Raw is always going to be best because it contains more information. It embeds a JPG with it, and if you like it, you can simply convert it as is, and if you don't it's easier to modify using a program that reads Raw images. When you edit a raw file, you change its JPG overlay, but do not change the file, so you can revert any time. When you edit a JPG file, you change it forever. Each time you change it it must be re-written, re-saved, and usually re-compressed.
JPEG is a "lossy" compressed format, and though usually very good, it does lose some information. The more compression you use the more it loses. It's often convenient to downsize an image, and that may help to control noise, but you can always do that later. Likewise, it's often handy to lower the quality of a JPG, simply to make it easier to transmit and store. You can lower the quality any time, but if it isn't there to begin with, you can't put it in.
If you have the time and card space, saving Raw plus JPEG can be a good idea, because it gives you a backup image, and that image can immediately be shared without conversion. Which JPEG option you use depends largely on what you expect to do with the files. If it's for backup, keep them large and fine.
Once upon a time, when storage was more expensive, Raw images might have been difficult to accommodate owing to file size, but nowadays, there's little reason not to shoot raw, unless you are doing long bursts that use up the camera's buffer space and cause it to stall. If that happens, switch to high quality JPEG, and lower size or quality only as needed.
Relative image quality can vary depending on what program you use to read files. The Nikon programs show you the JPG overlay pretty completely, so if you like a Raw image, you can just do a conversion on the spot. Some other programs may not read all the JPG overlay settings, so the initial viewing of a Raw image may look noisier or otherwise different from the JPG version. How a program translates a Raw image into the viewable JPG varies some, so you can only be sure by trying it.
Comments
JPEG is a "lossy" compressed format, and though usually very good, it does lose some information. The more compression you use the more it loses. It's often convenient to downsize an image, and that may help to control noise, but you can always do that later. Likewise, it's often handy to lower the quality of a JPG, simply to make it easier to transmit and store. You can lower the quality any time, but if it isn't there to begin with, you can't put it in.
If you have the time and card space, saving Raw plus JPEG can be a good idea, because it gives you a backup image, and that image can immediately be shared without conversion. Which JPEG option you use depends largely on what you expect to do with the files. If it's for backup, keep them large and fine.
Once upon a time, when storage was more expensive, Raw images might have been difficult to accommodate owing to file size, but nowadays, there's little reason not to shoot raw, unless you are doing long bursts that use up the camera's buffer space and cause it to stall. If that happens, switch to high quality JPEG, and lower size or quality only as needed.
Relative image quality can vary depending on what program you use to read files. The Nikon programs show you the JPG overlay pretty completely, so if you like a Raw image, you can just do a conversion on the spot. Some other programs may not read all the JPG overlay settings, so the initial viewing of a Raw image may look noisier or otherwise different from the JPG version. How a program translates a Raw image into the viewable JPG varies some, so you can only be sure by trying it.