Most Iris Arts images are taken with modern high resolution cameras that generate large digital files. Yet technology has evolved rapidly. Several of our popular images made only a decade ago—taken with the best cameras of the day—have small file sizes compared to today's standards. Those "smaller" files—especially when saved as jpegs—may benefit from special preparation if very large custom prints are desired.
The high-quality photographs from the Iris Arts website are made by a highly reputable commercial printer. Like most commercial printers, they prefer jpeg files in sRGB color space.
How our jpegs are prepared for the website
All of our photographs start out as RAW digital files. Our jpegs are made from the original RAW file, using careful processing to minimize artifacts, and then a small amount of sharpening is applied. The jpegs are stored securely on our website. Our photographs are made by our printer from those jpeg files.
We do not enlarge or shrink our "original" jpegs. Rather, the commercial printer scales the files to the print size requested by the customer. Most of our orders are in the 24"x36" size range, but with their sophisticated scaling algorithms, much larger prints can be made from even modest file sizes—with excellent results.
Panorama image made by "stitching" two overlapping images from a pocket-sized camera with a "small" 20MP sensor. The size of the stitched image is 29MP. That would make a 28" X 14" print at 240 dpi straight from the file. But, what if a client wanted a 60" wide print of this image from the jpeg? Click the image for a wider view of the same scene on the Iris Arts website. Photo: © Donald J. Rommes
Art consultants will often download our original jpeg files under our commercial license. They will then have someone of their choice make the print. We have no concerns about the quality of the very large prints they will make from our very large files, nor concerns about the quality of moderate-sized prints being made from moderate-sized files. We did wonder however, how the quality of the print would hold up when moderate-sized files were used to create the very large (>48 inches wide) prints sometimes needed by art consultants.
Testing print quality from two different jpeg creation strategies—jpeg first, then enlarge (the typical situation), versus enlarge first, then jpeg.
JPEG from the original RAW first, then enlarge
We decided to examine the quality of very large prints (63 inches wide at 240 dpi) made directly from our original moderate-sized (28MP) jpegs. We used standard Photoshop® interpolation to enlarge the image, employing conventional techniques to minimize noise or loss of sharpness resulting from the extreme enlargement.
Enlarge the original RAW first, then jpeg
We then went back to the original RAW file (with no sharpening). We opened it in Camera RAW, applied similar corrections as the first file, opened it in Photoshop® and enlarged it to the desired width of 63 inches using the Photoshop® resampling algorithm (Preserve Details 2.0). We then applied a small amount of sharpening and noise reduction. We then saved this file as a jpeg that would make a print 63 inches wide at 240 dpi.
We opened each file and compared the results.
Getting the best-quality large prints from a jpeg
It is generally accepted that the best fine-art prints are made by an experienced photographer and printer who starts with a RAW of TIFF file and uses an ink jet (or similar) printer.
But while custom-made ink jet prints from TIFF files are common in fine art circles, they are less common in our business for several reasons, most related to cost.
Jpegs are small, and commercial printing is convenient and economical. Moreover, most clients will not appreciate the difference between a commercial print from a jpeg and an ink jet print from a TIFF without a direct comparison—especially when viewed under glass.
So, jpegs it is. But, are there appreciable quality differences in jpegs—or are they all alike?
Our original jpegs (from the original RAW file) when enlarged by the printer, make very good large prints. But if the RAW file was enlarged first to the desired size and then compressed to the jpeg used for printing, would that make an even better large print?
Our original jpegs, when enlarged by the printer, make very good large prints. But if the RAW file was enlarged first to the desired size and then compressed to jpeg format, would the photo from that jpeg make an even better print? The answer is yes, but not by much.
Using the original, slightly sharpened jpeg, we enlarged it to a width of 63 inches. This is similar to what a commercial printer would do. We then applied a small amount of additional sharpening and noise reduction in Photoshop® which may not be done by the commercial printer. This is a crop of the right center, viewed at 50%. It looks very good.
This is a 100% crop of the lower left corner of the image above.
This is the same 50% crop of the image. We made this image from a jpeg—but started with the original RAW file (with no sharpening), opened it in Photoshop® and enlarged it to the desired width of 63 inches using the Photoshop® resampling algorithm (Preserve Details 2.0). We then applied a small amount of sharpening and noise reduction. We then saved this file as a jpeg that would make a print 63 inches wide at 240 dpi. This is equivalent to informing the photographer you will need a 63" wide print, having her prepare the image to be that size first, and only then save it as the jpeg that will be used by the printer. Not a huge difference perhaps, but superior to the first.
This is a 100% crop of the lower left corner of the image above.
Enlarge to the desired size first, then compress to jpeg
Original jpegs on our website are made from the original RAW files. Jpegs are compressed files. They are much smaller than RAW files but they lose a lot of information with the compression. Our commercial printer uses jpegs to make our commercial photographs.
The results from the jpegs are terrific for the majority of print sizes, but quality necessarily suffers somewhat with very large print sizes. That's because the information loss from the jpeg compression is magnified by the subsequent extreme enlargement and because the same number of pixels in the file have to be spread further apart to fill the larger print. .
If we were to first enlarge the RAW or TIFF file to the desired print size and then create the jpeg from which the print would be made, more pixels would be available and compression errors will not be magnified, so print quality is better.
If one enlarges the RAW or TIFF file to the desired size first and then creates the jpeg, more pixels would be available and compression errors will not be magnified, so print quality is better.
Of course, this requires the photographer to enlarge the TIFF or RAW file for the desired print size and resolution and then create the jpeg. That jpeg can then be used to make the print.
The cost is somewhat higher for the first print because the photographer has to spend time enlarging the RAW file to prepare the jpeg for the print. But the added cost for a single print may be worth it if print quality is of the highest importance.
The cost is somewhat higher for one print because the photographer has to spend time to prepare the image. But the added cost for a single print may be worth it if print quality is of the highest importance and it becomes insignificant if multiple prints will be made from that one "prepared" jpeg. .
Multiple prints made from one "prepared" jpeg give the best value to the art consultant
In situations where multiple copies of an image will be made from one "prepared" jpeg the cost difference becomes insignificant. The consultant pays the photographer once to create one "prepared jpeg." Thereafter, multiple prints can be made as per the terms of the commercial license.
In summary:
For highest quality prints in general
Although not shown here, our experience tells us that for the highest quality prints, use a skilled photographer/printer who starts from a RAW file and uses an ink jet (or equivalent) printer.
For the best quality in very large prints made from jpegs
Use a jpeg that was created after a RAW or TIFF file was enlarged to the desired print size. Avoid very big enlargements from smaller jpegs.
While this process may be more expensive for a single print, the added cost becomes insignificant if multiple prints will be made from that one "prepared" jpeg.
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