AdoramaPix Forums/Solutions Library/Preparing digital photos for printing

Resolution and image quality

Al Escudero
posted this on August 02, 2010 02:47 PM

Quantity IS Quality

If you want the best possible print, you need to upload the best quality digital file.  Sometimes photos might look just fine when you look at them on your computer screen, and you might wonder what’s up with us when we say we can’t print them. Photos that don’t have sufficient resolution will look all blurry and pixilated (blocky with jagged edges) when printed. 

Case in point: These horses look just fine at this small size. The image was shot at the camera’s lowest resolution setting and measures 368x256px. It would print out best at 3½x5.  

 quality1.jpg

Now take a look at what happens when we try to print this photo at a larger size.

Quality2.jpg

This is why AdoramaPix has guidelines for the minimum resolution that is required for a good quality print, and we just won’t print images that don’t measure up.

All the print sizes that are available for your images will be shown on the “Enter Quantities” page. If you are placing an order and don’t see the print size you want, it may be that your images don’t have sufficient resolution to support a larger print size. Switching to “Advanced Mode” will let you see exactly which of your images can be printed at what sizes.

Resolution: It’s not just for New Year’s anymore

Resolution isn’t just something you think about on New Year’s Eve and then forget about the rest of the year. Photographically speaking, it is the amount of digital information stored in your image in individual pixels, or dots of color (or shades of black and white, if your image is, well, black and white). The more unique pixels or dots of information stored in your image, the more detailed the image and the better quality the print will be. Lower resolution means less detail, and unfortunately, a lower quality print of the image will result (the blockiness and general blurriness we mentioned above).

Resolution is measured in megapixels (that’s a million pixels!) for your digital camera, and in individual pixels for images. Your camera might be a 6 megapixel model, but if you set it at a low resolution setting, your images might only measure 500x500 pixels.

This handy table shows the standard image resolution in pixels that average megapixel cameras will create. Remember: always use the highest resolution setting in your camera for images that you will want to print.

 

Camera megapixels                   Approximate standard image resolution in pixels

2 megapixels                                     1600 x 1200

3 megapixels                                     2048 x 1536

4 megapixels                                     2274 x 1704

5 megapixels                                     2560 x 1920

6 megapixels                                     2816 x 2112

7 megapixels                                     3072 x 2304

8 megapixels                                     3450 x 2300

10 megapixels                                   3650 x 2736

12 megapixels                                   4288 x 2850

16 megapixels                                   4600 x 3450

18 megapixels                                   5185 x 3450

20 megapixels                                   5475 x 3650

24 megapixels                                   6000 x 4000

 

This table shows the optimal and minimum image resolution for printing at AdoramaPix’s print sizes. We recommend image resolution of at least 300 pixels per inch (it’s abbreviated dpi for Dots Per Inch) for the best possible image quality, but we will print photos for images of at least 100 pixels per inch. Anything below that? You guessed it, the blocky blurriness.

 

Print size      Optimal Resolution              Minimum Resolution

                        For good print quality            less optimal image quality

                        300px per inch                      100px per inch

3.5x5               1500 x 1050                          500 x 350

4x5                  1500 x 1200                          500 x 400

4x6                  1800 x 1200                          600 x 400

4x12                3600 x 1200                          1200 x 400

5x5                  1500 x 1500                          500 x 500

5x7                  2100 x 1500                          700 x 500

6x9                  2700 x 1800                          900 x 600

8x8                  2400 x 2400                          800 x 800

8x10                3000 x 2400                         1000 x 800

8.5x11            3300 x 2550                          1100 x 850

8x12                3600 x 2400                          1200 x 800

9x12                3600 x 2700                          1200 x 900

10x10             3000 x 3000                          1000 x 1000

11x14             4200 x 3300                          1400 x 1100

12x12             3600 x 3600                          1200 x 1200

12x18             5400 x 3600                          1800 x 1200

16x20              6000 x 4800                          2000 x1600   

20x30              9000 x 6000                          3000 x 2000

24x36              10800 x 7200                        3600 x 2400

 

Comments

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Derek McCabe

A Canon 5D mk II shoots full frame at 5616 x 3744 pixels = approx. 120MB TIFF file

Adoramapix has a limit of 60 MB for uploading files to print. A 21 MB RAW files saved out as a TIFF is much larger than 60MB.

Please start permitting larger file sizes for large prints. We should not be forced to throw pixels out to make prints at 24" x 36" size

February 23, 2011 01:47 AM
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Benjamine Morrison

Saving that same image as a jpeg would cut it down to just a fraction of the 120mb you mention. Why not go that route? 

March 16, 2011 06:46 PM
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Justin Lancaster

It is generally not a good idea to save a print file as a .jpg as it automatically has compression built into the file type, which technically degrades image quality. That is most likely why he does not want to go that route. 

August 22, 2011 10:49 PM
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Ben Balk

I'm confused - i took a photo set on 15M Raw, i saved it after a few adjustments in Lightroom 2.3 as a TIFF 16 bit and its way bigger then 60 M. So when downsizing it to meet the 60M requirement (saving it as 8bit) by Adorama I can't get the suggested quality of a "good print" for 20x30. my resolution is now 4800 x 3860. HELP!?

December 12, 2011 10:22 AM
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Regina Mullen

If you have need to upload huge files, get a Pro account. Pro accounts (as of the date this is posted) have no image upload size limitations. 

Found the answer to this question on another page.  

July 01, 2012 12:37 PM
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Richard Remski

You indicate the "optimal resolution" is 300 pixels/inch, which I understand.  But is there an actual recommended *maximum* resolution, based on printer capability, and if so what is that value?  Does it differ for poster prints, standard prints, photo books, metal (aluminum) prints?

In other words, if I have a 6000 x 4000 pixel image (20X13.3inches at 300 pix / inch) and I ask you to print it out at half that (10 x 6.5inch or so), are you just reinterpolating the image down to 3000 x 2000 and then printing? Or do I get a really amazingly crisp 600dpi result?

May 31, 2013 02:33 PM
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Mike Colby

 

I have the same questions as Richard.  In fact, I have been asking the same question of a variety of book publishers for years, and I have never received a satisfying, factual answer once, from an of them.. I have to wonder if that's why Richard got no response here.

July 06, 2013 02:03 AM
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Richard Remski

Thanks for the response.  I understand that "dpi" is not the same at all as "ppi", since each printer 'dot' is only one color and multiples are needed to generate a single pixel.  And of course this differs with ink jet vs. dye sublimation printing. 

An (at this point, pretty outdated) article at Luminous Landscapes implies that no printers are really capable beyond about a 360 pixel-per-inch equivalent, but of course many printers are less than this (the typical 1440 dpi, at 6 colors, is more like 240 pixel-per-inch equiv).  http://www.luminous-landscape.com/tutorials/understanding-series/und_resolution.shtml 

I'd still really like to know what Adorama's book and other printers have as actual output capability.  I recently printed a 10x10" aluminized print, from an original that was 300ppi at that size, and still found the output just a tad soft compared to viewing the print at pixel density equivalent on my screen, which one would expect to work the other way around...my Surface tablet has a nice dense full 1080 screen, but that only works out to about 192 pixels per inch...so right now my guess is that the dye sublimation process on aluminum is only about 200ish effective ppi, despite supplying a 300ppi original.

Is it really too much to ask if Adorama's processing includes a step that in essence either upscales or downsamples resolution of any originals to a final pixel per inch value for printing, what that value is, and if that method varies depending on the type of output selected?  I for one would fully expect some products to offer better final image resolution, as printed, and would be willing to in some cases pay for better, as long as I am informed as to those options.

July 06, 2013 10:33 AM
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Al Escudero
AdorPix LLC

No Mike. Our printers work at 300dpi. You could have an image at 1200dpi, and it wont print any higher than the capability of the printer. Images will be down sampled to 300dpi.

July 07, 2013 02:31 AM
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Mike Colby

Al,

Thank you very much for claryfying that!  It helps a lot.

Is it the same answer for the Aluminum prints?  I just did a test of an 8x10 of a downsized TIF file that I had printed elsewhere as a 20x30 JPEG canvas print that came out perfectly (I have a calibrated monitor), and the quality was rather disappointing.  I am still waiting for the other company's 8x10 JPEG aluminum to arrive this week to compare with Adorama's, to help determine where something might have gone wrong.  

Thanks again.

 

 

July 07, 2013 04:33 PM
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Al Escudero
AdorPix LLC

As I understand it, all our products are done at 300dpi and you shouldn't experience any noticeable degradation of quality by using an image larger than 300dpi.

July 10, 2013 06:46 PM
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Janet Sanchez

Am I going to be disappointed in the quality and clarity of the metal prints if it shows that the DPI is FAIR (close to the top of the red going into the orange). I can't raise the DPI without choosing a smaller size and I need that size. 

If your website allows me to order it, will it look nice?  I tried to order some others but the wizard would not let me order them as big as I wanted.

July 16, 2013 02:56 PM
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Richard Remski

Janet:

A lot of that might depend on your application, subject matter, and of course the original file resolution.  Portraits for example might look just fine at "sub-optimal" DPI, which is why softening filters are applied to blur out really fine detail like wrinkles, pores, tiny freckles and grease reflections, etc whenever (ahem) 'seasoned' starlets are on the air (grin).  On the other hand, a macro shot of a fly's eyeball showing every composite facet in crystal clear focus, zoomed up to the point of pixellation, will be very disappointing.

You don't specify your size, but I'd say you can err a bit 'softer' on 'larger' prints, because in general people tend to view them from further away (IN GENERAL - not always). 

I've ordered at below 300dpi resolution (down into almost 200 dpi) and been reasonably satisfied, for larger prints on the metallic papers  (Actually a 24 x 16 metallic print cityscape I did that was only 200dpi still looked dang good up close).  For smaller ones, even 300dpi isn't always "enough" (I'm always at that ragged edge of thinking the print is a tiny bit less razor sharp than what I see on my screen). 

I think their scale only allows you to even order in the 100dpi - 300 dpi range, with 200dpi in the middle.  I don't remember the colors but you can scale from there.  Personally I'd hesitate going much below halfway, but I'm a very focus-oriented person in terms of what I "like" in photography.  I'd definitely believe if the wizard 'will not let you order' at a given size, that you'd have been disappointed if it had let you.

[I'll post again later - just ordered 2 24x16 metal prints on their latest sale, one was a file I manually uprezzed (Cubic) to force to 300dpi at that size, from an original of about 3200 pixels on the short axis (200dpi actual data source if scaled to 24x16").  The other was a 6000x4000 pixel original (e.g. 250dpi at that size).  Both were pretty crystal-clear focused subjects, so I can compare whether my own upscaling vs. theirs resulted in the more satisfying final print....at 24x16 I don't expect to stand 'nose on' the prints with where they'll be hung, so I was comfortable ordering even though neither original would have the pixels to go to 300dpi at the selected size.] 

July 16, 2013 04:18 PM
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Al Escudero
AdorPix LLC

Hi Janet. We will not let your images print at lower than 100dp, but the ideal image quality is 300dpi so the closer to that you can get, the better We can't make your image better than it is - unfortunately.

July 16, 2013 04:41 PM
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Janet Sanchez

Richard

Thank you so much for such great information.  I am not technical about this at all.  I am trying to order two 16 x 24 metal prints.  They are wedding portraits, not close up head shots but full length photos of my sons and their brides.  They were high res files from the photographer but when I uploaded them to my gallery and then tried to place the order, they were showing only fair dpi.  I would estimate the dpi to be about 150.  The wizard will allow me to do it.  I would imagine that my eye is not as fine-tuned as yours.  I just want a nice photo and I love the metal prints.

Do you think at that low of a dpi they will be okay for an untrained eye?  Customer service told me that if Adoramapix is willing to print it, it is a nice photo.  As an amateur Is there a way for me to raise the dpi of the file without going smaller?

Thanks - janet

July 16, 2013 04:43 PM
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Al Escudero
AdorPix LLC

If you have photoshop Janet, there are techniques you can use to up-res an image with varying results. If done well, you should be able to increase the file size within reason.

July 16, 2013 04:46 PM
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Richard Remski

Janet:  Full body type portraits, in a vertical format, will not likely be viewed 'super close' (nose-to-glass).  You say they were 'high res' from the photographer but what format were they?  JPG, TIFF...?  If JPGs, and not up into the 20MB type file sizes, then they probably had a fair amount of 'compression' applied during storage of the photo.  Even if the resolution is present, there might be 'artifacts' on outlines and such due to excessive compression ('banding' in the colors), and there may also be sharpening artifacts (if you zoom in on outlines, say of where someone's hair borders an out-of-focus background, can you see kind of a weird blotchy halo effect?).  Both of those might influence your satisfaction with a 24x16 print.

At the risk of stepping where I don't belong, if the files are from a photographer who was paid to do the work, do you have the right to make prints?  e.g. were these just digital files but you're supposed to print through him? I ask in part because of course as a (non-pro, wannabe) photographer myself who'd like to be paid someday for something, I don't really want to help someone else get sidestepped, but also (more pertinent to the discussion at hand) because if he sent you the files for 'digital use' (to post online, share on Facebook or wherever) they might not have been created with large printing in mind.  You might be able to ask him for higher resolution (or at least 'less compressed') files for printing purposes (assuming, per the earlier question, you're not already kind of cutting him or her out of the loop).

If you want to try to 'increase the resolution' yourself, this is a process called interpolation, which is basically a kind of digital guesswork.  Depending on the method this can improve the effective image - or not, depending on the assumptions made  (e.g. the computer takes a black pixel next to a white one, and if you ask it to make those 2 into 4, it estimates 2 gray ones between, or just makes it into two black and two white pixels with no 'net gain' in true resolution despite the extra dots...one preserves the edge, the other fakes in some gradient).  There are a lot of different methods but generally the best tend to be based on Lanczos and cubic interpolation methods.  As Al said, Photoshop has features for this but I suspect you don't have that.  Do a websearch for the terms "photo, interpolation, scaling" and you should find some free downloads that might help.  One is "Gimp" which I can't claim to have used for this purpose but is generally well regarded for basic manipulation.  A link to their help page on this topic is here:  http://docs.gimp.org/en/gimp-image-scale.html

I'm sure that when you provide images of less than 300dpi, Adorama is themselves doing some sort of interpolation 'up to' 300dpi for the printer (the printer itself might just do this 'automagically' when given a certain X by Y image pixel size and asked for an A by B print size).  But if you play with the different features in upscaling yourself you get to see the resulting files and compare. 

150dpi for full body portraits, not viewed up close, might be just fine on its own, but in your shoes I'd try to interpolate up to 300dpi and compare the outputs.  Another trick to try on the original: measure your monitor size along the horizontal axis (remember a "15.4 inch laptop" means a diagonal, not the horizontal size).  Take the ratio of it to 16 inches, e.g. if your monitor is 12" wide, that's 12/16ths or 3/4 of 16".  Now zoom up the picture on your monitor until only 3/4 of the width is still on the screen and 1/4 spills off to one side: that's the size of print you're asking for. Pan around to the faces or other details you would like to see well.  Are you satisfied with how it looks? 

July 16, 2013 05:28 PM
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Richard Remski

As an addendum to my July 16th post, at this point I've ordered four 16x24's, with originals varying from about 200dpi to 300dpi (interpolated).  I think the ones that are the most satisfying are the ones I interpolated up to 300dpi before submitting.  (I don't have any superfancy interpolator - just the one in Lightroom 4.3).

I still think the final print 'resolution' appears to be a bit less than 300 dpi, and now suspect that's part of the way dye submlimation works.  It may be printed at 300dpi, but the dots probably diffuse a little on impact/bonding to the aluminum.

July 26, 2013 05:38 PM
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Thomas Rickey

I just received a batch of metal prints and they are all crooked or cropped strangely – I ensured that there was a half-inch black border around every picture, some are missing the border entirely and not a single picture has a border that is the same width all the way around. Some are clearly slanted with the image extending all the way to the edge of the metal in one corner and an uneven amount of black showing on the opposite corner. Can I return these and have them reprinted?

September 10, 2013 08:34 PM
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Al Escudero
AdorPix LLC

Hi Thomas. manually applying a border to your images will almost always have these results. I made the following video for photo books but the same principles apply to metal prints. http://youtu.be/ap3DSJi1x5I Pay particular note to the part between 2m25s and 2m50s

Having them reprinted wouldn't fix the issue. You would have to remove the black border you added and make the images full bleed. Some amount of random shifting during the printing process is an unfortunate limitation of current printing technology.

 

September 16, 2013 12:07 PM
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ERIC JENSEN

1. Does the native 300 dpi resolution apply to the photo books as well as the prints, or do the books use a different process?  

2. Does the photo book ordering process provide a way to instruct you not to make any corrections, as you can do with print ordering?

Thanks in advance for the information.

May 27, 2014 12:08 PM
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Al Escudero
AdorPix LLC

Hi Eric. To address your questions:

1. Yes, the photo books are printed at 300 DPI also.

2. Yes, you can turn color correction off during the order step if you so choose. Note the red arrow below.

correction_option.jpg

Hope this helps!
AL

May 27, 2014 02:39 PM
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ERIC JENSEN

Many thanks, Al.  A quick reply, and exactly the answers I was hoping for.

Best,

Eric

May 27, 2014 03:38 PM
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Ravshan Rakhimovich

Hi Al.

How to order print panoramic images? Which size better for image 10000 × 3654 px?

July 11, 2014 03:18 AM
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Al Escudero
AdorPix LLC

Hi Ravshan. We have a few panoramic sizes such as 4x12 and 6x18. Those are the closest matches to the size you listed. If you don't want to crop the original image, print it letterboxed and then crop off any excess.

July 13, 2014 03:57 PM