Normal file size????????

[Frank Petronio]

The reference to anti-aliasing filter is also from very old versions of Photoshop and perhaps other ancient software. Sometimes scanned or converted vector/line art at a certain angle would develop "jaggies" or stair stepping pixelated patterns - the AA filter would blur things along contrasty edges.

[Barry Kirsten]

The reference to anti-aliasing filter is also from very old versions of Photoshop and perhaps other ancient software. Sometimes scanned or converted vector/line art at a certain angle would develop "jaggies" or stair stepping pixelated patterns - the AA filter would blur things along contrasty edges.

Ah yes, I remember that. In my Epson V600 scanner software there is an antialiasing tick-box which seems to be ticked by default Doesn't seem to be necessary for continuous tone subjects.

Thanks frank. Have a happy Christmas everyone.

Barry.

[rdenney]

Rick,

You simply resize without resampling. You can sharpen at the new size...
Lenny

But resizing without resampling just changes the scale at the edge of the picture, not the pixel dimensions. And the sharpening algorithms are calculated at the pixel level. So, if your radius is .7 normally, if you've resize to twice the resolution you normally print at, you'll need a larger radius--maybe 1.4--to accommodate it. If you always set those parameters from scratch for the look, then maybe it doesn't matter. I don't use much sharpening during targeting for big prints from large format anyway. But for small prints, I do, and resampling is easy enough and keeps the radius parameter meaning about the same thing.

Another process that benefits from resampling first is when one uses a very tight feathering in a selection. Feathering is defined in pixels and is not scalable. Jim Kitchen has discussed how some of the web-sized reductions of his images show a sharp line at the edges of his sky selections, but that they show smooth gradations at print size. That's an effect of performing pixel-level calculations for processes performed at much different resolutions than the output display.

Rick "maybe using a different tool than Lenny" Denney

[rdenney]

The reference to anti-aliasing filter is also from very old versions of Photoshop and perhaps other ancient software. Sometimes scanned or converted vector/line art at a certain angle would develop "jaggies" or stair stepping pixelated patterns - the AA filter would blur things along contrasty edges.

Actually, most digital SLRs have anti-aliasing filters in them. I don't think any scanners do any more, nor do most medium-format digital devices. Moire patterns between fine detail and the sensor array are more rare now with cameras often having sensor arrays finer than can be resolved by most lenses.

Rick "who does basic corrective sharpening at the pixel level for images from his Canon DSLRs" Denney

[jim kitchen]

Jim Kitchen has discussed how some of the web-sized reductions of his images show a sharp line at the edges of his sky selections...
Rick "maybe using a different tool than Lenny" Denney

Dear Rick,

How true, since I do not pay attention to the final image quality while posting on the net. My net images are actually from my 24X30 inch final print files, reduced to 800 pixels wide or tall, where I do modify the file to be an sRGB image before posting. So, when I reduce a file from 700mb at 720ppi to a file that is less than 1mb at 72ppi, artefacts and abnormalities surely abound...

jim k

[Lenny Eiger]

But resizing without resampling just changes the scale at the edge of the picture, not the pixel dimensions. And the sharpening algorithms are calculated at the pixel level. So, if your radius is .7 normally, if you've resize to twice the resolution you normally print at, you'll need a larger radius--maybe 1.4--to accommodate it. If you always set those parameters from scratch for the look, then maybe it doesn't matter. I don't use much sharpening during targeting for big prints from large format anyway. But for small prints, I do, and resampling is easy enough and keeps the radius parameter meaning about the same thing.

Rick "maybe using a different tool than Lenny" Denney

Ok, trying to figure out what you are actually talking about here.... It's true that I'm using a different tool, my sharpening is more often that not done at a Radius of .2.... I have never used anything so drastic as 1.4. However, I am often printing files for photographers that supply the files from other scanners and/or digital cameras. This week, it's a few from an iPhone... and if there is something to learn, I'm all ears.

Are you saying that there is actually a benefit to rezzing up? Or down? Why throw away lots of pixels of information? It doesn't make sense to me... sharpening seems to work fine at whatever size...

Lenny

[Barry Kirsten]

Ah yes, I remember that. In my Epson V600 scanner software there is an antialiasing tick-box which seems to be ticked by default Doesn't seem to be necessary for continuous tone subjects.

Thanks frank. Have a happy Christmas everyone.

Barry.

That's rubbish! Of course it's Unsharp Mask.

And I haven't started on the Christmas cheer yet. Sorry,

Baz.

[Frank Petronio]

Lenny, if I drop my image size down to being 800-pixels wide to post in a web gallery, I am using different sharpening settings to get pleasing sharpness for viewing in my web browser. Even if I start with a perfect, super sharp, and huge master file, dropping the size that much, 5-15x, I will still want to sharpen again before saving to web.

[Lenny Eiger]

Lenny, if I drop my image size down to being 800-pixels wide to post in a web gallery, I am using different sharpening settings to get pleasing sharpness for viewing in my web browser

Frank, I would agree. Of course. And one would certainly want to downsize for the web, there's a reason to make the file smaller. Maybe I misread him but Rick seemed to indicate that there was a benefit (other than moving files around) to downsizing or upsizing for printing. I set my size, sharpen, then print. (No resampling.) I certainly haven't had to set the sharpening to a larger radius for a larger image... just wondering if I'm missing something.

Lenny
Happy Holidays Everyone

[Bob Gentile]

All,

This has been a greatly illuminating thread. Thanks.