... totally agree on caipirinha (with mandioquinha frita or bolinhos de arroz or iscas de peixe as siders), but mojito is my second "the best"


filesize doesn't mean that much when dealing with jpgs. nor does compression if you take it in its literal meaning. in jpgs', "compression" actually means "resampling" and it doesn't necessarily entail a filesize decrease

it's a very sophisticated algorithm, based on human's eye perception, that *recreates* the image (at every "save") taking into account not each single pixel but a grid of pixels (finer or coarser, depending on the quality setting you choose)

jpgs' "resampling grid", also, "adapts" to what actually is in different areas of each single picture and it's way more effective on large, homogeneous, areas as, eg, a blue sky or a snow covered ground, preserving at the same time a much finer detail (and quantity of information) in "textured" areas

so if  you save a picture with an higher quality setting, its filesze will *probably* (it actually depends on so many factors that it's hard to tell) increase but what jpgs resampling will actually do is... increasing micro-contrast (when not actually "adding pixels" by interpolation) in areas with finer "textures".
in the long run you'll begin noticing artifacts. at first in homogeneous areas, then along those borders with greater luminosity contrast and finally also in finely textured areas. this will happen both if you just save without caring about the quality setting or if you take care and always increase it at every step

I mean... your eye will begin noticing these issues at a certain point, but if you look at the pixel level something will be there since the first (or second) "save" step!


anyway... back to iPhoto... maybe Apple has learned something, on proper jpg handling, since Aperture was introduced and there may have been fallbacks to iPhoto (as there have been from iPhoto to Aperture eg... Faces in Aperture too!! ==:-/ )

what I clearly remember is, as there's no *import quality* setting in iPhoto (one may assume, as it should be, no resampling is applied there but... truth is a different beast!), all portrait format pictures had, approximately, a 2/3ds filesize of similar landscape format images. I mean: right after import and still no editing!!! :-0


but also keep in mind, Geoff, that... I'm a (ehm.. cough-cough) "photographer" *and* Virgo ;-p

cheers
-- 
paolo



On 21/dic/2010, at 03.38, Geoffrey Heard wrote:

> Hiya paolo
> 
> A timely heads-up many thanks, but I'm not sure you are absolutely right on that.