Size of Photo for Full Bleed

[Steve]

I am preparing photos for a Classic Deluxe album with mainly Full-Bleed format. The instructions say a landscape format should be 14.63w x 11.3h (at 180 dpi [is this the same as ppi]) and the file size should be approximately 8mb. When I create a file with these dimensions (picture from a 6mp camera) at the lowest jpg compression, my file size is a little over 1mg. If I increase resolution to 240ppi (my normal resolution for injet printing) I still don't approach 8mb.

What should I be most concerned about - file size, ppi, picture dimensions, or a I missing something about the process.

Thanks for any information.

[Casey]

Don't worry about file size. A 6mp image will vary in aspect ratio depending on the camera, or settings, but it is in the area of 3000x2000 pixels, which is about 17mb uncompressed at the default 72ppi. So your image has plenty of resolution to spare. And for future reference, you cannot add resolution to a picture. Think of it like trying to add more flour to a cake that is already baked. Increasing the PPI only makes the file size bigger and does absolutely nothing else. It does not improve the quality in any way.

For this service, just concentrate on the picture dimensions. If you open your picture in Photoshop, go to Image Size, make sure Constrain Proportions is checked and Resample Image is unchecked, then change the Resolution (ppi) to 180. Your image should now be near the full bleed dimensions. You won't see any quality loss if you have to stretch it half-an-inch, or so, when you do the layout.

Good luck!

[Casey]

Correction:
Do not stretch your image. Apparently this layout software does not handle that very well. Instead, if using photoshop, set the crop tool to the exact dimensions and ppi then crop the image edge to edge. You may lose a bit on two sides, but it won't ruin the picture.

[Ellie]

Hi. I have a similar question, but my camera is only 3.2 MP and some of the image file sizes are about 500 kB (1200x1600). Will such photos look sharp enough at full bleed (landscape)?

[Casey]

Remember that most cameras save the images as compressed JPG files. So, your 1200x1600 image is actually about 5.5mb uncompressed. An image of this size will look best at or below a maximum of 8"x10" @ 150ppi, or 4"x5" @ 300ppi. Quality will degrade proportionately the further you push beyond this.

[Casey]

I forgot this software prefers using images at 180ppi, which for a 1200x1600 image would set the maximum recommended print size to 6.6"x8.8".

[Ellie]

So does that mean that if I "zoom out" the photo so it will print at a size smaller than full bleed, then it will improve the printed photo quality? This seems like the easiest thing to do (for a newbie)...

[Casey]

Yes, because the smaller you go, the higher the ppi becomes, so the printer RIP (raster image processor) has more information to interpolate from, which results in more accurate detail. Basically, any size below and up to the maximum for 180ppi will look great. Once you start pushing above the maximum the quality goes down since the printer must fill in the gaps as the pixel data is forced across a larger area.