Expecting more from Mpix?

Hi,

I had emailed Mpix last week and asked some questions that I couldn't find answers to anywhere on their site - just about color spaces, resolution, file formats etc. I got the below response back, which I have copied from my email. How come I can go to Costco or other "less professional" services and print 16 bit AdobeRGB files in uncompressed tiff or png formats, yet the Mpix site I signed up with because of rave reviews here and on other sites only allows the following? Also, I'm curious about the line of "the higher the resolution, the better the picture will be" when he specifies that the printer outputs at 250ppi. Wouldn't a file I sent at 300 or 360ppi just get capped off at 250 anyways because that's what the printer outputs at, and the other 50-110 pixels would just be tossed away regardless? Maybe I'm naive to associate high end printing with larger, uncompressed files, wider gamut color spaces and higher resolution. Am I missing something?
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Hi Randy,
We ask that all files be in 8-bit, sRGB, jpeg format. I have posted a chart below for minimum and optimal file resolutions for certain sizes being ordered. We suggest a dpi set anywhere between 250-300. Please let me know if you have any other questions.

Thank you!

What is the optimal resolution for printing?
We do not require a maximum resolution for the images you upload. The higher the resolution, the better the picture will be. It's that simple. The Mpix printers output at 250 ppi. However, we are frequently asked what the optimal resolution is for the prints we offer.
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Dont confuse PPI and DPI. Pixels per inch is a method of making sure your file has enough information to fill the image size. DPI is dots per inch, an old standard to measure a printers maximum resolution. Some software might allow you to set a low DPI so that the printer reads that you want a low res printout, sometimes used for proofing.

The human eye can only resolve a certain amount of detail, and the printer can only put so much detail onto the paper. If you have a headshot that's captured at 6000x4000px, but you print it on a 2x3 piece of photo paper, you're not going to be able to see every individual eyelash and pore and nose hair on that final print.

If you send a larger file, the printer driver is just going to resample it down to 250ppi - and then further rearrange the image data for the physical dots of ink that are laid down on the paper. So, yes, you're throwing away detail if you send a file that's too large for the final print size.

As for the bit depth and the color gamut - I don't know, I'll let someone else speak to that.

Hey, sure, things can be a bit confusing!

My advice is to do "test runs":

Have them print images at your "native resolution", a "no muss no fuss" approach, then submit files that you have resampled to say 250 ppi and then 300ppi.

As to the difference between the 16-bit tiff and the 8-bit jpeg, well for printing, assuming the jpeg is at a High Quality setting, it really shouldn't shake up the print quality and, because they do give the specs, stick with them! As to sRGB vs Adobe RGB, well, if they say that their printers handle the sRGB range best, work with them! Sure, there are printers that can work well with aRGB, feel free to research and check out whether some online providers will do that, run tests, be happy!