Still confused about image size

[echelonphoto]

I have 17" monitor which has a native resolution of 1900 x 1200 pixels. So, when I create a show with the files at 1024x768, the pictures only fill about half the screen...however, they do look very sharp. Now when I tried to resize my monitor

resolution to 1024x768, the photos were bigger, but they looked absolutely terrible...soft and pixelated. Then there is the problem of my projector, which is only 800x600...nothing really looks good on that. BTW...from another thread...it said

that dpi doesn't matter...I tried using a lower dpi (36) and the image was only half the size...so evidently...it does matter. Short of resizing my files to 1900x1200, which would make them too large for normal resolution monitors.

[Ken Cox]

MAYBE

have a look here

http://www.scantips.com/basics1c.html

and one of our members site

http://gdesroches.free.fr/formation/fnumerbase_en.htm

ken

[Lin Evans]

Don't try to display the photos at native size. If you let PTE do the resize they will fill your monitor screen automatically.

The ideal situation, assuming you have a video card up to the task would be to duplicate and resize your images using Photoshop or Irfanview, etc., to 1900 x1200 or whatever the closest actual aspect ratio for your own camera is. In other words just make the horizontal aspect 1900 and let the software work out the vertical.

Next set PTE to the default which is "fit to slide". Then when your slideshow plays on "any" monitor or computer system the slides will either be uprezzed or downsampled automatically to fit the system they are being viewed on.

For your projector, resize to 800x600. DPI really doesn't have anything to do with image size unless you are printing. DPI is a "tag" in the EXIF header which tells the printer how closely to space the pixels. The number of pixels is fixed by the file and the camera used. You can make more pixels by interpolation or fewer by resampling, but whatever "size" file you feed the printer the number of pixels can only be changed by the printer driver or software interpolation and resampling.

If you have a 1600x1200 image (2 megapixels) and you set the dpi to 300 then the print size will be exactly 5.33 inches by 4 inches (1600/300 x 1200/300). To get a different size print you must do one of two possibilities: You can move the pixels farther apart or closer together, i.e., change the dpi, or you add or delete pixels. Most printers have optimal dpi which reflect their print engines requirements so in almost all cases pixels are added or deleted (interpolation/resampling).

To understand dpi, you need to think of what happens when you move pixels closer together without changing the number of pixels. Moving them closer together simply makes the image smaller. When you spread them out it makes the image larger. But this "dpi" doesn't change the "quality" of the image in that it doesn't add resolution or detail nor does it remove resolution or detail. It simply tells the print or device how close or how far apart to print each pixel.

A display device can't move pixels closer together or farther apart. The pixel locations are fixed by the very nature of the monitor so what it can do is simulate what happens with different dpi settings by increasing or decreasing the number of pixels, not by moving pixel positions as done by print devices. Pixel size is fixed on a monitor so they can't really make larger or smaller pixels either, just "simulate" this by using several pixels to "represent" the content of a single pixel.

Something is definitely not right about using a smaller dpi and having a smaller pictures. Something else is going on because using a lower dpi makes an image larger not smaller. By a smaller number the pixels are being spread rather than moved closer together. Because they are spread out the apparent quality will diminish.

I can't tell you what is going on with you projector and pixel pitch (DPI) but I can tell you that it has nothing to do with PTE.

The bottom line is that for "most" PTE shows having the image for your own monitor set to the native display resolution as a match (in your case 1900x1200 or as close a possible without image distortion) will give you the best results. This assumes that your video card is up to the task (not a 32 meg or 64 meg card). If you have any deep zooms beyond 100% image size you may want to increase the size of those individual images. Don't worry, PTE will resize them at fit to screen but when you zoom in you have more resolution to work with.

Best regards,

Lin

I have 17" monitor which has a native resolution of 1900 x 1200 pixels. So, when I create a show with the files at 1024x768, the pictures only fill about half the screen...however, they do look very sharp. Now when I tried to resize my monitor

resolution to 1024x768, the photos were bigger, but they looked absolutely terrible...soft and pixelated. Then there is the problem of my projector, which is only 800x600...nothing really looks good on that. BTW...from another thread...it said

that dpi doesn't matter...I tried using a lower dpi (36) and the image was only half the size...so evidently...it does matter. Short of resizing my files to 1900x1200, which would make them too large for normal resolution monitors.