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05-29-2014, 06:45 AM - 2 Likes   #1
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New auto extension tubes for K and Q mounts

Looks like SRB Griturn are now offering
Kooka brand extension tubes for the K and Q mounts,
with full auto focus and auto exposure:

Auto Extension Tubes | Macro | SRB-Photographic.co.uk

The only downside appears to be
that while there is a full set (12, 20, and 36 mm) for the Q-mount,
there is only a 25mm tube for the K-mount.

Usual disclaimers apply:
I have no commercial connection with this,
and have not had a chance to try these yet.

But I'd like to get them behind my DA 70 and Q 01!

05-29-2014, 06:49 AM   #2
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Cool!
05-29-2014, 07:13 AM   #3
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Some months ago I have read that these Kooka extension rings could damage some Pentax lenses. If I understood this well, the rear element of some Pentax lenses could touch the front element of the extension ring. I suggest checking this piece of news ...
05-29-2014, 07:25 AM   #4
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QuoteOriginally posted by cport Quote
the rear element of some Pentax lenses could touch the front element of the extension ring. I suggest checking this piece of news ...
If there is an optical element, then it is not an extension tube. Extension tubes are just a hollow body with a mount at either end. There may still be an incompatibility with some cameras/lenses, such as the well-known k-mount issues on FF Canon bodies.


Steve

05-29-2014, 07:28 AM   #5
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QuoteOriginally posted by cport Quote
Some months ago I have read that these Kooka extension rings could damage some Pentax lenses. If I understood this well, the rear element of some Pentax lenses could touch the front element of the extension ring.
These are just empty tubes, no optical elements.


Added: Steve, you got there first!
05-29-2014, 07:30 AM   #6
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I just clicked through to the detail for the K-mount extension and noticed the real magic of this device. Not only does it have the A-contacts, it also has the AF drive pawl. I could not tell if it also has the pass-through contacts for in-lens AF motors.


Steve
05-29-2014, 07:41 AM   #7
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QuoteOriginally posted by stevebrot Quote
I could not tell if it also has the pass-through contacts for in-lens AF motors.
I suspect that the K-mount does,
since they certainly claim AF connectivity for the Q-mount version.

SRB Griturn are generally serious about what they offer.

I also found a Czech seller for the K-mount version,
although their with-tax price is slightly higher than SRB-Griturn's:

Kooka KK-P25 automatický mezikrou?ek 25 mm pro Pentax
05-29-2014, 07:42 AM - 1 Like   #8
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If you check Kooka's web site you will find that they have two Pentax AF offerings, a single 25mm tube and a two tube set with a 20mm and a 36mm tube. Link with details can be found at PENTAX - KOOKA OPTRONICS CO.,LTD

I wonder if all three are stackable?

05-29-2014, 07:54 AM - 1 Like   #9
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QuoteOriginally posted by bobell69 Quote
If you check Kooka's web site you will find that they have two Pentax AF offerings, a single 25mm tube and a two tube set with a 20mm and a 36mm tube. Link with details can be found at PENTAX - KOOKA OPTRONICS CO.,LTD
The AF designation,
and use of the word "autofocus" in the blurb,
are questionable for the 20/36mm tubes.


From the picture,
it seems as if the 20/36mm tubes are "dumb,"
no electrical or screwdrive connections.


From the Kooka instructions for the 20/36mm tubes:

b. Shooting
1. Set the focus mode switch on the lens to MF (M).
2. Focus the subject manually by turning the focusing ring and press the shutter button to take the picture. (At this point, you can check the focus using the focus mark in the viewfinder.)

(I see they have the exact same instructions for the 25mm tube,
but you can see the connections on the photo of that unit.)

Last edited by lytrytyr; 05-29-2014 at 08:00 AM.
05-29-2014, 07:56 AM   #10
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QuoteOriginally posted by bobell69 Quote
If you check Kooka's web site you will find that they have two Pentax AF offerings, a single 25mm tube and a two tube set with a 20mm and a 36mm tube. Link with details can be found at PENTAX - KOOKA OPTRONICS CO.,LTD

I wonder if all three are stackable?
the page says they are stackable
05-29-2014, 07:58 AM   #11
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QuoteOriginally posted by bobell69 Quote
I wonder if all three are stackable?
I don't see why not. I wonder why they don't sell all three together. Perhaps there seems to be more demand for just a 25mm tube?

It's good to see somebody is producing Auto AF tubes for K-mount.
05-29-2014, 08:03 AM   #12
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QuoteOriginally posted by Not a Number Quote
I don't see why not.
You could probably stack them, but would lose the AF/AE connectivity.
QuoteOriginally posted by Not a Number Quote
I wonder why they don't sell all three together.
Because the 25mm one has the connections, while the other two don't?
Different generations.

---------- Post added 05-29-14 at 10:04 AM ----------

QuoteOriginally posted by Not a Number Quote
It's good to see somebody is producing Auto AF tubes for K-mount.
And even more surprising for the Q-mount, but much appreciated!
05-29-2014, 09:00 AM   #13
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QuoteOriginally posted by lytrytyr Quote
You could probably stack them, but would lose the AF/AE connectivity.


Because the 25mm one has the connections, while the other two don't?
Different generations.

---------- Post added 05-29-14 at 10:04 AM ----------



And even more surprising for the Q-mount, but much appreciated!
Somebody screwed the pooch on the Kooka website. The photos for the Nikon, Pentax, Sony, Olympus and Canon tubes are all the same. They are labeled the same as "C-AF" on the tube. I'm guessing it's Canon pictured.

The electrical contacts are all wrong for K AF2, there's no screw drive and no aperture control levers.

KK-N25 - KOOKA OPTRONICS CO.,LTD
KK-C25 - KOOKA OPTRONICS CO.,LTD
KK-S25 - KOOKA OPTRONICS CO.,LTD
KK-O25 - KOOKA OPTRONICS CO.,LTD
KK-P25 - KOOKA OPTRONICS CO.,LTD

The text on the 20/36mm tubes reads:

QuoteQuote:
AF Extension tube set for Pentax (20mm,36mm)
Extension tubes are designed to enable a lens to focus closer than its normal set minimum focusing distance. Getting closer has the effect of magnifying your subject (making it appear larger in the viewfinder and in your pictures).

They are exceptionally useful for macro photography, enabling you to convert almost any lens into a macro lens at a fraction of the cost while maintaining its original optical quality.

This Autofocus Extension Tube Set (20/36mm) for Pentax from KOOKA contains two tubes of different length, a 20mm and 36mm, which can be used individually or in any combination to obtain the desired magnification.(An individual 25mm autofocus extension tube is available).
Canon mount

From Kooka's website AF tubes for Pentax

Last edited by Not a Number; 05-29-2014 at 09:45 AM.
05-29-2014, 09:58 AM   #14
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QuoteOriginally posted by Not a Number Quote
The text on the 20/36mm tubes reads:
. . .
From Kooka's website AF tubes for Pentax
The instructions I quoted earlier,
that limited the user to MF,
were also from the text for the 20/36mm tubes.

So without harder evidence,
I'm not convinced that the 20/36mm tubes
are as "autofocus" as the text you quoted appears to suggest.

We need to hear from someone who's actually handled these older tubes.
I am ready to trust SRB-Griturn when it comes to the new 25mm tube.
05-29-2014, 10:48 AM   #15
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KK-P56 - KOOKA OPTRONICS CO.,LTD
KK-P56
AF Extension tube set for Pentax (20mm,36mm)
QuoteQuote:
Description:

These tubes allows you take close-up photos using your Pentax SLR and lenses by placing one or more of these autofocus extension tubes between the camera body and the lens. The back of each hollow extension tube has a Pentax mount so that it attaches to the camera just as a lens would, and the front accepts a Pentax lens.

With metal construction and lens mount index, it can work with telephoto lens tightly, and mount the lens easily. The front and rear caps prevent the dust into the tubes. Designed with all the circuitry and mechanical coupling, these extension tubes are able to maintain autofocus and TTL auto exposure normally. The extension tubes have no optics. By moving the lens closer to subject this way, you get a magnified image. The greater the length of the extension tube, the closer the lens can focus.
MQ-P25
AF Extension tube set for Pentax(25mm)
MQ-P25 - KOOKA OPTRONICS CO.,LTD
QuoteQuote:
Description:

Extension tubes are designed to enable a lens to focus closer than its normal set minimum focusing distance. Getting closer has the effect of magnifying your subject (making it appear larger in the viewfinder and in your pictures).

They are exceptionally useful for macro photography, enabling you to convert almost any lens into a macro lens at a fraction of the cost while maintaining its original optical quality.

These tubes allows you take close-up photos using your Pentax SLR and lenses by placing one or more of these autofocus extension tubes between the camera body and the lens. The back of each hollow extension tube has a Pentax mount so that it attaches to the camera
just as a lens would, and the front accepts a Pentax lens.

With metal construction and lens mount index, it can work with telephoto lens tightly, and mount the lens easily. The front and rear caps prevent the dust into the tubes. Designed with all the circuitry and mechanical coupling, these extension tubes are able to maintain autofocus and TTL auto exposure normally. The extension tubes have no optics. By moving the lens closer to subject this way, you get a magnified image. The greater the length of the extension tube, the closer the lens can focus.
The instructions tell you to switch to and use the manual focus because "3. Manual adjustment is recommended for accurate focusing." That doesn't mean they don't support autofocus.

It would be bad marketing to claim the tubes have "all the circuitry and mechanical coupling" and "maintain autofocus" if this was false. But stranger things have happened.
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