Canon D7 - CF Memory Card

[essaytee]

I'm about to purchase a Canon D7. I have a question in relation to the CF memory card. Checking out various brand specs and I note that basically for a given gb storage the rated speed is the determining factor in price.

Given that the D7 specs indicate about 8 fps, obviously the faster rated memory cards the better. From what I can gather there are three speed rated cards, 30, 60 & 90 mb/sec. I'm looking at a 32 gb card but the price for the 90 mb/sec model is rather expensive but am not shying away from the price of the 60 mb/sec card.

So, is a 60 mb/sec CF memory card more than adequate for a D7? If my calculations are correct, shooting only JPEG images, each apprx 6.5 mb, equates to (60/6.5 = ) 9.2 fps (not that the D7 will achieve that).

Are there any other factors at play?

[etherial]

I assume you mean 7D rather than D7?

I have the 60mb/s Sandisk cards for mine and they work a treat, the card doesn't hold up the camera.

[Ray Heath]

G'day Steve

I thought internal buffer size was the detrmining factor for multiple shooting speed and quantity.

[essaytee]

Thanks for the replies. Yes, I meant 7D, what was I thinking?

[kevinj]

I use 30mbs in my 7D with no problems.

[Steve Axford]

It depends on the card and the camera. The rated speed refers to read speed, which is not really important in cameras where write speed is critical. Look up the references where they test the cameras and cards together to see which ones work the best. I think DPReview has some tests, but there are others.

[ricktas]

As others have said, the real write speed for 8fps shooting is entirely based upon the memory within the camera. When you take a photo, it is converted from an analog signal to a digital one in the chip on your sensor. That digital data is then forwarded to a buffer (memory) in your camera and from there is it written to the memory card. When shooting at 8fps, the limiting factor is the size of the memory buffer within the camera.

Where you will notice the difference with a faster card, is when you are copying the files to your computer. Also note that other factors come into play. Ie. USB/ Firewire speed when uploading.

[etherial]

But won't a slow card slow things down too? Once the buffer is full if the camera can't write the data to the card quickly enough things will slow down as you are then limited to the card write speed.

I haven't experienced this with my 7D but I certainly did on my 450D if I used a basic cheapo SD card rather than the Ultra 2 I had at the time.

[Steve Axford]

A slow card will slow things down as the speed of writing is based on the camera AND the card. If the card is fast enough it will have no effect, but if it is slow it will have an effect.

[Ray Heath]

But won't a slow card slow things down too? Once the buffer is full if the camera can't write the data to the card quickly enough things will slow down as you are then limited to the card write speed.

Yeh, but that won't affect the burst rate, it will only affect how fast the data is written to the card once the burst of exposures is finished.

Anyway were probably talking a difference in milliseconds which in practice will have little appreciable affect.

If you need to shoot a maximum burst as quickly as possible followed by another burst as quickly as possible I'd suggest your technique has other problems which you need to address.

[Steve Axford]

Ray, this is wrong. The card does effect how fast the camera will recover from a burst. If the card is slow, you will wait for a long time before you can shoot the next burst. If it is fast enough, you will wait for less time - and the difference could be tens of seconds, not milliseconds. It may be of little value to go for the very fastest card, but the very slowest will slow things down - noticeably.

[Clubmanmc]

The other factor is if you want to shoot video, but any card over 30mb/s will suffice...

I have allways used Sandisk cards, (been using them for the last 5 years)
and never had a bad write to one...

M

[essaytee]

Thanks everyone, good info.

What is the size of the buffer? I'm equating the buffer to being similar to computer RAM, which is very fast memory.

[Ray Heath]

Ray, this is wrong. The card does effect how fast the camera will recover from a burst. If the card is slow, you will wait for a long time before you can shoot the next burst. If it is fast enough, you will wait for less time - and the difference could be tens of seconds, not milliseconds. It may be of little value to go for the very fastest card, but the very slowest will slow things down - noticeably.

That is what I wrote Steve. The only point of difference is tens of seconds or milliseconds.

Regardless, you totally ignore my last statement.

[Steve Axford]

That is what I wrote Steve. The only point of difference is tens of seconds or milliseconds.

Regardless, you totally ignore my last statement.
To me, tens of seconds or milliseconds makes a huge difference. Your last statement doesn't make sense as many people want to shoot bursts on quick succession. I certainly do.

[Clubmanmc]

Thanks everyone, good info.

What is the size of the buffer? I'm equating the buffer to being similar to computer RAM, which is very fast memory.

the older Canon 1D models (my 1DII for example) used DDR RAM in them in 2004 and earlier, so i am sure its quite fast.... the buffer is about 350mb or so...

M

[MarkChap]

A slow card shouldn't affect the burst RATE, it will however affect the burst quantity.

A slower write speed will cause the buffer to fill and there fore you will get less shots in the buffer before it is once again full

[Ray Heath]

... many people want to shoot bursts on quick succession. I certainly do.

Why?

Seems to me if you need to shoot that many frames that quickly then your probably using the wrong technique and the wrong equipment. Why don't you just get a video camera?

And what of the other variables that will determine fps rate; shutter speed, image quality, focusing issues.

[MarkChap]

From the Canon web site

"Speed

Shooting Speed
8 fps / 90 shot max burst (JPEG), 15 (RAW)"

So if you are shooting JPEG you will be able to shoot for 11.25 seconds continuously before you fill the buffer, assuming the camera doesn't write a single file to the card.
In RAW you get 2 seconds before the buffer fills up, again assuming nothing is written to the card during that period.

My question is, how fast and for how long do you want/need to shoot continuously??

As for video, Canon, on page 149 of the manual advise that you need a card with a read/write speed of minimum 8 MB/s

[Steve Axford]

Why?

Seems to me if you need to shoot that many frames that quickly then your probably using the wrong technique and the wrong equipment. Why don't you just get a video camera?

And what of the other variables that will determine fps rate; shutter speed, image quality, focusing issues.

That's silly. If I wanted low res, blurred stills I would shoot video. If I shoot wildlife or sport, I want high burst speed and fast refresh time.

[Ray Heath]

And your response to Mark's post above is ...?

And you can post some images and explain how this technique of rapid firing gives you the results you feel you must achieve?

[Clubmanmc]

Ray,

I have very very rarely held the shutter down on full throttle at 8 fps (unless i was showing off to some body)

but i have had the buffer fill (i do shoot raw) and have maybe missed a shot (bear in mind thats only 14 frames in 2 seconds) and if the buffer clears slowly because of slow passing of info to the card from the buffer i could miss a shot...

if i shot jpg, i would never hit the buffer limit...

but

who shoots jpg any more...

M

[Ray Heath]

Ray,

I have very very rarely held the shutter down on full throttle at 8 fps (unless i was showing off to some body)

but i have had the buffer fill (i do shoot raw) and have maybe missed a shot (bear in mind thats only 14 frames in 2 seconds) and if the buffer clears slowly because of slow passing of info to the card from the buffer i could miss a shot...

if i shot jpg, i would never hit the buffer limit...

but

who shoots jpg any more...

M

Well.. needing to shoot more than 14 frames in 2 seconds is not the kind of photography that I'd be proud to put my name on.

"who shoots jpg any more" lots of us actually, but that's another argument.

[I @ M]

Well.. needing to shoot more than 14 frames in 2 seconds is not the kind of photography that I'd be proud to put my name on.



Ray, I really don't follow your train of thought on this one mate.

Camera manufacturers make their various models capable of fast frame rates for a reason.
Card manufacturers make their cards capable of keeping up with the camera for a reason.

Fast frame rates and fast cards are all tools in a photographers toolkit, just because you don't use them is not much of an excuse to criticise others for doing so.

[Ray Heath]

Ray, I really don't follow your train of thought on this one mate.

Camera manufacturers make their various models capable of fast frame rates for a reason.
Card manufacturers make their cards capable of keeping up with the camera for a reason.

Fast frame rates and fast cards are all tools in a photographers toolkit, just because you don't use them is not much of an excuse to criticise others for doing so.

Yeh, fair enough, I'm just presenting the other side of the argument.

Just because things are done and said and assumed doesn't make tham right. I've only asked people here to explain themselves in more detail. I'm willing to learn, but give me some facts and examples, don't just mindlessly sprout the accepted rhetoric.

[Kym]

Fast frame rates are good for Sports, Motorsport, Wildlife esp. Birding.
Back in the day I used a 250 frame film back and a motor drive - just a lot more expensive.

Darksome (Rich) explains why fast framerate is good for birding http://www.ausphotography.net.au/forum/showthread.php?t=16408

A lot of cams now have HD video, another reason for fast memory cards.

FWIW I shoot raw by default but will use JPEG when it makes sense. There is no right answer on that one.

Personally, for the sake of a few $ I would always get the fastest memory I could.

[I @ M]

Ray, I simply don't see any argument that has another side.

Fact. Fast cameras and cards exist.
Fact. People use them to obtain the results that they want.

As for sprouting "accepted rhetoric", I fail to see any of that either. I have presented 2 facts above, no rhetoric.

Facts and examples of fast frame rates and the successes that stem from them abound both on this forum and the net in general in such numbers as to become fact and not rhetoric as to the usefulness of them.

Think very fast moving small birds that sit still for less than 1/100th of a second at a time and you will more than likely never get the shot that you want by squeezing of single exposures.

Think advertising action, have a look at this video (http://blog.chasejarvis.com/blog/2009/10/chase-jarvis-tech-strobed-photo-sequences/) and then tell me how YOU would achieve that shot without a fast frame rate.
OK, you might not want to do that style of photography but don't knock others who do.

There is no "other side" to this argument because there is no argument.

[MarkChap]

Well.. needing to shoot more than 14 frames in 2 seconds is not the kind of photography that I'd be proud to put my name on.

"who shoots jpg any more" lots of us actually, but that's another argument.


I was specifically asked by a friend who competes in triathlon to do just that one morning.

I was there with the camera any way and he wanted a series of shots he could examine to check both his style and set up of the components in real world competition use.

And by the way, I was quite proud to put my name on them :th3:

[Clubmanmc]

Well.. needing to shoot more than 14 frames in 2 seconds is not the kind of photography that I'd be proud to put my name on.

"who shoots jpg any more" lots of us actually, but that's another argument.

I amctually shoot raw and jpg, sort the Jpgs and then fix what ever i need to with the raws... but thats another story...

with memory cards so cheap what would i want to shoot only jpg...

i have filled a buffer doing a wedding of all things...

the bride and groom were professional dancers, and as i do motor sport hired me to do their wedding dance,

no one had seen it, i had no plan, or did i know what was going on, which direction they were dancing nor how long it was going to last, but i knew one thing....

they had a room full of trophies, for Jive, rock n roll and a whole lot more... so i did not want to miss any of it...

i didnt shoot 14 frames in 2 seconds, the beat they danced to was a jive song, had a 4 / 4 beat from memory, so every 4th beat i took a shot... the camera didnt stop me taking a shot for the entire dance, (almost 3 mins...) and the red light didnt stop writing all those mins... with a slower card... i would have or could have missed opportunities...

my first camera a 300D was good for 3 fps, even on JPG mode, after the 12th photo it was backed up

so i am glad to have a faster camera and a faster card...

(just for the record the couple LOVED the shots of their dance)

M

[Clubmanmc]

Well.. needing to shoot more than 14 frames in 2 seconds is not the kind of photography that I'd be proud to put my name on.


well then

show us some thing YOU WOULD put your name on...

so we can be the judge...

M

[Ray Heath]

well then

show us some thing YOU WOULD put your name on...

so we can be the judge...

M

Note that I actually do use my name. So judge ... and an example of your work would be ...

[Clubmanmc]

well if i must...

my website is linked below... here are some of the high lights...

M

[Kym]

:wd: Ray :wd: Clubmanmc
Good images from both.
They also have nothing to do with the OP. So lets get back on topic which is benefits of fast memory cards.

Fast cards are better then slow(er) ones. For rather obvious reasons.
There are very good and creative reasons to use a fast frame rate + raw or FFR + JPEG.
Its only right/wrong in context.

[Ray Heath]

Ok, back on topic and my apologies Steve.

In your original post you quote read/write speeds in mb/sec, I have three CF cards all of which use a times rating i.e x4 (a quite old 256mb card), x100 and x120. How does this rating equate to mb/sec?

[essaytee]

Ok, back on topic and my apologies Steve.

In your original post you quote read/write speeds in mb/sec, I have three CF cards all of which use a times rating i.e x4 (a quite old 256mb card), x100 and x120. How does this rating equate to mb/sec?

I'm not sure, though I've noticed various sites selling cards also refer to x200, x400 etc. There must be a base value to which xNNN refers. Anyone else?

ps. btw, great photos.

[etherial]

If you need to shoot a maximum burst as quickly as possible followed by another burst as quickly as possible I'd suggest your technique has other problems which you need to address.

I've read this thread with interest - you want examples of when someone would use burst rates in quick succession. I do it all the time.

I shoot dog events, and part of that is getting movement shots when the dog is in correct stride. There is no way you can do it with a single shot, simply impossible. Nor with a video camera as the shots will not be sharp enough or at high enough resolution. Therefore you must shoot a burst sequence as the dog moves around the ring. And guess what...often there are more than one dog in the ring at any one time! So I pan following one dog, take a burst, then quickly turn to the next do the same...might do it for 4,6, maybe 10 dogs!

So yes there are times when you need that capability, hence why I bought a 7D.


So statements like this...



Well.. needing to shoot more than 14 frames in 2 seconds is not the kind of photography that I'd be proud to put my name on.


are simply ridiculous.

[Kym]

I'm not sure, though I've noticed various sites selling cards also refer to x200, x400 etc. There must be a base value to which xNNN refers. Anyone else?

ps. btw, great photos.

http://en.wikipedia.org/wiki/CompactFlash#Speed

http://www.robgalbraith.com/bins/multi_page.asp?cid=6007

[etherial]

I'm not sure, though I've noticed various sites selling cards also refer to x200, x400 etc. There must be a base value to which xNNN refers. Anyone else?

ps. btw, great photos.

Here is a good resource if you want to get deep into it...

http://www.hjreggel.net/cardspeed/index.html#speed-cards.html

[essaytee]

What I gleaned from the links provided (thanks) is that the base speed unit is 150 kb/sec, therefore x400 rated card is 400 x 150 = 60,000 or 60 mb/sec (or really fast and x600 faster still - and expensive).

[Steve Axford]

What I gleaned from the links provided (thanks) is that the base speed unit is 150 kb/sec, therefore x400 rated card is 400 x 150 = 60,000 or 60 mb/sec (or really fast and x600 faster still - and expensive).
But it doesn't mean very much. What you need to know is how it will work with your camera. Marketing blurb can be taken as a general indication, but not much more than that - and sometimes not even that.

Since you don't seem to have found the right pages, I had a look for you. Have a look at this.

http://www.robgalbraith.com/bins/content_page.asp?cid=7-10044-10297

I think Kym may already have posted this, but just to be sure you read it ...

[essaytee]

But it doesn't mean very much. What you need to know is how it will work with your camera. Marketing blurb can be taken as a general indication, but not much more than that - and sometimes not even that.

Since you don't seem to have found the right pages, I had a look for you. Have a look at this.

http://www.robgalbraith.com/bins/content_page.asp?cid=7-10044-10297

I think Kym may already have posted this, but just to be sure you read it ...

It means what it means, in theory. The theory is correct. I thought it was a 'given' that obviously the ultimate transfer (write) speed would depend upon the device writing the data, in this case a camera. I'm sure that was pointed out earlier in the thread.

[JorgD]

A similar question about CF speeds was asked before, and here was my response to the question 7 weeks ago, which I think still applies to the current question.

I use an Extreme III card rated at 30 MB/sec and and Extreme card rated at 60 MB /sec. When I got the Extreme card, I wanted to see how much faster it really is compared to the Extreme III card, so I ran some tests at my PC with my USB card reader. The 30 MB/sec card was faster than the 60 MB/sec card.

This result was of course slightly disappointing, so I started doing more research on this, starting on the Sandisk web page. It appears as they their wording and testing procedures changed over time. The Extreme III card has a through put of at least 30 MB/sec, the Extreme card has a throughput of up to 60 MB/sec. Looks like the words "at least" and "up to" actually cross over for me.

Doing further research, the 60 MB/sec card uses an UDMA interface rather than the PIO interface of the older cards. Now, unless your card reader can make full use of UDMA (which mine obviously could not), you will end up with no better and possibly worse performance than the older cards.

Testing both cards in my 7D shooting Raw images, both cards allowed 22 shots to be taken at high speed before the camera started to slow down. The stated buffer for the 7D is 15 raw. So from the cameras perspective there was no difference at all. Even shooting 1080p movie mode with the 7D, provided your card can accept at least 8 MB/sec, you will have no problem taking movies to your hearts content.

I recently purchased a Nexto Extreme external HD with card reader, and the Nexto could back up the images significantly faster from the 60 MB/sec card than the 30 MB/sec card, causing me to believe that it does make good use of the UDMA interface.

I personally would not spend a lot of money on a faster card as the camera can't make use of the faster speed and the USB 2.0 interface is also slower than most cards so you won't see any benefit there. The only time there is a benefit for higher card speed is if you have a UDMA enabled backup device like a Nexto, or if you have a UDMA CF card reader connected to Firewire 800 or USB 3 when it is released.

[Steve Axford]

It means what it means, in theory. The theory is correct. I thought it was a 'given' that obviously the ultimate transfer (write) speed would depend upon the device writing the data, in this case a camera. I'm sure that was pointed out earlier in the thread.

Not true. The write speed is dependant on both the camera AND the device it is writing to. It's a shame that there is so much fud going around.

[Clubmanmc]

A similar question about CF speeds was asked before, and here was my response to the question 7 weeks ago, which I think still applies to the current question.

I use an Extreme III card rated at 30 MB/sec and and Extreme card rated at 60 MB /sec. When I got the Extreme card, I wanted to see how much faster it really is compared to the Extreme III card, so I ran some tests at my PC with my USB card reader. The 30 MB/sec card was faster than the 60 MB/sec card.

This result was of course slightly disappointing, so I started doing more research on this, starting on the Sandisk web page. It appears as they their wording and testing procedures changed over time. The Extreme III card has a through put of at least 30 MB/sec, the Extreme card has a throughput of up to 60 MB/sec. Looks like the words "at least" and "up to" actually cross over for me.

Doing further research, the 60 MB/sec card uses an UDMA interface rather than the PIO interface of the older cards. Now, unless your card reader can make full use of UDMA (which mine obviously could not), you will end up with no better and possibly worse performance than the older cards.

Testing both cards in my 7D shooting Raw images, both cards allowed 22 shots to be taken at high speed before the camera started to slow down. The stated buffer for the 7D is 15 raw. So from the cameras perspective there was no difference at all. Even shooting 1080p movie mode with the 7D, provided your card can accept at least 8 MB/sec, you will have no problem taking movies to your hearts content.

I recently purchased a Nexto Extreme external HD with card reader, and the Nexto could back up the images significantly faster from the 60 MB/sec card than the 30 MB/sec card, causing me to believe that it does make good use of the UDMA interface.

I personally would not spend a lot of money on a faster card as the camera can't make use of the faster speed and the USB 2.0 interface is also slower than most cards so you won't see any benefit there. The only time there is a benefit for higher card speed is if you have a UDMA enabled backup device like a Nexto, or if you have a UDMA CF card reader connected to Firewire 800 or USB 3 when it is released.

I have seen the same results, a fire wire CF reader will get you a little faster... but at the price... its best to get the reader going and go get a cup of coffee...

M

[mkooper]

Thank you to all involved in this discussion. It has cleared up a lot of questions for me. I also use successive rapid bursts of shots in RAW + JPG for exhibition and performance dancing routines and have found that slow cards mean longer periods between bursts. However it is good to find that I don't have to spend $$ on the latest and greatest to get the best results.

--> Here (http://mkooper.smugmug.com/Commercial/Samples/2010-Fusion-Concert/11797349_eEYqQ#833389052_UxPiq) <-- are some examples as to why you would take rapid succession of photos in order to give the customer the best possible result for their money