Comparing images onscreen to final print. Help needed.

[parasko]

Can anyone advise at what percentage should images be viewed onscreen to accurately reflect the final look of the printed image?

I understand that you should always check at 100% view to check the effect of any image adjustments made, but is the final print more accurately represented onscreen by a 100% view or 50% (or another percentage)? I know many variables come into play here but for example, I am experimenting with the new 'shake reduction' sharpening filter in PS and I want to know how heavily I can apply this filter. At 100% artefacts appear in the image, at 50% they are not noticeable. Can anyone advise based on the following:

1. Image = A scanned 35mm transparency scanned at highest resolution of 4000dpi with my Coolscan 9000; file size 130mb.
2. Screen = Latest iMac 21.5-inch (1920 x 1080)
3. Printer = Epson 3880
4. Required Size of Printed Image = 11x 16 inch or 13 x 19 inch @ 300dpi

I don't have access to a printer (or printing experience) so I want to know how to best prepare files onscreen.

Any advice appreciated.

[Preston]

Here's a little trick I use...

Set the rulers in PS so that they read in inches.
Now, grab a real ruler and hold it next to the screen, aligning an 'inch' mark.
Adjust the view so that 1 inch on PS's ruler is the same as 1 inch on the 'real' ruler. Voila!

I use this trick when I start the sharpening process for printing.

IIRC, the optimum print resolution for the 3880 is 360 dpi, rather than 300.

--P

[parasko]

Thanks Preston,

I have just tried your 'trick' and my ruler and screen match up at 33.3% viewing on my 21.5 inch iMac. Considering that at 100%/50%/25% view onscreen the image looks sharper than at 66.7%/33.3%, I would've expected that the final print would have looked similar to one of the sharper percentages rather than the latter. Does this method take into account different sized prints?

Assuming the above is accurate for prints, would the 33.3% view also be the most accurate when preparing files for a personal website?

[Preston]

Parasko,

The viewing percentage doesn't matter. You can use my trick on an image of any size: It's the linear dimension, in inches, that matters for printing. For example, if I have a an image I want to print at 12 inches wide, I use my trick, and the image on screen will be 12 inches wide. The viewing percentage may be something like 25%, but I don't care about that. Now, if I want to print the image at 10 inches wide, I use my trick again, and the viewing percentage will be a different value. Again, I don't care about that. In short: as long as the 'virtual' ruler in PS and your 'real' ruler agree, you're good to go.

As far as images for the Web are concerned, I work with the ruler set to pixels, since I'm more concerned about the pixel dimensions for screen display. In this case, I set the 'view' to 100%.

Does this make sense to you? If you need clarification, please let me know.

--P

[parasko]

That's brilliant Preston! Great advice. Thanks.