Minimum Resolution

PixelPie · December 9, 2009

First off, my apologies if this has been posted in some way, shape or form but I've got myself so confused now that I just need to ask.

Print resolution; PPI, DPI, etc, confuse me. I'm not going to lie. I've got a really basic understanding but for me to try and explain it to someone else, it would be a loss cause. Anyway, I want to know, is there any way that I can restrain the proportions/resolution of an image so that it'll print a nice 11x14 but nothing really larger? And if so, what would those be? Is there a really simple formula for figuring this out in case I ever want to change it to a 5x7, 8x10, etc? :scratch

And, do you know of any excellent articles that explain this stuff, simply? The Web is full of articles that contradict each other. Thank you.

pathfinder · December 9, 2009

You may find some answers here

Miguel Delinquento · December 9, 2009

This Smugmug print table is very easy to understand and a good reference to be bookmarked.

ME

PixelPie · December 10, 2009

Thanks for those links. It was definitely easier to follow than some of the stuff I had read!

The Print Table states that the minimum for an 11x14 is 768x1024. So what kind of resolution could I set that to? In Pathfinder's article, it said "images destined for printing need resolutions in the order of 180- 360 pixels per inch" and that larger prints can be printed as low as 150 because of the viewing distance, which makes sense.

If I set an image file to the above dimensions at 150 or 180 pixels per inch, that would mean images smaller than that would be of poorer quality because the 4x6's and 8x10's are viewed closer and images larger will start to lose quality because of the dimensions. Is that right?

If I increase the ppi to something even higher but still under 300/360, would the dimensions, 768x1024, be enough to prevent the image from being printed at larger sizes but keep the small print sizes good quality?

Am I missing some sort of simple math? (never my best subject)

ivar · December 10, 2009

The SmugMug tables gives you the absolute MINIMUM resolution that is NEEDED for printing. More will be better usually.

PixelPie wrote:

If I set an image file to the above dimensions at 150 or 180 pixels per inch, that would mean images smaller than that would be of poorer quality because the 4x6's and 8x10's are viewed closer and images larger will start to lose quality because of the dimensions. Is that right?

If I increase the ppi to something even higher but still under 300/360, would the dimensions, 768x1024, be enough to prevent the image from being printed at larger sizes but keep the small print sizes good quality?

Setting PPI on an image that is being uploaded to SmugMug and printed doesn't do anything at all. It's the resolution that you need to worry about. Note that the SmugTable also doesn't say anything about PPI, but only talks about resolution

PixelPie · December 10, 2009

Usually when I upload to Smugmug, I don't worry too much about it as I can limit print sizes and what not but this is for a digital file that I'll be giving away, ideally with a restricted license. I figured I could write up a license but if I could restrict the file too, that'd be great!

I looked at a local lab here and they also had a chart for minimum resolution, best and unacceptable.

For an 11x14 the minimum given was 1650x2100 and unacceptable was 825x1050. So now I'm also curious why Smugmug's minimum is below that of the 'unacceptable' range of this other lab. Does that just have to do with quality of labs & printers?

Miguel Delinquento · December 10, 2009

More the criteria the lab uses to ensure a level of quality that meets their requirements. Some printers use different scaling formulas and algorithms. Without directly comparing prints, it is difficult to say which one delivers a product with better quality.

I have been impressed with the prints that Smugmug's services deliver. Bay Photo is considered one of the best printing services for professionals.

M

PixelPie wrote:

[deleted]

For an 11x14 the minimum given was 1650x2100 and unacceptable was 825x1050. So now I'm also curious why Smugmug's minimum is below that of the 'unacceptable' range of this other lab. Does that just have to do with quality of labs & printers?

pathfinder · December 10, 2009

ivar wrote:

The SmugMug tables gives you the absolute MINIMUM resolution that is NEEDED for printing. More will be better usually.

Setting PPI on an image that is being uploaded to SmugMug and printed doesn't do anything at all. It's the resolution that you need to worry about. Note that the SmugTable also doesn't say anything about PPI, but only talks about resolution

When Ivar says "resolution" what he is saying is the "total number of pixels, along both dimensions of the image". The total number of Pixels is fundamental, ppi is meaningless. Dpi refers to how printers spray ink on paper, and is usually 5 to 15 dots per pixel.

PixelPie · December 19, 2009

Just wanted to send my thanks. I think I have a much better understanding of it now as I reread your articles/posts along with a few others. Tks!

arodney · December 19, 2009

PixelPie wrote:

Print resolution; PPI, DPI, etc, confuse me.

This may help:

http://www.digitaldog.net/files/Resolution.pdf

PixelPie · December 24, 2009

arodney wrote:

This may help:

http://www.digitaldog.net/files/Resolution.pdf

Excellent article. Thanks. I don't think it can be explained any better.

Minimum Resolution

Comments