Architect1776 Loc: In my mind

Yep, but on a cellphone not visible.
My personal files are all saved at full resolution.
So you are absolutely correct.
Thank you.

terryMc Loc: Arizona's White Mountains

It's just what I do. I have rationalized that sending a lossy compressed file to be further compressed with lossy compression doesn't do it any good. It's no more difficult to send a PNG than JPEG. If it doesn't help, neither does it hurt.

wrbeng65UHH Loc: Tennessee

Thank you I will figure it out. What about emailing photos and getting good resolution? Can you help there, plz?

imagextrordinair Loc: Halden, Norway

The ideal image size for a Facebook image post can be up to 2048px wide, with flexibility in the corresponding height.

There is also a "high resolution" option you can enable within Facebook for uploading higher quality images.

An ideal example is 2048 x 1365 px or 1365 x 2048 px for full frame images, but remember the narrower dimension is flexible, and that will not cause the algorithm to re-edit your image.

imagextrordinair Loc: Halden, Norway

Most all printers will require a sized Jpeg. Use something like WeTransfer to send and receive your images, never use you email...

terryMc Loc: Arizona's White Mountains

I don't. I was just relaying what seems to be the conventional wisdom of many on Facebook, that Facebook "destroys quality," but if you send the same image in an email it will be great. I don't buy that, and if I need to give someone I know a large image, I just send them a link to Dropbox.

I haven't sent anything to a printer in many years, but if/when I do it's usually by their ROES. I won't send them a jpeg unless I have to.

CHG_CANON Loc: the Windy City

The same 2048px resizing applies to preparing your email attachments too. Hopefully, you're on your way to creating that LR User Export Preset, as described earlier, and the link below.

Recommended resizing parameters for digital images

CHG_CANON Loc: the Windy City

The UHH link above (Recommended resizing parameters for digital images) included another link in the references to something called the "Always up-to-date guide to social media image sizes".

https://sproutsocial.com/insights/social-media-image-sizes-guide/

A casual glance at the content of that site will show all the references are based on the pixel resolution of the image files; there are no references to the pixel resolution of the target devices. They never / ever even mention the idea of 'dots', just pixels of the image.

CamB Loc: Juneau, Alaska

"all the references are based on the pixel resolution of the image..." Thats why I don't bother with pixel resolution in this way. I don't use it in viewing or emailing in printing. Years ago I figured out what gives me the best quality for my files in megapixels and resolution. About eight presets covers everything. It took some testing, but I find that is so much easier to understand than numbers on a side. I would probably use a chart like yours if I was designing web pages.

bkwaters

I knew someone would mention DPI. They need to build AI into the reply box that blocks it. While still in rant-mode I will add don't zip jpgs.

MJPerini

a Couple of things
> CHG_Canon is correct, virtually every site that limits size does so with resolution limits.
There is a good reason for this, they host billions upon billions of images, a resolution limit allows them to control bandwidth needed to keep the site up and responsive 2048 long side is the same as the export preset found in many editing applications as "Fit within 2048 x 2048". It is actually more generous than some other sites.
> if you have seen it on the web it IS a JPEG. It was invented to make pictures smaller, standardized and easy to share on the WEB.They did a really good job, but JPEG is LOSSY Compression,...what is not used is not saved.
>Jpeg Recompression: if you download a JPEG to your editing application, you have effectively 'Saved it", if you edit it, and re-send it as a jpeg, Jpeg Compression will be RE-APPLIED and (on average 50-80% of data will be lost) you can mitigate this somewhat by exporting at a higher JPEG quality. But this is where "Facebook ruins your pictures" comes from .
> Similarly if you send at maximum quality and resolution in an attempt to show the best quality you can, from your D850, all you do is trigger the algorithm to re-size ..... and it will apply "Fit within 2048 x2048 with a quality slider at 5 or so) The bigger the difference between size of file SENT and size of file DISPLAYED the worse it will tend to look (more stuff gets thrown away.
> So in the digital world, if you want tour pictures to look as good as they can, you resize tour output to match the source's filter. That keeps you in control as much as possible.
> some email apps have similar limits
> the good news is that a well done JPEG that fits within the limits can look very good (all things being equal square files do better because you get to use the full 4 mb of free bandwidth (2048 x 2048)
> so Facebook got tarred with 'Facebook ruins your pictures' even though they have one of the higher limits for file size
Just for clarity, I very rarely post any pictures on any social media and do not have a Facebook account.

terryMc Loc: Arizona's White Mountains

Everything you said is what I have been preaching to the "Facebook ruins your image" crowd for years, and it falls on deaf ears. They're convinced that Facebook has some nefarious plan to destroy photography one iPhone image at a time. It's worse than stupid.

SuperflyTNT Loc: Manassas VA

If you’re just emailing for them to view online use the same sizing standards. There’s no reason for super high res files. If you want to email full resolution JPEG’s for printing just make sure you send the image as a file attachment and inserted in the email as an image. You’ll still be subject to any file size limit your provider might have.

Wallen Loc: Middle Earth

That is a good site for image guidelines they wanted for their website program. Its their chosen compromise for the window size and shape the viewer might preffer or have.

What I shared is an overview, how the 'Image size-Monitor size-Software limit' creates a limited space or parameters in which "us" posters may want to consider when choosing where our photo would look best.
And in that case, the monitor size & pixel count actually plays a big part.

Pixel resolution is missused specially in advertising to hype a product. In a digital image, pixel is the smallest unit. If we zoom close enought, they will show as boxes of singular color. But in doing so, the monitor is showing that box using many pixels.

In a one to one representation, a pixel in a monitor is supposed to show that singular box of the image. That box would have a specific color. To show that color, the "monitor pixel" would use 3(red green blue) actual pixels(which used to be dots, are now of many shapes and arrangements). That is a 3 for 1. Not a pixel per pixel image-monitor representation.

Hence, a 1080p monitor (1920x1080pixels) accepted as 2.1 megapixels, do not show a 2.1 megapixel color image. What it is showing is actually compressed to about 0.7mega pixels. The rest is lost unless the image is zoomed. One needs a 4k screen to show the full 2.1mp color image. And of course viewing distance also matters. That is why a 72dpi screen/image can get away with it.

If it really matters to the poster, he should know and decide where he want the image to look best. It may be better to post a smaller perfect image fit to the target platform, and the compromise; to let the website chrunch it for somewhere else.

Otherwise as others have commented, give a download link so viewers can access the original.

imagextrordinair Loc: Halden, Norway

I think you should educate yourself more on image sizing to understand what your not doing.

The "Maximum resolution you speak of has nothing to do with quality, storage or transfering data. If you save your data at a max of 6000x4000 pixels, then try to upload onto the web without any sizing effort, then expect the image to be processed by the website.

When you export you have the option to save as a web size and color image, and the size you choose is 2048 wide or tall. Just press shift- control- command- (or control) and "S" in Photoshop, and save the image to your file along with your full resolution Jpeg, and PSD file. After that, upload the web sized and color optimized image to Facebook.