Posted by Ron McCombe on November 20, 2009 at 3:30 PM
Hi Can you help me,
I don't understand how to achieve the following
I have posted two picture on the critique forum (avian)
The first one seemed to be OK (pure luck)
The second the picture of the woodpecker is quite small and contributors have asked if I can re-post the picture at a larger size which is 1200 pixels along its longest length.
If I set the length at 1200 pixels across the width the height is 822 pixels at 72 dpi and the file size is 2.52m
The maximum file size is 500kb
If I reduce the 72dpi the picture is heavily pixelated
My question is :-
How can I get 1200 pixels on the length and maintain decent picture quality e.g. 72dpi
Ron McCombe
Posted by Alan Olander on November 20, 2009 at 4:20 PM
DPI (PPI) means nothing in this case; it only matters when printing. Check resample when resizing and set the longest dimension to 1200. (Don't even worry what the ppi says as only the pixel dimensions matter.) Then, when saving as JPEG, compress to a quality level that gets you under the file size.
Try adobe's "save for web", it will remove all extraneous information that can take up a lot of space. 60-70% usually works, except for very highly detailed shots. Make sure to convert to sRGB/8bit before hand.
Posted by Phil Pogledich on November 20, 2009 at 6:27 PM
What Floris said. The only thing I would add is to hit "preview" to get an accurate read on the file size as you are preparing it using "save for web." It will tell you precisely how large your file is in kb/mb for the quality level you've chosen, and give you a screen shot of how it will look. And Alan is correct that dpi is nothing to worry about.
Posted by Ron McCombe on November 20, 2009 at 6:51 PM
Alan, Flris and Phil
Many thanks for the advice, I cant beive how easy it is to do, so simple
Many thanks again
Ron McCombe
Coldstream, Scotland
Posted by David Bostedo on November 20, 2009 at 6:54 PM
Ron - You should read this thread. It explains a bit the relationship between your image on screen and that "dpi" setting - and why "72 dpi" is meaningless.
What you want to do is set the pixel dimensions (1200x822 in your case) and just save it at that size. Then alter the JPG compression to reach the file size you want. (This is what Photoshop's "Save for Web" feature does, in addition to some other things which let you get a smaller file size without losing quality.)
Discussion
5 repliesI don't understand how to achieve the following
I have posted two picture on the critique forum (avian)
The first one seemed to be OK (pure luck)
The second the picture of the woodpecker is quite small and contributors have asked if I can re-post the picture at a larger size which is 1200 pixels along its longest length.
If I set the length at 1200 pixels across the width the height is 822 pixels at 72 dpi and the file size is 2.52m
The maximum file size is 500kb
If I reduce the 72dpi the picture is heavily pixelated
My question is :-
How can I get 1200 pixels on the length and maintain decent picture quality e.g. 72dpi
Ron McCombe
Many thanks for the advice, I cant beive how easy it is to do, so simple
Many thanks again
Ron McCombe
Coldstream, Scotland
What you want to do is set the pixel dimensions (1200x822 in your case) and just save it at that size. Then alter the JPG compression to reach the file size you want. (This is what Photoshop's "Save for Web" feature does, in addition to some other things which let you get a smaller file size without losing quality.)