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Fun with the Noktax (50/1.2)

Knorp

Well-known member
Just acquired this all manual lens and thought it appropriate to name it Noktax ... :eek:
Sorry, I have no cat nor dog, but here are some of the first results @f/1.2 !






WB slightly off

Closest focus distance (0,45 mtr). Pretty good, no ?

Kind regards.
 

tsjanik

Well-known member
Newest incarnation of the same lens - but still 30 years old! You are fortunate to find that lens, it's rather rare. The old manual focus Pentax lenses are wondeful and a great bargain.
Here are some taken with your lens' poor cousin, the f/1.4

Tom


_IGP0166 by tsjanik47, on Flickr




_IGP0179 by tsjanik47, on Flickr
 

Knorp

Well-known member
Tom, these are looking good, even by a poor cousin's standard ... 😜
Obviously the jury is still out whether my 50/1.2 is any good at all.
It came with front and rear caps only (no box), but it's almost mint as far as I can see.
Bought the hood separately.

Kind regards.
 

Knorp

Well-known member
Yup that's the lens alright. Thanks for the link, Tom. I'll have a look and hopefully its characteristics are not too bad.
What I've read before purchasing it should be okay though.
There are three versions with the same optics formula, only the last iteration has this A(uto-aperture) feature and different coating.

Kind regards.
 

D&A

Well-known member
Hi,

I've shot Pentax for over 35 years and virtually all of the Takumars (including the last of the screw mounts, the SMC Takumars) and their near identical SMC Pentax K mount lenses were/are splended. Later on as the K mount lenses continued in their development, new optical formulas were developed for SMC K mount pentax lenses that had no screw mount counterparts. The 50mm f1.2 is one of them, as there was no screw mount Takumars faster than f1.4. Although somewhat soft wide open, the 50mm f1.2 is still highly sort after and an extremely nice lens. Some lovely images posted above!

Dave (D&A)
 
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Knorp

Well-known member
Hi Dave,

thanks for this interesting background information, much appreciated !

Kind regards.
 

Knorp

Well-known member
Something odd with this lens. When it's fully locked in the camera mount, the aperture remains wide open at f/1.2 no matter how I turn the ring.
Unlocking it and turning the lens 10 degrees or so makes the aperture ring fully operational.
For a manual lens I'm surprised to find this little lever at the back of the lens that actually operates the aperture.
The lever somehow must hit something inside the housing of the camera.

Anyhow, nothing better than the zoo to try out a 'new' lens, no exception this time ... :eek:
And nothing fancy of course.













 
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tsjanik

Well-known member
WOW, fabulous Bart, you've got a winner there. The lever and behavior is normal. If you push the green button to measure exposure you will see the lens stop down, or push the DOF preview on the power switch and of course when an exposure is made. There is a small arm inside the body on the left side as you face the camera. I really like the last shot; you obviously have no trouble with the manual focusing.

Tom
 

Knorp

Well-known member
WOW, fabulous Bart, you've got a winner there. The lever and behavior is normal. If you push the green button to measure exposure you will see the lens stop down, or push the DOF preview on the power switch and of course when an exposure is made. There is a small arm inside the body on the left side as you face the camera. I really like the last shot; you obviously have no trouble with the manual focusing.

Tom
Mmm, seems I missed all bells&whistles of this nifty camera or dSLRs in general for that matter :eek:.
I suppose we M-users still live in the Dark Ages.
Or is it just me ... :shocked:

But seriously, the DOF preview works indeed (in M-mode) with this manual lens too.
And the image is made with the chosen aperture value.
So far so good.

But I like to set aperture and leave the shutter speed to the electronics.
So right then: why doesn't my camera engage aperture adjustment when in Av-mode ?
Also the DOF preview is not working.
Beats me ... :cussing:

Kind regards.
 

tsjanik

Well-known member
..........But I like to set aperture and leave the shutter speed to the electronics.
So right then: why doesn't my camera engage aperture adjustment when in Av-mode ?
Also the DOF preview is not working.
Beats me ... :cussing:

Kind regards.
By setting the aperture ring and using the green button in M mode you are de facto in Av mode. Pentax cameras from the era of your lens had a mechanical coupling to transmit aperature information. The mechanical coupling is absent in their DSLRs.

Please post more shots from that lens

Regards,


Tom
 

Knorp

Well-known member
By setting the aperture ring and using the green button in M mode you are de facto in Av mode. Pentax cameras from the era of your lens had a mechanical coupling to transmit aperature information. The mechanical coupling is absent in their DSLRs.
Thanks Tom, but there IS a mechanical coupling !
In M-mode the selected (manual) aperture is selected and used.
You can actually hear the coupling doing its work and the photo has more DOF as expected.

But why can't this all work in Av-mode, I wonder ?
I mean everything is there ! What am I missing ?

Kind regards.
 

Knorp

Well-known member
Doing some more reading, it's now clear to me, though not the technical aspect, this lens is not going to work stopped down with automatic shutter speed in Av-mode.
Although I've read a bit of tape will get you the first three stops, but why bother if its main purpose and attraction is to be shot wide open, right ?
So therefore I'll stop asking questions and better start shooting now.

Kind regards.
 

benroy

Subscriber Member
Bart: all the hanky-panky and monkeying around with the lens aside, the zoo pictures, especially the last one are terrific.It ain't the lens that made the difference in these pics, it was a damn good photographer!

Roy Benson
 

Knorp

Well-known member
Although I'm used to handle fast glass, I'm surprised to find it quite difficult to get consistent focus with this lens.
Here's my dad patiently posing :)

 

Knorp

Well-known member
Walking through rainy Amsterdam.
Again I found myself flabbergasted by the inconsistent focus hit rate.
I'll setup my LensAlign Pro some time soon for some serious testing.









 
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