Dismantle Tokina 400mm AF 5.6

[Pistnbroke]

I have this lens and it works fine at contrast +3 but there is a slight mist in the 2nd element. I can remove the two front elements  and get down to the iris level but the rear element defeats me . I can engage the tool in the long tube (40mm) but it will not unscrew. I note all the parts are held with a touch of varnish and wonder if heating the mount with a soldering iron will break the seal...any advice welcome.

[Erik Lund]

You can use a solvent like acetone put a few drops on the threads and wait a few seconds.

[Pistnbroke]

The tube I want to remove contains the lens.. it moves back and forth with the focus ..far too deep to get a tool to the actual lens( well my lens tool anyway) ..the tube has the notches but wont shift ...I don't fancy running acetone down the outside ...good tip though.

[Hugh_3170]

Try a fine artists camel hair brush of suitable length.  Don't overload the brush with acetone and be prepared to make more than one application of the acetone if it won't budge after the first application.  Good luck.

[Erik Lund]

How is progress? If your having trouble maybe post a couple of images of the predicament

[Pistnbroke]

Thanks  Eric  for offering to help ...so often I  give information (not this site) and all you get is silence..

I have managed to take the whole "front " off the lens which got me down to the diaphragm but the cloudy lens is not the one behind the diaphragm .
I have attached photo of the mount end and marked the tube I am trying to get out with two dots of white in the notches. This tube moves in and out as you focus.
The lens on its inner end is not the one that is cloudy.
The tube will not move and must have an inaccessible outer thread locked with varnish...I don't want to pour acetone into the lens !!!

Any advice ..I did  think of laying a 25w soldering iron in the tube to heat it up .....
The lens works fine with +3 contrast and only cost me $50  inc post but I still don't want to mess it up even though I bought a Sigma 400mm f5.6 which is perfect.

[Erik Lund]

Sorry but I have no clue, let it rest in piece,,,

[John G]

Sorry to divert away from the Tokina subject.
Is the lens tool pictured, the type I need to remove a Nikon 85mm f1.4 ais rear element.
I have a mould on a glass surface in this zone.

John

[Erik Lund]

Yes!

Usually called a lens spanner, the one in the picture looks like a nice one,,,

[John G]

Thank you Eric
www.mengsphoto.com is a good place to source a selection of lens spanners, including the type in the photo.

[Pistnbroke]

Got the spanner on e bay about £10  ..think I will try the hot soldering iron as there is minimal chance of damage and if that's no good let it RIP.
Will let you know.

[Erik Lund]

Usually several tips, sizes and shapes are needed,,, There seems to be no standardization for lens tools,,,

[richardHaw]

Get the right screwdriver   

[Erik Lund]

If that doesn't work get a hammer

[Pistnbroke]

Well I concluded that the "tube" which moves to focus may be moving to focus  on some straight splines so wont rotate. The rear element was held by an inaccessible ring so I machined the pins on the lens spanner so I could reach it ( lathes and mills are great arn't they !")  I took out the rear element ..easy and then cleaned the rear of the next element and it seems to have cleared the lens ...

Wahoo as Ken Rockwell would say.

thanks everyone until next time...