Image quality conundrum

I recently got a new laptop which has a better screen than my old one. I find that images look best on this when viewed at their largest size. I obtain this by opening the jpeg in Windows Photo Gallery, then clicking on the slide show/full screen button at the bottom and pausing on the image I want to view. This seems to provide as clear a view of the image as I can obtain on this computer.

There's one thing I find perplexing though. The image appears much crisper at this magnification than at the smaller one in the Windows Photo Gallery page. Now on all my previous computers images always appeared more sharp the smaller they were - which is what I would expect. Not on this one though. In fact some images that I edited on previous computers can appear to slightly lack sharpness in the WPG page, only to look oversharpened in full screen mode.

Re-sizing and sharpenening images does result in a boost to how an image will look in the WPG page. However, when opened in full screen the image shows a deterioration in quality. This is particularly noticeable when I try to re-size from 1000 pixels width to 800 - which was previously required for the fortnightly comp. Now I'm confused as to what to do - as I'd like what is viewed on the forum to approximate as closely as possible to the original image, but I'm confused by how my computer is behaving.

If anyone can shed some light on this it would be much appreciated.

Out of interest - and as an aside - do others re-size their images when posting on the forum?

Last question first - yes. 800 pixels wide is ideal. Any bigger is a waste of memory and will not improve image quality. It will also slow down loading and probably distort the web page as well.

I'm not sure that the Windows display is the best way to view your images - it is probably making all sorts of decidions for you that are intended to enhance poor quality images from compact cameras.

I would view in Photoshop, and in fact always do.

Thanks for the feedback John. The thing about Photoshop - though perhaps this is down to my thickness - is that I don't know how to view a full image at a larger size than the size it adopts when I'm editing. Is there a way to view the image using the whole screen in Photoshop? If not then that's surely a big restriction - certainly on my 13.3" screen!

Near the bottom of the tools pallette (left of screen) there are three buttons - normal view, grey background and black background. Click the one of choice and to remove all the tools and pallettes press the Tab key on the keyboard. To reinstate them, press Tab again.

That gives you the latgest possible uncluttered view against a background colour of your choice.

More thickness, I fear - I can't find these buttons. I have Elements 6 and I assume that the view is the same as CS.

Below the tools palette on my screen I have the set foreground/background colour. These don't respond if I press tab, there is just a box for selecting the fg/bg colour.

Following advice from Daniel Bridge when I've re-sized images of late I've done it by halving and then re-sharpening and halving and re-sharpening till I get down to 800 pixels. However, I've found there is always a significant drop in quality from ca.1,000 to 800. Any ideas where I'm going wrong?

The technique of downsizing in stages has been around for a while, but personally I can't see the logic behind it.

Until somebody comes up with a convincing reason for doing this, I shall continue to downsize in one go.

G

If you are using CS2 or later, then opt for "Bicubic Sharper" when resampling to downsize for the web. This will maintain sharpness better than standard Bicubic.

I'm going to differ from Daniel's advice and say I would resize in one go.

However, I normally use Bicubic and downsize in one go using the crop tool. I enter 1000px wide for EPZ or 800px wide for this forum, leaving the height blank to sort itself out, and then of course a resolution of 72ppi.

Possibly helpful would be to save your large image unsharpened and then apply the appropriate amount of sharpening to the reduced size image. For the web I use sharpening of 50%, radius 2, threshold 3.

A full sized image for print needs more sharpening than that - I'd go for at least 100%.

Here you go George link

I also resize in one go though, don't ask me why but I simply do.

Crickey John I never go anywhere near 100% sharpening - we are talking unsharp mask I take it. I have some 12x18" prints that I resized in PS either enlarging or reducing and just took their suggested process to do it. Looks as I expected and decently sharp - well actually at least one is killer sharp.

I too cannot see any point in repeated sharpening. On Mattmatic's advice I keep a full size master PSD then adapt that for use on web or use for printing and always resize to the dimensions I want and apply unsharp mask after that as a last step. Is that a sound procedure?

I have noticed that I shouldn't assess the sharpness of any image at anything less then 'actual pixels' in any viewer as it seems misleading.

Another thing that baffles while we're on sharpness is how some lenses seem to need more USM that others. The 70 ltd needs very little and sometimes none after a resize while the 21 usually needs some. I don't really see how that can be as the USM is required due to digital processing - or at least I thought so.

Mike

Yes, I think so.

Because you know it's best?

As I said, Stefan, until somebody comes up with a convincing reason for doing this, I shall continue to downsize in one go.

That link shows some small, over-sharpened images, and provides no convincing explanation for why stage sharpening is a good idea.

G

Hi,
You can perform the same function by using the F key on your keyboard, First Press gives an image on a grey background, Second is again Grey but you can move the image around a lot more and third gives a black background (These are the default colours you can change them to anything you like) Fourth Press reurns you to normal screen and as John says hitting the Tab Key removes the Tool Pallet a further hit on the same key restores it.

Best Regards - Pete.

Same thought here, it looks over sharpened although the crop has more details.
I do it in one go since I can't be bothered by it and have always found the results good.

As for Mike, I mostly used a number around the 150% and didn't heard anyone complaining of being to sharp although I do some steps after that that makes the image a bit softer again.

Doh!

Have just figured out what I was doing wrong. I was trying to view in the Edit section rather than the Organize one. Have only recently shifted from PSP X2, hence the ignorance.

Thanks Pete & John for your assistance.