How can I enlarge a print properly?

[c_k17]

<p>I have 12 MP available, though I have to do some cropping like maybe reducing it to 7MP to make a print up to 20X30, I have been dissatisfied with previous prints, color problem, pixels, etc. it just looks bad. I know I'm not a professional, but does it have to be so difficult to get at least some type of good result?<br>

I've seen these wedding photos that look just as nice as its small 4X6 version, do I need a different lab? Photoshop upsizing? I'm sort of tired of playing around with megapixels only to receive similar results.<br>

I don't expect in depth info about this, but pointing me to the right direction would be very helpful so I can do better research.<br>

Thanks.</p>

[jim_manganella]

<p>Are you getting 300 DPI photos? The rule at mPix is 100 pixels per inch...</p>

[976photo]

<p>Sounds like maybe you're cropping too much? The MP rating really isn't the factor so much as the actual pixel dimensions of the final image. The formula is to multipy DPI by the size of the print you want and that gives you the pixel dimensions you need.</p>

<p>So if you want to print a 20x30 print, at <strong>100 DPI</strong>, you need an image that's <strong>2000x3000</strong> pixels or larger. If you want a 20x30 print at <strong>200 DPI</strong>, then you need an image that's <strong>4000x6000 </strong>or larger. If you want a 20x30 print at <strong>300 DPI</strong>, then you need an image that's <strong>6000x9000 </strong>or larger.</p>

<p>Most people will tell you for best print quality you should stay between the 200 - 300 DPI range. You can still print at the 100 DPI range, but the picture will not look as good up close, you'll need to view it from farther away.</p>

<p>Also, be sure you're not over-saving your JPEG images. Each time you re-save a JPEG image, you lose quality. That may be a factor as well.</p>

[jim_manganella]

<p>I think Luc might have his equations backwards. At 300 dpi you need 2000x3000 pixels for a quality 20x30 inch enlargement.</p>

[Matt Laur]

<p>Jim: No. 20 inches times 300 pixels per inch = 6,000 pixels.</p>

[frank uhlig]

<p>And at 300 dpi the size comes to 54 MB (6 x 9 = 54), not the 7 MB you have available .... after the crop.</p>

<p>Problem solved: your input file cannot generate nice enough print output. Case solved. Now, at 100 dpi it can since 2 x 3 = 6 < 7 !</p>

[jim_manganella]

<p>If ignorance were bliss! We're talking DPI not pixels.<br>

<br />"For Printers and scanners, the individual points of color are often called 'dots' rather than pixels. Because the output of a printer is paper which is usually measured in inches, the term DPI or Dots Per Inch is used to communicate the scale or physical size of each pixel."</p>

[Matt Laur]

<p>Jim: No. None of these conversations - especially as they relate to file resolution as JPGs are sent to a lab or even to your own printera - are ever about ink dots. It's about PPI. The term DPI is frequently used/mis-used in this context. </p>

[James G. Dainis]

DPI and PPI are used interchangeably since a small printed pixel looks like a dot. If printed at 300 pixels per inch, each printed pixel is 1/300th of and inch or you can call it a dot and say each dot is 1/300th of an inch.

 

Mathematically, one should deal in like terms.

 

for a 3000 pixel wide image;

 

3000 pixels / 300 pixels/ inch = 10 inches.

 

"pixels" cancel out and one is left with 10 inches, the width of the photo.

 

3000 pixels / 300 dots per inch = 10 pixels inch per dots, which is a bit confusing.

[976photo]

<p>DPI is (or was) usually referred to when printing, because printers don't print in pixels, they print in dots. With the evolution of digital cameras, every thing is referred to as pixels now, because that's what a digital image file creates, pixels not dots. In essence, all a pixel is is a digital "dot" but since the computers can not deal in aperfectly round circle to create a dot, then a square pixel is created. Likewise, a printer can not splash a tiny square pixel onto a paper, so it splashes a round dot.</p>

<p>But honestly folks, it's not that important if you stick a letter D or a letter P up there, what's important is the <strong>numbers</strong> involved when you're trying to determine the size you need.</p>

[dbcooper]

<p>Maybe we should keep our eye on the ball and help out the OP.</p>

<p>There area few ways to uprez an image for printing big. Photoshop can do it better than it used to...the conventional wisdom is to use Image/Image Resize/Bicubic Smoothing, then re-sharpen and adjust the image as needed. There are some special progs made just for that purpose that seem to get better results if you care to go that way (e.g. Genuine Fractals).</p>

<p>A pro lab/printing service might be your best answer. Sounds to me like the wedding pics you saw might have been done that way. Shop carefully...services, prices and quality vary.</p>

[markdeneen]

<p>I think a good <em><strong>minimum</strong></em> for decent enlargements is about 150DPI (or pixels per inch if you prefer). For 16" width then, you need 16 x 150 pixels in the width dimension of the image. That's 2400px wide - easy to achieve with a 12MP camera.</p>

<p>More importantly, might be the kind of processing you are doing in the software. If you pay attention to sharpening and noise reduction and contrast curves, you can fairly easily get good results. When you are ready to SAVE your file, check the IMAGE SIZE. It ought to say something like 2400 x 3000 at 72 DPI for a 16 x 20 print. When you save the JPG be sure to select MAXIMUM quality. This is usually a slider control.</p>

[charlesheckel]

<p>All the responses above have been about resolution, but printing 12 MP or even 7 MP at 20x30 should not present a problem with resolution. You could have problems with focus, motion blur, exposure, noise, flare, coma, color management, and so on which wouldn't necessarily be noticeable at 4x6 but would stand out like a sore thumb at poster size. It could also be a problem with the lab you're using, or with communication between you and the lab. Hard to tell if you don't download an image so we know what you're talking about.</p>