5Dmk3, which SD , is raw slow ?

I am buying a 64gb CF card and was thinking to either buy

a smaller SD card for JPG only

or to get a 64gb SD card and have RAW to both cards

will RAW to both cards be much slower ?
is the speed difference noticable ?
would RAW to both cards be a problem and should i go for a smaller SD card just to take JPG as backups ?

One of the the things I did not like in 5DII was the high speed frame rate being 3.9. Great camera for shooting still objects. Not so good for action/sports/wildlife​. So when my wife got me a 5DIII, I ordered Lexar 32GB 1000x (UDMA 7) cards in a two pack. I also made sure to upgrade Lexar CF reader to UDMA 7. So shooting raw only (jpgs can be made from them), and only writing to one CF card that is UDMA 7, I get the fastest write rates from buffer to card. And of course the Lexar reader gives me fasterest downloads via USB 3. Of course if you are not shooting action, writting to two cards in parallel might be OK. Much has to do with what you want to shoot.

http://www.learn.usa.c​anon.com …tanding_burst_r​ates.shtml

thank you.

though for me writing to both cards at the same time as a backup is one thing i want to do and am trying to find out if doing that will slow down the burst rate speed (by saving to two cards instead of one)

and which speed SD card to buy to help avoid that if i want the SD to also save RAW instead of JPG

You can write to both cards. In that case I would want fast cards as I have hear that writing to both does slow down the total writing speed. Again that may not matter if you are not doing high speed frame rates for action/wildlife. I would say that you want the fastest SD card you can find so that it keeps up with the CF speed. I have never used SD cards, so I have to suggest you look online for finding the highest speed SD cards.

If I were a wedding photography, I would definitely be writing raw to two fast cards. So much of a wedding are the memories of a lifetime for the couple...and there is no do over if you miss or lose the shot.

I did some research on this already. Unfortunately, the SD slot in the 5D MIII will not support anything faster than the UHS-1 Speed Class. So as far as write speeds to the SD card, you do not need anything faster than a Sandisk Extreme 45 MB/s SD card.

Bryan

bps wrote in post #14495693
I did some research on this already. Unfortunately, the SD slot in the 5D MIII will not support anything faster than the UHS-1 Speed Class. So as far as write speeds to the SD card, you do not need anything faster than a Sandisk Extreme 45 MB/s SD card.

Bryan

excellent, as that is what i ordered

thank you

So if you are going to write to both cards....the write speed is very slow (45MBs) compare to a potential 100MBs writing only to UDMA 7 CF cards. For many subjects it will not matter. But for action shots that could be a PITA. I guess I am sticking to UDMA 7 CF cards.

Rob Galbraith's comparison table shows that most SD cards are almost at the same speed for models above the 45mb/s

btw, i was wondering if i would notice a difference when shooting raw between a Sandisk Extreme UDMA 60 mb/s CF card and the 45 mb/s SD card ?


another thing: why are CF cards usually more reliable and durable than SD cards ?

i'm hesitating between buying a 64 CF or SD card for my future 5DM3

Why an SD when you can get faster CF?

Smaller, easier to find in a pinch/on holiday/in an emergency, and a ton of devices with built-in SD card readers (laptops) while very few still support CF.

Makes for good backup, I guess.

for me the idea was to have a back up of my CF card.

dont know if they speed issue would be noticable if saving two cards as RAW and if saving JPG as the backup would be much faster ?

If comes back to what/how you shoot. If you don't need to record high speed shooting sequences, you might never have a problem writing to both cards in parallel. That would be the case for me shooting landscapes. But when it is time to shoot action (wildlife, sports), I would want the fastest CF card and not cripple that speed by trying to write in parallel to a relatively slow SD card.

You can always put bot cards in, default to writing to both, and turn off writing to SD when starting action shoots. You could store that behavior to the C1, C2, C3 settings. I use C1 for landscapes and could set it up to record to both. I use C2 for wildlife and C3 for birds in flight. So for C2 and C3, write to CF only.

Got lots of experience here with the 1D cameras.....

Pretty simple. If you need backups, write JPEGs to the SD card (more later), I tried that and never really used them so I quit doing it. You can write BOTH to the CF card at about the same rate...


Bear in MIND that if you shot RAW and JPEG.... Your BUFFER SIZE will be smaller (check it), by a couple RAW frames.

If you don't have a SD reader handy, I just use the camera to copy files from the SD to the CF and then load the CF to the computer.

For me the SD is good for overflow and thats about it. CF cards are so fast now that when the camera switches to JPEG it about stops....

Card speed. Fastest for both (I'd limit myself to 32GB, 64GB is really huge and I shoot a lot)..... Keep in mind RAW on the faster CF card will write probably faster than the smaller JPEG files to the slower SD card. Still buffer frees up as the RAWs get written.

For your question, speed isn't as much an issue writing RAW to the CF and JPEGS to the SD card.

A strategy I use is WHEN SPEED ISN"T AN ISSUE, I WRITE RAW TO THE SD CARD. Shooting static airplanes, the RAW files go to SD and that saves me space on the more expensive CF cards for later use. You can switch the card you are writing to in a split second in the 1D cameras (not up on the 5D3)

I started using 600X Lexar cards and they are super fast. Caution all speed ratings are not equal. I shoot airshows and full buffers used to be a problem. Not now. SD cards, the fastest are still too slow for my uses. For people shooting nature, it really shouldn't matter....

Best of luck, more questions please ask.

Mark H

no RAW on SD ? too slow ?

actually, i'm asking because i was probably considering using SD cards only

I currently use Sandisk Extreme CF and SDHC in my 5D Mark III, both 16GB. CF is rated at 60MB/s and SDHC at 45MB/s.

I shoot with both cards in redundancy mode (same RAW file to both cards).