What's the down-side of excessive resolution?

[SilverDollar@adobeforums.com]

I've read that too high resolution in your layouts is bad for image quality. Can anyone explain why this is?
For instance - the client sends me an image at 300dpi at 10inches across. I scale it down 33%. Effective resolution= like 900 dpi. Is that a problem? When the printer makes his plates and his 180 lpi line screen is applied, isn't the excess info just harmlessly lost?

Or is there any harm in making press ready PDFs with downsample settings that will toss the data?

It's an extra step for me to re-res all the images. How much is my quality suffering if I don't bother?

Lance

[tman@adobeforums.com]

simple answer about quality suffering if you don't bother...NONE.
modern rips and server software will automatically down rez images to match the imagesetter/platesetter resolution...only downside is larger files...really not an issue nowadays.

[Buko@adobeforums.com]

What's the down-side of excessive resolution?




Loss of quality. this is fine for quick and dirty but not for high quality work. when you down sample you are throwing away pixels. if you let the RIP do it you have no control. This is why it is best to do it in Photoshop using Bicubic sharper. You may even want to sharpen it a bit more after. If you let the RIP do it then you don't have the option to sharpen it up after you downsample. That is why the image suffers. Contrary to tmans opinion.

[Martin_Sammtleben@adobeforums.com]

In article <3bc20041.1@webcrossing.la2eafNXanI>, [email]Buko@adobeforums.com[/email]
wrote:

> Loss of quality. this is fine for quick and dirty but not for high quality
> work. when you down sample you are throwing away pixels.

That's the standard answer that's been given for years.

There's plenty of samples around comparing the same image, one instance
with excessive resolution and another one with "optimised resolution",
and there's indeed a difference in sharpness.

However in all the samples I've seen, the difference was so subtle that
you'd be hard pushed to notice it *without* a direct comparison.

--
Cheers Martin

[Jay_Chevako@adobeforums.com]

Other down-sides, larger ID file sizes, The image previews are created
at 100%, but you then shrink down to 33%, you have 3 times the amount of
data stored that you need. This can add up fast with photo heavy
publications. The other thing is more processing time, less of a factor
with faster computers.

There are scripts and plugins floating around that will do this
automatically re-size and re-import images for you, I prefer to do this
manually, because I like to manually sharpen each image. There is an old
school train of thought that you don't hear much any more that you
should rescan in images at 100% and avoid re-sampling all together.

[url]http://www.ledet.com/margulis/PP6_Chapter14.pdf[/url]
This ought to lead to some controversy on the subject
Jay