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SanDisk CompactFlash Speeds

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Looking for more memory cards for my DSLR, I divided deep into the CF specification, history, and marketing. It’s a mess. Here I’ve focused on the SanDisk CF cards, as that’s what I usually get. More specifically, I wanted to know, which name or specification corresponded to which speed, and what I could expect from the that card when taking a lot of pictures, e.g. hundreds of pictures as part of a panorama.

Over at Digital Photography Insights, Rob Galbraith already has very extensive tests with different cards. Currently, only the EOS 5D Mark III list is covering most relevant CF cards, but tests with the Canon 50D is also planned. Looking forward to it. Also of interest from his page is the various card readers. This led me to the Addonics ADSACF which connects the CF reader directly to the internal SATA bus, and achieves read speeds of more than 90 MB/s. At ~$30, it looks like a very good buy.

Before digging into the SanDisk cards, a bit of background and relevant documents. The CF specification is guarded by the CompactFlash Association, and you have to buy the detailed docs, however they’ve started applying some cute icons to each of the more recent versions. Still, it does not tell you a lot about the read/write speed; e.g. the CF 5.0 and 6.0 specifications carry the same icon. Wikipedia has a bit more detail on the older CF specifications. It mentions that the first CF revisions were using PIO (Programmed input/output); PIO mode 2 since the beginning in 1995, and mode 4 in 2003, with DMA 33 in 2004. According to Rob Galbraith, several of the cards implement dual protocols, i.e. both PIO and UDMA. I’ve not been able to verify this anywhere else, but it seems to make sense, for backwards compatibility. Of course, when operating in PIO mode, one will not be able to take advantage of the speed the newer cards are rated for.

Current CF cards are based on PATA mode, so the UDMA (Ultra Direct Memory Access) modes apply. I’ve lifted he relevant table from the current Wikipedia article, as shown below. Of some relevance is also the speed rating used for SD cards. Here the “x” rating is based on the CD-ROM transfer speeds, e.g. 6x means 6 * 150 kB/s, or 900 kB/s. Some of the Lexar, Kingston, and other CF also use this in the name of the cards, but not SanDisk.

Mode Number Also called Maximum transfer rate (MB/s) Defining standard
Ultra DMA 0 16.7 ATA-4
1 25.0 ATA-4
2 Ultra ATA/33 33.3 ATA-4
3 44.4 ATA-5
4 Ultra ATA/66 66.7 ATA-5
5 Ultra ATA/100 100 ATA-6
6 Ultra ATA/133 133 ATA-7
7 Ultra ATA/ - - -

Back to the SanDisk cards, though. SanDisk itself is not very good at keeping old product pages around, so a lot of the references I found was at Digital Photography Review; they keep their articles around. The story starts in 1994, with SanDisk defining the CompactFlash standard, batteling it out with other companies and cards like Miniature Card, SmartMedia, and later MMC/SD, various Memory Stick formats, and xD-Picture Card.

The first article I can find on dpreview, is an updated product range of “larger capacity CF cards of 64MB, 80MB and 96MB”. No mention of speed, but another article from the same date talks about 1.4 MB/s as high-speed. Later on, the different product lines have been overlapping, upgraded, and renamed, and thus adding a lot of confusion. Add to that strange “marketing” products like the 2007 “Ducati Edition” (4 and 8 GB cards at 45 MB/s), and the terrain starts to get difficult to navigate. Also note, the “Extreme” line has two incarnations, its inital series from 2003, which was just called “SanDisk Extreme”, and the newer UDMA versions; not sure which year they were introduced. The same is the case for the initial “Ultra” line.

Below I’ve listed the SanDisk CF product lines I could find, with best effort searches for largest size, and guesses at standard / IO mode. The model prefixes where partly from Amazon, with hints from the Nikon approved cards page. Feel free to get in touch if you have further information.

Name Model number
prefix
Speed Largetst Size Modes Year Source
Standard SDCFB ?? ?? PIO 2 ??
Ultra ?? 2.8 MB/s 512 MB PIO 2 2001 dpreview
Extreme ?? 6 MB/s 1 GB PIO 2 2003 dpreview
Ultra II SDCFH 9 MB/s 8 GB ? PIO 4 2004 dpreview
Extreme III SDCFX3 20 MB/s 16 GB PIO 4 /
UDMA 2
2004 dpreview
Extreme IV SDCFX4 40 MB/s 8 GB PIO 4 /
UDMA 4
2006 dpreview
Extreme III SDCFX3 30 MB/s 32 GB PIO 4 /
UDMA 4
2008 dpreview
Extreme IV SDCFX4 45 MB/s 32 GB PIO 4 /
UDMA 4
2008 dpreview
Ultra SDCFH 30 MB/s 16 GB PIO 4 /
UDMA 4?
?? SanDisk
Extreme SDCFX 60 MB/s 32 GB PIO 4 /
UDMA 4?
?? SanDisk
Extreme Pro SDCFXP 90 MB/s 64 GB PIO 4 /
UDMA 6
2009 dpreview
SanDisk
Extreme Pro SDCFXP 100 MB/s 128 GB PIO 4 /
UDMA 7
2011 dpreview
SanDisk
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Lego Panorama

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I’ve discussed panorama robots in the past, and here is a new creation. James Catan has created several Lego robots to do timelapse and and pan/tilt pictures. One of them were recently presented in Gadget Review, and shows holding a Canon Rebel XT with a kit lens. So not quite 5D, 200mm f2.8 as with Jeffrey Martin’s rig. Yet still a good and simple setup.

Another interesting pan & tilt product comes from Sparkfun. It is a robot arm, consisting of servos and and a claw. It will definitely not hold a SLR, but possibly some smaller pocket cameras or phones. As far as I understand, the complete robot arm comes in several parts which you’ll have to add to your order separately.

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Tripod ballhead

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Here’s an interesting tripod ball head which also can pan smoothly. Acratech GP Ballhead. At $400, I’ll probably have to wait a bit, but interesting never the less. Their promo video is worth watching.

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Canon 60D

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I’m a bit late to the release party of Canon 60D, however, the solid reviews are starting to come in. That’s always a bit more interesting than press articles copy-pasting the release notes from Canon. Both Digital Photography Review and DigitalRev compares the new camera to Canon 7D. The former includes a comparison to 50D, while the later compares to 550D. In summary, it’s starting to get rather hard to compare and distinguish these bodies (unless you worry about minute details). The features are similar, the price points are 200 Euros or less in difference. So if you’re choosing from the high end, 7D is probably the way to go right now.

60D does video just like 7D, however this does still not interest me. Perhaps most interesting, is that unlike 50D, they’ve switched to SD cards (rather than CF which is still used in the high end models). It begs the question of whether CF will be completely replaced in next rounds of updates, within a couple of years.

A very minor feature I would welcome is the star rating. Reviewing the pictures on the camera, you can assign stars based on the quality (or whatever you choose for your own encoding scheme). That would certainly speed up publication of my images. Which reminds me, I have some pictures I need to shift through…

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Panorama Robots

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It somehow seems inevitable; if you are into photography and electronics, you want to build a panorama robot. Coupled with very good software to stitch and render a panorama image, the results can be breathtaking even with little effort. For the stitching software, I recommend Hugin, the open source panorama stitcher. On a modern OS; just go yum / apt-get install hugin. For a good intro into setting up and shooting the single frames which goes into your panorama, see Robert. Cailliau’s article.

Once you’ve taken a few pictures, maybe five or even ten with a fairly wide angle lens, you realize that you can get even more detail if you use a zoom lens. Maybe 200 or 300mm. However, now you have to take hundreds of pictures to cover the same area in your finished panorama. This is were the robots come in.

The pocket camera on the turn table below is a very cheap solution; about 15 Euros. I have not found a specific product or manufacture name, though. It shows up in searches for “Panorama Drehteller“. Next to it is a more professional solution, the Gigapan Systems Epic 100 Panorama Robot. It can take a DSL, and pan both horizontally and vertically. You need both if you plan on using a 200mm lens.

So if you’re only into photography, and not DIY and soldering, those are maybe some of the solutions you’d go for. However, if you are able to build one yourself, what is stopping you? Nothing, it seems, judging by the number of home made panorama bots. Here is a Lego Mindstorms competition to build a pano bot with the winners from 2008. Here is a Jason Babcock’s second go at a panoramic turntable, using ULN2004A and BX-24 micro-controller.  And here is T. Emrich’s system which looks like a very solid setup, and clever control: His early work resulted in a horizontal rotation only solution. Later on, he built the GigaPanBot or Gigapixel Panorama Robot with complete freedom on both axis, seen in the picture below. Maybe most impressive, is how the whole system fits into his camera bag.

So what if you want to build your own. Well, nothing is stopping you, and there is plenty of parts to pick up to make a simple first system. Babcock’s first attempt was using a stepper motor from an old fax. Or you could buy a new stepper motors for less than 20 Euros.

To help you on your way, there’s the DollyShield, which I spotted on the Arduino Shield List. It includes control of two DC motors, shutter remote for the camera, joystick buttons and a LCD. “It is designed to provide an inexpensive and easy-to-use interface for two-axis motion control integrated with a camera.”