Simple explanation regarding scan resolutions

The higher your scanned resolution, the higher the quality and therefore, the better the job I can accomplish for you.  A full grasp of this process is a complex and lengthy subject, beyond the scope of this page. 

Web/Computer Viewable:
If your photo is only for viewing on your computer, for  e-mail, or used only on the web, then scanning at 72 DPI (Dots Per Inch) is appropriate. 72 DPI is the "standard" resolution for computer images.  At 72dpi, if you scan a 4"x 5" photo, it will sort-of appear 4"x 5" in size on your computer screen (sort-of, because everyone has a different screen size).  If you scan it too high (say 300 DPI), it will look huge and beyond the screens edges, unless you have a photo viewing program that adjusts it for you. 

Regarding a 72 dpi (dots per inch) image - if you print this same image, it will have terrible looking quality.  Physical prints need a much higher resolution.

Resolutions For Printing
If you want to print photos from your own scans, then the common choice is 300 DPI (Dots Per Inch), assuming you want to print a photo the same size or smaller than your  original. (Scans for sending to LunchBoxPhoto must be much higher, detailed further below.)  If you want your photo printed larger than the original, then it must be scanned at a higher resolution to include more detail.  If you scan a 4"x 5" and want to print 8"x 10", you need to scan it at 600dpi for your own reprints. 

One point to remember regarding increased resolutions, a 600dpi resolution file size is FOUR TIMES the size of a 300 dpi file.

Example: 3x4 inch photo 
  300 dpi =  1.08 MB file size
  600 dpi =  4.32 MB file size
1200 dpi = 17.28 MB file size

Here's the math:  A 3x4 inch photo - (3 inches x 300 dpi) x (4 inches x 300 dpi) = 900 x 1200 pixels, which is a total of 1.08 million pixels total.  However, at 600dpi -  (3 inches x 600 dpi) x (4 inches x 600 dpi) = 1800 x 2400 pixels, which is 1800 x 2400 pixels, which is a total of 4.32 million pixels. Note that a full CD disc only holds 650 to 700 MB.

Scanning for LunchBoxPhoto requires a higher resolution...

Depending on the photo size, when I scan I use 600 to 2400 dpi for photos that are intended to be printed. In order to work at a professional level of quality I need a higher scan resolution.  This ensures you receive a quality product. 

 Use this chart (or the calculator below it) for scanning your photos

If your original 
photo size is...		 and the size 
you want to 
print is...		  
Use this dpi
for Retouch & Repair when needing an Excellent Print		 Good Print Website or
Computer
Viewing
4x6 or 5x7 4x6, 5x7 600 dpi 300 dpi 150 dpi
8x10, 11x14 1200 dpi 600 dpi 300 dpi
16x20, 18x24, 20x30 2400 dpi 1200 dpi  
8x10 or 11x14 4x6, 5x7 300 dpi 150 dpi 72 dpi
8x10, 11x14 600 dpi 300 dpi 150 dpi
16x20, 18x24, 20x30 1200 dpi 600 dpi  

Important! Your scanner may have FIXED scan resolution numbers.  In that case, pick the one closest to, or higher than, this calculator suggests. Or as high as your scanner will go if it is limited. 
We scan for free, so you can always mail your photos to us. 
 

...or... Calculate Your Scan Resolution this way

 
What is your purpose for this file? ...use...
      600 dpi - For excellent Prints when we retouch your Photo.
      300 dpi - For OK quality Prints.
     150 dpi - For website or computer viewable photos.
Enter (dpi) number suggested above:
Quality Factoring: ( Leave this as 1 )

     

    Next, for example, if your original print is 5x7 and your desired use is 8x10, 
then you would enter a '5' in the next Original Width field, 
and enter '8' in the following Needed Reproduction field. 
Width of your Original Photo (for example):
enter 4 if - it is 4x6  
enter 5 if - it is 5x7  
enter 8 if - it is 8x10		 inches
Width of needed Reproduction (for example):
enter 4 if you need 4x6   
enter 5 if you need 5x7   
enter 8 if you need 8x10  		 inches
Press this button:

< Suggested Scan Resolution (DPI - Dots Per Inch)

 

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