Printing

[William]

How do I determine the largest physical size that my image can be printed. For example a web sized image may struggle to be acceptably printed to 6x4 but a full resolution image from my camera may reach to A1. How do I work this out?

[Fast Glass]

It all depends on whats your lowest acceptable dots per inch or dpi. For smaller prints such as 8x10 and 11x14 200/350 dpi would be fine for most people. At larger prints such as 20x30 and above 200 or lesswould still be accetable because you are staying farther away.


Personally I don't liketo print anything less than 350/400 dpi for smallerprint sizes, because I like to look close up at the dietails and not be inhibited by resolution. But that's just me.


Toget a idea ofhow big you cangojust print a 8x10 at the dpi you expect to use and stand back at your typical viewing distance tosee if thats excceptable to you. Enlargement programs also help.


John.

[William]

Thanks for that. So does that mean a 350 dpi image of 3,500x3,500 pixels would print 35"x35". Are pixels and dots the same thing?


On my monitor many of my images still look good at full size (1:1, or Ctrl Alt 0 in PS). What would full size be in printing terms?

[Fast Glass]

So does that mean a 350 dpi image of 3,500x3,500 pixels would print 35"x35".

3500 pixels / 35" = 100 dpi. Sooo, I guess you can't print at 35" and 350 dpi.[]


Resolution divided by print size equalls dots per inch.

Are pixels and dots the same thing?

Yes. One pixel equals one dot, but your printer will print at whatever print resolution you set. Lets say 1400 dpi like on my R1900, the print may only be 100 dpi but the printer will interpolate it to 1400 dpi. There is only 100 dpi of dietail, but it will be much smoother and wont be asjaggedand pixelated.

On my monitor many of my images still look good at full size (1:1, or Ctrl Alt 0 in PS). What would full size be in printing terms?

You just do the math in reverse, most moniters are between 80 to 100 dpi. Lets say 100 dpi. Take 3500 pixels and divide by 100 dpi, thatequalls 35".


If you ask Daniel Browning what's the ideal resolution he'll tell you 1200 MP or so![:O]


BTW, 3500 pixels at 2 to 3 aspect ratio is about 8 MP, using a rebel XT,30D or the like?[8-|]


Hope this helps,


John.

[William]

Ok, that all makes sense now. Looks like my 30D is a little short on pixels when it comes to printing anything large, unless I stitch my images. I might try some samples, as you suggest, to see what I can get away with. Thanks for your help John. []

[Fast Glass]

Or upgrade to Phase One. Which by the way has 80MP. Oh, you do have a hole burning in your pocket. Right?[:P]


Cheers,


John.

[Daniel Browning]

How do I determine the largest physical size that my image can be printed?

Well, it depends on viewing environment (distance, lighting, vision, etc.) as well as your own personal standard of resolution.


For example, several films in theaters have been viewed at 70 feet wide with only 0.3 MP. That's 0.9 pixels per inch. (Yes, that's less than *one* PPI -- forget 300 or 150ppi). Even a 2K digital film 50-foot theater is only 3 PPI). But I would bet that you are not as easy to please as the average film goer, and you're probably going to be closer to the the print.


If you scale your viewing environment with print size, then you can effectively print as large as you want. For example, that web-sized image barely prints 6x4 acceptably, but you could actually print it 2000 miles wide if you want -- all you have to do is view it from the moon and it will look as sharp as possible.


So once you've decided on the viewing environment, all that's left is how much resolution you prefer, personally. If you want to avoid the perception of softness, I suggest trying for 150ppi.