[Ronald Oakes]

I'm completely "FED UP" using aluminum Foil , or Aluminum tape , on some of my Takumar Lenses in order to use the "Green Button" metering in "M" mode on my Pentax DSLR !

Is there any other alternative anyone uses ?

If it were available ? How many of you would buy an inexpensive adapter (appx $22-$25) that would do this , and yet maintain Infinity focus on many of your regular focal length Takumar lenses , at least in the 24-55mm range ?

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Last edited by Ronald Oakes; 03-08-2018 at 04:03 PM.

[boriscleto]

How would you have an adapter with a flange that would maintain infinity focus? The flange would have to be the same thickness as aluminum tape...

[Ronald Oakes]

how would you have an adapter with a flange that would maintain infinity focus? The flange would have to be the same thickness as aluminum tape...

Top Secret ! All will be disclosed at the End of the Poll.
Nothing goes between the mounts directly. There is nothing added at all that will affect the Register distance.

[pepperberry farm]

I use a piece of conductive tape - sticky on one side, stays on the lens and I don't have to find a piece every time I change lenses....

would you like a strip - I've been giving it away...



edit... I see you have that as an option...

never mind me...

[Ronald Oakes]

I use a piece of conductive tape - sticky on one side, stays on the lens and I don't have to find a piece every time I change lenses....

would you like a strip - I've been giving it away...

I don't understand ? The lens base is too narrow and doesn't cover the contacts ?
Pict ?

[pepperberry farm]

I don't understand ? The lens base is too narrow and doesn't cover the contacts ?
Pict ?

I'm way off base, but you are working with M42 lenses, not K-mount, right?

my Porst 55/1.2, with conductive tape:

[Ronald Oakes]

I'm way off base, but you are working with M42 lenses, not K-mount, right?

my Porst 55/1.2, with conductive tape:

Nope ! Only Takumars , not M42 or K mount lenses in general.

---------- Post added 03-08-18 at 06:21 PM ----------

How would you have an adapter with a flange that would maintain infinity focus? The flange would have to be the same thickness as aluminum tape...

Look at the base of one of your takumars (24mm-55mm) very closely , now....think "outside" the box ! It can be done , unfortunately only within a standard deviation , not all Takumar lenses will work with it , but my 24-55mm lenses will !
Even Aluminum tape will affect the registration distance (to a lesser degree) if placed between the lens and body mount.

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Last edited by Ronald Oakes; 03-08-2018 at 05:27 PM.

[thazooo]

Av ???

[Ronald Oakes]

Av ???

True...Av mode will work....kinda anyway.
However I like having full control in M mode.
My experience is Av mode tends to overexpose somewhat erratically.

[vonBaloney]

I usually use Av for m42, so maybe I'm missing something, but since when does the green button not work with (non-conductive) m42s in M mode? (I'm still using a K-5 -- newer models don't do this?)

[Ronald Oakes]

I usually use Av for m42, so maybe I'm missing something, but since when does the green button not work with (non-conductive) m42s in M mode? (I'm still using a K-5 -- newer models don't do this?)

I don't think its model specific. The base of a lot of the takumars just simply doesn't cover the contacts on the lens mount.
I have only been Pentax DSLR since the K30 , but everything after that has this shortcoming using Takumars.
Remember....we are talking Tak's here...not M42 lenses in general.

[vonBaloney]

I don't think its model specific. The base of a lot of the takumars just simply doesn't cover the contacts on the lens mount.
I have only been Pentax DSLR since the K30 , but everything after that has this shortcoming using Takumars.
Remember....we are talking Tak's here...not M42 lenses in general.

Just tested with a couple of lenses -- works fine, even on a lens that doesn't touch the contacts. (Even works with no lens at all.) As long as "Use Aperture Ring" is set to "permitted" -- do you have that setting set?

[6BQ5]

I would rather have some sort of firmware update that removes the requirement for shorting the terminals.

[Ronald Oakes]

Just tested with a couple of lenses -- works fine, even on a lens that doesn't touch the contacts. (Even works with no lens at all.) As long as "Use Aperture Ring" is set to "permitted" -- do you have that setting set?

Yes....its always enabled.
Don't tell me after all this....I'm about to learn something ?
I was always "listening" when I hit the green button.....heard nothing.
However now I "See" that it does take a new reading silently , each time I push it , and sets the exposure value accordingly.....!!!!!
""Crapola"" !!!!.....What have I missed out on for the last 5 years ?

Now I'm really confused.....what is it I'm doing when shorting the contacts ? It does the same thing , but I "Hear" it !
I don't know how this has happened....I somehow equated Hearing it with working , and Silence with not working ?

[vonBaloney]

Yes....its always enabled.
Don't tell me after all this....I'm about to learn something ?
I was always "listening" when I hit the green button.....heard nothing.
However now I "See" that it does take a new reading silently , each time I push it , and sets the exposure value accordingly.....!!!!!
""Crapola"" !!!!.....What have I missed out on for the last 5 years ?

You are "listening" for it to move the aperture lever in a K-mount lens and stop the thing down, but on a m42 it doesn't do anything because there is no aperture lever and you need to stop it down yourself before you hit the green button so you'll get the right reading for that aperture. So -- completely silent, nothing is moving. (A K-mount stays wide-open until you hit the button, and then stops it down for a second to take the reading. That's the whole reason you need the button since they refuse to read it mechanically like on the old film bodies.)

---------- Post added 03-08-18 at 08:13 PM ----------

I guess if you have a lens that shorts the contacts or you trick it with foil, you might hear the attempt to move the aperture lever even though it doesn't actually do anything. I don't think any of my m42s are conductive unless I made them so with foil tape -- the only time I've done that is if I wanted to use them with the AFA 1.7x adapter, which does require shorted contacts to get the auto-focus going.