Format You Camera's Memory Card In Camera Only? Maybe Not!

Ever since I switched from film to digital photography, I had heard that we should only format and reformat the camera's memory card "in camera" and never in a computer.  Formatting in the computer, I had been told, risked introducing corruptive anomalies in the card chancing that the camera may not be able to recognize it, thus rendering the card unusable.

Recently, I was listening to a photography podcast and this very topic arose.  One of the podcasters mentioned that he had had a conversation with a tech rep at one of the major memory card manufacturing companies and the tech rep told him that the best practice was to  a) after downloading the card's contents into the computer, one should reformat the card in the computer itself, then b) again, reformat the card in the camera in which it will be used.

The rationale, he said, was that reformatting in the camera did not delete the images nor the directory, only made them unrecognizable.  I know this is true as I had previously recovered hundreds of images from a card I had reformatted in my camera.  However, he went on to say, the technician said this could eventually lead to problems with the card.  Reformatting in the camera would totally remove the contents AND the directory, giving one a clean card.  Then, by reformatting it again in the camera in which it will be used would set up the appropriate recognition of that camera manufacturer and file system.

This is the first I had heard of this procedure, so I thought I would delve into it and investigate a bit more to see what I could find out and try to determine best practices.  So, since I used a variety of manufacturer's cards, I emailed Lexar, Sandisk, Transcend and Hoodman and asked for a technician to respond to my inquiry, which was "what is the best procedure for reformatting CF and SDHC memory cards?"

I received responses from Lexar, SanDisk and Transcend within hours.  I never received a response from Hoodman.  I felt that was a shame as Hoodman markets themselves heavily to professional photographers in that their quality, durability, etc., of their cards is very high.  But, they didn't even bother to respond to a customer's email so I'm not sure how much confidence I now have in their products.  But that is just me.

To ensure accuracy, I am copying and pasting the companies' responses directly from their emails to me.  Lexar was the most comprehensive, Transcend reiterated the tried and true procedure that had been told to me for years, Sandisk's first response might have been written by a 3rd grader from another country as I'm still not sure what it said.  They sent me a survey as to my experience with their customer service and I indicated the type of response I received.  The next day I received an email apologizing and an indication that the matter was being escalated.  The following day a technician answered my inquiry.  My thanks to Sandisk for listening to feedback and quickly resolving the poor response.

Here are the answers:

Lexar

Thank you for contacting Lexar. At one point in time this was true, formatting in the computer could cause damage. With modern cards this has changed. Most modern flash products have a limited number of times you can write files to a single sector on the card (a sector is a block that holds a 1 or 0 also known as a bit.). This number is quite high and most of the time the card is retired before the card reaches this limit. When you format in a camera, you delete a small amount of information that tells; cameras, photo software and your operating system what sectors your photos are stored on. This means that the photos are still stored on the card and can be recovered, unless they are overwritten by new photos. For example, this information would be on sectors 1,000 to 1,100 while the photo would be on sectors 1,200 to 15,000,000. When you format on the computer, you delete all data on the card and not just this small amount of information, this also helps clean any corruption on the card and will extend the life of the card by ensuring that all sectors are written to evenly and that one does not get over used.
 The biggest reason to format the card in the camera is to ensure that the settings on the card match what the camera requires. The reason to format on the computer is to clean the card of corruption and ensure that all sectors are written to evenly.
 We recommend formatting the card in the camera before every shoot and formatting the card in the computer once every 6-8 months or around 30,000 photos.

Transcend

Thanks, we are glad you are enjoying using our Transcend products!       While it will not ruin or damage the card, it is not necessary, nor does it serve any added purpose to format the card in both the PC and then your camera.  Also if a card is formatted in a Mac PC, the file system might be changed to their Mac only one, which would make it incompatible with other devices.      It is best just to format the card in the camera.

SanDisk

I apologize for the lack of information in the prior email from SanDisk. Formatting memory cards in the camera or PC accomplishes the same thing (in general). Memory cards currently emulate removable disks, so they use FAT32 and exFAT format developed by Microsoft (MS DOS) years ago. So both camera and computer are doing the same thing. The article below will describe the same and reason is to improve performance. Formatting releases all the erased memory (since MS DOS doesn't really delete files only marks as OK to reuse the data area). With the files released, the memory card can then clean up and prepare for new data. this helps maintain performance. A full format (instead of quick format) can be used if the memory card is still exhibiting slow performance. http://www.steves-digicams.com/knowledge-center/how-tos/troubleshooting-repair/3-steps-to-format-your-memory-card-for-digital-cameras.html 

I'm not sure where the format first time in camera theory came from, except to note that it might be related to early days when card compatibility was in question. Or just to verify that a new card appears to be functional and create the DCIM folders in advance. But again a format can help performance which is why some Photographers prefer to format before every shoot. I will say that new high end video cameras (4K, VPG enabled) that are coming out will need to format the card when inserted since they read some card configurations to map out performance to fill the card with high data stream. But this doesn't apply to other cameras, yet. Feel free to give me a call for any additional questions you may have, or some more insight into how memory cards work.

There you have it.  The definitive word directly from the manufacturer's technicians seems to be less than definitive.  I'll let you draw your own conclusions as to what may be best for you and decide for yourself what procedure you choose to follow.  But it was worthwhile getting the information directly from technicians at the companies who are manufacturing the memory cards.

Thanks for looking.  Enjoy!

Dennis Mook

Many of my images can be found at www.dennismook.com.  Please pay it a visit.  I add new images regularly.  Thank you.


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