DPI Numbers for Printing Quality
Discussion
Thought I'd add some fuel to the old DPI debate. As we know magazines demand 300 dpi images for printing. Our photo club had a demo from Tetenal's dealer when digital printing was new that showed how 200 dpi images were of photographic quality, 180 dpi were still acceptable but below that you started to get into problems with jagged lines appearing - 150 dpi was definitely unsatisfactory to even the untutored eye.
Well, a semi-pro photographer friend just asked me to print out a wedding photo for him. It was taken using a digital SLR and was 13MB in size. Fair enough for something to be printed out at 12x10", but he wanted it printed out to 16x20". Bit of a risk I thought but as he was paying I printed it out. I must say I was pleasantly surprised by the result, sharp, clear no jaggies, no problems whatsoever and he had a delighted customer - who then had to find enough space to display it !
So, should magazines still demand 300 dpi originals when the software exists that can generate decent output from quite coarse master data ? Should they ask for a minimum file size instead ?
Well, a semi-pro photographer friend just asked me to print out a wedding photo for him. It was taken using a digital SLR and was 13MB in size. Fair enough for something to be printed out at 12x10", but he wanted it printed out to 16x20". Bit of a risk I thought but as he was paying I printed it out. I must say I was pleasantly surprised by the result, sharp, clear no jaggies, no problems whatsoever and he had a delighted customer - who then had to find enough space to display it !
So, should magazines still demand 300 dpi originals when the software exists that can generate decent output from quite coarse master data ? Should they ask for a minimum file size instead ?
te51cle said:
So, should magazines still demand 300 dpi originals when the software exists that can generate decent output from quite coarse master data ? Should they ask for a minimum file size instead ?
Well exactly.
However file size is no arbiter either: I could submit a really cruddy bitmap!
te51cle said:
Yep, how can quality be quantified ? Bit like measuring string. Could a graph be produced giving image size vs. minimum file size - I think it would be based on a square law rather than being a straight line from a proportional relationship.
I have seen this done before, but it's really only a basic rule of thumb type thing. Especially with JPEG, the filesize can swing around a lot, and from the same camera a smaller sized file is often a better quality than the large one.
My feeling about this from a professional viewpoint is yes, Magazines and publishers should maintain a standard of materials, i.e. 300dpi for print images.
As a very busy book designer I have, over the past few years, worked with in excess of 25,000 digital images, when dealing with this volume of material it is essential to be confident of the quality of files coming into me. Getting to print PDF stange and discovering at FlightCheck that images are of lo quality is not only frustrating is is expensive in terms of the time and money used to correct the problem.
What you haven't considered is where the print is placed, there are still vast differences between printers and the RIPs they use, be they in Germany of the Far East, maintaining the highest quality in images potentially eliminates another pitfall in the process.
As for the file size issue, this all boils down to the algorithms that the compression software uses and the manner in which the files are saved, so that is really no guide at all, other than a very, loose one. An eps file saved with Jpeg compression will be a lot smaller than the same file saved with Tif compression, in the same way as a white page will be a smaller file size than a multi coloured one. It really boils down to the data that is being compressed/saved.
Tim
As a very busy book designer I have, over the past few years, worked with in excess of 25,000 digital images, when dealing with this volume of material it is essential to be confident of the quality of files coming into me. Getting to print PDF stange and discovering at FlightCheck that images are of lo quality is not only frustrating is is expensive in terms of the time and money used to correct the problem.
What you haven't considered is where the print is placed, there are still vast differences between printers and the RIPs they use, be they in Germany of the Far East, maintaining the highest quality in images potentially eliminates another pitfall in the process.
As for the file size issue, this all boils down to the algorithms that the compression software uses and the manner in which the files are saved, so that is really no guide at all, other than a very, loose one. An eps file saved with Jpeg compression will be a lot smaller than the same file saved with Tif compression, in the same way as a white page will be a smaller file size than a multi coloured one. It really boils down to the data that is being compressed/saved.
Tim
I don't have much experience in this area, having never submitted a photo to a magazine , but I've read a PS book recently which talked about the same issue. It too pointed out that you can get perfectly good prints at lower than 300dpi res and in some cases this is true.
I don't think that magazines should demand 300dpi images just so that they can claim to be publishing at the highest standards, afterall if you can't really see the difference, who will know.
I do think they should ask for 300dpi images though, they cannot know that *every* image they get will print ok at, for example, 200dpi. So asking for photos at 300dpi will ensure that the images they get are *at least* at a printable quality.
If you were submitting a photo for printing, surely you would want the greatest chance of it being published and a bit of enlargement prior to sending it would be worth it in the end..
I don't think that magazines should demand 300dpi images just so that they can claim to be publishing at the highest standards, afterall if you can't really see the difference, who will know.
I do think they should ask for 300dpi images though, they cannot know that *every* image they get will print ok at, for example, 200dpi. So asking for photos at 300dpi will ensure that the images they get are *at least* at a printable quality.
If you were submitting a photo for printing, surely you would want the greatest chance of it being published and a bit of enlargement prior to sending it would be worth it in the end..
rj_vaughan said:
I don't have much experience in this area, having never submitted a photo to a magazine , but I've read a PS book recently which talked about the same issue. It too pointed out that you can get perfectly good prints at lower than 300dpi res and in some cases this is true.
I don't think that magazines should demand 300dpi images just so that they can claim to be publishing at the highest standards, afterall if you can't really see the difference, who will know.
I do think they should ask for 300dpi images though, they cannot know that *every* image they get will print ok at, for example, 200dpi. So asking for photos at 300dpi will ensure that the images they get are *at least* at a printable quality.
If you were submitting a photo for printing, surely you would want the greatest chance of it being published and a bit of enlargement prior to sending it would be worth it in the end..
With the greatest respect, there is nothing better than real world experience.
Some of the crap that I've had submitted by people who 'think' they know what they are doing has to be seen to be believed.
We do not claim to be publishing at the highest standards, what we try to do it cut out the crap. Yes, you can use images at resolutions down to 200dpi, and even lower res images can be 'rescued' by judicious use of interpolation, but this should not be considered acceptable, and should be the exception rather than the norm'.
I fail to see the problem with asking for good quality raw materials, if you want to be published then supply what you are asked to supply. ('you' not directed at you, its used in its general form).
Tim
>> Edited by TT Tim on Monday 13th December 09:13
Its also worth remembering that its 300dpi AT ACTUAL SIZE that is required. Ie, if you are printing at 5"x10", the file needs to be 300dpi at that size. If its a 10"x20" image at 150dpi, you can half its size and therefore double its dpi. I'm a graphic designer and for very small images (e.g just illustrative images) we've sometimes used a 72dpi digital compact file - once you shrink it right down it can look ok.
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