Home · Register · Join Upload & Sell

Moderated by: Fred Miranda
Username  

  New fredmiranda.com Mobile Site
  New Feature: SMS Notification alert
  New Feature: Buy & Sell Watchlist
  

FM Forums | Canon Forum | Join Upload & Sell

1       2       3      
4
       5       6       end
  

Archive 2021 · IS unit of RF 100-500mm not parking - a mechanical weakness?

  
 
Zenon Char
Offline
• • • • • •
Upload & Sell: Off
p.4 #1 · p.4 #1 · IS unit of RF 100-500mm not parking - a mechanical weakness?


Yes if they did that it would be added to the cost of the lens. Rechargeable for when you sell it?

bobbytan wrote:
They can sell this, solve the problem, and make some money from it?






Jan 14, 2021 at 12:37 PM
RCicala
Offline
• • • •
Upload & Sell: Off
p.4 #2 · p.4 #2 · IS unit of RF 100-500mm not parking - a mechanical weakness?


The cracks we see are NOT in the IS unit, they are in the front focusing group. Looking through the lens the cracks seem to move with the IS unit when we shook it, because optics and all. But the IS units, while not parkable, seem very sturdy. We literally rattled it in our hands as hard as we could and it cared not.

Now why the front focusing element cracked, I do not know. It's not directly impacting any other element, we fit them all back together and it's not possible. Maybe there were a couple of defective elements or something. But we're looking into it and Canon knows about it.









Jan 14, 2021 at 12:40 PM
cputeq
Offline
• • • • •
Upload & Sell: Off
p.4 #3 · p.4 #3 · IS unit of RF 100-500mm not parking - a mechanical weakness?


Thanks for the update Roger, love your contributions to the photographic community.

That said, could be just some defective glass - it happens. If this was a faulty design, I'm sure it would be much more prevalent.

Edit - could also just be bad luck - just the right tap to crack glass.



Jan 14, 2021 at 12:46 PM
cpe1991
Offline
• • •
Upload & Sell: Off
p.4 #4 · p.4 #4 · IS unit of RF 100-500mm not parking - a mechanical weakness?


RCicala wrote:
The cracks we see are NOT in the IS unit, they are in the front focusing group. Looking through the lens the cracks seem to move with the IS unit when we shook it, because optics and all. But the IS units, while not parkable, seem very sturdy. We literally rattled it in our hands as hard as we could and it cared not.

Now why the front focusing element cracked, I do not know. It's not directly impacting any other element, we fit them all back together and it's not possible. Maybe there were a couple of defective elements
...Show more

Thanks so much Roger for posting this important information.



Jan 14, 2021 at 12:53 PM
bobbytan
Offline
• • • • • •
Upload & Sell: On
p.4 #5 · p.4 #5 · IS unit of RF 100-500mm not parking - a mechanical weakness?


That's entirely up to the seller and it would depend on the cost of this battery powered parking rear cap.

Zenon Char wrote:
Yes if they did that it would be added to the cost of the lens. Rechargeable for when you sell it?





Edited on Jan 14, 2021 at 12:58 PM · View previous versions



Jan 14, 2021 at 12:56 PM
EB-1
Offline
• • • • • • •
Upload & Sell: Off
p.4 #6 · p.4 #6 · IS unit of RF 100-500mm not parking - a mechanical weakness?


RCicala wrote:
Let me clarify a bit.

The lenses with cracked IS glass is alarming to us, we've never seen that before. But it most definitely is a shipping thing, in every case the lens was fine when it left and damaged when arrived. None have ever failed while being used or carried around by a photographer.

Many of you know how we pack: padded, then in a soft case, then padded in a Pelican case. We have lenses that have literally been run over by the delivery truck survive just fine. BUT all that packing doesn't keep internal components from being
...Show more
EB-1 wrote:
I surely hope that LensRentals decides to use extra padding in future 100-500 shipments.

EBH

arbitrage wrote:
They will need to start shipping them attached to a powered on R5/R6...

EB-1 wrote:
Why do you think they are safer when powered on? I doubt that. You would need to do the drop test (shipping study) both ways. It would be rather difficult to simulate the powered drop test without invalidating the results.

EBH

EBH

cpe1991 wrote:
For the same reason you are safer wearing a seat belt in a car in a crash. You are constrained against being thrown against a hard surface on rapid deceleration.


I see no indication that the lens is parked when the power is on. If you have ever bumped an IS lens in use it visibly moves to the extent of travel. IS forces are rather weak in comparison to probable impact g forces that cause the cracking. A proper solution is to redesign the IS unit to withstand higher shock when unpowered, but Canon probably will not do that unless failure rates are high. It's cheaper to lose a few units than make design and production changes, stock multiple parts, etc.

EBH



Jan 14, 2021 at 12:58 PM
lighthound
Offline
• • • • • •
Upload & Sell: Off
p.4 #7 · p.4 #7 · IS unit of RF 100-500mm not parking - a mechanical weakness?


RCicala wrote:
The cracks we see are NOT in the IS unit, they are in the front focusing group. Looking through the lens the cracks seem to move with the IS unit when we shook it, because optics and all. But the IS units, while not parkable, seem very sturdy. We literally rattled it in our hands as hard as we could and it cared not.

Now why the front focusing element cracked, I do not know. It's not directly impacting any other element, we fit them all back together and it's not possible. Maybe there were a couple of defective elements
...Show more

Well I guess this is great news that it's not a design flaw caused by the "new to Canon" floating IS unit. Now the question is what happened to these four front focusing groups. It's hard to say but it almost looks like the fracture might have started at the edge around the 5 o'clock position in the photo. All speculation at this point but I wonder if there could have been a small flaw along the edge not visible due to the mounting hardware then when shipped during cold weather and it received one of those 3G's drop/hits it caused them to fracture.

Did the fractures in all four lenses look the same? Perhaps originating from the same location?

By any chance do you know when you received the 4 lenses? Were these out of the very first release or were they from different time frames?

Thanks for doing such great work and keeping us informed Roger!



Jan 14, 2021 at 01:21 PM
brad-man
Offline
• • •
Upload & Sell: Off
p.4 #8 · p.4 #8 · IS unit of RF 100-500mm not parking - a mechanical weakness?


RCicala wrote:
The cracks we see are NOT in the IS unit, they are in the front focusing group. Looking through the lens the cracks seem to move with the IS unit when we shook it, because optics and all. But the IS units, while not parkable, seem very sturdy. We literally rattled it in our hands as hard as we could and it cared not.

Now why the front focusing element cracked, I do not know. It's not directly impacting any other element, we fit them all back together and it's not possible. Maybe there were a couple of defective elements
...Show more

Thanks very much Roger,
Very useful. At least we can pretty much rule out a design flaw and likely blame it on an assembly/manufacturing defect. Looking forward to your tear-down of this lens...



Jan 14, 2021 at 01:26 PM
Sy Sez
Offline
• • •
Upload & Sell: Off
p.4 #9 · p.4 #9 · IS unit of RF 100-500mm not parking - a mechanical weakness?


Well, weather a design flaw, or manufacturing defect, Canon can't very well blame it on user misuse, and deny warranty. Makes me more confident in acquiring one; though I think I'll put it off for a "short" time, until the facts become apparent.


Jan 14, 2021 at 02:03 PM
cpe1991
Offline
• • •
Upload & Sell: Off
p.4 #10 · p.4 #10 · IS unit of RF 100-500mm not parking - a mechanical weakness?


EB-1 wrote:

I see no indication that the lens is parked when the power is on. If you have ever bumped an IS lens in use it visibly moves to the extent of travel. IS forces are rather weak in comparison to probable impact g forces that cause the cracking. A proper solution is to redesign the IS unit to withstand higher shock when unpowered, but Canon probably will not do that unless failure rates are high. It's cheaper to lose a few units than make design and production changes, stock multiple parts, etc.

EBH

This is described in earlier post, which you may have missed:
When I have the 100-500mm on the R5 and powered off, the IS wobbles from side to side when I shake the camera and lens. When I do the same when the lens is powered up, the IS unit does not wobble within the lens but moves with it. This shows for the RF system, the IS unit is not parked when the power to the lens is turned off or when it is removed from the camera, but is held more firmly when turned on.
As I described earlier, the behaviour of the EF system is different. When I have the 100-400mm II on a 5DSR and remove the lens without turning off the power first, the IS system wobbles and makes a loud noise. If I power down before removing the lens, the IS system is rigid in the lens and does not wobble within the lens when shaken. Accordingly, I gave the advice that in order to park IS in the lens, you should power down the EOS 5 series or similar camera before removing the lens.

This is not inconsistent with what you have seen. You looked at the IS with the power on, and that is when I find the EF IS unit is not parked. Crucially, however, turning off the power in the EF system parks the the IS. In the RF system, the IS unit is never parked.




Jan 14, 2021 at 02:43 PM
Zenon Char
Offline
• • • • • •
Upload & Sell: Off
p.4 #11 · p.4 #11 · IS unit of RF 100-500mm not parking - a mechanical weakness?


EB-1 wrote:

I see no indication that the lens is parked when the power is on. If you have ever bumped an IS lens in use it visibly moves to the extent of travel. IS forces are rather weak in comparison to probable impact g forces that cause the cracking. A proper solution is to redesign the IS unit to withstand higher shock when unpowered, but Canon probably will not do that unless failure rates are high. It's cheaper to lose a few units than make design and production changes, stock multiple parts, etc.

EBH


You can sure hear it park or whatever does when it shuts off. From the manual it states that it can be damaged disconnecting the lens before the IS shuts off. Not sure if that is the same canned warning for EF lenses. I'm sure I read somewhere more details about leaving power that can mess up the IS unit. I'll see if I can find it.








Jan 14, 2021 at 02:48 PM
lighthound
Offline
• • • • • •
Upload & Sell: Off
p.4 #12 · p.4 #12 · IS unit of RF 100-500mm not parking - a mechanical weakness?


A thought just occurred to me although I don't think it could possibly be related due to the damage is in the front, but who knows.

What is the one thing that is unique about this RF 100-500 lens?
You can not retract it completely when a TC is installed. There is some type of mechanical stop that is engaged when the lens detects a TC is mounted.

Could this possibly have anything to do with the front focusing group if a user slammed/retracted the lens back hard enough? Is there some type of structure running up through the lens that could transfer this "shock" from the lock mechanism up through to the front focus element group?

Just a thought and probably not related.
I just love murder mysteries and can't help myself. Who killed RF!
Back in the 80's it was who killed JR.


Yeah, I know. I need to back off from the coffee.



Jan 14, 2021 at 02:50 PM
EB-1
Offline
• • • • • • •
Upload & Sell: Off
p.4 #13 · p.4 #13 · IS unit of RF 100-500mm not parking - a mechanical weakness?


Sy Sez wrote:
Well, weather a design flaw, or manufacturing defect, Canon can't very well blame it on user misuse, and deny warranty. Makes me more confident in acquiring one; though I think I'll put it off for a "short" time, until the facts become apparent.


Has anyone received a lens from Canon that was cracked?

EBH



Jan 14, 2021 at 03:13 PM
Sy Sez
Offline
• • •
Upload & Sell: Off
p.4 #14 · p.4 #14 · IS unit of RF 100-500mm not parking - a mechanical weakness?


EB-1 wrote:
Has anyone received a lens from Canon that was cracked?

EBH


I haven't been in touch with everyone who's received "a lens" from Canon, so can't answer that question.



Jan 15, 2021 at 08:34 AM
Imagemaster
Offline
• • • • • • •
Upload & Sell: On
p.4 #15 · p.4 #15 · IS unit of RF 100-500mm not parking - a mechanical weakness?


Zenon Char wrote:
You can sure hear it park or whatever does when it shuts off. From the manual it states that it can be damaged disconnecting the lens before the IS shuts off. Not sure if that is the same canned warning for EF lenses. I'm sure I read somewhere more details about leaving power that can mess up the IS unit. I'll see if I can find it.


Geez, on it goes with speculation and "the sky is fallling", instead of just waiting to find out the real facts. Meanwhile all sorts of photographers are using the lens with no problems and enjoying themselves capturing great images with the lens.

And then we get further incorrect information posted that the manual states that it can be damaged disconnecting the lens before the IS shuts off.

No, it does not say DAMAGED , it says this may cause the lens to MALFUNCTION .

Hardly the same. Cameras and lenses malfunction all the time without any damage occurring.







Jan 15, 2021 at 09:12 AM
Zenon Char
Offline
• • • • • •
Upload & Sell: Off
p.4 #16 · p.4 #16 · IS unit of RF 100-500mm not parking - a mechanical weakness?




Imagemaster wrote:
Geez, on it goes with speculation and "the sky is fallling", instead of just waiting to find out the real facts. Meanwhile all sorts of photographers are using the lens with no problems and enjoying themselves capturing great images with the lens.

And then we get further incorrect information posted that the manual states that it can be damaged disconnecting the lens before the IS shuts off.

No, it does not say DAMAGED , it says this may cause the lens to MALFUNCTION .

Hardly the same. Cameras and lenses malfunction all the time without any damage occurring.


My post has nothing to do with this cracked element. I’m referring to what the manual says. DSLR/EF combo is different because IS shuts off after 2 seconds. I’m sorry for spoiling everyones fun. I don’t know the long term effect of continually removing an RF lens before IS parks. Be my guest and don’t shut the camera off before swapping lenses.



Jan 15, 2021 at 09:58 AM
Imagemaster
Offline
• • • • • • •
Upload & Sell: On
p.4 #17 · p.4 #17 · IS unit of RF 100-500mm not parking - a mechanical weakness?


Zenon Char wrote:
My post has nothing to do with this cracked element.


But this thread does, as well as parking.



Jan 15, 2021 at 10:23 AM
Zenon Char
Offline
• • • • • •
Upload & Sell: Off
p.4 #18 · p.4 #18 · IS unit of RF 100-500mm not parking - a mechanical weakness?




Imagemaster wrote:
But this thread does, as well as parking.


I suggest the membership look up the definition of malfunction and decide for themselves.



Jan 15, 2021 at 10:54 AM
cpe1991
Offline
• • •
Upload & Sell: Off
p.4 #19 · p.4 #19 · IS unit of RF 100-500mm not parking - a mechanical weakness?


I started this thread because of the report by Roger and I wanted to find out if there were any forum members evidence. Now that Roger has stripped down the broken lenses and found that the damage appears unrelated to the unparked IS unit, I am relieved and wont' worry any more.


Jan 15, 2021 at 02:25 PM
dcisive
Offline
• • •
Upload & Sell: On
p.4 #20 · p.4 #20 · IS unit of RF 100-500mm not parking - a mechanical weakness?


While you all are obsessing over some "theoretical" flaw in design by some of the most competent engineers in the business around the world, I'm off enjoying the remarkable shots taken with this wonderful accurate lens and all it's attributes. I've never experienced one defective or problematic Canon lens over the last 25 years I've been buying many of them. But then I don't drop them. smack them into a mountain while hiking, hand it to a child to play with, take it to a rumble, send it across country via UPS and FedX on a regular basis nor use it as a weapon. Perhaps that's why they always work flawlessly.


Jan 15, 2021 at 02:33 PM
1       2       3      
4
       5       6       end




FM Forums | Canon Forum | Join Upload & Sell

1       2       3      
4
       5       6       end
    
 

You are not logged in. Login or Register

Username       Or Reset password



This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.