Why aren't all images printed? Options

[pandy]

When I need to read something a little complicated that I try to learn I like to print the page. Not on paper, but to PDF, so I can make annotasions and notes.

With this page some images print and some don't. They are all ordinary inline images.
https://photographylife.com/how-to-read-mtf-charts

To list a few (this is with FF)...
The first image with the graphs (How to Read MTF Charts) doesn't print.
The second one (Reading is Easy) does print.
The third (with the heron) does print.
The fourth (portrait of a guy) doesn't print.

And so on. There's a blank space where the lost images should be, so I solved my problem by copying the missing images and paste them in their respective place. I have an old copy of PDF-XChange Viewer that lets you do all sorts of handy things.

But I can't stand a mystery. Why does this happen?

I thought maybe it was FF acting up. But I tried with several other browsers and they all did it, but not necessarily with the same images. In fact FF printed more images than the others. Vivaldi also ignored the print style sheet I guess is used and printed the right sidebar that isn't there in FF. Ad images and all. Since browsers don't act the same, it can't me a messed up print style sheet.

[Christian J]

Seems some images are not loaded until you scroll down to them (in browser view). Once I made sure all images were loaded in the browser window they appeared in FF print preview as well.

The page also seems to use webp images (even with image URLs using .png extensions?) in case it matters.

[pandy]

Seems some images are not loaded until you scroll down to them (in browser view). Once I made sure all images were loaded in the browser window they appeared in FF print preview as well.

Ha! Aren't you clever? I didn't notice that. Here I have been copying and pasting since I started this thread. I just finished the article, i.e. I read it at the same time.

Any idea why this happens? I mean, normally the whole page loads without the need to scroll. At least it appears to do.

The page also seems to use webp images (even with image URLs using .png extensions?) in case it matters.

Really? I just opened a couple to check they weren't background images and noted the png extension. Klutz! Not you, the webmaster.

Thanks! There's something seriously wrong with my head. I can't just let go of things like this even when they don't really matter and I had no bright ideas myself. Unusual, I know.

[Christian J]

Any idea why this happens? I mean, normally the whole page loads without the need to scroll. At least it appears to do.

Maybe it's just random delays on some images? The reason they appear to load once we scroll down to their placeholders is because we stop and wait for them there. In a couple of cases I had to wait over 5 seconds (with a slow connection).

Thanks! There's something seriously wrong with my head. I can't just let go of things like this even when they don't really matter and I had no bright ideas myself. Unusual, I know.

It's a good motivation to learn new things.

[pandy]

I never noticed a delay. But I guess you scrolled much faster since you weren't reading.

[Christian J]

But if the images had time to load while you were reading, they should be available when you opened print preview (according to my theory above). Or did you return to the page to print preview at a later browsing session, when your cache had been emptied?

[pandy]

It's a long article. I didn't read more than part of it before I decided to print. But strange that the top image didn't print.

I tested and it worked for me too when I had loaded the whole page. All my work for nothing, eh?

[Christian J]

I like to print the page. Not on paper, but to PDF, so I can make annotasions and notes.

Seems you can make annotations directly in the PDF viewer of Firefox 106: https://www.theregister.com/2022/10/18/firefox_106_arrives/

[pandy]

You can with a lot of PDF programs. That's why I print to PDF.

[Christian J]

Yes but now you can do it directly in Firefox, without a PDF program.

[pandy]

Why would I want to do that? I guess a PDF is created and saved anyway. It just isn't so obvious where it is.

[Christian J]

So you don't have to open a separate PDF program. But to each their own...

[pandy]

I save those for later when I have time and am inclined to read them and I want to read them more than once. I rather open a PDF from my hard drive then find the URL to the web page and evoke the PDF reader in FF.

I had a program once, an IE addon, that was rather cool. It let you annotate webpages. I've seen programs like that now too, but their purpose seem to be sharing. This was personal. The annotation files were on my HD and stayed there