The benefits of writing raw to one card and jpeg to another.

Professional body cameras with two card slots quite often put people in a dilemma of which way to send data to the memory card (SD or other cards). So, here are six reasons why you might like to save raw files to one card and jpeg images to the other card… Plus a couple of reasons why you may not want to.

Quite a bit of extensive research on various professional and amateur groups and forums was done for this, plus of course common sense and a general knowledge of how data transfer works. Hopefully this will be of use for you and your camera.

Positive reasons to shoot raw in one card and jpeg in the other:

Faster than writing raw to both cards.

No matter how fast your memory cards or camera are, there will always be times when you want to push the cameras abilities. Taking into account that uncompressed raw files are around 50mb (lossless compressed 25mb) and jpegs between 12-15mb, you can instantly recognise that writing to 50mb files will be slower than writing a 15mb and 50mb file.

Singularly this won’t matter too much, but once you start using bust modes, things quickly change. Of course if you have a super fast UHS-II or better SD card you make things slightly easier, but it still affects writing capabilities when writing two large files to the card.

Less buffering due to faster writing.

As described in the section above, bigger files take longer to write. Your camera has a buffer that can store so many files in memory before getting full while it’s writing and you are firing off shots.

Writing raw to one card and jpeg to another will alleviate these problems considerably, and you will experience less buffering.

Raw files and jpeg files separated for convenience.

When you plug your camera into your computer later, you can choose which card to copy the files from. For many they may choose to only use the raw files and knowing they are safely going to the computer they may only take these files off. Similarly the same goes for the jpeg images.

Of course, it is also helpful when transferring data off your card when in the field or when needed quickly. You can just grab the already processed jpegs and share them straight to social media or whatever you need to do with them.

Can use smaller card in jpeg slot for cost saving.

When you first get your camera, you may already have a smaller card, or may not be able to afford two expensive large fast cards. Because jpegs are so much more smaller, you can happily use a smaller card size than the card you’re using in the raw slot should you so wish to with no detrimental affect to speed etc.

You can easily flick through and delete images in camera from either card without making a mistake.

With your camera in playback mode, it’s possible to switch between card slots. This means you can actively look at the jpeg or raw images individually and review or delete whichever is needed in camera without confusing the jpeg for the raw.

It’s only a simple thing, but out in the field it can be a very important thing, ensuring you only manage the actual file type that you are targeting, without threat of losing the raw (or jpeg if that’s what you need).

Can have more room on the jpeg card for video work due to space jpegs take.

A lot of photographers who take the odd video as well will write the video files to the jpeg card as there is always more room on this card than the card that holds the raw files. It makes sense for all of the reasons mentioned beforehand.

Negative reasons to shoot raw in one card and jpeg in the other:

There are very few negative reasons for using the card slots in this way, so rather than bullet point headings, we’ll just take a quick look.

Firstly of course, it means that if your card holding the raw file gets corrupt, then you are only left with the jpeg files. For amateur photographers, this is not an issue, but if you are a professional photographer who specifically shoots raw and needs those files, then shooting raw to both cards would make sense in that situation.

Secondly, you may be wanting to shoot both raw and jpeg to each card, for complete safety in your work. This of course is around twice as slow as writing raw to one card and jpeg to the other as you are writing four files instead of two. Again, only you can decide if that is important to you.


If you’re not going to be pushing the cameras frames per second, and you’re perhaps a landscape photographer or product photographer, then chances are you won’t need to worry about the burst rates of your camera. However, for general shooting, everything from animals, insects, birds, people, sports, your kids, transport and aircraft etc while walking around you’ll possibly need to think about using this method of saving images.

You have to remember, that these days, reputable SD cards are much better quality than they were, and you stand a very small chance of losing the data. You probably have more chance of losing your camera (or getting it stolen) or destroying it in some other way. Assuming of course you look after your cards and change them every few years.

Hopefully there’s enough in this article to explain why it’s beneficial to shoot raw on one card and jpeg on the other, regardless, keep shooting!!!

Published by Mark G.Adams

Fujifilm And Olympus Documentary Photographer, YouTuber & Blogger.

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