johngault007 Loc: Florida Panhandle

Agreed, formatting for initial use in camera is probably wise.

For the sake of discussion, I formatted an SD card in FAT-32, popped it into my camera and took a few shots. The camera (Canon T7i) created the directory structure, retained the files, and I was able to retrieve them.

So there is other (maybe less desirable) ways.

Longshadow Loc: Audubon, PA, United States

Because the card is already in the computer, so after the files have been transferred and backed up, I delete them from the card, while it is in the computer, then put the card back in the camera.

Longshadow Loc: Audubon, PA, United States

Well, we all agree on formatting the card in the camera.

johngault007 Loc: Florida Panhandle

Brokenland

Formating the card in the camera, writes data to the card that the camera understands. if you format elsewhere then place in the camera, you're asking for trouble and corrupted files which may never be recoverable.

johngault007 Loc: Florida Panhandle

Formatting converts the file system to FAT-32. The directory structure (folders) are written after formatting by the camera's operating system. Basically the same as typing (mkdir dcim) in linux/unix.

Silverrails

Have Always heard & Understood that a Digital Photographer should always "Reformat" your Memory cards in the Camera in which the card was used to create your Images.
There is a Technical reason for "Reformatting" your memory card in your Camera, but I do not recall that reason at the present time. Research this subject, maybe "Google" this subject online.

Scruples Loc: Brooklyn, New York

Please don't format!

After I fill a card, I send copies of the photographs to my external hard drive.
I know these cards get expensive! But here is why I don't format a used card.
I have lost count of the number of times friends have formatted the wrong card. Get ready for the anxiety and pain. Did you lose those precious photographs forever? It is possible to retrieve them? Sometimes, the answer is NO and YES to both questions. Sometimes the answer is not so simple.
I buy two or three cards when they are on sale. Keep two in my bag. When I finish the card, I label it and store it in my card safe. I have 24 cards saved. I place the dates on the label. When I need a specific photograph I go to my hard drive. If I want to do something like cropping I find the photograph on the original card, crop it down and then save it to my external hard drive.
As for manufacturer, capacity or speed, I'm not really very picky except about read and write speeds. I won't buy a card over 64GB. If I lose a 128GB or a 256GB I will lose a lot more photos.

In the end, please don't format your cards. Please don't risk the anxiety of erasing very precious photos. Redundancy isn't always a bad thing. Besides I like to be redundant because it is fun to repeat yourself.

Happy Shooting!

Longshadow Loc: Audubon, PA, United States

That's because it's probably the most propagated tidbit of information.
Please, if you find it, let me know! I'd be real interested in seeing it.

Edit:
Sandisk's website tells you how to delete files on a memory card. They do not say don't do it for a camera card.
https://kb.sandisk.com/app/answers/detail/a_id/2281/kw/deleting%20files

Still looking for "why format each trip"...

johngault007 Loc: Florida Panhandle

I do have to say thank you for keeping the prices low on SD cards for the rest of us!

If you are comfortable with that process, and it works for you, then that is all that matters.

LFingar Loc: Claverack, NY

Makes absolutely no difference. Have your neighbor's kid format it if you want. The formats used, FAT16, FAT 32, and ex-FAT are industry standards. They are determined by card size, not by your camera. They are identical no matter where the format is done. That is the only way it can be done if you want to be able to read a card in multiple devices. If the format is not correct your camera will tell you.
Cameras do put their own folders onto the cards but they do that whether you format or not. Here's an experiment I did some time ago with one of my Canons when I got a new SD card: Unwrap the card, put it in your computer and you will see some manufacturer files. Security, recovery utility, etc. Format the card. Now you don't see any files. Put it in the camera, turn the camera on, wait 3 or 4 seconds, turn the camera off. That's all. Put the card back in your computer and you will see all the usual folders that your camera uses. That's how Canon works and I'm betting that Nikon and all the others do also. The camera does not put it's own unique file system on the card. In the first place there is no need to. In the second place, your computer wouldn't be able to read it without specific software. It would be the same as when manufacturers change RAW file formats. Photo editing programs can't read them until they are updated with the proper ACR plug-in.
There is a valid reason for occasionally formatting SD cards with Canon cameras. For SD cards Canon's menu has both a standard format and a Low Format. The standard format does only the directory. Just like a quick format in your computer. The Low Format does the directory and the entire data area of the card. Typical formats of the data area write random 1's and 0's. Canon's Low Format writes only 0's because Canon, for some reason, writes data using only 1's. (It could be the other way around, but, you get the idea.) When it gets to a sector that is formatted randomly the camera then has to re-format that sector before it can write to it, slowing things down noticeably. If you look in Canon's digital manual for your camera you will see that it tells you to do a Low Format occasionally to restore full write speed. I specify digital manual because I never use the paper one so I don't know what it contains. Otherwise, formatting is usually unnecessary. Your SD card doesn't contain little images that can be smudged into each other. All it contains, like any other digital drive, is 1's and 0's, and your camera knows exactly how to use them.

Longshadow Loc: Audubon, PA, United States

Architect1776 Loc: In my mind

I do not.

jerryc41 Loc: Catskill Mts of NY

Sometimes I'll delete all the pictures on a card after I import them into my computer. Usually, I format in the camera.

Silverman Loc: Michigan

Now I have heard here at UHH that you must "Reformat" your memory card in your Camera. Safer, more efficient, Clears card properly of all data,