How to correct blurred photos in screensaver?

[Twin B]

I have a 24" 2010 iMac running OS 10.5.8. I'm using photos in iPhoto as the screensaver & some are blurred. I read that all the photos must be in the same format, .jpeg for example, but I can't track the problem much beyond there. Several questions:

1. Is there an easy way to change photos in other formats like .bmp into .jpeg, using my iMac?

2. Must all the photos in all the different albums be the same format, or can the photos in one album be .jpg, another album have .bmp, etc.?

3. The photos are different sizes, some tiny and others big. Is there an ideal size where all the photos will be clear, i.e. 900X800? I've noticed the blurred photos are smaller than 500X300.

4. Is there an easy way to change the photos to be the ideal size, considering some of the photo albums have 150 pictures? I dread going thru each picture changing the size.

I'd appreciate any helpful answers. Thanks, Joe.

 

[0007776]

Your photos are probably blurry because they are too low of resolution. The photos should be clear if they are high enough resolution to match your screen's resolution, I don't remember what that is on your computer. Unfortunately you can't do anything to increase the resolution since it wont add any detail and it's what your computer is automatically doing. Basically 500X300 is going to look bad on any screen that is much higher resolution than 500X300.

 

[simsaladimbamba]

Enlarging a low resolution (low res) photo will not enhance it, as 300 x 200 pixel do not contain enough information to be properly scaled to 1280 x 800 pixel.

Example:

Image at 300 x 201 pixel (thumbnail version):

Image enlarged to 1280 x 858 pixel (thumbnail version):

Original image at 3872 x 2592 pixel (thumbnail version):

 

[Twin B]

Phooey. OK. Thanks for taking the time to reply mrkramer & simsaladimbamba.

 

[Flynnstone]

If you like the pictures, then they will need to be small.
Perhaps, combine several low res pictures on a larger canvas like your screen size. Then the screen saver will not "expand" them.

 

[Twin B]

That's a good idea Flynn. Is there a fast and easy way to do that? I don't know how but I can look it up in my Leopard manual, the 'Missing Manual' as it's called.

 

[bols59]

Previously Clear Images Are Now Blurry

I download images 300+ pixels & everything has been fine. Two days ago I noticed blurry images coming up on my screensaver. These images were fine when I downloaded them to screensaver. It's not just one image from one webpage, but multiple images from multiple pages/sources.

I have not adjusted anything in iPhoto to manually cause this to happen.

(But I refer to any Mac as, "Open the pod bay doors, Hal", Mac software is intentionally written to confuse the end user, eventually resulting in a lifetime's supervised medical care.)

 

[bols59]

I never go below 300 pixels for a screensaver photo in iPhoto.