Resampling

[Graham004]

I have been reading the threads related to DPI,Bicupic, resizing but still unclear about the best way to retain image quality. My initial images would be raw+jpeg at maximum size. Once copied to pc they then appear as 72dpi unless I use canon DPP that retains the size at 240dpi.These I then resize to mostly 6x4 or 12x18 at 300dpi. If the initial size file is upsized from the 72dpi using resampling is the image degraded.Some books I have read recently tell me that resampling softens the image should not be used to retain image quality for printing. To maintain quality should I always use software that keeps the original file size and pixels and downsize for selective prints without resampling using bicupic sharpening and / or upsize from 72dpi to 300dpi bicupic smoother without resampling. Few questions in there, thanks in advance

 

[MisterE]

I have done lots of home printing and had thousands of online prints done and I have never resized to a dimension or dpi.

For home printing, all the software I use (Photoshop, ACDSee mostly) fits the image to the paper and prints perfectly. No resizing or anything.

For online printing, for quicker uploads I've reduced the filesize from around 12 to 15mb down to about 3mb and again had perfect 6x4 prints. Maybe the file size could go smaller, I don't know. For 30x20in prints I've reduced the file size to just under the 10mb limit for Photobox's upload and again had perfect prints. On the web page I can adjust the print to either shrink to fit the paper or crop the picture to fit as required.

So, unless I've misunderstood you, are you getting too bogged down unnecessarily over resizing and dpis?

 

[Graham004]

It seems that I am really "bogged" down in image adjustment, alteration, resizing, sharpening etc. Over the last six months I have been taking 100s of photographs and attempting to achieve perfection using photoshop. I appear to spend a ratio of 1 taking pictures and 4 messing around with image software. At the end of the day images sometimes appear far worse then when I started. Maybe just leave it to the in camera settings and use software for cropping and occasional adjustment

 

[MisterE]

I haven't used it nor had the need for it for a long while, but if you're looking for the 'ultimate' program for printing photos, then a multitude of loyal users swear by QImage Pro http://www.ddisoftware.com/qimage/ It does resizing, resampling, sharpening etc and it's supposed to be the dog's......

 

[StewartR]

Don't worry about the DPI value that's embedded into your photos. It's irrelevant. What matters is the number of pixels.

If you want to make 6x4 prints at 300 PPI (pixels per inch) then you need an image which is 1800 x 1200 pixels. That's significantly smaller than the output from your 5D and pretty much any image editing program will be able to handle that.

If you want to make 18x12 prints at 300PPI then you need an image which is 5400 x 3600 pixels. That's about 19MP and will require a modest amount of resizing, which is well within Photoshop's capability.

Don't forget to re-sharpen each image after you've finished resizing it - smaller or larger - to retain optimal sharpness.

 

[Graham004]

Thanks for all the invaluable information. Been looking at QImage Pro and it seems too good to be true and at a very reasonable price. Will be downloading trial version later today then probably studio version that works directly on raw files.

 

[MisterE]

Let us know some day if it's worth it or not. No rush.