Printing help/advice please

[Bear Dale]

Ok this is going to probably be really painful for old hands, but this is something I've always really had a hard time wrapping whats left of my grey matter around.

My camera produces an image that is 5616 x 3744 pixels.

When I'm printing out and A4 sized print, should I use the above size or should I use the size that I use for posting on AP which is 1024 x 683 pixels?

What about for A3 or A2 sized prints?

[Warbler]

Personally, I resize all my print images to exact pixel dimensions. 8x10 is 2400x3000px and so on. This is for prints at 300dpi. Of course metallics require 400dpi, so just multiply the required size by the print resolution to get the size required.

[I @ M]

Jim,
by the pixel dimensions of the image produced by your camera it conforms to the 2:3 aspect ratio which is common for slr / dslr sensors.
3744 divided by 2 = 1872
1872 multiplied by 3 = 5616

If you are printing an "off ratio" picture such as A4 you are wasting valuable pixels along one edge. :D
A4 = 210 x 297 mm

210 divided by 2 = 105
105 multiplied by 3 = 315

Putting your 2:3 aspect ratio output onto an A4 paper results in a loss of 18 mm of pixels on the long edge.

If you crop the image to conform with the A4 dimensions then all you have to do is to resize the image to those parameters.
If you don't want to crop, simply have it printed on 8 x 12 inch paper, that conforms to the 2:3 ratio and is the most reasonably common paper size closest to A4.

8 inches = 203.2
12 inches = 304.8 mm

8 inches divided by 2 = 4
4 multiplied by 3 = 12

or in mm

203.2 divided by 2 = 101.6
101.6 multiplied by 3 = 304.8

I think that you are better off resizing your image to the physical paper dimensions at which you wish to print taking into account whether your printer ( either the one at home on the desk or the commercial printer down the road ) requires 200 or 300 or whatever DPI specified to print at.
Different software has different ways of doing that

[Bear Dale]

Thank you both very much for your posts.

My printer is a Canon MP990, I have just read the manual and for the life of me I can't see anywhere were it mentions what DPI it prints in or how to change that, it only mentions DPI for scanning.

I@M I've read your reply more than a few times and I'm truly not trying to be an utter boof head here, but I'm lost :o:o:o

In easypeasy terms :) what pixels should my images be for an A4 sized print? I still can't work it out, even with your detailed formula :o:o:o

- - - Updated - - -

I just showed my wife your post and she "think's 2480 X 3508 pixels is the answer is that right?

[Kym]

Lets simplify the maths...

5616 / 3744 = 1.5 (your sensor)
3 / 2 = 1.5
12 / 8 = 1.5
15 / 10 = 1.5

But A4 = 297 x 210 mm as a ratio 297 / 210 = 1.414
(all A size sheets have the same ratio)

:)

[I @ M]

Jim, as best I can explain it ---- (puts easypeasy hat on) ---- to fit an image from a native 2:3 ratio camera (yours) on to A4 paper you either have to crop to the size of the paper or "squash" it into the area uncropped and have a horribly distorted image.

Your software should have an option to give a "custom crop", set that to 210 x 297 mm and apply it. You will then see that the number of pixels has taken care of itself and changed.

Don't worry about the pixels, they will take care of themselves when you set a crop to the output size of the print.

I reckon that for an A4 print on your Epson 300 DPI will give you all the quality that you will need. :)

[Warbler]

Didn't realise you were going to use an inkjet. You're using CS6 as I recall. Just set a custom crop to the size you want and set the resolution at 300dpi. When you crop your image it will resize for you. Can't go wrong. I haven't used a home printer since 2003. Why bother when proper photographic prints from pro labs are so cheap anyway.

[I @ M]

Jim, I will see if pictures can help better than words.

When I start out the image dimensions are thus ---

https://dl.dropbox.com/u/9582534/crop%20a4%20b.png

I set a custom crop in software to 297x210 ---

https://dl.dropbox.com/u/9582534/crop%20a4.png

That then shows me the area I have to play with on that ratio.

https://dl.dropbox.com/u/9582534/crop%20a4%20a.png

I perform the crop and then resize the image to A4 and I end up with ----

https://dl.dropbox.com/u/9582534/crop%20a4%20c.png

Once again, I am not pressing any buttons to alter the pixel value, as I perform the crop and resize the pixels are being changed in line with the output size.

Sorry, that is the way my software works, I am sure that whatever you use will have something very similar.

[Matwil]

When I started out doing my own printing I had the same problem. AFter a while I found it easier to settle on some standard sizes, (and standard matts). Most times I cropped especially for printing and the aspect ratio and allowed the software to handle it. In many programs the DPI is set when you crop or resize. Then I started printing larger sizes A3 and A2. I found it easier to use OnOne's Resize 7 as it handles the resizing to the larger print sizes very well. You can try it and see if it suits your purposes by downloading a 30 day trial. They also have very good training videos so you know what you are doing rather than flying blind. The site is http://www.ononesoftware.com/downloads/


http://www.ononesoftware.com/downloads/

[Bear Dale]

Very much appreciate all the replies, the help and explanations given to me.