OK I will try to be fair with my answer to your questions here. Remember these are just my thoughts and opinions. I am not an expert on this.
First of all I can only speak from experience of the
KOMPUTERBAY 32GB Professional 1000x CF. I have never used the
Sandisk cards
.
I can only inform you from my experience and what I have read regarding these cards. Also I only used this card in the
5DMKII so I can only talk about how it performs in this camera.
1) The '
data bus' inside the camera is the
limiting factor for how much
speed you will get from a card. Read/write speeds will be advertised as higher than you will actually get because it will be capped by the
hardware limit.
At the moment (I think) the
maximum speed I seem to be able to get is around
79.0 MB/sSo if you bought a
Sandisk it would probably be the same (because of the
hardware limit). I suspect this, but
can't confirm this, because I have
not used the
Sandisk cards.
I will note that the recording speed can be '
variable' on the
Komputerbay cards. What I mean by this is that one recording may only enable something like
250 frames at a
resolution of 1880x1058. However it is more '
normal' to expect around
1151 frames (around
48 seconds). This can vary all the way up to nearly a minute at that resolution. At that resolution it is not stable enough
yet to break the 1 minute barrier (
I think).
2) As for '
safety', because of what I have mentioned above; I would say they are
not fully reliable but you can just about work with it. I am not so sure if I would want to be in a wedding situation where you would want to know that you are guaranteed a set duration of recording?
.
I would say these cards (
Komputerbay) are fine if you are making a film/video where you can do
several takes. I wouldn't trust it to be able to get the take
every time. I would find it a
very interesting challenge (but not a comfortable one) to film a wedding with this card.
What I have established (
I may be wrong here?) is that the Sandisk cards are
less 'variable' and
more 'reliable' in the respect of
'constant' performance.
There has been much debate about why the
Komputerbay cards are so much
cheaper? One thing that is rumoured is that they are actually '
seconds' or '
rejects' that have not passed quality control tests(?). This is
purely speculative but it wouldn't entirely surprise me and would go some way to explain why the performance is so variable.
I can only speak for the card that I have; but I would say
variability is the word when it comes to
Komputerbay and
performance.
3) The performance can even be
variable between the
different cards and
card capacities (the
128GB cards have had some
bad reports). From what I have read, and experienced; I am lead to believe that the
32GB and the
64GB Komputerbay cards are the
most reliable. (Please anyone correct me if I am wrong on this?)
4) OK I can't work out the figures for exactly one minute because, at full resolution, I can't record for that long. I can say however, that,
47 seconds, at a
resolution of
1880 × 1058, is
1127 frames, which has a
file size of
3.92GB (I can get '
continuous' recording at
slightly lower resolutions).
My experience of recording
RAW is that it
eats space pretty quickly. A
16GB card is totally out of the question (
seriously). I would suggest that you get as many cards as you can afford. I would say (for me) a
couple of
64GB cards (but even better 4
) would be
perfect.
I must
emphasise that the card fills up
pretty damn quickly with
RAW. It is one of the
caveats of
RAW.
Unfortunately. For me the
benefits (in terms of
dynamics and pure
retention of quality) of
RAW far
outweigh any of the
negatives.
So to summarise (in my opinion of course
). I would say if you want '
reliability' then maybe you should consider the
Sandisk Extreme Pro. Forget about the maximum speeds because the cameras are
not capable of reaching the
maximum speeds that the cards can deliver.
If you are willing, and have the time to do a number of takes for a shot, then the
Komputerbay cards are certainly a good starting point
. I will say that it's the
variability of performance on the
Komputerbay cards that is the main issue.
Unfortunately. I will say that I am '
happy' with mine with all of its
shortfalls.
I wish you luck and hope that helps some.
