connection point cleaning - HELP!!

[danny]

I am reasonable sure that I need to clean the connection points on my lens/camera…

1. I first noticed an error with my D7000 where i can focus, and take a photo however I need to repress the shutter release to re-ingage the shutter.
2. Using my brand new D610 I sometimes get a message saying that the lens is a non-CPU lens (it is)
3. Also when using new camera I am having trouble locking auto-focus at 200mm on my 70-200mm.

4. after following some advise via AP I cleaned the lens with a rubber which seems to resolve the issue.

HOWEVER, after about 200-300 shots one or all of the problems happens again. So, i was thinking that this means that there is some more stubborn 'dirt' on the connections that needs a better clean.

Is there another way? Or should I take my gear somewhere to get it cleaned and if so how much does that usually cost?

Cheers
danny

[ricktas]

alcohol..metho.. and a cotton bud, be gentle and do not use so much metho that it drips off.

[davsv1]

Jaycar http://www.jaycar.com.au/productView.asp?ID=NS1436 have an American product specifically designed for electronic contacts, get the liquid / cotton bud type application not the spray on one.

[arthurking83]

Or alternatively, if you have any sensor cleaning fluid such as eclipse, it also works.
(apparently)It's 100%, water free ethanol, so works similarly to any other contact cleaning fluids.

BTW: does this happen only with the 70-200 lens. if so, which brand/model type is it.

If it does happen only with this particular lens, does the lens-to-camera fit have any amount of backlash in it. Not all do, and having some can be normal.
if it doesn't have any lash, where you can't feel any slack being taken up if you twist the lens whilst mounted to the camera then there isn't much else you can do with this test.
But if there is a very small amount of looseness between lens/camera .. if the problem happens again, can you eliminate the error if you play with this small amount of slack?

The slack I'm referring too is felt when using the same motion on the lens as you would in mounting/removing the lens but without pressing the release pin ... not a bending motion(as in trying to snap the lens off the camera!!).

[danny]

Or alternatively, if you have any sensor cleaning fluid such as eclipse, it also works.
(apparently)It's 100%, water free ethanol, so works similarly to any other contact cleaning fluids.

BTW: does this happen only with the 70-200 lens. if so, which brand/model type is it.

If it does happen only with this particular lens, does the lens-to-camera fit have any amount of backlash in it. Not all do, and having some can be normal.
if it doesn't have any lash, where you can't feel any slack being taken up if you twist the lens whilst mounted to the camera then there isn't much else you can do with this test.
But if there is a very small amount of looseness between lens/camera .. if the problem happens again, can you eliminate the error if you play with this small amount of slack?

The slack I'm referring too is felt when using the same motion on the lens as you would in mounting/removing the lens but without pressing the release pin ... not a bending motion(as in trying to snap the lens off the camera!!).

I think this could also be part of the problem as there is some backlash. Should there be?
It's a new tamron lens.

Danny

[arthurking83]

Not sure if 'there should be' .. but like I said, there ususually is a small amount.

Strange thing is that this is random.

I have a few lenses and there's no rhyme nor reason to which lens does have some, and which lens doesn't.

Tammy 28-75/2.8, fairly cheaply made in most aspects(lens hood, plastic body shell quality) yet zero slack at the mount to the camera.
Nikon 105VR(I think a bit too overpriced, but still a nice lens in many ways regardless) feels as tho it has the most amount of slack!
Tammy 24-70VC .. just a wee bit
Sigma 50/1.4 .. not enough to call it slack, but the most minute millionth of a mil movement
Nikon 180/2.8 ais(maybe 20 yo .. maybe more) zero!

I just mounted my older Tammy 70-200/2.8(non VC model) on the D800E and it has a similar 'not enough to call it slack' amount as the Sigma 50/1.4.
BUT on the D300(where it basically lives) it has more slackness in the mounting point.

So, if there is just the smallest amount of slack in the camera lens combo .. if you see this problem again, try to wriggle the lens a bit and see if it changes anything at all.

Reason is, there may be a possibility that one of the spring loaded contact pins on the lens could be compressed a bit too far.
I've personally never seen this on any of my CPU lenses, but I did have it happen to the CPU chip I mounted to my old 500/8 mirror lens.
Stupidly I started fiddling with it to 'fix it' and ended up ripping the housing apart :D(my bad for not just being more careful with it).

FWIW: I think the slack between the camera lens is due to the locating pin on the camera mount and a recess in the lens.
Near the lens release button on the camera is a small protruding pin on the mount surface. With the lens removed, if you push the lens release tab, you will see the locating pin also slide into the mounting face and disappear. It just locks the lens into place.
The recess that this pin locates itself into, is at about the 270° mark if you hold the lens so that the white mounting dot is situated in a north like orientation.
This recess is a small oval shaped dip in the mounting face of the lens. It's a machined out recess that is shaped across the face of the mount, and I suspect that tolerances differ between lenses/cameras.
Note that all my Tamron lenses also have another machined out groove just above this locating notch too.
None of my modern Nikon lenses use this scalloped out groove thingy, but all of the older lenses I have(and had) have this other groove.
I don't know what that one does tho.
Some of my Sigma lenses also don't have this other groove, but another one does.
I find it strange that Tamron still has it on their newer type lenses the where even Nikon seem to have stopped machining this one on lenses much older than my Tamron lenses.

[danny]

Thanks Arthur!! Photography is such a wonderful thing. Just when you think you are starting to get "some" knowledge you learn something totally new :o

There is certainly more slack on the D7000 compared to the D610 with the Tamron. My 50mm is tight on both bodies.

I think you are spot on. I will be testing out your theory ASAP. A huge thank you for your (and others) advise. What is a relief is that it is somewhat normal.

[danny]

Arthur, I am now sure you are right about the backlash. when the lens reads that it is a non CPU lens I click it more towards lock and it fixes itself. Next time I am in sydney I will take it back to Georges and ask them what they think.

[arthurking83]

OK, strange.
IIRC you've only had the lens a short time, maybe the tolerance in the recess is just a bit too much on your lens or something.
I find it very unlikely that a contact spring on the lenses contact block has compressed itself in such a short time.

FWIW: I remember many years back I had a slightly similar issue with the Sigma 10-20mm. Go that lens in 06, and used it heavily on the D70s from that day forward.
Same sort of issue where the camera seemed to lock up every now and then, and randomly and the first thing I thought was contacts dirty.
I was out in the bush so had nothing to clean it with one day, and removed the lens to see what the issue may be. lens back on and everything OK again. put camera on tripod a few seconds later and nada!
A few minutes later, the problem just stopped of it's own accord.
There is no, and has never been, any slack in the Sigma - D70s mount yet had this problem appear every now and then.
So it just stopped! I can't remember any time after this particular bush trip where the lens did this again.
Then I got a D300 in late 07, and never saw the problem. Same with the D800, used the Siggy for about a year as my UWA lens and never saw the problem.

Did it fix itself? was the problem real .. did I dream it .. etc.
I've never really mentioned it at the time, as it was a problem that was never really a problem(if that makes sense).

Anyhow, hope it all works out for ya soon.

[danny]

I think I am going to have to take the lens back and ask the dealer their thoughts. I am assuming that if the backlash is so significant that it doesn't always work than it is not working 'properly'. Happy it is still under warranty.

[danny]

Quick update -

Contacted dealer and I intend to take it back when I am next in Sydney. I've got the phone number for Tamron Australia also so I might give them a call to see what they think.