Xsi burst speeds

Rocketman766

Not sure if I titled this correctly, but I was looking for info about number of shots in continuous mode when shooting with a Canon Xsi. I will be shooting in Raw and I found where it list maximum bursts in Raw mode as 6 shots. My question is how long do I have to wait between burst series? I don't think I will be doing alot of burst, just a few here and there. This will be at an indoor sporting event. I will be renting an EF 135mm, f2L USM to shoot this. I know the Xsi isn't the greatest sporting event body, but thats what I currently have until I get better and can also afford something better (few yrs at least..) Thanks.

ziggy53

Rocketman766 wrote:

... I was looking for info about number of shots in continuous mode when shooting with a Canon Xsi. I will be shooting in Raw and I found where it list maximum bursts in Raw mode as 6 shots. My question is how long do I have to wait between burst series?...

It depends upon how quickly you can clear the shot buffer, which is mostly dependent upon transfer to the memory storage card. The faster the card, the faster the buffer gets cleared.

As the card fills you may see a slow down in transfer speed. I generally stop filling the card when it gets around 75% to 80% full and put in a new card.

You can easily test your card's transfer speed by ripping off a round in continuous and then counting the seconds until the transfer/busy light on the camera stops.

I do think the XSi has a "smart" buffer that allows you to start taking some additional pictures after some of the buffer is unloaded, but I'm not sure about that.

Rocketman766

as always, ziggy is on the spot with the answer... I will be using a 30mb sandisk card... ( i think i got that right, the mb might be MB...can't remember...) Hope it wasn't a stupid question, but I forgot my owners manual at home and I am really anxious to use the 135mm lens and hope to get some great shots.. I will post in the sporting section after the competition..2 weeks away...

ziggy53

Rocketman766 wrote:

as always, ziggy is on the spot with the answer... I will be using a 30mb sandisk card... ( i think i got that right, the mb might be MB...can't remember...) Hope it wasn't a stupid question, but I forgot my owners manual at home and I am really anxious to use the 135mm lens and hope to get some great shots.. I will post in the sporting section after the competition..2 weeks away...

I hope it is not a 30 Megabyte card. That would only hold a very small handful of images.

For the XSi and RAW files you really should be looking at the 4 Gigabyte cards. Specifically, for that camera, I would look for a couple of the Sandisk Ultra III, 4 Gig cards at least. I would not trust a single card for critical events.

divamum

Rocketman766 wrote:

as always, ziggy is on the spot with the answer... I will be using a 30mb sandisk card... ( i think i got that right, the mb might be MB...can't remember...) Hope it wasn't a stupid question, but I forgot my owners manual at home and I am really anxious to use the 135mm lens and hope to get some great shots.. I will post in the sporting section after the competition..2 weeks away...

30mb? That will give you about 10 pictures shot in raw. If that really IS what you're using (I'm going to guess you're probably mis-remembering it, but just in case) consider getting some other larger, cards for the occasion, probably 4g or 8g cards - newegg.com often has them at very good prices if you have time to order onlin and they ship pretty fast. If you have to pick them up "in person", look for deals so you don't wind up paying $50 for a $15 card (I got a good deal IRL at Target, of all places - look for sale stickers!).

Wolftep

I'd be willing to bet the 30MB is the speed, not the size, in which case it's possibly a SanDisk Extreme III card, which should do very well with data transfer from the camera to the card.

dlplumer

Wolftep wrote:

I'd be willing to bet the 30MB is the speed, not the size, in which case it's possibly a SanDisk Extreme III card, which should do very well with data transfer from the camera to the card.

+1 correct

Rocketman766

sorry guys, didn't mean to confuse or look stupid, I just assumed everyone would know I meant the speed... I think the ones I have are 8 gig cards, and yes they are Ultra III cards. I have about 4 or 5 in my bag already so I am ready when the urge strikes to snap some shots..... thanks for keeping me in line guys.

dlplumer

I just purchased a delkin udma (40 mb speed) 16 GB. Certainly not necessary for the XSi which I have, but necessary for my 50d which is a 15 mp 6.3 fps beast. I use these bursts frequently when shooting birds in flight.

divamum

Rocketman766 wrote:

sorry guys, didn't mean to confuse or look stupid

Wolftep wrote:

I'd be willing to bet the 30MB is the speed, not the size, in which case it's possibly a SanDisk Extreme III card, which should do very well with data transfer from the camera to the card.

Ok, colour ME stupid because I've not heard of speed in this context - none of my Transcend or Kingston SD cards indicate the speed other than as an X factor ie 133x, 120x, 150x.

Educate me: how does the 30mb factor into this, and what is it measuring?

Thanks!

dlplumer

divamum wrote:

Ok, colour ME stupid because I've not heard of speed in this context - none of my Transcend or Kingston SD cards indicate the speed other than as an X factor ie 133x, 120x, 150x.

Educate me: how does the 30mb factor into this, and what is it measuring?

Thanks!

30mb would be equivalent to 300x I believe. The cards you have are relatively slow. Nothing wrong with them, just not good for high speed bursts.

divamum

dlplumer wrote:

30mb would be equivalent to 300x I believe. The cards you have are relatively slow. Nothing wrong with them, just not good for high speed bursts.

Tx for the explanation. These are all older cards that I already had for sound gear where that isn't as big a deal. I guess next time I shop for cards I have something else to look for - thanks for clarifying that!

Wolftep

divamum wrote:

Educate me: how does the 30mb factor into this, and what is it measuring?

Thanks!

Under optimum conditions, the card is capable of 30MB per second read/write speed.

mercphoto

divamum wrote:

Ok, colour ME stupid because I've not heard of speed in this context - none of my Transcend or Kingston SD cards indicate the speed other than as an X factor ie 133x, 120x, 150x.

Educate me: how does the 30mb factor into this, and what is it measuring?

Its measuring the data transfer rate -- 30 MB per second. It actually tells you a lot about the speed of the card, because it is an absolute measure. Those silly "X factor" ratings however are relative measures and tell you next to nothing -- 120 times faster than what, exactly?

divamum

mercphoto wrote:

Its measuring the data transfer rate -- 30 MB per second. It actually tells you a lot about the speed of the card, because it is an absolute measure. Those silly "X factor" ratings however are relative measures and tell you next to nothing -- 120 times faster than what, exactly?

Which is something I have wondered since I bought my first SD cards 3 years ago. And now I know what it's all about - I can't believe it's taken resarchaholic-me that long to come across this...

Wolftep

mercphoto wrote:

Those silly "X factor" ratings however are relative measures and tell you next to nothing -- 120 times faster than what, exactly?

Actually, there is a formula to figure out the "X factor". Each "X" is equal to 150KB per second.

dlplumer wrote:

30mb would be equivalent to 300x I believe. The cards you have are relatively slow. Nothing wrong with them, just not good for high speed bursts.

So in this case, the 30MB card would actually be comparable to a 200X rated card. 200*150KB/sec = 30,000KB/sec = 30MB/sec

ziggy53

The real thing to become informed about is how fast a given card transfers information in "your" camera. That, for me anyway, is the critical factor.

That's why I post links to Rob G's most excellent testing pages.

For the Canon XSi that link is again:

http://www.robgalbraith.com/bins/camera_multi_page.asp?cid=6007-9424

Note that the ratings vary bay card "and" by camera, and the manufacturers' speed ratings do not coincide. I tend to trust Rob's figures because he has nothing to gain from the testing other than attracting users to his site.

As a rule the highest end Sandisk cards do generally pretty well in the Canon, Nikon and Sony cameras. Unfortunately Rob doesn't test all cameras.

Wolftep

Great point Ziggy!

You can have a Sandisk Extreme III 30MB card, but if your camera does not support UDMA, then you're not going to get anywhere near that transfer rate. As in any case, the file transfer will only be as fast as the weakest link.

Edit: Also, that is a great website you mentioned there. I only wish he had more on the non-Canon/Nikon brands.

ziggy53

dlplumer wrote:

I just purchased a delkin udma (40 mb speed) 16 GB. Certainly not necessary for the XSi which I have, but necessary for my 50d which is a 15 mp 6.3 fps beast. I use these bursts frequently when shooting birds in flight.

Dan,

Did you see the 50D card speed tests?:

http://www.robgalbraith.com/bins/camera_multi_page.asp?cid=6007-9672

dlplumer

ziggy53 wrote:

Dan,

Did you see the 50D card speed tests?:

http://www.robgalbraith.com/bins/camera_multi_page.asp?cid=6007-9672

Thanks Ziggy. My card is not even on that list. It's a Delkin UDMA PRO 16gb, and is rated at 45MB/sec or 305x.

I have the same card in a 4GB version and it is faster than anything else I have tried including the Sandisc Extreme III rated at 30 MB

What do you think?

PS Oh, it is on the list with a s--t rating. Doesn't match my actual experience using it. Not sure what to make of it. It sure is expensive.

Robinivich

dlplumer wrote:

Thanks Ziggy. My card is not even on that list. It's a Delkin UDMA PRO 16gb, and is rated at 45MB/sec or 305x.

I have the same card in a 4GB version and it is faster than anything else I have tried including the Sandisc Extreme III rated at 30 MB

What do you think?

PS Oh, it is on the list with a s--t rating. Doesn't match my actual experience using it. Not sure what to make of it. It sure is expensive.

I wouldn't worry too much about it. People can get real excited about fast CF cards, but from what I've seen, and what I've seen reviewed, the camera is often the weakest link unless you've got a really slow card. Less so with very recent sports cameras, but still. You'll probably see the biggest difference while you're waiting for an 8 or 16 gig card to unload onto the computer.

Rocketman766

Well, a few lessons learned today. It was the first time I got to use my Xsi at one of my daughters competitions. First lesson...lighting... I NEED and will acquire a f2 or f2.8 lens for these indoor events. Second lesson.. location, don't settle for sitting on the sidelines, get in the middle to take the good shots. 3rd lesson, my card and camera handled the bursts just fine (from an amateurs point of view ), it was limited by shutter speed (see lesson about lighting above..) So basically, I don't think I need to worry about my bursts or the cards ability to handle the way I take pics ( at this time...)