Shrinking large images in Photoshop

<p>The still photos that I shoot with my GoPro have a size of 2840p X 2880p and 53in X 40in. If I try to shrink the images to something like 4X6 the quality suffers. What am I doing wrong? How can I shrink the image without changing the quality?Thanks,<br>

Gary</p>

<p>Hi Gary,<br /> If you are doing this through the Image Size... option uncheck the box that says resample image. This will keep the amount of pixels the same while changing the listed size. In reality this isn't really changing anything at all except a part in the meta-data that records physical dimensions. It isn't really that necessary, and in fact does nothing to change the digital file and only comes into play when printing, but even then not that much. On the other hand if you want a smaller file size there isn't much to be done that won't loose quality in some way by throwing away pixels or compressing the jpg file and leaving some artifacts. So I guess I should ask the question, Why do you want these images smaller and what is the final use for them?</p>

<p>As Matt said, the problem seems to be in the resolution that the images are imported. It is probably set at 72ppi which produces a huge, but almost unprintable print size. Uncheck the 'resample' box and change the resolution to something like 360, which is the native resolution for Epson printers. No pixels will actually be changed, only the instruction for interpreting them. You can, and probably should, change this in your import program like ACR to a default that is correct for your printer. 72 became a standard for monitors, but it is pretty much meaningless nowadays since your software will rescale it to fit. You may also be able to change this in the camera.</p>

<p>Dear Matt and Curt,<br>

Thank you! Thank you for perfect answers. <br>

I need to shrink the images because I am sending them via email to 1. A person who is using them in his blog and 2. A vacation resort that is using them as part of their online advertising. <br>

And yes, I was using "image size" in Photoshop; I should have included that info in my question...sorry.<br>

Thanks again for your help. I sincerely appreciate it.<br>

Cheers,<br>

Gary</p>

<p>For the person using them for their advertising I would suggest biting the bullet and sending them the full sized file as they are not large by current standards.<br />For web use I normally resize to 700 pixels across and I normally, almost always :-), sharpen the small file before posting. I have not used PS for some years but I would expect it has a one click 'sharpen' tool which is most likely sufficient without getting into using USM where you have to enter three parameters. 700 pixels across fits on the page with the usual 'junk' around it we see when using Outlook Express without the recipient having to scroll to see the whole picture. It is also the maximum standard for PN and if you organise a new file size of between 50 and 100 Kb you should not notice any degradation from the re-size process.<br />In PS/PSE I believe the re-size menu gives you a scale of 1 to10 and elsewhere it displays the new file size as you change that setting. Except for PN I no longer bother about file size, PN requires no bigger than 100Kb, as I now have broadband ... but in dial up days it was different :-) If your freinds have broadband I see no reason to reduce the file size which is likely to be around 300<400 Kb and that will download quickly for them.<br />One rather important point when you have made the small 'web file' you chage its name slightly before saving it .... if you just click the 'save' button the computer will overwrite the original camera file and you will be left with just the low resolution web file. I use the 'File/Save As' command and when prompted for file name simply add 'W' to the file name ... that way I can tell at a glance which file is which in the future.</p>

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<p>I need to shrink the images because I am sending them via email to 1. A person who is using them in his blog and 2. A vacation resort that is using them as part of their online advertising. </p>

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<p> <br>

In this case, both dpi (ppi) and inch measurements are completely irrelevant. I would recommend taking the advice above about sending a full size file. Use Dropbox if it ends up being too much to email</p>

<p>If you do shrink, try BICUBIC SHARPER in Photoshop when resizing. I do this and have no need to sharpen. Resize by adjusting pixel, not inches etc. Sesizing to 768 pixels high should be as small as you need to go.</p>

<p>Can OP tell us HOW his shrunk images' "quality suffers"? In sharpness, in color/tone, etc.?</p>

<p>A doctor writing prescriptions without finding out what bothers the patient is irresponsible.</p>

<p>In sending camera files to people I used to burn a CD but if your computer doesn't have this feature then transfer the file to an SD or other card that your client confirms they have equipment to read.<br>

Experienced photographers know what is likely to happen and take measures to avoid the problems. Of course if you pixel peep the downsized files nothing will help LOL</p>

<p>When you change image size, I suggest you do so by opening each image you wish to resize as a smart object in Photoshop. When you resize the image does not pixilate or lose definition, even when you go back to any other size. The key is to do a "save" of the smart object, not a "save as." I hope this helps. Larry</p>

<p>Once again I own a debt of gratitude. Larry, JC, Simon and Jeff; thank you so much. Photo.net is a fantastic community because of people like you who take the time to help fellow photographers. I appreciate your time and efforts. Robert, thanks man but we can consider the patient cured. <br>

Cheers Everyone</p>

<p>There may be an advantage to 'saving as a smart object' .... I don't use Photoshop these days ... but the point of using 'save-as' instead of 'save' is that the second over writes the original file with the compressed small version which is the last thing anybody wants. Save As prompts you for both the file name, a different one please if only just adding one letter* or number to the original file name, and how you want to file it ... as a jpg, png, or psd for three of the many options available to you. Personally I don't trust some of the fancy names PS gives things ... but that is me :-).</p>

<p>*My system is to add the letter W when I make a small file for web use and often if I make a work-up of a file that I don't want to name then I add Z which needs two keys next to each other with my left hand :-) Then both files live side by side in the folder but I can tell which is which at a glance.</p>

<p>In both instances, the pics will be used for the web. I use the "save for web" option in PS. First I make the resolution 96 dpi, then save for web. In the Save for Web dialog box is where i re-size the image to the desired pixel dimensions. The results are excellent.</p>

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<p>First I make the resolution 96 dpi</p>

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<p> <br>

There's absolutely no reason to do that. The web doesn't use "dpi."</p>

<p>When you use the "save for web" option in ps it reduces the resolution to 72 dpi automatically. I've found the best results by reducing to 96. Your pics will retain their sharpness and still be optimized for web usage. When the pics come from my camera, they are 300 dpi and quite large in file size. I thought the question was was about shrinking the size without losing resolution. INHO, this is the best way to optimize, resize and retain high quality to your pics.</p>

Here is a photo at 300 dpi:<BR>

 

<img src="http://jdainis.com/300_ppi_cannon.jpg"><P>

Here is the photo at 72 dpi<BR>

 

<img src="http://jdainis.com/72_ppi_cannon.jpg"><P>

 

Here is the photo at 1000 dpi:<BR>

 

<img src="http://jdainis.com/1000_ppi_cannon.jpg"><P>

Here is the photo at 10 dpi:<BR>

 

<img src="http://jdainis.com/10_ppi_cannon.jpg"><P>

 

 

 

All four photos are 500px x 338px and 149.76 KB. Changing the dpi tag of the image file did absolutely nothing just as changing an image file of a dog from "dog.jpg" to "cat.jpg" would also do nothing. Still, I'm sure that there are people who would believe that now the image would be that of a cat.<P>

 

DPI has nothing to do with resolution. Resolution is either image size as in pixel width by height or sharpness as in lp/mm. DPI is a print command used when printing. If you have a 3000 pixel wide file image and you wanted a 10 inch wide print you would print at 300 DPI to do so (3000/300 = 10). <P>

 

If someone tells you that you get greater resolution by saving at a higher DPI they are dead wrong. DPI has nothing to do with image display quality. In the images above the 1000 dpi photo does not have 100 times the resolution of the 10 dpi photo. There is no difference at all. Both photos are identical in image size and file size.

Let's try an image tag of 100,000 dpi:<P>

 

<img src="http://jdainis.com/100000_ppi_cannon.jpg"><P>

 

Nope, still the exact same photo at 500 x 338 and 149kb.

<p>At one time I had three cameras with native resolutions of 72,180,and 300 dpi .... so obviously the 300 dpi must have been the best ... at the time in fact it was but not becuase of its native resolution :-) Canon,Panasonic,Nikon respectively .... GO NIKON GO! LOL!</p>

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<p>native resolutions of 72,180,and 300 dpi </p>

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<p> <br>

That's not "native resolution." It's what the software sticks in the box, which for some reason needs a number in it. It's completely meaningless in terms of the resolution of the camera.</p>