Advice please - unforeseen problems printing photos

[Elines]

As part of my weekly photography class we have got a project going where we are trying to sell our photos at a local market. Even if I don't sell anything it will be a good experience!

This is the first time I have had any photos printed for about 5 years - maybe longer.

Anyway - one problem I have hit is that pictures that look pin sharp when viewed on the PC screen were 'rejected' when I tried to load them on to a print website (photobox). I say 'rejected' but what actually happened is that they were accepted but the site said quality was 'poor'. I didn't go ahead with ordering any of the poorly rated images, so I don't know what they would actually look like. The size I was ordering was 12" x 8"

I don't know why any were rated 'poor'..

I have tried to think of what might help explain it and there are several things that I have thought of:
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• one was a close up picture of a wasp. The original photo was much smaller - I had magnified it and the photo showed individual hairs on it. Maybe magnification had something to do with it

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• some were pictures I had copied off the internet and then gimped heavily eg to swirl colours around etc to create an abstract image - maybe the original image wasn't of good enough quality

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• one picture was one I had taken myself with my own camera and gimped slightly - slight whirl effect. To me this was the most surprising 'poor' image, as ungimped photos from the same camera have produced good photos. So does manipulating an image affect its 'quality'??

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Any comments/explanations would be very helpful - as would any advice on how I can tell before I go through all the hassle of gimping/downloading/uploading to a printer's web site whether or not an image will be of good enough quality to print.

 

[bikething]

what were the pixel dimensions of the files ? As in height x width in pixels

 

[Glyn]

Hi Elines,

my guess would be the image dimensions will be too small for a decent print.
As a very rough rule of thumb, for web images you should look for images at around 72 pixels per inch (PPI), whilst for printing, you would aim for around 300 PPI (it's not that clear cut, but it's a good place to start from...)
You should be able to see the image dimensions by looking at the properties of the image - for the size you're looking at (12x8), you should probably look for a minimum of 2000 pixels on the smallest side

 

[Elines]

what were the pixel dimensions of the files ? As in height x width in pixels

Hi Elines,

my guess would be the image dimensions will be too small for a decent print.
As a very rough rule of thumb, for web images you should look for images at around 72 pixels per inch (PPI), whilst for printing, you would aim for around 300 PPI (it's not that clear cut, but it's a good place to start from...)
You should be able to see the image dimensions by looking at the properties of the image - for the size you're looking at (12x8), you should probably look for a minimum of 2000 pixels on the smallest side

Thanks for this - last time I had photos developed pixels weren't involved (I was using film then).

So I will see if I can find the 'ppi' to see how it varied. First time I've heard of it.