[Miguel]

The corporate relationship between Hoya and Tokina is ambiguous, and thus great sport to ponder endlessly. Legally they may co-license patents, but as a photographer the only thing that matters to me is whether the lenses are good.

Tokina lenses do not have Quick Shift capability which is too bad. The push/pull clutch is OK, but forces you to exert some force when doing so may be detrimental to the shot. Their 50-135mm f 2.8 sister to the DA* Pentax lens does, however, have a nice tripod mount. And it is noisier than the Pentax SDM.

Their new 16-28mm f2.8 lens I will purchase for use on a Canon 5DMKII. It is a shame that model as well as the 11-16mm f2.8 is not available in a Pentax K-mount.

Tokina doesn't seem to make any junky lenses these days.

M

[deadwolfbones]

Just got my Tokina 16-28mm f2.8 for Nikon, sold my D300s, getting my D700 on Monday, have to check out this DC motor on Monday... Anyway, Tokina builds pretty sweet lenses...

Let me know how you like that Tokina, luke.

[philbaum]

Tokina lenses do not have Quick Shift capability which is too bad. The push/pull clutch is OK, but forces you to exert some force when doing so may be detrimental to the shot. Their 50-135mm f 2.8 sister to the DA* Pentax lens does, however, have a nice tripod mount. And it is noisier than the Pentax SDM.


M

Wrong, Tokina does have quick shift:

To use the one-touch focus clutch mechanism,

from the link provided above for Tokina on the 12-24 f4.

I forget all the details but there is some technology agreement between the companies and both are Japanese companies.

[slocant]

Wrong, Tokina does have quick shift:

from the link provided above for Tokina on the 12-24 f4.

I forget all the details but there is some technology agreement between the companies and both are Japanese companies.

By reading the descriptions below, it seems that Focus Clutch Mechanism and One Touch Focus Clutch Mechanism are quite different from Quick Shift Focus.

Cheers,

Focus Clutch Mechanism

Tokina AT-X PRO series lenses all feature the patented “Focus Clutch” Mechanism for switching the lens between auto focus and manual focus modes.

The manual focusing ring can move (be snapped) back and forth between an AF and MF position. When the focusing ring is forward in the AF position, it is not engaged to any of the internal focus gearing and will turn freely. Without the added weight of the metal ring the camera can auto focus the lens more quickly and smoothly.

For manual focus, simply rotate the focus ring all the way to one side or the other on the focus travel, either infinity or it’s closest focusing distance, then pull back (towards the mount plate) on the manual focus ring. While pulling back, rotate the ring from one side of the focus travel to the other. When the gears align, the focus ring will snap back into the MF position and the lens can be focused manually.

To return the manual focus ring to auto focus mode, simply snap the ring forward from any point.

One Touch Focus Clutch Mechanism

A refinement of the focus clutch mechanism has been incorporated in the AT-X 280 AF PRO Nikon and Canon mount, so that now the lens’ focus ring can be snapped back to the manual focus position at any time, from any position. This improvement means it is not necessary to change the AF/MF switch (on the body with Nikon or the lens with Canon) every time the lens is changed from auto focus to manual focus mode.


Source: Tokina

[Miguel]

Sorry Phil, but you are the one who is mistaken here.
I own a Tokina AF lens, do you?
The AF/MF changeover is a push/pull clutch mechanism. Not a Quick Shift by any means.
Some Canon lenses,BTW, do have a quick shift-like action.

M

Wrong, Tokina does have quick shift:



from the link provided above for Tokina on the 12-24 f4.

I forget all the details but there is some technology agreement between the companies and both are Japanese companies.

[gawan]

The AF/MF changeover is a push/pull clutch mechanism. Not a Quick Shift by any means.

Right — also, the Tokina version of the 'DC' AF motor is NOT an ultrasonic, but a mechanical in-the-lens motor. See for example this review:

Tokina AT-X 124 PRO DX II AF 12-24 mm f/4 review - Introduction - Lenstip.com

[Aegon]

The Pentax DC motor is also not ultrasonic. It uses DC instead of AC, there are no waves, the speed is adjusted by amperage instead of frequency.

[FullertonImages]

So by not being ultrasonic, does that mean the the new DC motor won't be as quiet as USM/SDM/BDSM?

[gawan]

So by not being ultrasonic, does that mean the the new DC motor won't be as quiet as USM/SDM/BDSM?

Quote from the Lenstip review (see link above):

The Tokina still doesn’t boast an ultrasonic autofocus mechanism and, in the case of the 12-24 mm II model, you can hear it at once. We must admit, though, that the buzz, emitting by the mechanism, is not very loud. We can even risk a statement that this is one of the more silent motors without ultrasonics.

[FullertonImages]

So we're talking louder than SDM, quieter than screw drive?

[kales]

The corporate relationship between Hoya and Tokina is ambiguous, and thus great sport to ponder endlessly. Legally they may co-license patents, but as a photographer the only thing that matters to me is whether the lenses are good.

Tokina lenses do not have Quick Shift capability which is too bad. The push/pull clutch is OK, but forces you to exert some force when doing so may be detrimental to the shot. Their 50-135mm f 2.8 sister to the DA* Pentax lens does, however, have a nice tripod mount. And it is noisier than the Pentax SDM.

Their new 16-28mm f2.8 lens I will purchase for use on a Canon 5DMKII. It is a shame that model as well as the 11-16mm f2.8 is not available in a Pentax K-mount.

Tokina doesn't seem to make any junky lenses these days.

M

Miguel,
I once had a Nikon D700 with 50/1.8 attached in my hand, and found that D700 screw drive is much much much more silent than my pentax bodies.
pentax SDM also suffers from its speed which is really very slow. had I have a choice I will choose to use screw, cauz I care more about speed than silent.

[kales]

So we're talking louder than SDM, quieter than screw drive?

quiter than pentax screw^_^
I could not figure out why pentax screw is louder than nikon. It sounds like pentax screw drive noise contains more higher frequency contents.

[deadwolfbones]

Miguel,
I once had a Nikon D700 with 50/1.8 attached in my hand, and found that D700 screw drive is much much much more silent than my pentax bodies.

Really depends. The 85/1.8 I have is much louder than any of my Pentax lenses, though that seems to be the focus mechanism in the lens and not the screwdrive itself.

[solar1]

describe any typical dslr lens motor that isn't direct current.

I do not believe there are, or can be any alternating current lenses.

The Pentax DC motor is also not ultrasonic. It uses DC instead of AC, there are no waves, the speed is adjusted by amperage instead of frequency.

[ogl]

The Pentax DC motor is also not ultrasonic. It uses DC instead of AC, there are no waves, the speed is adjusted by amperage instead of frequency.

Extra-smooth SDM autofocus operation
A DC motor built into the lens’ AF (autofocus) unit assures extra-smooth autofocus operation. Since it features a rotation-free mechanism to keep the focus ring stationary during autofocus operation, the user can hold the lens in exactly the same way as when using this lens in the manual-focus mode.


No doubt, that DC is more simple and reliable version of SDM.
It's not ring motor. But we don't have description of DC motor from Pentax, that's why we can't say anything about it.