Steve's Digicams Forums

Steve's Digicams Forums (https://forums.steves-digicams.com/)
-   General Discussion (https://forums.steves-digicams.com/general-discussion-11/)
-   -   [Recovered Thread: 43067] (https://forums.steves-digicams.com/general-discussion-11/%5Brecovered-thread-43067%5D-41716/)

Silent Momo Dec 30, 2004 4:30 PM

I have a Canon A400 and was wondering if a Large resolution photo (2048x1536 pixels), which is intended for 8.5x11 prints, can be printed on 4x6 paper. Please let me know.

Wildman Dec 30, 2004 9:00 PM

Yes... printing big files on smaller paper works fine

Nicolas Dec 30, 2004 10:03 PM

Actually I doubt that a resolution of 2048x1536 is intended for 8.5x11 prints.

That means a 3mp camera and it will print photo quality pictures at 4x6 and 5x7, provided that you use the full resolution of 2048x1536. It will give you excellent results at 8.5x11. But seriously, no resolution is intended for a particular print size.

Silent Momo Dec 30, 2004 11:10 PM

Nicolas wrote:
Quote:

Actually I doubt that a resolution of 2048x1536 is intended for 8.5x11 prints.

That means a 3mp camera and it will print photo quality pictures at 4x6 and 5x7, provided that you use the full resolution of 2048x1536. It will give you excellent results at 8.5x11. But seriously, no resolution is intended for a particular print size.
Thanks for responding Nicholas, but I don't know what you mean exactly. The 2048x1536 resolution figure is what my Powershot manual suggested for 8.5x11 prints, but from your answer, are you suggesting that this is not enough resolution? That the quality would not be very good for 8.5 by 11 prints but good for 4x6 prints? Please let me know.

TunafishJoe Dec 31, 2004 12:25 AM

[align=center]And I Quote From[/align]
[align=center]http://www.acdsystems.com/English/Co...2002-06-08.htm[/align]
[align=center][/align]
To figure out what size prints you can make from today's digital cameras, you have to first break down the pixel measurements. For example, a 4.1-megapixel camera works out to a picture with dimensions of 1704 x2272pixels at its highest resolution; a 3.34 megapixel camera works out to 1536 x 2048 pixels;and, a 2.24 megapixel camera works out to approximately 1280 x 1600 pixels.

For a reasonable quality print you need approximately 150 pixels per inch of resolution (we'll call this medium quality), while for professional quality prints you need at least double that. For simplicity's sake, pick either the long or short dimension of the print/camera resolution and work with that one. For this instance we'll use the long edge of the print. Let's work through a couple of examples:

2.24 Megapixels
Maximum print size (medium quality) for a 2.24 megapixel camera: 1600 divided by 150 = 10.7." Using this example, you could get a medium quality print of up to about 10 inches (so you could get a medium quality 8"x10")

Maximum pro quality print size would be 1600 divided by 300 = 5.3". In this case, you'd be able to get a pro quality print at 3.5" x 5".

3.34 Megapixels
Maximum print size (medium quality) for a 3.34 megapixel camera: 2048 divided by 150 = 13.65", so you'd be able to get a medium quality print of close to 11" x 14".

Maximum pro quality print size would be 2048 divided by 300 = 6.8." In this case, you'd be able to get a pro quality print at 5" x 7."

4.1 Megapixels
Maximum print size (medium quality) for a4.1 megapixel camera: 2272 divided by 150 = 15.14", so you'd be able to get a medium quality print of close to 11" x 14" with the option of cropping an inch around the edges to emphasize your subject some more.

Maximum pro quality print size would be2272 divided by 300 = 7.57." In this case, you'd be able to get a pro quality print at 8" x 10" with a border.

Keep in mind that these guidelines are not absolute! Your lens, lighting, CCD quality and method of printing all play a part in the final results. Also, the resolutions quoted are based on optical resolution and not interpolated (upsampled) resolution. The formulas can be applied to cameras of any resolution, or you can work the formula backwards to find out how many megapixels are required to get the image quality you require at the size you will be printing. Good luck!

TunafishJoe Dec 31, 2004 12:45 AM

[align=center]Heres another take from[/align]
[align=center]http://www.megapixel.net/cgi-bin/fs_...egapixels.html[/align]
[align=center][/align]
[align=center]



Camera

Screen image

Printed image


Image Resolution
=
Image size at 72 PPI
(pixels per inch)

=
Image size at 300 DPI
(dots per inch)


A
640 x 480
=
22.58 cm x 16.93 cm
(8.889 in. x 6.667 in.)

=
5.42 cm x 4.06 cm
(2.133 in. x 1.6 in.)


B
800 x 600
=
28.22 cm x 21.17 cm
(11.111 in. x 8.333 in.)

=
6.77 cm x 5.08 cm
(2.667 in. x 2 in.)


C
1024 x 768
=
36.12 cm x 27.09 cm
(14.222 in. x 10.667 in.)

=
8.67 cm x 6.5 cm
(3.413 in. x 2.56 in.)


D
1280 x 960
(1.3 megapixel)

=
45.16 cm x 33.87 cm
(17.778 in. x 13.333 in.)

=
10.84 cm x 8.13 cm
(4.267 in. x 3.2 in.)


E
1600 x 1200
(2.1 megapixel)

=
56.44 cm x 42.33 cm
(22.22 in. x 16.665 in.)

=
13.55 cm x 10.16 cm
(5.333 in. x 4 in.)


F
1800 x 1200
(2.3 megapixel)

=
63.5 cm x 42.33 cm
(25 in. x 16.665 in.)

=
15.24 cm x 10.16 cm
(6 in. x 4 in.)


G
2048 x 1536
(3 megapixel)

=
72.25 cm x 54.19 cm
(28.444 in. x 21.333 in.)

=
17.34 cm x 13 cm
(6.827 in. x 5.12 in.)


H
2400 x 1600
(4 megapixel)

=
84.67 cm x 56.44 cm
(33.333 in. x 22.22 in.)

=
20.32 cm x 13.55 cm
(8 in. x 5.33 in.)
[/align]

TunafishJoe Dec 31, 2004 12:49 AM

[align=center]Oops.. well, the first line of each letter is the camera resolution, the second line is screen resolution, and the third line is print resolution at 300 dpi.[/align]

Nicolas Dec 31, 2004 8:36 AM

What I was suggesting is not that the results would be bad at 8.5x11, just that they wouldn't be photo quality, just excellent. And mind you, but excellent results is VERY acceptable IMHO. I base myself on the same kind of thinking Joe made. 300 ppi is photo quality, but its VERY hard to see the difference unless you go below a certain number of ppi and that depends on you. I printed a picture at about 110ppi to see what I could tolerate and to my surprise the result was quite impressive, the pixelization is noticeable when you look at the picture from very close, but at a reasonable distance it is perfectly clear.

So, a picture taken at 2048x1536 resolution and printed at 8.5x11 will be 180 ppi, which is going to give you excellent results, but not photo quality ones.

Silent Momo Dec 31, 2004 3:25 PM

Thanks for posting guys. I have another question about quality: if 8.5 by 11 photos are printed on 4x6 paper, will the quality be noticeably better?

TunafishJoe Dec 31, 2004 4:18 PM

That all depends on the resolution of the original image...

If you have a 2mp camera, approximately 1800 x 1200 and you print it on an 8x10 page you will see pixels, if you print it on a 4x6 you wont. But lets say that if you have a really old camera, circa 1998 and it can only shoot 640x480 you will see pixels no-matter 8x10 or 4x6 or even 3.5x5. In fact if you want photo quality prints from that small (using the 300dpi formula) you can only print a 1.5x2 inch photo.





[align=center]DO THIS[/align]


[align=left]-Find the resolution of your image[/align]


[align=left]-Divide each side by 300[/align]


[align=left][/align]


[align=left]You now have the size in inches that you can print a photo quality photo.[/align]
[align=left][/align]
[align=left]EDIT:[/align]
[align=left][/align]
[align=left]What do you mean 8.5x11? Where did you get this figure in the first place??[/align]


All times are GMT -5. The time now is 3:10 PM.