5D MkIII buffer

[ScubaX]

I found this discussion pretty interesting, not from all the tech stuff on the cards (I have a Networking degree, but it now bores me to tears), but rather the capabilities of the 5DMKIII, that is what really interests me. I've shot some air shows gunning at F16's as fast as I can only to rarely hit the buffer limit - and that was with a lot of shots.

So I set my 5D3 up with 7 brackets and Raw to the CF and Large JPEG to the SD card. The CF is a Sandisk Extreme Pro UDMA 7 32GB freshly formatted in camera. The SD is a class 10 Eye-Fi Pro/X2 16GB quick formatted in the camera.

I tried this a few different ways, the first time and each time I was able to easily get all 7 to both cards. Then I paused for a second after the first burst of 7 and another 7 without issues. On the final try I hit the buffer at 16 shots.

The next try was with a format again, and only to the CF and I got 21 without hitting the buffer and gave up after that.

I think its your card - or an issue with your camera, but I think more likely the card.

 

[AvTvM]

I have to say that I do not agree about the SD slot being crippled. If the camera has been designed to use UDMA 7 CF cards it should have also been designed to accomodate UHS-1 SD cards. To the best of my knowledge the two specifications came out at about the same time. (Nov 2010 and May 2010 respectively). As Canon built the ability to save file to the two cards into the camera they should have made it a realistic proposition.

Canon should have just put 2 UDMA-CF slots into the 5D III, rather than 2 different card formats. Most people who bought/are buying 5D III already have a bunch of reasonably fast to extremely fast CF cards.

Absolutely no need to build a consumer-type SD-card slot into a large, pro/enthusiast-oriented DSLR like the 5D III.

Only if Canon finally came out with a super-compact FF mirrorless cam [A7/R sized] with space really at a premium, I'd accept even dual Micro-SD-slots, of course UHS-II capable.

 

[mikejkay]

Valvebounce - Yes, my laptop is running Windows 7. Too much trouble to resuscitate one of my XP desktops. However, I find it very curious that when formatting cards in the 5DIII for the SD there is the option of a low level format while for the CF there is no option for a low level format. Presumably the CF format is the equivelant of the Windows Quick Format.

 

[mikejkay]

ScubaX - Good to have direct data. You are right about my CF card, it's only 300x. With this card only selected the camera will fire off 13 shots before the buffer is filled, so your Extreme Pro UDMA 7 at 1000x can only manage an additional 60%. Not quite what you would expect. I can't justify the outlay for this increase in performance, I only want to get 7 bracketed RAW shots on CF with JPEGS automatically saved to SD. I will try and borrow a 600x or 800x CF card and see if the slight improvement is enough for me to achieve this.

PS - have you tried you 5DIII in a u/w housing yet?

 

[Ian_of_glos]

I have to say that I do not agree about the SD slot being crippled. If the camera has been designed to use UDMA 7 CF cards it should have also been designed to accomodate UHS-1 SD cards. To the best of my knowledge the two specifications came out at about the same time. (Nov 2010 and May 2010 respectively). As Canon built the ability to save file to the two cards into the camera they should have made it a realistic proposition.

For anyone following this thread, and who is interested, I have formatted my UHS-1 SD cards and this makes no discernible difference to the time taken to the number of burst shots achievable or the time taken to clear the buffer (compared with the cards formatted in my laptop).

Not to worry, the 5DIII is still a brilliant camera. Pity I can't use it properly!

That is a reasonable point, but unfortunately Canon did not design it that way. The 5D mk3 does not support the faster UHS-1 (ultra high speed) standard for SD cards, which means that no matter which SD card you use the write speed cannot exceed 20MB/sec. What's worse is that if the 5D mk3 detects the presence of an SD card it sets the default write speed to the slower card - so the write speed of your CF card will be limited too. I shoot a lot of sports, and when I bought by 5d mk3 initially I accepted the idea that I needed two cards - in case there was a problem with one of them or so I could keep a RAW and JPEG copy of each file on separate cards. However, I was continually having problems with the buffer filling and I was not able to keep up with the action. Now I have removed the SD card completely and since then I have not had a problem. In my opinion having an SD clot on this camera is a complete waste of space - they would have done better to make two CF slots available.
I use the sandisk UDMA6 CF card which is rated at 90MB/sec. Never tried a UDMA7 card but at the moment I don't need it.

 

[East Wind Photography]

Valvebounce - Yes, my laptop is running Windows 7. Too much trouble to resuscitate one of my XP desktops. However, I find it very curious that when formatting cards in the 5DIII for the SD there is the option of a low level format while for the CF there is no option for a low level format. Presumably the CF format is the equivelant of the Windows Quick Format.

SD normal format just erases the file table. Each sector write must be erased first before writing. Low level format does the erase at format time thus speeding write speeds. I always LL format for camera use.

CF is different. It doesnt need to erase first...so only one format option.

 

[Drizzt321]

I have to say that I do not agree about the SD slot being crippled. If the camera has been designed to use UDMA 7 CF cards it should have also been designed to accomodate UHS-1 SD cards. To the best of my knowledge the two specifications came out at about the same time. (Nov 2010 and May 2010 respectively). As Canon built the ability to save file to the two cards into the camera they should have made it a realistic proposition.

For anyone following this thread, and who is interested, I have formatted my UHS-1 SD cards and this makes no discernible difference to the time taken to the number of burst shots achievable or the time taken to clear the buffer (compared with the cards formatted in my laptop).

Not to worry, the 5DIII is still a brilliant camera. Pity I can't use it properly!

That is a reasonable point, but unfortunately Canon did not design it that way. The 5D mk3 does not support the faster UHS-1 (ultra high speed) standard for SD cards, which means that no matter which SD card you use the write speed cannot exceed 20MB/sec. What's worse is that if the 5D mk3 detects the presence of an SD card it sets the default write speed to the slower card - so the write speed of your CF card will be limited too. I shoot a lot of sports, and when I bought by 5d mk3 initially I accepted the idea that I needed two cards - in case there was a problem with one of them or so I could keep a RAW and JPEG copy of each file on separate cards. However, I was continually having problems with the buffer filling and I was not able to keep up with the action. Now I have removed the SD card completely and since then I have not had a problem. In my opinion having an SD clot on this camera is a complete waste of space - they would have done better to make two CF slots available.
I use the sandisk UDMA6 CF card which is rated at 90MB/sec. Never tried a UDMA7 card but at the moment I don't need it.

Not so! The SD slot is useful to have a Eye-Fi card and/or other SD card that has MagicLantern installed

I'm not 100% certain on the timing, but at the design & prototyping time I don't think any UHS-I hardware was available, even for testing. I could be wrong about that though. The other question to ask is, can the DIGIC handle 2 very fast cards at the same time? I'd be willing to bet that the DIGIC doesn't even have enough high-speed data lines to support UHS-1 + CF.

 

[eyeland]

+1 for ML on the SD
With the new .mlv module under development, one can further use the SD slot in conjunction with the CF slot for a bit more bandwidth for raw video.
That said, dual CF or a faster SD slot would have been great but as always, we can't have it all

 

[ScubaX]

ScubaX - Good to have direct data. You are right about my CF card, it's only 300x. With this card only selected the camera will fire off 13 shots before the buffer is filled, so your Extreme Pro UDMA 7 at 1000x can only manage an additional 60%. Not quite what you would expect. I can't justify the outlay for this increase in performance, I only want to get 7 bracketed RAW shots on CF with JPEGS automatically saved to SD. I will try and borrow a 600x or 800x CF card and see if the slight improvement is enough for me to achieve this.

PS - have you tried you 5DIII in a u/w housing yet?

The 13 shots you obtained in RAW to a UDMA 6 CF card are exactly what Canon says it will do on page 121 of the manual. I tried this again without bracketing and got 18 shots, which matches that same chart for UDMA 7 CF cards. While you may think that too is not fast enough, it matches Canon's claims. I don't see any Canon specs for writing to two cards at once, but as others have said that puts a much larger strain on the capacity of the buffer.

I would love to use my 5D3 underwater, but for now I am grounded - and the housing prices are really expensive. I also prefer video underwater and the 5D3's focus for that is not very usable when chasing after a shark or turtle and getting him in focus. My current UW system is an ancient Sony mini-DV in a Light and Motion housing. It was state of the art at one time - but SD is now just ugly in comparison to HD.

 

[mikejkay]

ScubaX - Page 123 in mine! I should have read the manual but they make me go cross eyed. Should have spotted the data though, it is very relevant. I can imagine the bods at Canon saying RTFM.

Two points; the table in my manual gives a maximum burst of 7 (RAW + JPEG) for a pre UDMA 7 card. I can only get six shots (with a 300x card) which is the cause of my initial grouse. The second point is that going to UDMA 7, at a very considerable cost, will only increase the burst to 18. A mere 38% increase is, IMHO, not worth the candle. Worse, as has been discussed ad nauseam, using a UDMA 7 card will not make a jot of difference to the reported maximum burst of seven if the camera is set up to back up JPEGs to a SD card in slot 2.

On a maudlin note, I went from a Nik V to a Canon A95 in a housing before being ordered by my doctor to give up. If I hadn't had to give up I would probable have put my old 20D or even the previous D30 into a housing and given it a crack (and my buddy nightmares).

 

[ScubaX]

In the table a maximum burst of 7 (RAW + JPEG) for a pre UDMA 7 cards, that applies to only the CF card - not writing to two cards but writing both files to the same card. Wasn't your issue with writing to two cards with RAW + JPEG? If it can just make 7 with one card, I don't see how it could do it with two cards.

But you now know the answer, a faster card will get you to 7 brackets RAW + JPEG to two cards while running and gunning.

I always wanted a Nikon V, until I saw video from someones Light and Motion system on a dive in the Channel Islands (Southern California) - I was hooked on it immediately. They just needed to ask "MasterCard or Visa?".

 

[mikejkay]

You're right, again! I have decided to stay with what I've got and limit my bracketing to five shots and stick to backing up JPEGs to the SD card in Slot 2. This will still be an improvement over the 7D......and, who knows, I might get it right one day and not feel the need to bracket my exposures.

Thanks for the help.

 

[tron]

In the table a maximum burst of 7 (RAW + JPEG) for a pre UDMA 7 cards, that applies to only the CF card - not writing to two cards but writing both files to the same card. Wasn't your issue with writing to two cards with RAW + JPEG? If it can just make 7 with one card, I don't see how it could do it with two cards.

But you now know the answer, a faster card will get you to 7 brackets RAW + JPEG to two cards while running and gunning.

I always wanted a Nikon V, until I saw video from someones Light and Motion system on a dive in the Channel Islands (Southern California) - I was hooked on it immediately. They just needed to ask "MasterCard or Visa?".

The size of the files increases with ISO, plus for jpegs it must increase with high noise reduction.
Maybe the numbers Canon states are for ISO 100 with noise reduction to normal.

 

[ScubaX]

My test shots were at ISO 1600 1000/2.8.

I was just looking at Canon USA for something, and noticed Canon says: "Up to 6.0 fps continuous shooting". Did they change the advertised fps at some point? That's different than my experience and the manual. I guess they are being slightly conservative to avoid disappointed customers.

 

[tron]

My test shots were at ISO 1600 1000/2.8.

Just as a test. Make an experiment (AEB 7 shots) with ISO 100 and exactly the same setup that failed at the 6th shot to see what happens...

 

[ScubaX]

My test shots were at ISO 1600 1000/2.8.

Just as a test. Make an experiment (AEB 7 shots) with ISO 100 and exactly the same setup that failed at the 6th shot to see what happens...

Me or the other Mike? I didn't have a failure at 6. But I like the idea and will give it a test run.

 

[tron]

My test shots were at ISO 1600 1000/2.8.

Just as a test. Make an experiment (AEB 7 shots) with ISO 100 and exactly the same setup that failed at the 6th shot to see what happens...

Me or the other Mike? I didn't have a failure at 6. But I like the idea and will give it a test run.

OK, sorry! I assumed you were having the problem. I thought I was addressing OP!

 

[mikejkay]

tron - 'tis I. High ISO ight be the problem, the camera is still set up for night/indoor shooting. I will run the test at ISO 100 as you suggest. Camera is all packed up for an early start off to Spain in the morning so it will be Tuesday probably.