pixel size versus actual size

[kikker]

Can somebody explain the difference between pixel size versus actual size zoom? Know resized images don't look sharp when viewing with actual size bot ok when viewing pixel size. The question is related to size images the proper way for web sites.

[Old Bruce]

12 minutes ago, kikker said:

size images the proper way for web sites

Web sites do not care about PPI/DPI. Web sites do not know abut inches or mm. Websites need width pixels by height pixels.

Work in Pixels for measurements, view at 100% EDIT: Pixel Size zoom to see what the image would look like on a web page on your computer. You can export the image as a PNG or a JPEG and then open that file with your favourite web browser to see it as it would appear on a web page.

[Old Bruce]

I really should read what I write before posting.

Pixel Size not 100% for an accurate "what will it look like on a web page".

[BofG]

15 minutes ago, Old Bruce said:

Web sites do not care about PPI/DPI

That's not strictly true, CSS and JS can act on the device pixel ratio. You can also have src sets for image tags to have the browser select the appropriate size for the display.

[Ron P.]

@Old Bruce,

I'm a little confused, hopefully you can clarify for me. Isn't the Pixel Size view, the same as viewing at 100%? What I'm interpreting that to be is 100% of the Pixel Size, correct? Web browsers, I use Firefox, use View Actual Size, and Full Screen, and it's not presenting a 100% zoomed view. Just tried this, and I had to use the magnifier to zoom in to a real 100% of the actual pixel size. 

Plus websites tend to do other things to images, which is a whole other discussion. 😉

[kikker]

Good to see that I am not the only one confused 😀 Would be great to see a simple explanation of what Zoom 100%, Actual Size, Pixel size exactly does...

[Old Bruce]

100% takes into account the PPI/DPI so 300 DPI will give a different size than 72 or 96 DPI. These are common commercial printing and screen resolutions. Pixel size makes one pixel from the document be one Pixel on the (particular) screen.

300 DPI will pack 300 pixels into an inch onscreen, 72 DPI will make more than four inches on the screen.

If you are working for web images forget about DPI just work at Actual Pixels zoom and with pixels as your Units of Measurement.

Think of blueprints for a house, the scale is given as 1/8 inch to the foot. Take that blueprint and shrink it down to a small paper size, the scale will say 1/8th inch to one foot and it will be wrong. We can go nuts trying to figure this stuff out. So keep your workflow as simple as you can.

[Old Bruce]

3 minutes ago, kikker said:

Good to see that I am not the only one confused 😀 Would be great to see a simple explanation of what Zoom 100%, Actual Size, Pixel size exactly does...

Try it out for yourself. Make a series of documents at different DPI settings then make a 1 inch square in each of them. Export them as PNGs. View in a web browser, while you look at each document at 100%, Pixel Size and Actual Size does.

Quickly you will see that you are going to have a 300 pixel sized square and a 72 pixel sized square in your web browser.

[Ron P.]

35 minutes ago, Old Bruce said:

Make a series of documents at different DPI settings

Disclaimer: Using DPI as a unit of screen measure is still misleading. It has been since waaaay back when they first started this usage of Printer units, for Screens.

How does one make documents with DPI=DOTS per Inch, when monitors have no dots. Monitors have Pixels. For screen, the correct measurement is Pixels Per Inch. I understand that they are used interchangeably, but that does not make it correct.

I just took an image, created new document sizes. The only change made was to the DPI settings. I did not allow for resampling. Starting with the default of 72 (on a pc is actually wrong, since it's an Apple/Mac setting, 96 is correct for PCs). My image at 5496 x 3670pxs at 72 dpi, is the same as on using the 400 dpi. Same Pixel resolution, 5496 x 3670, same size on disk of 1.58 MB. So how is changing just the DPI going to change the screen appearance, without resampling?

I realize that Serif does some algorithms in the background when changing the DPI, if you have resample selected. When you do you're changing the size, resolution of the image.

[Old Bruce]

3 minutes ago, Ron P. said:

I understand that they are used interchangeably, but that does not make it correct.

I am aware that I am guilty of adding to this misunderstanding. I am trying to change my advice giving in order to increase clarity. 

 

5 minutes ago, Ron P. said:

My image at 5496 x 3670pxs

Again, apologies for my inaccurate advice. I should have explicitly stated that I was talking about creating files with shapes and text and pixel brushes. Meaning something made from scratch, not using photos.

[R C-R]

7 hours ago, Ron P. said:

Isn't the Pixel Size view, the same as viewing at 100%?

It is for me, & the document DPI setting (whether it really means PPI or DPI doesn't matter, just that it is what the value is labeled as in Affinity) does not affect that. The DPI setting does affect the Actual Size view but not those other two.