EDIT:
gvarner wrote:
If you’re a hair splitter, Elements has 8 bits/channel, LR and PS have 16.....
That might have been the case with five year old and older versions of Elements.... But it's not true with Elements 2019.
First, 8 bit is the correct color depth for most common uses of images. It's what you want for most printing processes, including a photo quality inkjet you might use at home. In fact, some printers require it. It's also what you should use for any online display or sharing of images.
16 bit color is useful
during post-processing.... That's simply because it's better to have the palette with all those additional colors and tonalities while making adjustments and tweaks to your images. 8 bit color has 17 million distinct colors and tonalities. That's actually more than the human eye can distinguish and it sounds like an awful lot.... until you consider that 16 bit has 281
trillion distinct colors and tones!
When you set your camera to save JPEGs, they're 8 bit. When you save RAW, they're either 14 bit or 12 bit, but the RAW conversion software you use will interpolate them as 16 bit. This includes Elements, which at it's core uses the same Adobe Camera Raw images processing engine as Lightroom and Photoshop use. It's somewhat simplified in Elements, but very similar to Bridge in Photoshop. Older cameras made 12 bit RAW files, while most newer ones produce 14 bit (a few make full 16 bit, but mostly just medium format). Many Nikon models offer a choice of saving either 12 bit or 14 bit. I'd recommend the latter, unless you have a shortage of memory card storage space (but add'l memory cards aren't expensive, so there's little excuse for a shortage).
When you work with a RAW file in Elements, it's 16 bit. In fact, I think recent versions of Elements are able to save 16 bit TIFFs. I don't think it can save PSDs. And I believe some filters or feature might not be available in 16 bit mode. More info about 8 bit versus 16 bit color can be found here:
https://www.photoshopessentials.com/essentials/16-bit/Another limitation of Elements involves layers. It used to be that you needed Photoshop to use the powerful layers and masks tools to make selective adjustments to images. But now you can also do it in Elements. However, you can't save a file with layers from Elements (you
can save a PSD file with unflattened layers in Photoshop... Lightroom doesn't allow you to work with layers at all). Basically this just means you have to complete any layers & masks work that you're doing in Elements, before saving and closing the file. With Photoshop you can save it unflattened, then reopen and do more work on it later.
But, perhaps more importantly, in Elements you can only work with layers in 8 bit mode. Not in 16 bit mode (which you can in Photoshop). This generally isn't a problem. Just do global work first in 16 bit, then do the selective work with layers and masks later in your post-processing work flow.
If you use Elements to open a 16 bit file that was left with unflattened layers, before you can do any further work on the file Elements will give you choice of either flattening the layers or converting the file to 8 bit. HOWEVER, since you can't save an unflattened file from Elements, it won't be a file that you created. It must have come from another source to be both 16 bit and have unflattened layers. This is not a situation most amateur photographers will encounter very often. It's more common for commercial work.
When you have completed work on your image, you'll usually want to convert it to 8 bit and save it as a JPEG. That will be correct for most non-commercial uses.