Hi lads and lasses, a trick I use when pictures are too large or for my eyes the font too small is to hold the 'Ctrl' key and use the mouse scroll wheel to temporarily enlarge or reduce the page. Look at what ever then scroll t'other way back to normal. Yes, if you scroll to reduce a large picture you can't read the tiny font (at least I can't) so read it first, but hey, I get scrolling practice. You can do the same with the 'Ctrl and + -" keys too.
Also works in emails with too small a font for old eyes waiting for the cataracts to be bad enough for the medical profession to correct.
BUT, as has been said 640 x 480 is good 800 x 600 also works.
John B