Frying a camera through a usb port

[WPalank]

I have never connected any of my digital cameras to a usb port on my computer for image download and have always used a card reader. It just seemed to me that there would be some inherent risk.
That being said, quite often I will see posters that talk about connecting their camera directly to a computer who are then warned by others that their is a potential for "frying their camera". Has anyone seen this in actuality? I am not an electrician, so is just that the potential exists? Thanks.

[gwelland]

There's an inherent risk in using the USB connector but hopefully typically failure results in just frying the USB connector components vs killing the entire camera. I can't vouch for the M8 but I'm sure it uses standard USB reference circuitry (I'm sure Mark Norton can confirm/deny).

I had a similar issue when I was using a Kodak 645M digital back which used firewire - these were notorious for frying the connection circuit if you plugged in or removed a live connector. (Firewire in general seemed to suffer this a lot more than USB).

Given the choice, I'd avoid using the USB connection not just because of the electrical concerns but also because the mechanical stresses of USB connection/disconnection plus the fact that the USB cover will get looser over time with use.

[marknorton]

The USB interface provides a limited amount of current to power downstream devices; an absolute maximum of 500mA and even that has to be "negotiated" by the device. It's a real convenience though, the ability to plug keyboards, mice, modems, phones, card readers and the rest without a separate power supply.

The available power is not enough to even charge, still less run, an M8 so I expect little or no use is made of that facility. The signal lines are likely provided with over-voltage protection but clearly, if you somehow connected a USB cable to a wall socket, you would get the repair bill you deserve. Connected to a PC as intended, it will be fine.

I agree with Graham; the connector is a fiddle and I imagine hardly anyone uses it, which is why I have repeatedly suggested a charging/docking cradle.

[jaapv]

I have a Casio EXILM os something like that and it has a docking cradle, which is a pain, as it is the only way of charging the battery. But it is an inconvenient shape to carry, small as it is.

[marknorton]

I wouldn't suggest it should be the only way to either to extract images or charge the battery but a docking cradle, located where you usually download images where you can just drop the camera into the cradle would be convenient.

[Photoskeptic]

While I have never used the USB port on the M8, I've always used the one provided on my LX-1 p&s and I've owned it over two years. No problems. But, then again, if it did get fried - no big loss

[WPalank]

Graham and Mark,
Thank you for your quick replies. I agree about the potential problem with the usb port by connecting and re-connecting the usb-camera chord, but how would that be any different from connecting and re-connecting the card reader usb input? Is it because the camera has a voltage or electric potential? (I apologize about my nomenclature, as I am probably using it incorrectly. But I hope I am painting a clear enough picture about what I am truly asking.)

[marknorton]

The mini-USB connector is good for 10000 insertion cycles and will typically connect ground before any of the other pins and disconnect it last. I really don't think you have anything to worry about.

[gwelland]

I suspect that the plastic/rubber USB door will fail in some way before 10,000 insertion cycles. It's a friction fit that seems destined to loosen up over time.

I admit that I wouldn't worry too much about blowing up your camera via the USB port. The tolerances on the mini-D connector seem pretty tight so the chances of crossing pins on cable insertion/deletion would be pretty low.

If the USB cover were more robust then I'd probably consider using it. As it is, I'd worry eventually about mechanical wear of the cover. The metal base plate/lug and more solidly built locking mechanism seem like they would last a lot longer in regular use.

[robsteve]

Originally Posted by WPalank

Graham and Mark,
, but how would that be any different from connecting and re-connecting the card reader usb input? )

The difference is if you have a problem, you only loose the card reader and perhaps the card. In my case, I think my SD card readers cost $14 and a second one I have came with a Sandisk card. In other words, you are risking a total of about $50 using an external reader, while plugging the camera in all the time, at the least you are risking having to get the USB socket replaced eventually, which I bet would be more than $50.

Robert

[Mauribix]

William, frequently, problems concerning USB powering start from the USB connector itself.
Often I see front USB dock or additional USB port connected in the wrong way.
I was plugging a Kingston USB pen (4gb) on a front USB port at one of my clients' PC when it suddenly started to smell like burnt, and then died, so this is why connecting a camera via USB may be of some risk.
I checked the USB port after my pen's epitaph to discover that +5V and -5V cables inside the pc where inverted, so that was the problem.
I guess otherway that the risk is almost null if you plug and unplug USB devices in the correct way (disable via software the device before unplugging for first).
Anyway I learned the lesson well, and I won't be connecting anything worth more than 15€ directly to any computer's USB port...

[marknorton]

I think to write off using all USB just because you have seen isolated examples of incompetent installation is ridiculous. Granted, the USB functionality of the M8 is not great but if I had more use for it, I wouldn't hesitate connecting it to a USB port I knew to be functional.

[Mauribix]

Sorry Mark, but maybe you missed one of the things that I wrote: i.e. that the risk is almost null.
Anyway if the risk was even less, I don't think it's ridicolous to avoid the risk itself considering that you can find even unqualified assemblers, so this is what I did with worthy things.Just my experience.