150-450 loses communication intermittently while carrying

fehknt · 01-19-2017, 09:32 PM

So, it's not much of a problem for actual shooting but I noticed today that when carrying my K3-ii + 150-450, using a strap that attaches to the tripod threads on the camera, that the aperture setting would occasionally flip to F-- indicating it lost communication with the lens when the lens mount flexes slightly under the load. Whenever I'm shooting, I'm supporting the lens and camera and it's all good but wanted to see if there were others out there that saw this.

Am I simply putting too much stress on the mount? I wouldn't have thought so, but maybe I need to switch to using the tripod threads on the lens for carrying.

**tduell** · 01-19-2017, 09:49 PM

Probably dirty contacts.
Give the contacts on the lens and the camera a clean with a fine dry cloth, one of those microfibre cloths for cleaning specs are ideal, and see how that goes.
I am regularly changing lens on my cameras and the 150-450 does show this behaviour every now and then and good clean does the trick.
I would add that using the tripod mount to carry the lens and camera is also a good way of taking the load off the mount. I have a sling strap attached to the tripod mount which is a good way of carrying the load.

Cheers,
Terry

biz-engineer · 01-19-2017, 10:02 PM

Mine did it in cold weather when I let the combo be handled by someone who wasn't used to use long lenses. When lenses are heavier than the camera body , the system must be handled by the lens collar, carrying heavy lenses by the camera body can even damage the mount. It should become a habit to always carry heavy lenses by the lens collar.

noelpolar · 01-19-2017, 10:37 PM

I let my 150-450 hang from the camera with my Blackrapid strap connectd to the camera tripod socket... on both the K3 and K-1 for over a year now. No issues....70-200/2.8 lens before that.... no issues. Camera and lens doesn't hang down nicely for me if strap is connected to lens foot.

biz-engineer · 01-20-2017, 01:27 AM

Originally posted by noelpolar

I let my 150-450 hang from the camera with my Blackrapid strap connectd to the camera tripod socket... on both the K3 and K-1 for over a year now. No issues....70-200/2.8 lens before that.... no issues. Camera and lens doesn't hang down nicely for me if strap is connected to lens foot.

Wow, that's pretty robust gear for this way of use.

noelpolar · 01-20-2017, 03:32 AM

Originally posted by biz-engineer

Wow, that's pretty robust gear for this way of use.

I must admit.... I'd just taken for granted the K5/3/1 stainless chasis and mag bodies were made to take it.... And all that weight in the 150-450 must be there for a reason!

I also lift/swing the lens to eye at times with just the one hand (RHS) on the camera.... I've not sensed any give etc.... and I'm cognisant of that type of thing.

werfor42 · 01-20-2017, 04:00 AM

Originally posted by fehknt

So, it's not much of a problem for actual shooting but I noticed today that when carrying my K3-ii + 150-450, using a strap that attaches to the tripod threads on the camera, that the aperture setting would occasionally flip to F-- indicating it lost communication with the lens when the lens mount flexes slightly under the load. Whenever I'm shooting, I'm supporting the lens and camera and it's all good but wanted to see if there were others out there that saw this.

Am I simply putting too much stress on the mount? I wouldn't have thought so, but maybe I need to switch to using the tripod threads on the lens for carrying.

Hello everyone. I'm new here, but I have the same Problem as you have. I haven't got the Pentax 150 - 450 but I've got an older Sigma 120 -400 where the same problem occurs occasionally. Cleaning the contacts may help, but i think the problem exists because of the connection pins. They are very small and if there ist a very little twist between lens and camera (it often occurs when the lens ist changed very often ) the pins loose contact so that this error message appears. That is why canon and Fuji have scmall squares as lens contacts. So tis will never occur with Canon and Fuji lenses. The Nikon usere have the same problem.

pete-tarmigan · 01-20-2017, 06:54 AM

If the strap is attached to the camera body's tripod socket, that sounds like too much weight torquing the mount. That is one of the reasons why manufacturers build such heavy lenses with tripod mounts.

fehknt · 01-20-2017, 10:45 AM

In general I agree that some really big lenses need to use the tripod mount, but given that the tripod mount is removable on this lens for handholding, so I would have expected it to be designed to be OK without using it.

I'll see how it goes with cleaning contacts; I'm also using a Blackrapid and also prefer the way it hangs on the camera mount compared to the lens mount.

01-19-2017, 09:32 PM	#1
fehknt Senior Member Join Date: Oct 2015 Posts: 142	150-450 loses communication intermittently while carrying So, it's not much of a problem for actual shooting but I noticed today that when carrying my K3-ii + 150-450, using a strap that attaches to the tripod threads on the camera, that the aperture setting would occasionally flip to F-- indicating it lost communication with the lens when the lens mount flexes slightly under the load. Whenever I'm shooting, I'm supporting the lens and camera and it's all good but wanted to see if there were others out there that saw this. Am I simply putting too much stress on the mount? I wouldn't have thought so, but maybe I need to switch to using the tripod threads on the lens for carrying.

01-20-2017, 03:32 AM	#6
noelpolar Veteran Member Join Date: Oct 2013 Location: Goolwa, SA Photos: Gallery Posts: 4,310	Originally posted by biz-engineer Wow, that's pretty robust gear for this way of use. I must admit.... I'd just taken for granted the K5/3/1 stainless chasis and mag bodies were made to take it.... And all that weight in the 150-450 must be there for a reason! I also lift/swing the lens to eye at times with just the one hand (RHS) on the camera.... I've not sensed any give etc.... and I'm cognisant of that type of thing. Last edited by noelpolar; 01-20-2017 at 03:38 AM.

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01-19-2017, 09:49 PM	#2
tduell Loyal Site Supporter Join Date: May 2015 Location: Melbourne Posts: 1,517	Probably dirty contacts. Give the contacts on the lens and the camera a clean with a fine dry cloth, one of those microfibre cloths for cleaning specs are ideal, and see how that goes. I am regularly changing lens on my cameras and the 150-450 does show this behaviour every now and then and good clean does the trick. I would add that using the tripod mount to carry the lens and camera is also a good way of taking the load off the mount. I have a sling strap attached to the tripod mount which is a good way of carrying the load. Cheers, Terry

01-19-2017, 10:02 PM	#3
biz-engineer Pentaxian Join Date: Feb 2015 Photos: Gallery Posts: 12,253	Mine did it in cold weather when I let the combo be handled by someone who wasn't used to use long lenses. When lenses are heavier than the camera body , the system must be handled by the lens collar, carrying heavy lenses by the camera body can even damage the mount. It should become a habit to always carry heavy lenses by the lens collar.

01-19-2017, 10:37 PM	#4
noelpolar Veteran Member Join Date: Oct 2013 Location: Goolwa, SA Photos: Gallery Posts: 4,310	I let my 150-450 hang from the camera with my Blackrapid strap connectd to the camera tripod socket... on both the K3 and K-1 for over a year now. No issues....70-200/2.8 lens before that.... no issues. Camera and lens doesn't hang down nicely for me if strap is connected to lens foot.

01-20-2017, 01:27 AM	#5
biz-engineer Pentaxian Join Date: Feb 2015 Photos: Gallery Posts: 12,253	Originally posted by noelpolar I let my 150-450 hang from the camera with my Blackrapid strap connectd to the camera tripod socket... on both the K3 and K-1 for over a year now. No issues....70-200/2.8 lens before that.... no issues. Camera and lens doesn't hang down nicely for me if strap is connected to lens foot. Wow, that's pretty robust gear for this way of use.

01-20-2017, 04:00 AM	#7
werfor42 Guest	Originally posted by fehknt So, it's not much of a problem for actual shooting but I noticed today that when carrying my K3-ii + 150-450, using a strap that attaches to the tripod threads on the camera, that the aperture setting would occasionally flip to F-- indicating it lost communication with the lens when the lens mount flexes slightly under the load. Whenever I'm shooting, I'm supporting the lens and camera and it's all good but wanted to see if there were others out there that saw this. Am I simply putting too much stress on the mount? I wouldn't have thought so, but maybe I need to switch to using the tripod threads on the lens for carrying. Hello everyone. I'm new here, but I have the same Problem as you have. I haven't got the Pentax 150 - 450 but I've got an older Sigma 120 -400 where the same problem occurs occasionally. Cleaning the contacts may help, but i think the problem exists because of the connection pins. They are very small and if there ist a very little twist between lens and camera (it often occurs when the lens ist changed very often ) the pins loose contact so that this error message appears. That is why canon and Fuji have scmall squares as lens contacts. So tis will never occur with Canon and Fuji lenses. The Nikon usere have the same problem.

01-20-2017, 06:54 AM	#8
pete-tarmigan Veteran Member Join Date: Apr 2009 Location: Conception Bay South, New-fun-land Photos: Gallery Posts: 1,272	If the strap is attached to the camera body's tripod socket, that sounds like too much weight torquing the mount. That is one of the reasons why manufacturers build such heavy lenses with tripod mounts.

01-20-2017, 10:45 AM	#9
fehknt Senior Member Join Date: Oct 2015 Posts: 142 Original Poster	In general I agree that some really big lenses need to use the tripod mount, but given that the tripod mount is removable on this lens for handholding, so I would have expected it to be designed to be OK without using it. I'll see how it goes with cleaning contacts; I'm also using a Blackrapid and also prefer the way it hangs on the camera mount compared to the lens mount.