

    another question:

    i stumbled across this table. it says that the best S8R print only needs 4MP and above. why is it so? i thought to have the full non-interpolated print, it should need 8MP?

  10. #10

    Default Re: PS raw and Printing questions.

    Quote Originally Posted by satay16 View Post
    WOAH.... my cam only got 6.1MP . guess i have to step down the print size then.
    Not necessarily. You can still interpolate and depending on the picture and the original quality may still be good. In a sense everything is "artificial" even what your eye apparently sees, so its OK to insert a few thousand more such pixels in a picture. Alternatively you can still print at S8R at 250dpi instead. Pics can still look good at 200 dpi.

  11. #11

    Default Re: PS raw and Printing questions.

    Quote Originally Posted by satay16 View Post
    another question:

    i stumbled across this table. it says that the best S8R print only needs 4MP and above. why is it so? i thought to have the full non-interpolated print, it should need 8MP?
    So it means that you dont need 300 dpi for a good picture. For 200 dpi you need only 2400 by 1600 which is about 3.8MP. I think that is how 4MP is arrived at.

  12. #12

    Default Re: PS raw and Printing questions.

    Quote Originally Posted by espion View Post
    So it means that you dont need 300 dpi for a good picture. For 200 dpi you need only 2400 by 1600 which is about 3.8MP. I think that is how 4MP is arrived at.
    ohhh.....................i see. btw, normal printing shop, how many dpi do they use?

  13. #13

    Default Re: PS raw and Printing questions.

    ask them

  14. #14

    Default Re: PS raw and Printing questions.

    Quote Originally Posted by espion View Post
    ask them
    kk.

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