PBase

I have been posting pics on PBase for several years and recently noticed something. It could have been happening all along and I just didn't notice.

When I compare one of my images on PBase to the same image in PS CC (at 100% size), the PBase image is larger on my screen than the image as seen in PS. Because of this it doesn't look quite as good on PBase as when I view it in PS.

I have tried different settings (my default setting is to save it in PS to 72 dpi with the largest dimension being 800 pixels) and then save for the web with a final size of about 200 KB.

Here's some specific information:
My monitor is set to 1920 x 1080 resolution. I tried a short test on one of my images - I had processed it to be 72 dpi with 800 pixels vertical dimension and 667 pixels horizontal dimension.When I view this image on PBase, it is 21 cm wide on my monitor. When I view the same image (the JPG I posted to PBase) in PS CC it is only 16.5 cm wide. My monitor is approximately 47 cm wide, giving it a resolution of approximately 41 pixels per centimeter (1920 pixels divided by 47 cm). If the image is 667 pixels wide it should be approximately 16 cm wide on my monitor (667 pixels divided by 41 pixels/cm). This 16 cm calculated width is the same as the width I measured when viewing the original image in PS. What is happening in PS to cause the image to display at a larger observed size in PBase?

Thanks for any help.

My understanding is that DPI only has a meaning when printing images; it has no meaning when viewing an image on a screen. In the latter case it's only the number of pixels in the image's width and height, together with the actual resolution of your screen that determines the size on screen (assuming zoom is 100%).

What happens if you open the JPG directly from file in your web browser? Is it the same size as when you open it from Pbase, or the same size as when you view it in PS?

When I do this with one of my jpeg files, the size on screen of the local file and the Pbase copy are identical.

Also, when I open the same jpeg file in either of the photo editor packages I use (Raw Therapee and Darkroom), with the zoom level to 100%, it is again the same size on screen.

Sorry I can't compare it in Photoshop as I only run on Linux these days.

reticulatus wrote:My understanding is that DPI only has a meaning when printing images; it has no meaning when viewing an image on a screen. In the latter case it's only the number of pixels in the image's width and height, together with the actual resolution of your screen that determines the size on screen (assuming zoom is 100%).

What happens if you open the JPG directly from file in your web browser? Is it the same size as when you open it from Pbase, or the same size as when you view it in PS?

When I do this with one of my jpeg files, the size on screen of the local file and the Pbase copy are identical.

Also, when I open the same jpeg file in either of the photo editor packages I use (Raw Therapee and Darkroom), with the zoom level to 100%, it is again the same size on screen.

Sorry I can't compare it in Photoshop as I only run on Linux these days.

Thanks for the reply. I have found an easy solution. With my PBase pages open in my browser (Firefox) I hit the "control minus" keys. It reduced the size of everything and now the pic is exactly the same size when viewed online or in PS.