Let me first state for the record that my Dealer, his Canon Rep, and the Canon Rep regional boss have all been hands and feet above the rest in terms of helping me with this matter. They've gone above and beyond in terms of speedy service and speaking one-on-one. All that being said, I do think it's important that others hear what has happened to my brand new C300:

On Monday morning my C300/EF arrived all shiny and new. I popped open the box, hooked up Monitor, slapped my DS-10 wedge on the bottom, slid in a 32gb SanDisk, and put my Zeiss 35m 1.4 ZE on the front. I shot a little around the house, played with some of the Color Styles and decided to head out to get some real action on the card.

I headed down to the Arts district where they set up food trucks for lunch and began firing away. I used my Zeiss 35mm ZE first, then my Zeiss 85mm ZE, then my Canon 70-200. Everything was going smoothly then came the bomb-shell: I popped off the 35mm then popped on the 85mm, WITHOUT TURNING OFF THE CAMERA, and suddenly nothing......dead.......no power anywhere. I changed the battery, came home and switched to AC, hit the reset button.......nothing............I call the tech support line. Patrick at canon support was more than helpful, we tried working through different issues but nothing came to pass. He issued a service report and they sent me the UPS slip to ship it back. Not ten minutes later I hear from my dealer, he too was very supportive and helpful. Then I heard from his Canon Rep, again awesome customer service. And finally I get a call from his boss, again all great support.

My camera is in Canon Tech hands now, more than likely it's a blown fuse from the 3rd party Zeiss Lens. But let me be clear, THAT'S MY ASSUMPTION and for the recored Canon is still trying to do their due diligence on their end.

With that all being said, may I highly suggest that everyone POWER DOWN YOUR CAMERA WHILE YOU CHANGE LENSES. Better to be safe than sorry, right?

I'll keep you all updated as it progress.

-Dave

Good to know. Have done a few shoots from November to now, with a mixture of lenses, sometimes not powering off when we changed lenses, with no problems.

I'll be curious to see if it was your ZE lenses. I've used my ZF lenses with no issues, but there's no communication with the camera.

Scary... changing lenses, third party of not, while the camera is powered on should not cause a problem and be fully supported. Please, keep us updated on your case. I am also using a mixture of Canon EF and Zeiss ZF lenses with Novoflex adaptors and have not had any problem so far. With the Novoflex adaptor, there is no electrical connection to the ZF lenses.

Great to know David. And sorry about having to return your baby so quickly after having just opened it.

I always got in the habit of powering down my XL-H1 when I changed lenses because someone, not sure who, put the fear of God into me that I could do serious damage to the camera if I didn't. Not sure if that was true or not. But at least it trained some muscle memory. I power down my 7D during every lens change too.

Robert, I had the fear of God put into me about changing lenses on a hot camera on my very first shoot (guess why), and am the same as you, always power off even though I know it doesn't matter anymore.

Now I'm DEFINITELY not changing that habit!

ive got all sorts of lenses and to be honest, i havent been powering off, and ive never had a problem

Hot swapping lenses on DSLRs is a way of life for photogs, I'd be surprised if Canon had not thought of that on the C300, they know better.

I am just returning from the middle east where I was shooting like crazy switching lenses constantly... I probably hot-swapped my lenses 200 times in the last 10 days, and never had a problem. All of my lenses are EOS EF though. This kind of scares me now, it would have been a disaster to have had that happen over there! I think I'll be powering down between swaps now. At least the 300 boots up rather fast, so not a big time lag to do that (as long as I remember to do it!)

Hot swapping lenses on DSLRs is a way of life for photogs, I'd be surprised if Canon had not thought of that on the C300, they know better.

Sorry but no, Canon USA specifically recommends *against* hot-swapping lenses on any SLR, from the film days up through digital today, *especially* with regard to third-party lenses. I have been invited by Canon USA to help out behind the EOS counter at enough trade shows to witness this cautionary warning first-hand many, many times. Crossed contacts is a practice the company frowns upon and the fact that many photographers do it regularly and without issue does not change this. Canon has never endorsed hot-swapping lenses, and most likely they never will.

Wow... good to know! That's why I love this forum. I would have continued to do things the way I have been, but as of this moment have changed my MO for good. Thanks for the info.

Regarding hot swapping lenses, this could also affect the "untwist" lens method used on DSLRs.

Back in the dark (poorly exposed?) ages, 5D2 users needed to set their apertures, hold the DOF button and untwist the lens to lock the aperture on Canon-compatible lenses. We would then point our cameras at bright and dark objects, hoping to hit Exposure Lock at just the right instant to get close to a 1/60 shutter. Not to mention that we were shooting 30.0 fps...

But the lens twist days are not over. DSLRs open their apertures between shots to allow bright views for framing and focus. Each time you snap a photo, the aperture closes down. This is unfortunate for time lapses in that the aperture never closes exactly the same, shot to shot. This leads to flicker and dancing bokeh shapes for tight aperture sequences. The solution? Set the aperture, hold the DOF button, and untwist the lens.

Fortunately, I've never had a problem with this method. That said, Canon should include an aperture-lock mode for timelapse shooting. They know we shoot time lapses. They know we don't want flicker and dancing bokeh. They don't want us to hot-swap lenses.

...We need a timelapse mode on Canon DSLRs.

Now, back to the C300 discussion. (Though C300 users should note that you still need a DSLR if you want to shoot 5.6K RAW time lapses...)

UPDATE (Kinda):
So, Canon was kind enough to send me a long-term loan until I get my baby back. It's impressive because they want to recreate the exact scenario that caused the problem in the first place, then fix it and make sure it doesn't happen again. It's another reason why I chose the Canon path over "the-one-we-shall-not-name." Rather than blame operator error and make me sit in the waiting cue again till my camera is fixed, they're being very accommodating and trying to solve the actual problem not just the symptoms, while at the same time letting me continue to generate income off the "loaner." Impressive.

-df

Interesting (and impressive, on Canon's part)
But would this not indicate that Canon does not see a problem with hot-swapping then?

Nope, I wouldn't read it that way at all... see my post above. Canon will never condone hot-swapping lenses. In this case, they're taking care of a customer with a high-dollar item. It is, after all, the right thing to do. But I really don't think it should be taken as an okay to start hot-crossing the lens contacts.

UPDATE (Kinda):
So, Canon was kind enough to send me a long-term loan until I get my baby back. It's impressive because they want to recreate the exact scenario that caused the problem in the first place, then fix it and make sure it doesn't happen again. It's another reason why I chose the Canon path over "the-one-we-shall-not-name." Rather than blame operator error and make me sit in the waiting cue again till my camera is fixed, they're being very accommodating and trying to solve the actual problem not just the symptoms, while at the same time letting me continue to generate income off the "loaner." Impressive.

-df

Yup. I've had this personal experience with Canon, too. And it's why I'm a huge fan and will continue to be.

Nope, I wouldn't read it that way at all... see my post above. Canon will never condone hot-swapping lenses. In this case, they're taking care of a customer with a high-dollar item. It is, after all, the right thing to do. But I really don't think it should be taken as an okay to start hot-crossing the lens contacts.

which does make sense, however the quote about 'trying to solve the actual problem' is what I find interesting if that is indeed the case. either way, I'm not crossing contacts ever again!

I have been invited by Canon USA to help out behind the EOS counter at enough trade shows to witness this cautionary warning first-hand many, many times.


Canon USA is sorely mistaken. In the first place, even if there was a danger from changing lenses on a powered-on camera (which there isn't), turning the camera off wouldn't make the slightest bit of difference. You see, the camera *doesn't* turn off. Get out your multimeter and take 10 seconds to check the contacts on your lens mount. You'll find that they put out the exact same amount of juice whether the camera is on or "off". I just double-checked both my Canon 5D2 and Nikon D800 and confirmed it. So if there really was any issue, you would have to take the battery out and wait for the capacitors to discharge.

Sorry but no, Canon USA specifically recommends *against* hot-swapping lenses on any SLR, from the film days up through digital today, *especially* with regard to third-party lenses.


Aside from trade shows, where are all these recommendations? Canon puts a ton of ridiculous warnings in their manual to cover every conceivable danger ("warning: do not look into sun with remaining eye", etc.) and several that aren't conceivable ("When operating the viewfinder diopter adjustment control with your eye to the viewfinder, care should be taken not to put your finger in your eye accidentally.", p.15, D800). So if there was even the slightest, remotest possible chance of an issue, it would be in there. But I can't find anything of the sort in my 5D2 manual.

So what was the outcome David???

All fixed by Canon months ago. Have shot terabytes of footage since then without a single problem.

Canon tech and sales were outstanding and, as I mentioned before, they all went above and beyond all expectations in finding out what was wrong. I couldn't be more happier. I'm even starting to consider my options for the C500.

Take care,
Dave

I'm not sure that I can avoid hot swapping lenses, given how slow the C300 is to boot. I guess I'll just keep my fingers crossed.

All fixed by Canon months ago. Have shot terabytes of footage since then without a single problem.

Canon tech and sales were outstanding and, as I mentioned before, they all went above and beyond all expectations in finding out what was wrong. I couldn't be more happier. I'm even starting to consider my options for the C500.

Take care,
Dave

What specifically was the problem that they solved? Was it a problem with your camera or a global problem affecting all models?

I have been hot-swapping both C300 and a 550d. Daniel's answer above is interesting. Why isn't it in any manual?

I'm not sure that I can avoid hot swapping lenses, given how slow the C300 is to boot. I guess I'll just keep my fingers crossed.

That's the reality. To power down and power up again takes time. Power down is 2.5 seconds and power up is approximately 5 seconds. So however adept one is at changing the lens you are looking at it taking about 10 seconds. With the power down time one should really count to 3 before changing the lens.

So if you are in a live documentary scenario these amounts of time can seem very long.

I was interested to hear Daniel Browning's comments about checking the terminals with a multimeter and finding no difference between the camera being on or off but I don't really want to take the risk of loosing the use of the camera whilst on location.

I had heard about the fuse blowing on a C300 from threads on user forums before I got my camera and most of the time I remember but there have been several occasions when I haven't shut the camera down and fortunately nothing has happened.

I think it is an inbuilt design fault with the C300 and it will be interesting to see if it occurs with the C100.

Pretty rubbish for a $16k camera. Are Canon going to do anything about it?

This falls into the realm of expected user behavior for which one does extensive quality control testing with both ones own lenses and those of other vendors. Much like the current requirement for certifications of other hot disconnect scenarios such as USB and thunderbolt. There should be absolutely no requirement to shut a camera down to change lenses.

I'm not clear on something in this discussion. While I don't own a C300 (but am lurking because I'm considering one), I have a 5D Mkiii and 7D and both shut themselves off if I accidentally push the button and start to take off the lens. ( I use both Canon and Sigma lenses). I've never had it not turn the camera off (or whatever state it is in when not on -grin). Does the C300 (and the C100) allow themselves to stay *on* when swapping lenses? That would be good, I guess, but not like the standard Canon setup on their DSLRs.

I agree that it shouldn't blow your camera either way. Likely this was a fluke. But it's nice to know that Canon did you right by working it out.

That's really interesting Al. My 7D does not turn itself off when I change lenses. Mine has the original firmware from a couple of years ago.

I think something was lost in translation when this thread came back to life...I originally posted this back in March. It is now December. My camera has been fixed. When it came back (in April) I even purposely did a hot swap (multiple times) to try and make it fail. It was fixed. What ever the issue was, it was fixed. I think all the knee-jerking reactions, (especially 9 months after I first posted and especially by those that don't even own the camera) is uncalled for. I was an early adopter and I fully expected there to be some early issues (just like my 5dMII, just like my Nissan Titan, just like my first Ipod #1). And for the person who said problems with a $16k camera is rubbish, I think you need to take a step back and look at every single high-end camera that has ever been issued and tell me which one never had issues on Model #1 (some of us are old enough to remember the Sony D300 & D600's).

I think it's time for this thread to die.

-df

And to reinforce Canon's position on this, why do you think the C500 is like this now? (see pic)

I think something was lost in translation when this thread came back to life...I originally posted this back in March. It is now December. My camera has been fixed. When it came back (in April) I even purposely did a hot swap (multiple times) to try and make it fail. It was fixed. What ever the issue was, it was fixed. I think all the knee-jerking reactions, (especially 9 months after I first posted and especially by those that don't even own the camera) is uncalled for. I was an early adopter and I fully expected there to be some early issues (just like my 5dMII, just like my Nissan Titan, just like my first Ipod #1). And for the person who said problems with a $16k camera is rubbish, I think you need to take a step back and look at every single high-end camera that has ever been issued and tell me which one never had issues on Model #1 (some of us are old enough to remember the Sony D300 & D600's).

I think it's time for this thread to die.

-df

David, I have to admit that until I read this last post I thought your C300 was fixed -- as in working again -- but you still needed to power down the camera before swapping lenses. I also purchased a C300 last March, and, based on forum advice, I have been powering down for every lens change, which is not convenient, because I am afraid I will damage the camera. After reading the end of your story, I think I should send my C300 to Canon now, while it is still under warranty, and have it fixed, so I don't have to worry about hot swapping. I agree that it is typical for high end cameras to have issues early on, but I wish Canon would inform owners when there is a fix.

I talked with Canon Cinema EOS tech support today about a fix for the lens hot swap issue. The rep I spoke with said there is no fix. Hot swapping lenses on the C300 may or may not damage the camera (a matter of luck?). Warranty coverage of damage due to hot swapping is handled on a case by case basis. The instruction manual states that the camera should be switched off when removing or attaching lenses (page 33).

How about hot-swapping the C100? Anyone heard?

The C100 manual also states that the camera should be switched off. Whether Canon have improved way the fuses blow we won't know unless cameras start dying due to hot sapping lenses. I'm not going to risk it on mine that's for sure.