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USB card reader vs USB cable to camera direct

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ramblinwreck:
Hi,

A recent thread on the Support forum ("PM, Nikon D90, Windows 7 and Ingesting") brought up a something I'm curious about. Please let me quote some text from that thread:


--- Quote ---...downloading is usually faster, and safer, with a card reader anyway...
--- End quote ---
(vs a direct cable connection to a camera)

My question is WHY is it safer?

I've heard/read this numerous times but I do not understand why. I tend to think the opposite.

I tend to think there is a greater risk in the camera not working if, through repeatedly removing/inserting the card, I were to damage the internal card<->camera contacts, than if I were to damage the external USB connection. I figure there would be a near 100% chance of camera failure if the internal card contacts are damaged or worn down (as the camera uses this connection for normal operation), and something less than 100% chance of camera failure if the external USB connection is damaged or worn down (e.g. perhaps I just lose the USB cable connect function). Does this go against conventional wisdom?

Now I understand that using a card reader gives (a) better speed and (b) allows use of PM's ingest capability direct from card (e.g. for cameras with no "mass storage" mode like D90), but I do not understand the "safer" argument.

Why is using a card reader safer?

Thanks
Chris

Hayo Baan:

--- Quote from: ramblinwreck on January 11, 2010, 01:03:14 PM ---Hi,

A recent thread on the Support forum ("PM, Nikon D90, Windows 7 and Ingesting") brought up a something I'm curious about. Please let me quote some text from that thread:


--- Quote ---...downloading is usually faster, and safer, with a card reader anyway...
--- End quote ---
(vs a direct cable connection to a camera)

My question is WHY is it safer?

I've heard/read this numerous times but I do not understand why. I tend to think the opposite.

I tend to think there is a greater risk in the camera not working if, through repeatedly removing/inserting the card, I were to damage the internal card<->camera contacts, than if I were to damage the external USB connection. I figure there would be a near 100% chance of camera failure if the internal card contacts are damaged or worn down (as the camera uses this connection for normal operation), and something less than 100% chance of camera failure if the external USB connection is damaged or worn down (e.g. perhaps I just lose the USB cable connect function). Does this go against conventional wisdom?

Now I understand that using a card reader gives (a) better speed and (b) allows use of PM's ingest capability direct from card (e.g. for cameras with no "mass storage" mode like D90), but I do not understand the "safer" argument.

Why is using a card reader safer?

--- End quote ---

Chris, as I was the one hinting at a card reader being more safe, I'll give you some reasoning for this statement.

The way I look at it (and this is something that is agreed upon by many), one of the design aspects of memory cards was their intended use, this includes inserting and ejecting them frequently. If you take a at an SD or CF card for instance, you can see how this design aspect is implemented.
An SD card has very large contacts. Inserting/ejecting them is easy and actually well guided; there is no way of bending anything without real force.
A CF card contains many more and uses pins to make the connection. This does sound fragile, but inserting a CF card is again guided, making it impossible to insert them wrongly without force. Ejecting a CF card from the camera is (usually/always?) done using an eject key which again makes it impossible to bend the contacts. So all in all, this again is a very robust and safe implementation. (Note: I have heard of and actually seen people with bent pins, but this was invariably after applying force when insert the card (wrongly), and/or with badly designed card readers where the CF card guides aren't "deep" enough).

Now take a look at the design of the camera USB connector, you can image it breaking off with only little force (the connector actually works as a lever) as everything is pretty fragile looking (much more so than the SD/CF card slot where the whole card is kept quite firmly)

Oh, and then I haven't even mentioned the fact that it is so easy to bump your camera off your (crowded) desk when off loading your images. If this happens, the connector inside the camera will almost definitely have broken off (perhaps even worse). A card reader is much smaller and lighter, and even if you bump this off your desk, it is highly unlikely anything bad happening.

So yes, using a card reader is safer (IMHO) :D

Kirk Baker:
And:

Transfer speeds are faster on dedicated card readers (at least I've never heard of a camera that is faster than a quality card reader.)
The camera's batteries can discharge during transfer (this cannot happen with a dedicated card reader since it is powered by the computer.)

-Kirk

ramblinwreck:
Hayo and Kirk - I appreciate you taking the time to reply.

I do not shoot high volume (i.e. not a pro), so I can live with (admittedly slower) download speed and (virtually unnoticeable) battery drain for my own volume of work.

However - I was interested in the "safety" aspect of using a card reader vs a direct cable connection to camera.

I do follow and understand Hayo's response (thanks Hayo!), but (and perhaps I'm speaking mainly to non-Pro Nikon bodies here) there are plenty of folks out there with Nikon DSLRs reporting "CHA" errors (which according to Nikon means: 'error accessing memory card'). I realize there could be any number of causes for this (bad card, improper formatting/deleting, sloppy tolerances in the card slot or card itself, etc), but it does seem to affect quite a few Nikon users - in particular, D90 users.

In any case, I've seen enough of these reports to make me not want to touch my SD card any more than I have to. Conversely, I've never heard of anyone with an unusable camera because the USB port is broken (though I realize me not hearing about it is not proof that it never occurs).

Perhaps my fear is unfounded, but I will probably still use my USB camera cable. For my type of shooting I do not give up much by not using a card reader.

...
...

Oh yeah - and I will be extra careful not to knock my camera off the desk while connected. ;)

ramblinwreck:
OK so curiosity got the best of me, and while I'm unable to find any "official" USB specs or data from the card manufacturers, but I keep finding these numbers:

Sandisk/Transcend/Lexar cards are rated at 10,000 insertion/removal cycles (minimum)
Mini-USB connector - designed to "allow up to" 5,000 insertion/removal cycles

Interesting.

Chris

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