IainD
Well-known member
I have had an Acratech failure also. D3s and a 500 f4. I caught them prior to impact!
QD failed, one off or has this happened to others
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BrianMM
Active member
IainD: I have been regularly using Acratech clamps (both the original and the current versions) for almost five years and never had a problem so I'm really interested to understand the nature of the failure that you experienced. Did the clamp actually break or did it release accidentally?
For what it is worth: I found very early on that rails from different manufacturers which purportedly meet the Arca Swiss dimensional specifications typically have the correct dovetail angle and width but have a varying thickness from the outside edge of the dovetail to the base. This is a blatant design/manufacturing flaw and a real opportunity for a problem with lever-type clamps. Consequently I only use rails that have identical dimensions from dovetail to base so that the clamping pressure is set once on each of my Acratech clamps which then work correctly and hold the rails securely.
For what it is worth: I found very early on that rails from different manufacturers which purportedly meet the Arca Swiss dimensional specifications typically have the correct dovetail angle and width but have a varying thickness from the outside edge of the dovetail to the base. This is a blatant design/manufacturing flaw and a real opportunity for a problem with lever-type clamps. Consequently I only use rails that have identical dimensions from dovetail to base so that the clamping pressure is set once on each of my Acratech clamps which then work correctly and hold the rails securely.
eaj101
Well-known member
I've had several 'failures' of Arca-style clamps (not the Acratech, though) that were really user 'failure'. I neglected to make sure that the clamp had actually engaged and closed properly before letting go. In one case it dumped my Z9 on the gravel, luckily undamaged. My own stupidity is a constant challenge
IainD
Well-known member
I had an Acratech Arca Swiss dovetail bracket with a lever lock to attach my BlackRapid strap to my 500 f4 and D3s. I was demonstrating it to a colleague, and locked it on, checked it and then let my gear hang from it. I had my hand on the lens foot, as I always do. The lever just sprang open. It had clicked shut, as I was showing my friend how ir works. It just opened.
It sounds like user error, but I was actually going through the process in detail. I do not believe I messed it up. I tried out a second time and it popped open then too. I still have it if you would like to have it! I don't recommend it though.
The Acratech is adjustable. I had adjusted the jaws to suit the plate on my 500. I had the tension as right as I could- not too tight.
BrianMM
Active member
IainD: Thank you very much for the detailed description of the Acratech clamp failure which is very interesting to me.
I tried some quick tests with each of mine (I have four, but none with the sling attachment) and I have so far been unable duplicate the problem you had with yours. I cannot get the clamps to open, and that includes the old Mark I, unless and until I manually release the spring-loaded locking lever. On each of my clamps the heel of the lever locks securely into the detent machined into the pivot hub and I cannot force the clamp open with the lever locked and I cannot get the lever to release on its own due to the retaining spring compression.
At the moment I'm recovering from surgery so I have lots of idle time and will undertake more extensive testing in the near future. However, I plan to continue using my Acratech clamps unless I can duplicate the problem you had.
I tried some quick tests with each of mine (I have four, but none with the sling attachment) and I have so far been unable duplicate the problem you had with yours. I cannot get the clamps to open, and that includes the old Mark I, unless and until I manually release the spring-loaded locking lever. On each of my clamps the heel of the lever locks securely into the detent machined into the pivot hub and I cannot force the clamp open with the lever locked and I cannot get the lever to release on its own due to the retaining spring compression.
At the moment I'm recovering from surgery so I have lots of idle time and will undertake more extensive testing in the near future. However, I plan to continue using my Acratech clamps unless I can duplicate the problem you had.
IainD
Well-known member
I actually bought a second one, thinking it might just be faulty, but I never got around to using it. I switched to QD! and now some are reporting problems with QD too!
Hope your recovery goes well.
I
Hi everyone! I have a 500 PF with a Hejnar foot; I want to attach this lens to a black rapid strap with a Really Right Stuff QD Strap Swivel (D-Loop); does it work and is it safe?
Hi Cristobal. I have a Z9 with the 500PF and the Hejnar foot specifically for that combination. I use the Magpul strap with QD connector. With the Hejnar foot it balances real well. I‘m new to the QD connector and so I doubled up and attached the Black Rapid safety strap from the Magpul QD D ring to the L frame (Kirk). I’ve been using this setup for about 2 months. I give it a tug when I first start out, and it seems to be very safe.
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Thank you very much for your quick and convincing answer! checking at B&H to see if they sell too the Magpul QD D ring (easier to send in Canada). I took a look at your Hejnar foot and curiously it doen't look like mine (photo enclosed); do you believe that my Hejnar foot is compatible with the QD?
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IainD
Well-known member
The central socket in the raised section, centrally, just to the right of the screw thread is the QD socket. It has the central ring for the ball bearing of the QD to catch on. I have a slightly different foot. I have the H129-500, specifically for the 500 and it is a bit longer than the H129. It is intended to help balance the lens on a gimbal, I think, but your foot is also excellent!
I
Thank you very much! Mine is too the H 129-500 (4.3 '' long).
So Hejnar makes several feet for the 500mm PF. The H 129-500 is the “standard“ foot as far as I can tell. They also make one specifically for the 500 PF with the Z9. It is NFR-006. It moves the QD attachment point closer to the camera body for better balance. I purchased this to ease the stress on the camera/lens connection point.
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I used to use the Peak Design connectors with one on the lens and one on the camera. There was another thread in this forum that discussed
Safe ways to carry a large lens with a strap? (Where to attach strap.)
and I determined that my method probably wasn’t the optimal approach. I tried the Magpul strap with QD on the RRS foot that I had on the lens. But I didn’t like the balance. The FTZ adapter moves the lens further away from the camera and so the balance point is upset. @Patty15 mentioned the Hejnar foot specifically for the Z9 and 500PF in that thread, so I purchased it. It hangs very comfortably and balanced. So far so good. And kudos to @Patty15 !IainD
Well-known member
That is a new one to me! I have not looked at the website since I got mine some time ago.
I was surprised as well. I had the RRS foot on it for several years, when I was using it with my D500 and then D850, well before the Z9. So when it was mentioned in that other thread, I had to go look. In my opinion it resulted in better balance with the Z9. I still have the RRS foot for use with my backup DSLR.
Welcome! I like the balance of the longer Hejnar foot a lot. Glad it's worked for you.
As Terry said, the QD connectors vary by manufacturer. The Kirk ones had a recessed release, safe albeit harder to use. The next generation from Kirk has a protruding button with a bar over it to protect against accidental release. The genuine Magpul is similar to the original Kirk but with a protruding button.
The other thing to remember is that these have moving and wearing parts so they do require some level of inspection and maintenance.
If those balls don’t move out to the correct position, it’s not going to secure properly.
The other thing to remember is that these have moving and wearing parts so they do require some level of inspection and maintenance.
If those balls don’t move out to the correct position, it’s not going to secure properly.
iimage
New member
I had a Magpul QD fail once—I had to use a bit of grease on the little nubs, as they wouldn’t spring out to hold. Now I test them every time I pull out the Z9. I think they need a little love and care to ensure they are engaging.
Good reason to have a secondary safety strap attached to the camera itself. Belt and suspenders can help avoid embarrassing accidents.