SD vs CF cards

Hi,

I've been considering some new flash cards for my 5D mk3. I'll be shoot some action still with high speed burst, and my son may be shooting video as well. So my question is does it matter using SD vs CF cards for a given speed and capacity. For example

SanDisk Extreme Pro 32 GB SDHC Class 10 UHS-1 (95MB/s


vs.

Transcend 32 GB Compact Flash Card 600X ( 92 MB/s read and 87 MB/s write)

The Sandisk is actually about 1/3 cheaper ($66 vs $99). The CF cards seems more "robust" but I don't think that matters much since they'll spend most of their time in the camera or a case. And the CF can get misaligned during insertion and cause bent pins (happen to me a couple of times).

So, given this, wouldn't the SD card be better choice since its cheaper and all else is the same? Your feedback is appreciated.

The SD card is cheaper because it relies on a the processing power in the camera to act as a controller. With CF card, the controller is in the card, hence the higher cost. In general the CF route is faster but to be honest it isn't easy to answer your question. Perhaps others have thoughts. It has been said that ifvyou install both, then the write speed defaults to that of the SD card.

The 5D3 doesn't write to SD cards very quickly, I very much doubt that it would be able to take advantage of that fast a card and you would find yourself waiting whilst it clears the buffer.

The CF should be very fast however, I only use a 400x transcend in my 5D3 and it clears at a rate of almost two (raw) shots a second (so will clear a full buffer in around 7-8 seconds and can still shoot at almost 2fps indefinitely, even with a full buffer).

How on earth have you managed to bend pins TWICE? I have swapped CF cards thousands of times and never managed it once yet?

I'm using both the Sandisk Extreme Pro 16GB and Transcend 32GB X400 UDMA 7 cards and they are both very similar in performance. When I use the USB3.0 reader, they are essentially the same speed.

I also have the Sandisk 64GB Pro SD card and write speed is slower in camera but read is comparable to the CF from the external reader.

sandpiper wrote in post #16381441
How on earth have you managed to bend pins TWICE? I have swapped CF cards thousands of times and never managed it once yet?

This is quite easy on a cheap CF reader which has a shallow slot. The card only slides in about 1/3 of the way in so there's some wiggle room. I once was in a rush and jam the card right in, and the end pin flatten out. Fortunately, I was able to open up the reader and bend the pin right back.

In my 7D, I've never had issues. The card slides almost fully in and so the CF card and pins are nicely aligned.

In the meantime, I've stumbled upon this link, which appears to give the nod fully to the CF card since there are no bandwidth limitations like there is for the SD card.

http://www.robgalbrait​h.com …e7de5.html?cid=​6007-12452

A fast CF card will be about 4x faster than a fast SD in a 5dIII. The 5DIII is going to max out at about 20MB/s for SD card writes. For buffer filing burst CF is the way to go.

Here's a link showing various cards write speeds on a 5DIII

^^^
Thanks for the link. For performance, the CF cards are the way to go. I better save my pennies elsewhere

SD cards are waterproof

I agree CF cards perform faster and generally better. However SD cards have one advantage. SD cards are waterproof and CF cards are not. Many photo journalists and travel photogs who fill numerous cards before download, and those who shoot specifically around water, are using SD cards. If they drop a camera or backpack in water, the SD card will be fine. Gear may be dead, but if they can retrieve the SD cards, days or weeks of work will be saved.

CAPhotog wrote in post #16382686
I agree CF cards perform faster and generally better. However SD cards have one advantage. SD cards are waterproof and CF cards are not. Many photo journalists and travel photogs who fill numerous cards before download, and those who shoot specifically around water, are using SD cards. If they drop a camera or backpack in water, the SD card will be fine. Gear may be dead, but if they can retrieve the SD cards, days or weeks of work will be saved.

CF cards are pretty good around water too, there have been many tales of people throwing clothes in the washing machine and finding a CF card in a pocket afterwards. The cards always worked fine once dried out. A magazine once carried out tests to try and destroy a CF card and it wasn't easy, they washed it, drove a truck over it and various other tests and it kept on going. I can't remember what they did in the end to break it, but it wasn't something likely to happen by accident .

Do you have a reference for where it says CF cards aren't waterproof? It surprises me.

If photojournalists are using SD cards, what cameras are they using? The normal PJ cameras (Canon 1D series and the Nikon equivalent) don't accept SD cards, which is kind of odd if that is what they would want to use.

I think it is more that SD cards have a guarantee about water but CF cards do not. This info was given at two unrelated workshops, one was a Canon 5D III shooter, the other shooting different Nikon models. Was surprised myself. By the way, I'm labeling their work as photojournalism because they travel on assignment and shoot on location for extended period which were the scenarios they mentioned for water concern. Apparently the reason is because the controller is built into CF cards and not SD cards. One referenced the manufacturer, I think it was Sandisk, guarantees the SD card is waterproof for 72 hrs but does not offer the same guarantee for CF cards. Just checked online and appears to be correct. Additionally, someone asked if SD cards are too slow, but it was pointed out there are faster ones now so performance is relative.

Speaking of durability, did anyone see the test DigitalRev did with a Canon 7D? Some gear is definitely robust even if not meant to be used under such conditions.

http://youtu.be/RCT-YMgjm9k

Regarding bent pins, I've experienced it too with card readers though not cameras. I still prefer CF when possible.

http://www.cinema5d.co​m/news/?p=2652

One issue in discussing CF cards and waterproof is defining "waterproof." There actually are ISO specs that define multiple levels of waterproof all the up to immersion at a significant depth. In 2010 Delkin (see link) had a CF card thst was waterproof to DoD standard and claimed at the time it was the only card to meet that standard, which is rather stringent.

CAPhotog wrote in post #16382841
I think it is more that SD cards have a guarantee about water but CF cards do not. This info was given at two unrelated workshops, one was a Canon 5D III shooter, the other shooting different Nikon models.

Just note that world-class photographer doesn't mean world-class engineer.

That doesn't really matter. Both SD and CD needs to have electronics inside. There isn't a significant difference in environmental sensivitivity of the controller chip compared to the memory chips. And there isn't a significant difference in how well you can seal the electronics of a SD or CF card.

The only real difference is that you can use cloth and dry the contact points of a SD card, while there are no good method to dry the pins of a CF card - so the CF card would need more time to try up before you insert it into a reader.

One issue here is that manufacturers only certifies products when they see a significant advantage of doing it. This means that there are lots of uncertified products that are behaving great despite not having any official stamp on them.

It isn't easy to get controller-less cards to match the fastest cards with internal controller. This because the internal controller can do tricks that requires extra data transfers if done externally.

What we want is memory cards using the SATA-600 specification, allowing us up to 600MB/s of raw transfer rates. But SATA - just as the original IDE standard that was part of the original CF design - is a solution with controller in the device.

Speaking of durability, did anyone see the test DigitalRev did with a Canon 7D? Some gear is definitely robust even if not meant to be used under such conditions.
Lots of equipment is quite robust. But the big issue is how they behave long-term, i.e. if they age well. When web sites does abusive tests, we would like to see one-year-after tests too, after the test subjects have been returned to normal, and regular, use after abusive tests have been performed.

http://youtu.be/RCT-YMgjm9k

Don't take a photographers word for it.

The plug for world-class engineers is great, but are there any sharing their manufacturer tests or independent lab work with photographers? If not, I still need to put professional field expertise, trusted reputations, and bigger pay checks than mine into perspective.

Agree the issue of waterproofness is relative, much like waterproofing a child. In the Sandisk FAQ it says something about 1m of immersion in salt or fresh water plus similar shock and X-ray testing, so I think someone wearing a pocket protector was probably involved. Yet when a card fails, the warranty is only good for the purchase price so that could be all it is worth. Meanwhile, a warranty on SD cards but not CF cards is food for thought based on manufacturer economics. Nothing absolute in any of this including the military-spec Delkin card linked above which was not in the same market as normal CF cards. We might assume there are military-grade SD cards too, and we all know companies never exaggerate in press releases or when meeting testing specifications .

I did say SD cards were waterproof above and should work on my writing style or have made it clear this was casual and in relative terms based on others who have more experience than me. As mentioned, I prefer using CF cards and will add I hope to never experience an accidental Maytag test myself.

As for the DigitalRev video, it was a follow up test like a number of tests they've done on that camera model over the years. Their goal was a light dose of skepticism, trial and error, and practical experience. It was also good for a fews laughs in case anyone missed it. The wheelchair test and setting it on fire were possibly not conducted by a world-class engineer to meet ISO standards, but I'm not sure .

Just note that trusted professionals are still just telling "seems to work for me", which isn't really hard facts. Especially since you don't really see trusted professionals telling "doesn't work for me" about the CF cards.

It might be hard to produce military-grade SD cards because of the way the connectors work - pin connectors are way better when you need to pass vibration tests. All forms of edge connectors have notorious issues with vibrations - their main advantage is that they are cheap to produce. And the problem is even bigger when you can't control both sides of the connection, i.e. both the SD card and the hardware that is expected to grip the card and keep it from rubbing the connections. There are military-grade equipment that has similar connection, but not using a slide design - they instead insert the equipment and then apply a very large pressure on the connectors after the device has been inserted. This allows for many times higher contact pressure - a 10 gram device might be clamped down with 10 kg which stops the contact surfaces from movement relative to each other.