Blowing things up

A question we are frequently asked is "how big can I print my image file?" and it's a difficult one to answer. There are guidelines at our online shop, but these are essentially 'manufacturers recommendations' that we have adopted from Epson and Noritsu. All too often the size of a precious photograph falls below this standard but this doesn't mean it is unusable. The recommendations aim towards exhibition-quality standards and ensure there are no discernable 'artefacts ( squiggly bits ) that a competition judge would criticise.

The same rules apply to traditional methods of printing: if an passport photograph of a favourite grandparent is enlarged to 8"x10" then one would expect the quality to suffer. The enlarged image won't be as sharp and imperfections that were not visible on the passport size now become splodges, but does this matter? Family photographs have an emotional value to us that mean we ignore the imperfections which would horrify a competition judge.
So it is with digital images: enlarged digital photos have their own types of imperfection when enlarged more than recommended, but they can still be usable.

"So...how big can I print my image file?!"

Below are some examples that show what happens when an image is enlarged 'too far'.

Sample A

Sample B
full size section image 9Mb image section

Section of original 17Mb file with text

Reduced to 9Mb file and enlarged to match

Sample C

Sample D
4Mb image section 1Mb image section

Reduced to 4Mb file and enlarged to match

Reduced to 1Mb file and enlarged to match

Penguin Samples Explanation

penguin original image

A section of the original, that is in focus and has fine detail, was enlarged and text added. This section was then reduced in size to produce equivalent file sizes of 9Mb, 4Mb and 1Mb. The method is not precise but the result does illustrate the effect one might expect to see when a digital file is enlarged too much. Typically images taken from a web-page ( where files are necessarily small ) and then printed would show this effect. It is likely to be breaking copyright law as well!

Is the quality good enough?
In this particular case we are used to seeing very high quality photographs of wildlife and many people would be find the imperfections of Sample D unacceptable if the print were to hung on a wall at home.

How closely will it be examined?
Large prints tend to be viewed at a distance, not close up as for a postcard size, so one can be less critical of minor faults. The exception would be an exhibition or gallery where visitors have an infuriating habit of scrutinising an image from a couple of inches away, hence the need for best possible quality for competitions.

So what does work?
The illustration below is a good example of when 'bad' quality is still acceptable and one that we see quite often. The story behind it might run like this "John never stopped talking about that trip when he was a boy and he now works for Cunard so we thought we'd pin this up at his 21st birthday party" Perfect. OK so the quality isn't good but it does it matter?


Faded old family snap

Enlarged up for family party
old print of boy on boat enlarged section of print

Set out in this way it is obvious that beauty, or quality, is indeed in the eye of the beholder and the best judge of what is acceptable is the person paying for the print. At The Darkroom we will tend to ask questions to establish how a print will be used: if it is to be framed; if it is being used as a one-off at a party; if there is no alternative or original photograph to hunt out of the loft? Knowing the answers to these subjective criteria can help us advise "How big can it go" and ensure the client is pleased with the result and is not being asked to pay more than is necessary.


The Darkroom UK Ltd
www.the-darkroom.co.uk
01242 239031