memory cards: CF vs. SD

<p>I'm wondering what the difference is between SD and CF cards. My D90 has an SD card as does my Canon G10. I notice the pro cameras -- Canon and Nikon -- use CF cards. Why? The D300 can accept either.<br>

CF cards are physically larger. Do they write faster for sports? Is that why pro cameras use them?</p>

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<I>Allan is apparently referring to the Nikon D300S, which can accept one Compact Flash and one Secured Digital memory cards. The original D300, non S, can only accept one CF card; it is not compatible with SD cards. -- Shun Cheung

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<p>I think the technology (read/write speeds) for CF cards progress faster than SD, but this might change in the future.</p>

<p>Until recently the CF cards were faster than the SD cards in R/W speed. They were also available in larger storage sizes than the SD cards. I doubt that it is a valid reason but I think the smaller SD cards are much easier to misplace.</p>

<p>Just my opinions though.</p>

<p>HLA</p>

<p>SD cards are fragile compared to CF cards. I think it's relatively easy to damage an SD card by accident. I had a cheap SD card fall apart in my hands once. </p>

<p>I would put both cards in the D300s and have the piece of mind that I would have a backup card.</p>

<p>Inside the camera and seated there, the practical differnece is negligible. Outside the camera, CF has all the advantages of a human finger-adapted size and robustness. Longevity for a SD card you try to replace in the field is very short: once you drop it or misplace it, it's gone (I clocked the longevity to about 5 minutes under real-world situations).</p>

<p>So I prefer CF. We really don't need anything smaller.</p>

<p>Some people think that SD cards have fewer problems, probably because EARLY CF-cards and CF-card-equipped cameras had some real regular issues But today there's really no difference in reliability at all, as both are very mature mediums. In the D1 days, every now and then we'd have a card just stop working forever. With the Kodak DCS we had the same thing happen once or twice. We never were able to determine whether it was the camera or card at fault. Cameras and cards in use now aren't going to be a problem.</p>

<p>CF has MUCH faster throughput possibilities, but even for sports, the really fast SD cards can often keep up (at least they can on my D90 shooting what seems like forever in jpeg mode with an Extreme III Class 10 card). SD is more fragile (although the slot is, imho, a far better design than CF) and easy to lose (I've never lost one, however), but on the other hand the CF slot in the camera is also potentially super-fragile, but usually not a problem.</p>

<p>We may get, sometime in the near future, a new standard that has the robustness of CF but the "slot-robustness" of the SD cards. It matters nothing to us now, since no cameras will take them.</p>

<p>For now, just use what your camera requires and don't worry about it. And if you have a D300 and use only one card, use CF if you can.</p>

<p>I only own CF cards so I don't really know what I am talking about. I have never had a single problem with a CF card, knock on wood.<br /><br /><br />However the contacts of the CF card have always made me nervous. The possibility of bending a pin is there. I like how the SD card contacts. The contacts are accessible so they can be cleaned if necessary and there is nothing to bend. But that is all just theoretical.</p>

<p>I used to think the connection pins for CF cards are vulnerable (those pins are inside the camera). I have bent pins on some cheap card readers, but I have never done so on an actual DSLR after 8 years of shooting digital.</p>

<p>Last year, I bought some SD cards to test the D300S with, and in no time I broke one older SD card my wife has been using; it cracked on the side of the card. That whole package is fragile.</p>

<p>Read/write speeds on CF cards are faster, or at least the fastest CF cards are faster than the fastest SD. But technology is changing rapidly so that it may not hold true.</p>

<p>My fingertips are larger than SD cards. I like the CF card's form factor (for handling) and survivability.<br /><br />Untold hundreds (thousands, no doubt) of CF card swaps later, I've never had a single CF card (or socket pin, on cameras or readers) fail.</p>

<p>Eleven years of hard use of CF cards: no problems, no broken pins, no cards lost. (0 out of approx. 100 cards in service over all these years).</p>

<p>Two years with SD cards: 4 cards (67% of population) lost in field, 1 broken. The last one will sit inside my UV-modified D40x until the camera breaks down.</p>

<p>I prefer CF to SD cards for the exact reasons Bjorn mentions. They're much more human-handle friendly, they're tougher and bigger. There comes a point when something is actually too small. Take those micro-SD cards for instance. I'm always careful putting in the CF card. There's no reason to tempt fate.</p>

<p>Besides their advantages by design (faster throughput rates, CRC for correcting read/write errors, mechanisms for an even wearing of the memory banks, a more versatile specification whereas storage medium can be flash or micro-disk drives, or whatever comes in the future), CF cards are made to withstand more abuse.</p>

<p>I have put at least two of my CF cards through the washing machine (forgetting them in some jeans pocket) and once they dried out (when the jeans dried out) they kept performing like new, data wasn't even lost. SD cards on the other side have turned out to be quite fragile, they bend and break with very little effort on your side.</p>

<p>The "disc" controller is built into CF cards, whereas the controller resides in the reader/writer for SF cards. Consequently, SF cards have far fewer pins and are much smaller. A built-in controller has inherently more comprehensive access to the memory, but I think technology is catching up.</p>

<p>SF card are also sealed much better. This may be a moot point, since I've had two CF cards go though a complete wash/dry cycle in the laundry, and come out perfectly operational, without losing any memory.</p>

<p>There are several fundamental types of CF cards, with different performance levels and even theoretical longevity. I've read and forgotten which is which, except that high performance cards tend to be several times as expensive as the slow, unreliable types. Cameras use the former, thumb drives tend to the latter.</p>

<p>annoyingly, the price is the main difference.... and it ticks me off when i buy cf cards for my canon 40d, i just purchased another 8 gig card and compared to what i pay for an 8gig sd card for the fujisd2000 compact superzoom i own, i pay 8 to ten times as much for a cf card for the canon. i have 8gig sd cards i picked up for 20 bucks canadian during christmas-season sales. That doesn't happen with CF cards. The cheapest i've seen 8 gig cf on sale for is in the 70 buck range. Because there are now millions of cameras taking sd cards in the hands of amatuers, there are not only millions more cards being made, but the stores selling them use the sd cards as "lost leaders" in flyer-sales to get customers in the door. With Cf cards now being mainly only still used in pro and prosumer cameras there is not the volume of buyers attached to them for the stores to worry about using them as lost-leaders and dumping them at no profit to get you in the door. </p>

<p>The only advantage of SD cards is that there is a 'lock' slide switch so that you don't accidentally erase its contents. It serves as a quick visual reminder to separate the full cards and fresh cards in the field.</p>

<p>@ Isaac</p>

<p>Yanno, I never even thought to use the lock function as an indicator of full or not, I always just put them in separate pockets in my pants/bag. Interesting idea.</p>

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I have two cameras that use CF cards and two that use SD cards. I have had good performance from both types of cards. Only 2 of 47 CF cards failed and 1 of 4 SD cards failed.</p>

<p>Until recently, I did not even know that SD cards had a lock mechanism. I became aware of the lock when I accidentally locked a card and my camera informed me that the card was locked.</p>