Which CF card?

martinfuge

martinfuge

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Martin
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Hi

What the best CF card to buy to use with the Canon 7D when you high continous shooting with quick buffering to the camera? An example of what I mean is for example at an airshow, I am looking for a card so I can take continous shoots wihtout waiting a while and the camera saying busy.

I have read about 600x and 50/60mbs is that what I need to be looking for?

Cheers
 
i use the Sandisk Extreme 32gb card
been ok with buffer around 20 pictures on raw
 
Your 7D will probably benefit from using faster cards. Whether the improvement is worth the expense only you can judge.

In my 5D3 with either a 60 MB/s CF card or a 160MB/s CF card the RAW buffer capacity doesn't change from 13. However I get an extra 8 frames from the camera before the FPS starts to slow from the 160MB/s due to the camera being able to write faster to the card.

With the 160 being 35-50% dearer than the 60 its quite an additional expense if you don't need the extra performance. I'm quite happy to pay it for my 5D3 but I use 60-95 MB/S in my MkIV as it has a bigger buffer and I never max it out.
 
As above re speed - with regards to which, I'd opt for Sandisk or Lexar cards
 
Make sure you don't buy one that only does mb/s. Milli bits are no good, you need MB, mega bytes. Pedantic, yes but an important point IMO.
 
martinfuge said:
What the best CF card to buy to use with the Canon 7D when you high continous shooting with quick buffering to the camera?
Click to expand...

On the 7D card speed has zero impact on the number of shots you can take before the buffer fills. Once the buffer has filled (around 24 raw files - which should be enough for almost everybody) the card speed will effect the time it takes for the buffer to clear - up to a point. The 7D cannot write at much more than 50 MB/s - so a 60MB/s card will be fast enough.
 
hollis_f said:
On the 7D card speed has zero impact on the number of shots you can take before the buffer fills. Once the buffer has filled (around 24 raw files - which should be enough for almost everybody) the card speed will effect the time it takes for the buffer to clear - up to a point. The 7D cannot write at much more than 50 MB/s - so a 60MB/s card will be fast enough.
Click to expand...

Whilst the buffer capacity remains the same the camera is writing to the card as the buffer is filling. If it can write faster then it extends the number of frames before the buffer cuts the frame rate.


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As I posted earlier I get an extra 8 frames before the buffer cuts the frame rate. That is worth the extra outlay to me but maybe not to others.
 
Gaz J said:
Whilst the buffer capacity remains the same the camera is writing to the card as the buffer is filling
Click to expand...

No it isn't.


Here is a test I did on the 7D measuring the number of raw images before the buffer fills. There is no difference at all between a 1.5 MB/s card and a 45 MB/s card. If the camera was writing to the card whilst filling the buffer then the 45 MB/s card would be able to write 135 MB while the buffer was filling. The fact that the buffer fills after the same number of files means that it isn't writing until the buffer is full.
 
Well your results seem at odds with other tests carried out and,whilst a different camera, the 5D is definitely writing to the card whilst the shutter is pressed as the buffer capacity never changes irrespective of the speed of the card but number of frames before slowdown increases.
 
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