changing resolution

[Molly_G@adobeforums.com]

I have a photograph that is 192 dpi jpeg. I need it to be 300 dpi and tiff file. Question: If I go into image size and change resolution from 192 to 300, what happens? Are more dots per inch being created out of nowhere? Does it change the quality of the photograph at all? Also, if I want to change the file type to tiff, do I just go "save as" tiff instead of jpeg? Thanks for your time!

[John_Slate@adobeforums.com]

More pixels, not dots.

The new pixels are interpolated from the old, so it is like guessing.

The image will soften a bit.

Most important: You will not improve the image quality any, so increasing to 300ppi will really only give you a bigger file without a real improvement, so IMHO I would leave it at 192ppi.

In an ideal world you would rescan the original at a higher rez to begin with.

[Molly_G@adobeforums.com]

Can you increase the resolution by reducing the dimensions?

[Ramón_G_Castañeda@adobeforums.com]

Can you increase the resolution by reducing the dimensions?




Sure; just change the resolution to whatever you want in Image Size, making sure that Resampling is NOT checked and see what your dimensions change to.

[ken_upham@adobeforums.com]

Also remember that everytime you resave as a jpeg, you lose quality.