Can I make an SD card lie to my camera about its speed?

[nineclicks]

I have a Sony a7iv and my V30 sd card is perfectly sufficient for my needs.

 

However, if I want to shoot a timelapse with S&Q mode at 1fps in 4k 140Mbps 4:2:2 10bit, it tells me I need a "higher than" V60 card. Obviously this is not true, since 140Mbps is the playback speed, the actual bitrate to the card would be more like 5Mbps. Further I could easily do 1fps 14 bit raw in photo mode as well (this is what I used to do, but with 4k 10bit I'd like to switch to video). There is also an all-intra mode that would be like 10Mbps to the card but it tells me I need "higher than" V90 for that. Clearly they have just not bothered to build in the math since the S&Q mode is variable.

 

I am wondering, if the camera seems to know the rating of the card. And you hear about counterfeit SD cards. Is it possible to modify a cheap SD card to pretend to be V90 so that I can use it in these low performance demanding situations? This would not be for critical work.

[kirashi]

12 minutes ago, nineclicks said:

I have a Sony a7iv and my V30 sd card is perfectly sufficient for my needs.

 

However, if I want to shoot a timelapse with S&Q mode at 1fps in 4k 140Mbps 4:2:2 10bit, it tells me I need a "higher than" V60 card. Obviously this is not true, since 140Mbps is the playback speed, the actual bitrate to the card would be more like 5Mbps. Further I could easily do 1fps 14 bit raw in photo mode as well (this is what I used to do, but with 4k 10bit I'd like to switch to video). There is also an all-intra mode that would be like 10Mbps to the card but it tells me I need "higher than" V90 for that. Clearly they have just not bothered to build in the math since the S&Q mode is variable.

 

I am wondering, if the camera seems to know the rating of the card. And you hear about counterfeit SD cards. Is it possible to modify a cheap SD card to pretend to be V90 so that I can use it in these low performance demanding situations? This would not be for critical work.

Whether this is true or not is clearly not of Sony's concern, as page 20 of the user manual dictates the speed of memory card required. Unless you can rewrite the camera's firmware (you'd need the source code), your best option is to use the appropriate memory card. Most cameras perform an on-camera speed check, so even if you found a way to malign the memory card headers the camera would still validate the read / write speeds from / to the card itself.

https://helpguide.sony.net/ilc/2110/v1/en/print.pdf

 

 

[nineclicks]

I appreciate your effort.

 

Any other curious humans like me happen to know where I might look to learn about how SD card header information works, or how people rewrite them? My main issue is that I don't seem to have the words to turn up this kind of information on google.

[Vilacom]

On 6/10/2022 at 9:31 PM, nineclicks said:

I appreciate your effort.

 

Any other curious humans like me happen to know where I might look to learn about how SD card header information works, or how people rewrite them? My main issue is that I don't seem to have the words to turn up this kind of information on google.

You’re kind of asking something that…doesn’t really exist?  Like the use case you’re looking for is so niche(my camera requires a higher speed memory than the specific task I’m using it for is not something I’ve literally ever heard any photographer say) and SD cards aren’t terribly expensive to start with, people who actually have a camera typically just use the correct speed memory for it.

If you’re absolutely set on modifying the camera’s software to trick it you’re probably going to have to find someone who has worked in development with SD memory and has software engineering experience with the camera brand you have.  Trust me when I say, spend the $100 for a quality memory card

[Imbadatnames]

It’s not just the speed of the card it’s the buffer on the camera too with overhead etc etc 

[nineclicks]

On 6/12/2022 at 1:40 AM, Vilacom said:

modifying the camera’s software

That's not what I was asking. It was my mistake for asking here, this is not a camera question. I have a v90 SD card, that's not the concern. I've made some progress in learning about SD card headers elsewhere, thanks.