Accidental Lens Release

[michaelgirman]

  My 24-105L just fell off my 5D mkIII and rolled into the Seine.  The lens release button is way too sensitive and it is so easy to accidentally unlock without realizing it.  I went to twist the zoom ring and the lens rotated and dropped off.  Blogs are full of compaints of this occurance on mkii's.  

  This is definitely a design flaw.  It's not user error.  The button should be relocated or made to require more force to release  or have a detent position.  

  It's a shame that you have to gaffer tape a $2300 lens to a $2000 camera.  Be forewarned.  

[Ron2]

"The lens must also be turned, while the release button is held down"

Wrong: False information

Once the button is pressed the lens will move freely for the other
99% of the lens travel without the lens release button been held down.



A big difference to what you are saying.
Because the base knuckle of the index finger provides the start (press the button down) the mistaken focus movement which is twisting the lens takes over and does the rest - Twist the lens off without having to hold the button down

[ebiggs1]

Ron2,

You almost had me convinced, maybe just cause I had not done it, some thing might be happening.  But after reading that unfortunate series of events convinced me it is user error.  With out doubt!  Seriously?  This is the most convincing theory about a person not paying attention to what they are doing, I've heard.

"Take a 5DM3 with a 24-70 lens, shoot down, Let the camera rest on your focusing hand. Humour me for a sec, rest the camera on your focusing hand (because there is no problem doing that on the mark 2 and mark 1 or 1D), 

It is only a problem on the 5D Mark 3

With the weight of the camera on your focus hand you wont know or feel that the lens release button has been accidentally pressed in by your index finger base knuckle

You also wont suspect it has been pressed in as this is unique to the 5D mark 3 so it has never happened before

Start to focus manually and the lens will be moving not the focus ring (its smooth action will feel like the focus ring moving)

Once the lens is on the move the button does not have to held in. You will be moving clockwise (from behind the camera) because that is what you do if the focus is against the stop one way you go the other way

There will be no focus through the view finder, but for the unsuspecting your reaction will be to move the lens more (because you are thinking you are moving the focus ring) and in no time the lens will come off.

A frequent and often needed photographic scenario (shooting down) aligns all the ducks in a row for this to happen on a M5D mark 3"

[Ron2]

You are welcome I have been saying that since page 7 with pictures. Did you miss that?

Did you also miss that People are saying it has never happened to them before, only now with the Canon 5D mark 3. 

Instead if your normal rhetoric which does not answer the question have a go at answering the question please

What has changed on the 5D mark 3 to cause this to happen now and not before?

I compared earlier versions of the 5D and the 1D. Here are my findings

1 The button has moved out from under the protection of the lens by 4mm because of this it is now possible for the focus hand to depress the button where in the past it was not possible 

2 The button is much larger so the outside edge of the button now sticks out nearly 6mm more from the lens than previous models

3 The button is now not recessed into the camera body and has lost the protection that part of the body surrounding the button provides

The result: It is possible now for the first for the focus hand to depress the lens release button accidentally and turn the lens off in one move.

That is an accident just waiting to happen

And quite an insane design change on the part of Cannon IMO

By the way one of your early threads said you have tried this on a 5D mark 2 and cant get it to happen. (incidentally that is exactly our point it does not happen on a mark 2)

Why did you try on a mark 2 when the problem is reported on a mark 3?

[Waddizzle]

---

@Ron2 wrote:
"The lens must also be turned, while the release button is held down"

Wrong: False information

Once the button is pressed the lens will move freely for the other
99% of the lens travel without the lens release button been held down.



A big difference to what you are saying.
Because the base knuckle of the index finger provides the start (press the button down) the mistaken focus movement which is twisting the lens takes over and does the rest - Twist the lens off without having to hold the button down

---

Excellent point, "99% of the lens travel . . . ".  Because the only way to move the first 1% is by holding down the button.  Period.

I challenge you to press the release button, hold it down, and then release the button.  Is your lens still locked in place?  It should be.  If not, your mount is not working properly.  

Maybe one "fix" for your problem is to use a battery grip.  I rest the bottom left corner of the camera on the heel of my left palm.  The only sure "fix" is to pay better attention to what you're doing.  If you're aware of the "issue", then why is it a problem for you?  Adjust your shooting habits, and move one.

[Ron2]

Are you aggreeing to the explanation is correct to why this has not happened before to people?

If not then can you answer why this has not happened to people before

Because that is what this thread is about

[Waddizzle]

---

@Ron2 wrote:

Are you aggreeing to the explanation is correct to why this has not happened before to people?

If not then can you answer why this has not happened to people before

Because that is what this thread is about

---

The fact that my post seemingly went over your head is exactly why your lenses drop to the ground for no good reason.

[Ron2]

You are avoiding the question

[John_SD]

---

@Ron2 wrote:
You are avoiding the question

---

Actually, you have been given the answer multiple times by multiple people. 

The real question now, Ron2, is why are you looking for sympathy?

[Ron2]

You still avoiding answering the question. Is that summary correct of the answers given multiple times

[schmegg]

It's a simple case of lack of comprehension by some here Ron.

They can't understand that it's reasonable for someone to feel that the current design is not optimal. They will not admit that it is possible for a lens to become loose on it's mounting accidentally even though the camera/lens combination has been handled in a reasonable way. It seems, because they can't comprehend this, they wish to shout down those of us that can.

Hopefully, Canon are wiser and can at least look into this and consider it further in future designs.

I'm sure almost everyone except the most thick-headed would agree that a well designed lens mount system would prevent accidental release of the lens in all but the most violent and freakish circumstances.

Lets look at the design again, but from a logical point of view this time.

To remove a lens, two seperate actions are required.

1. A button must be pressed, Until this happens, the second action cannot be excuted.

2. The lens needs to be rotated before it can be seperated from the body.

Sounds like a solid enough design. And it is. And, realised properly, it should be almost impossible for this to occur without the express and deliberate actions of the photographer.

However, the critical part of this design is in step one, because step two can happen easily without much deliberate interaction from the photographer while the camera is being carried - a reasonable use case for a camera.

So, to make the entire design as sound as possible, the first step needs to be designed in such a way as to virtually eliminate the possibility of it accidentally occurring. In other words, the likelyhood of a bayonet lens mount system allowing an accidental release of a lens is mostly proportional to the likelyhood of an accidental press of the lens release button occurring.

And, with larger, more prominent lens release buttons, this likelyhood increases and makes the design less effective in terms of lens mount security.

This is a no-brainer and it frankly astounds me that some here are arguing the point!