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View Full Version : Megapixel size = What size print



Kyle72
26-09-2010, 2:51pm
Hi all

Hope i have posted this in the correct section if not could a mod or admin please move to the correct section.

What i want to know is does the megapixel size refer to how big of a photo you can print without it going blurry or pixelate

And does anyone have a chart to what size or know where to find a guide to help make a decision on what size i want to print.

And last question can anyone recommend a good place that turns your photos into good quality prints, at a large size.

Thanks

William
26-09-2010, 2:58pm
:umm: I have Canvas prints done from my 8.2 MP 30D @24inches x 16inches tack sharp and look excellent :)

etherial
26-09-2010, 7:39pm
I'm certainly no expert but the way I understand it this is where dpi comes into it. You can print the same image at 300dpi and again at 72dpi and get vastly different sizes.

It depends a lot on what sort of distance an image will be viewed from, think billboard and you might be able to have 1 dpi and viewed from 100m it might look fine. On the other hand the same image might need to be printed at 600dpi on a postage stamp to get the detail required.

This link might help clear it up too...

http://www.rideau-info.com/photos/mythdpi.html

I'm not aware there is any hard and fast rule on this but here are a couple of sites that have a basic guide that might be useful.

http://www.microscope-microscope.org/imaging/image-resolution.htm
http://www.digicamguides.com/print/ppi-print-size.html

OzzieTraveller
26-09-2010, 7:48pm
G'day Kyle

Pixels & publishing & printing all go hand-in-hand, but for many of us (in the beginning) it can become a bit of a maths-nightmare

Your camera shoots in pixels ... for this example I'll say it shoots 3000 x 2000 pixels, making 6,000,000 pixels or 6mpx overall
Magazines print at 300DPI and most domestic colour printers print at about 200DPI - tho they can print a lot finer if you ask for it

If you submitted to a magazine publisher, where the mag was printed "at 300DPI", then the printer would say "3000 pixels divided by 300DPI = 10inches" ... ie- it could do a single page easily
If you home-print at 200DPI, then 3000 / 200DPI = 15 inches

However, if you send this image to a commercial printer and, say, ask for a 20inch print, the machine will 'stretch' and realign the pixels to fit the 20inch paper - the result being that you would see it as 'okay' to 'maybe a bit soft' ... but hang it on the wall and view it at a reasonable distance, and it will look okay for sharpness. If you ever get the opportunity to view a roadside hoarding up close, the pixels are 'horrific' - but from the road, it looks quite okay

Hope this helps a bit
Regards, Phil

kiwi
26-09-2010, 7:51pm
how "big" is your file in mp ? and how big do you want to print ?

rwg717
26-09-2010, 7:58pm
Just as a quick guide, Scott Kelby quotes the following print sizes in his book "Digital Photography" as rule of thumb:
3 mpx = 5"X7"
4 mpx = 8"X10"
5 mpx = 11"X14"
6 mpx = 13"X19"
8 mpx = 16"X20"
12 mpx = 24"X36"
As mentioned in previous posts, quality can vary substantially between printers:)
Richard

ZedEx
26-09-2010, 8:16pm
IMO you can throw the idea of megapixels out the window. Pixels are nothing without a sharp lens, spot on focus etc. Also, the thing with larger prints is that you'll often be viewing them from a greater distance, so you can stretch the boundaries. It's not like billboards are taken with 10 billion pixel cameras (although a medium format would help ;p)
So yeah, as Richard mentioned above, that's a good rough guide, but don't consider it a hard and fast rule. I've seen plenty of files from 21 megapixel cameras that aren't worthy of anything over 12x18in :p

Kyle72
26-09-2010, 9:19pm
Thanks for all the replies, It now gives me an understanding on how it works and what to look for. I currently have the fujifilm which shoots about 12mp from memory, it has taken some good photos, and want to do a couple of large prints to hang on the wall of family shots and my little girl, but also whe i get my new camera when i finally decide in what to get i want to do some landscapes and hav printed and hangin on the wall.

The other thing is, i need to understand inches better and releated it to a size in mm or cm, I know how to work it out just have to do a few calculations to understand the sizes that have been posted up in this thread.

Thanks

ZedEx
26-09-2010, 9:32pm
Sorry about the inch thing, it's the standard in the photo industry so I use it all the time as I work in lab :p Luckily my parents hammered it into me as a kid, cos my generation as a whole have no exposure to it (i'm only 21).
So with your fuji compact especially, 12mp doesn't mean much. You can understand what I mean yeah? Your 12 megapixel fuji is not capable of taking as clean shots as say my 12mp canon 5D full frame dSLR with a $1800 lens - even both under ideal circumstances?
Best thing to do is blow them up on the computer screen and try to estimate each shot on how big it will go, or take your files to a good pro printing lab and they should be able to tell you some maximum print sizes


Thanks for all the replies, It now gives me an understanding on how it works and what to look for. I currently have the fujifilm which shoots about 12mp from memory, it has taken some good photos, and want to do a couple of large prints to hang on the wall of family shots and my little girl, but also whe i get my new camera when i finally decide in what to get i want to do some landscapes and hav printed and hangin on the wall.

The other thing is, i need to understand inches better and releated it to a size in mm or cm, I know how to work it out just have to do a few calculations to understand the sizes that have been posted up in this thread.

Thanks