Picture size

[mercmanuk]

Hi all, wife is typing this so grammar will be better - might be OK photographer but rubbish at typing! I have a Canon 400D 10million pixels. What size picture can I go up to? I have done A4 could I go up to A3, A1 and beyond? Could you please tell me the basic rules of what I need to do this and when would I start losing definition, sharpness etc.
Regards Mark.

 

[Steep]

A3 A3+ easily, A2 possibly without having to size the image up.

 

[andrewc]

depends what distance you intend to view the picture from...

 

[StewartR]

There is no limit to the size of "decent quality" print you can get from a 400D.

Whether or not it looks decent depends on how far away you are when you look at it. The bigger the print, the further away you'll be, so you can get away with lower resolution.

On the Cambridge In Colour web site, there's a resolution calculator. For somebody with 20/20 vision, it suggests:
- 350 ppi when viewing at 25cm
- 175 ppi when viewing at 50cm
- 87 ppi when viewing at 1m
- 18 ppi when viewing at 5m

(ppi = pixels per inch)

Your 400D will give you 3888x2592 pixels to play with. So, assuming you have a high-quality image to start with, and a good printer, you can have:
- a 12"x8" print at 324ppi, which will look really sharp even with your nose up to it
- a 24"x16" print at 162ppi, which will look good from a couple of feet away
- a 48"x32" print at 81ppi, which will look good from about 3 or 4 feet back
- you get the idea

Thing is, if you had a 48"x32" print, you wouldn't want to look at it from only 3 or 4 feet away. I guess 10 feet or so would be more reasonable. And from that distance it will look great.

If you get every pixel printed out 1m square, you'll have an image about 3.9km x 2.5km which will look AWESOME from a plane at 35,000 feet. Admittedly it would be a bit tedious putting all the pixels together. And you'd need a big flat space to do it. And it would probably be expensive. Though you could probably get some sort of arts grant for a project like this.

 

[mrgubby]

[S1]A very good post from StewartR [/S1]

 

[mercmanuk]

There is no limit to the size of "decent quality" print you can get from a 400D.

Whether or not it looks decent depends on how far away you are when you look at it. The bigger the print, the further away you'll be, so you can get away with lower resolution.

On the Cambridge In Colour web site, there's a resolution calculator. For somebody with 20/20 vision, it suggests:
- 350 ppi when viewing at 25cm
- 175 ppi when viewing at 50cm
- 87 ppi when viewing at 1m
- 18 ppi when viewing at 5m

(ppi = pixels per inch)

Your 400D will give you 3888x2592 pixels to play with. So, assuming you have a high-quality image to start with, and a good printer, you can have:
- a 12"x8" print at 324ppi, which will look really sharp even with your nose up to it
- a 24"x16" print at 162ppi, which will look good from a couple of feet away
- a 48"x32" print at 81ppi, which will look good from about 3 or 4 feet back
- you get the idea

Thing is, if you had a 48"x32" print, you wouldn't want to look at it from only 3 or 4 feet away. I guess 10 feet or so would be more reasonable. And from that distance it will look great.

If you get every pixel printed out 1m square, you'll have an image about 3.9km x 2.5km which will look AWESOME from a plane at 35,000 feet. Admittedly it would be a bit tedious putting all the pixels together. And you'd need a big flat space to do it. And it would probably be expensive. Though you could probably get some sort of arts grant for a project like this.

Many thanks for that informative post, you know your stuff,

Regards Mark.