Pixel Dimensions for Printing - DPChallenge Forums

Canon EF-S 15-85mm f/3.5-5.6 IS USM

07/21/2004 02:20:04 PM · #1

Images come off my camera at 2048x1536 (3mp). When I go to print them at the Fuji Kiosk at my local photo center the printed images are smaller or more cropped than my original digital image, borders I have created are also cut off. I assume I will need to adjust/crop my original images to another dimension before printing but I do not know what those dimensions are. I want to keep it as close to the original size as I can for better image quality. I've searched online for this information in vain.... anyone got the answer or a link? Thanks!

Dana

superdave_909

Canon EOS-60D

07/21/2004 02:25:09 PM · #2

check your dpi setting,
2048x1536 @ 96dpi isn't really suitable for printing
the kiosk probably changed the dpi to something like 150dpi by default
which would actually make the pixel dimension/image size smaller.

cpanaioti

Canon EOS-40D

Canon EF 70-300mm f/4.5-5.6 DO IS USM

07/21/2004 02:34:02 PM · #3

First figure out the aspect ratio: 2048/1536 (1.33 to 1)

Then compare that to the aspect ratio of the print you're trying to make. If they don't match then cropping will happen. If you want a specific crop you'll have to do the cropping yourself before you take them to print.

8 x 10 = 1.25 to 1 (10/8 = 1.25)
4 x 6 = 1.5 to 1 (6/4 = 1.5)

Message edited by author 2004-07-21 14:35:02.

garlic

Canon EOS-10D

Sigma 15-30mm f/3.5-4.5 EX Aspherical DG DF for Canon

07/21/2004 02:34:15 PM · #4

Also check the dimension of the prints. If the are not 3:2 (like 6x4 in.) then you have to crop something of your picÂ´s.

marginalwarfare

Canon EOS-300D Rebel

Canon EF 70-200mm f/4.0L USM

07/21/2004 02:34:33 PM · #5

You just need to make sure the proportions are correct for the size print you're making. Your picture as-is has a 3/4 aspect ratio, so 6x8" prints should work fine. Just about anything else will need cropping though.

Canon RF 24-70mm f/2.8 L IS

07/21/2004 03:16:58 PM · #6

I understand that I need to crop them, not a problem, however to what dimension do I crop them? for say a 4x6 or 5x7 or 8x10. I am absolutely horrible with numbers so figuring out the aspect ratio is beyond me :( Is there not a table that shows what it would be? omg I hate to sound so blonde... lol

kirbic

Canon EOS R5

07/21/2004 03:26:13 PM · #7

Are you using Photoshop, or other editing software?

Canon 12x IS USM (S3 IS built-in Lens) -- 36-432mm (35mm EQ)

07/21/2004 03:35:33 PM · #8

I use Microsoft Image Pro 9. In my cropping option is allows me to make a square from pixel dimensions I enter, then I move the square over the image and it crops it to those specific dimensions. This is why I need the number or pixels that comes closest to my original and is equal to a 4x6, 5x7 or 8x10 print. Does that make any sense?

example:

Message edited by author 2004-07-21 15:56:17.

GeneralE

Canon PowerShot S3 IS

07/21/2004 03:59:21 PM · #9

If you go to this Help Page it lists all the print sizes in both inches and pixels.

kirbic

Canon EOS R5

Canon RF 24-70mm f/2.8 L IS

07/21/2004 04:01:26 PM · #10

In Photoshop you can select the rectangular marquee (selection) tool and set the aspect ratio. From the drop-down "style" selection, choose "Fixed Aspect Ratio". For a 5x7 in portrait orientation, enter 5 in width, 7 in height.
You can now select any portion of the image, but PS will limit the selection to the correct aspect ratio. No math required.
After selecting the portion you want, select Image > Crop. You now have your desired crop, in the right aspect ratio. You could just send to your printing service like this, and specify that you want it sized to fit. You can set the size & DPI if you wish:
Right click on the image header, and choose "Image Size". Make sure "resample" is unchecked, but that "Constrain Proportions" is checked. Look at the image size & DPI; now type in the corect width or height (you only need to enter one). Now the image size is correct. The DPI has changed, because the number of pixels has not, but the size has (make sense?). If the DPI is below about 150, theprint aquality may begin to suffer. At this point, resampling may improve the look of the print, however it cannot create detail.
Let's say you go through the above and find that the DPI is 120. You wish to raise it to 200. To do this, again bring up the "Image Size" dialog, and this time check the "Resample" box. Do not change the size, but change the DPI to the target value. Now you will find that the size has not changed, but the size in pixels has increased, since you increased the DPI. Again, no math required.
Hope this helps.

airatic

Olympus E-410

Olympus 14-42mm f/3.5-5.6

07/21/2004 04:13:43 PM · #11

Under the "Select a Proportion" menu, you should be able to select the common sizes, rather than custom.

Also, increasing the DPI while not changing the image size is not a great idea, it decreases the quality of the image since it's guessing what pixels to add.

kirbic

Canon EOS R5

Canon RF 24-70mm f/2.8 L IS

07/21/2004 05:33:06 PM · #12

Originally posted by airatic:

...Also, increasing the DPI while not changing the image size is not a great idea, it decreases the quality of the image since it's guessing what pixels to add.

As I stated in my post, you never can get additional detail. You do not, however lose detail, so you will not lose quality. On the contrary, you will certainly percieve higher quality from a printed, upsampled image vs. one with too low a DPI for the print size. The transitions between pixels will be smoothed as a result of the interpolation (guessing), eliminating the "blocky" look. The print will still be somewhat soft, but that is always preferred to blocky.