Is this expected in enlarging?

Discussion in 'Digital Photography' started by Rudy Marcelletti, K8SWD, Aug 25, 2003.

  1. I took a couple of images on a 3.2 mp camera (Minolta Xt) at the highest
    quality setting (fine) and the largest file size. Then I cropped and
    enlarged what I wanted (just a dirt bike going over a jump with nothing buy
    clear blue sky), then saved the file. The saved file was only about 150k
    and the original was about 1.2 mb. I did not enlarge too much, but the
    resulting photo was somewhat on the grainy side, compared to the full photo
    with all the extra detail. Some graininess was to be expected due to the
    enlarging, but not too objectionable for what I was doing--just goofing
    around. So, after cropping and enlarging, should I expect such a smaller
    file? What is the best way to keep the image "crisp" when enlarging--if
    there is one?

    BTW--it seems that my 2.1 mp camera (Oly C700UZ) with its nice optical zoom,
    takes better far away shots than the 3.2 mp Minolta Xt--but I have not had a
    real opportunity to compare fairly. The Xt on close up photos (across a
    table or room) seem really nice!

    --
    Rudy Marcelletti, K8SWD
     
    Rudy Marcelletti, K8SWD, Aug 25, 2003
    #1
    1. Advertising

  2. Rudy Marcelletti, K8SWD

    Nils Rostedt Guest

    > I took a couple of images on a 3.2 mp camera (Minolta Xt) at the highest
    > quality setting (fine) and the largest file size. Then I cropped and
    > enlarged what I wanted (just a dirt bike going over a jump with nothing

    buy
    > clear blue sky), then saved the file. The saved file was only about 150k
    > and the original was about 1.2 mb. I did not enlarge too much, but the
    > resulting photo was somewhat on the grainy side, compared to the full

    photo
    > with all the extra detail. Some graininess was to be expected due to the
    > enlarging, but not too objectionable for what I was doing--just goofing
    > around. So, after cropping and enlarging, should I expect such a smaller
    > file? What is the best way to keep the image "crisp" when enlarging--if
    > there is one?
    >


    Cropping and enlarging will always reduce quality. An example: if you crop
    that 3.2 Mp picture to 1/3 of its original width and height, you end up
    with a 0.35 Mpixel image - which is surely grainy. The file sizes you
    mention indicate about that amount of cropping. The same thing happens if
    you use digital zoom for filling the frame. Optical zoom is usually better
    than cropping and enlarging.

    The file sizes also depend on the JPEG quality level you use. Many programs,
    such as the freeware Irfanview that I use, allow you to set different JPEG
    quality levels. The file size may vary as much as 5x depending on the
    quality level, for the same number of pixels.

    Just my $0.02
    Nils
     
    Nils Rostedt, Aug 25, 2003
    #2
    1. Advertising

  3. Rudy Marcelletti, K8SWD

    gr Guest

    "John M" <> wrote
    > A 150k jpg will generally create a pretty lousy print - even at 4x6


    Not true at all. It will produce a good 4x6 or even a 5x7 just fine.
    Resolution is more important than compression, anyway. A 150k jpeg at a
    normal compression level might be a 1024x768 or 1280x960 image. That's
    plenty big enough to print at 4x6 or perhaps 5x7.
     
    gr, Aug 26, 2003
    #3
  4. Rudy Marcelletti, K8SWD

    Don Stauffer Guest

    Depends on how much you cropped. File (memory) size is NOT a good
    representation of the resolution of a file. Instead, after cropping
    recheck the horizontal and vertical pixels. The product of the two
    tells how many pixels are left. It is PIXELS, not kilobites of memory,
    that establish resolution.

    Another thing to do is keep track when you say you ENLARGED it. Did you
    resample (add pixels)? If so, by how much. Resampling with good
    algorithms can give maybe a forty or even fifty percent increase and
    still be useful. However, doubling the (linear) resolution is usually
    beyond practical limits.

    "Rudy Marcelletti, K8SWD" wrote:
    >
    > I took a couple of images on a 3.2 mp camera (Minolta Xt) at the highest
    > quality setting (fine) and the largest file size. Then I cropped and
    > enlarged what I wanted (just a dirt bike going over a jump with nothing buy
    > clear blue sky), then saved the file. The saved file was only about 150k
    > and the original was about 1.2 mb. I did not enlarge too much, but the
    > resulting photo was somewhat on the grainy side, compared to the full photo
    > with all the extra detail. Some graininess was to be expected due to the
    > enlarging, but not too objectionable for what I was doing--just goofing
    > around. So, after cropping and enlarging, should I expect such a smaller
    > file? What is the best way to keep the image "crisp" when enlarging--if
    > there is one?
    >
    > BTW--it seems that my 2.1 mp camera (Oly C700UZ) with its nice optical zoom,
    > takes better far away shots than the 3.2 mp Minolta Xt--but I have not had a
    > real opportunity to compare fairly. The Xt on close up photos (across a
    > table or room) seem really nice!
    >
    > --
    > Rudy Marcelletti, K8SWD


    --
    Don Stauffer in Minnesota

    webpage- http://www.usfamily.net/web/stauffer
     
    Don Stauffer, Aug 26, 2003
    #4
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. JCP

    Enlarging Font

    JCP, Nov 18, 2005, in forum: Firefox
    Replies:
    8
    Views:
    3,718
  2. Sandy Bremmer

    Enlarging text via mouse

    Sandy Bremmer, Jul 25, 2004, in forum: Computer Support
    Replies:
    7
    Views:
    524
    JamesBenson
    Jul 29, 2004
  3. don

    IE 6 is not enlarging text

    don, Aug 1, 2004, in forum: Computer Support
    Replies:
    3
    Views:
    554
    Carol2
    Aug 1, 2004
  4. ivan clough

    enlarging windows

    ivan clough, Apr 12, 2005, in forum: Computer Support
    Replies:
    1
    Views:
    1,102
    Sentient Fluid
    Apr 13, 2005
  5. Simon
    Replies:
    0
    Views:
    715
    Simon
    Sep 2, 2003
Loading...

Share This Page