I'm looking for Extension tubes for the k5

LightSpeed · 12-25-2011, 10:21 PM

I would like some recommendations on extension tubes.
What I'm looking for is something that has contacts where the cameras light meter still works and I can set Fstops.
Auto focus would be nice, but not really needed.

I do not know how one would set the aperture on the lens (100mm wr macro) without contacts that allow communication from the camera to the lens.

excanonfd · 12-25-2011, 10:40 PM

Originally posted by LightSpeed

I would like some recommendations on extension tubes.
What I'm looking for is something that has contacts where the cameras light meter still works and I can set Fstops.
Auto focus would be nice, but not really needed.

I do not know how one would set the aperture on the lens (100mm wr macro) without contacts that allow communication from the camera to the lens.

If the tubes have contacts then the body sets the aperture values. What you are looking for is something like Vivitar AT-23 extension tube set but they are rare and expensive. Another option is to buy some Teleconverters with contacts, remove the glass and use them as extension tubes. If you can locate a 2x, 7 element TC and a 4 element TC then you can have some variation in lengths of the extension tubes. 1.4x TC would also work but they retain their value better as a Teleconverter than a glassless extension tubes.

Hope this helps,

**jeffshaddix** · 12-25-2011, 10:43 PM

I just got a Vivitar AT-23 extension tube set (12mm, 20mm, 36mm). It has all the contacts including AF. Unfortunately these things are rare to be sure, on ebay they usually go for $100+. I found mine in a local camera shop, it had been sitting there for many years. I got it for $75, which in their mind I'm sure was a big win for them. Of course they think Pentax died with Hoya and don't bother to read up on photography on the newfangled interwebs...but I digress...

Anyway, look for a Vivitar set that has P/Z listed on the box. The "Z" refers to the old auto-focus Pentax camera line. It may also be listed as KR, which is the Pentax/Ricoh combo mount also from the film era.

RioRico · 12-25-2011, 10:45 PM - **3 Likes**

AF tubes are rare and costly. A-type tubes, with the aperture contacts but no AF, aren't real cheap and available either. I've found the cost-effective approach is to get old A-type TCs and remove the glass from them. My 2x TCs averaged US$15 each (shipped). These are both about 25mm thick; I've seen M-types as much as 30mm thick. If a 100mm macro will reach 1:1 magnification by itself, then with four such deglassed TCs, each 25mm thick, you can reach 2:1. And four TCs will probably cost rather less than 100mm of A-type extension tubes.

EDIT: Clarification highlighted above. But I just checked the DFA100WR specs and it DOES go to 1:1, right? So the numbers are correct.

If you're handy with a soldering iron, there's another trick: Get just one A-type TC, and almost any used bayonet bellows. Doesn't matter if the bellows are for Pentax, Nikon, Exakta, OM, whatever, as long as the mounting plates are held on by screws. Remove the mounts from the TC. Pull the mounts from the bellows and replace them with the PK-TC mounts. Solder wires to connect the contacts of the front and rear mounts. Now you have an A-type bellows!

Last edited by RioRico; 12-26-2011 at 11:26 AM.

ivoire · 12-25-2011, 11:34 PM

https://www.pentaxforums.com/forums/photographic-equipment-sale/167877-sale-k...sion-tube.html

The Kenko 25mm Uniplus Tube DG (extension ring) is an accessory exclusively designed for use with standard AF lenses to shoot subjects at closer distance with higher magnification. Magnification ratio for the Uniplus Tube 25 is about 1/2 when used with a 50mm standard lens.

Provides perfect coupling with automatic aperture, TTL metering and AE mechanism. AF support is dependent on your lens' maximum aperture. As a rule, the lens has to be set to f/5.6 or brighter in order for the camera's AF system to work.

This DG Extension tube has upgraded "Gate-Array IC" circuitry to work better with digital SLR's and some of the digital SLR lenses.

LightSpeed · 12-26-2011, 12:06 AM

PM SENT.
This will be for my K5 by the way

Bruce · 12-26-2011, 12:13 AM

Originally posted by RioRico

If you're handy with a soldering iron, there's another trick: Get just one A-type TC, and almost any used bayonet bellows. Doesn't matter if the bellows are for Pentax, Nikon, Exakta, OM, whatever, as long as the mounting plates are held on by screws. Remove the mounts from the TC. Pull the mounts from the bellows and replace them with the PK-TC mounts. Solder wires to connect the contacts of the front and rear mounts. Now you have an A-type bellows!

One vote for the MacGyver Award for Rico!

**mattt** · 12-26-2011, 08:57 AM

Originally posted by Bruce

One vote for the MacGyver Award for Rico!

+1 to that!

bluestringer · 12-26-2011, 09:31 AM

With a Pentax 100mm F4 Macro, which does 1:2 on it's own, how much tube do I need to get 1:1? Thanks.

creampuff · 12-26-2011, 09:36 AM

Originally posted by bluestringer

With a Pentax 100mm F4 Macro, which does 1:2 on it's own, how much tube do I need to get 1:1? Thanks.

You'll need another 50mm extension.

RioRico · 12-26-2011, 11:35 AM

Originally posted by bluestringer

With a Pentax 100mm F4 Macro, which does 1:2 on it's own, how much tube do I need to get 1:1? Thanks.

Originally posted by creampuff

You'll need another 50mm extension.

Quite right. Be aware that adding extension means the lens will not focus to infinity. (That *should* be obvious, right?) Far-focus drops to about 31cm / 12in.

bluestringer · 12-26-2011, 12:23 PM

Ok. Thanks. I've found a 3x TC that may be just about right after removing the glass.

RioRico · 12-26-2011, 02:04 PM

Originally posted by bluestringer

Ok. Thanks. I've found a 3x TC that may be just about right after removing the glass.

You'll want to measure the thickness. The 3x TCs I've seen are about 40mm thick. The closer you get to 50mm thickness, the closer you'll get to 1:1 magnification.

zapp · 12-29-2011, 02:12 AM

Originally posted by bluestringer

Ok. Thanks. I've found a 3x TC that may be just about right after removing the glass.

There may also be some mechanical parts in the way...

Anyways, I can see a need for macro tubes and extensio tube from PENTAX.

philbaum · 01-01-2012, 02:04 AM

I've got a Promaster 1.7x TC. I want to turn it into a permanent extension tube because my camera has a hard time locking a focus through the 1.7x.

I'm, able to remove the 3 philips screws that hold the Px contacts ring easily enough with a #000 philips screwdriver but that uncovers a threaded castellated cylinder with 2 180 deg apart slots that seems to thread onto the lens module and hold it in place. The castellated slots are less than 1/16" width and i'm not sure how to get a grip on the cylinder to unscrew it from the lens mount???

Any help much appreciated, i can send a photo if needed.

Phil

12-25-2011, 10:21 PM	#1
LightSpeed Banned Join Date: Dec 2011 Posts: 639	I'm looking for Extension tubes for the k5 I would like some recommendations on extension tubes. What I'm looking for is something that has contacts where the cameras light meter still works and I can set Fstops. Auto focus would be nice, but not really needed. I do not know how one would set the aperture on the lens (100mm wr macro) without contacts that allow communication from the camera to the lens.

12-26-2011, 09:31 AM	#9
bluestringer Veteran Member Join Date: Nov 2011 Location: Cotton fields of South Georgia Photos: Gallery Posts: 2,748	Question for RioRico With a Pentax 100mm F4 Macro, which does 1:2 on it's own, how much tube do I need to get 1:1? Thanks.

01-01-2012, 02:04 AM	#15
philbaum Veteran Member Join Date: Oct 2007 Location: Port Townsend, Washington State, USA Posts: 3,659	How do i remove the lens element? I've got a Promaster 1.7x TC. I want to turn it into a permanent extension tube because my camera has a hard time locking a focus through the 1.7x. I'm, able to remove the 3 philips screws that hold the Px contacts ring easily enough with a #000 philips screwdriver but that uncovers a threaded castellated cylinder with 2 180 deg apart slots that seems to thread onto the lens module and hold it in place. The castellated slots are less than 1/16" width and i'm not sure how to get a grip on the cylinder to unscrew it from the lens mount??? Any help much appreciated, i can send a photo if needed. Phil

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12-25-2011, 10:40 PM	#2
excanonfd Veteran Member Join Date: Jan 2010 Location: Vancouver, BC Posts: 1,421	Originally posted by LightSpeed I would like some recommendations on extension tubes. What I'm looking for is something that has contacts where the cameras light meter still works and I can set Fstops. Auto focus would be nice, but not really needed. I do not know how one would set the aperture on the lens (100mm wr macro) without contacts that allow communication from the camera to the lens. If the tubes have contacts then the body sets the aperture values. What you are looking for is something like Vivitar AT-23 extension tube set but they are rare and expensive. Another option is to buy some Teleconverters with contacts, remove the glass and use them as extension tubes. If you can locate a 2x, 7 element TC and a 4 element TC then you can have some variation in lengths of the extension tubes. 1.4x TC would also work but they retain their value better as a Teleconverter than a glassless extension tubes. Hope this helps,

12-25-2011, 10:43 PM	#3
jeffshaddix Site Supporter Join Date: Jun 2010 Location: Colorado Posts: 1,473	I just got a Vivitar AT-23 extension tube set (12mm, 20mm, 36mm). It has all the contacts including AF. Unfortunately these things are rare to be sure, on ebay they usually go for $100+. I found mine in a local camera shop, it had been sitting there for many years. I got it for $75, which in their mind I'm sure was a big win for them. Of course they think Pentax died with Hoya and don't bother to read up on photography on the newfangled interwebs...but I digress... Anyway, look for a Vivitar set that has P/Z listed on the box. The "Z" refers to the old auto-focus Pentax camera line. It may also be listed as KR, which is the Pentax/Ricoh combo mount also from the film era.

12-25-2011, 10:45 PM - 3 Likes	#4
RioRico Veteran Member Join Date: Jun 2008 Location: Limbo, California Posts: 11,263	AF tubes are rare and costly. A-type tubes, with the aperture contacts but no AF, aren't real cheap and available either. I've found the cost-effective approach is to get old A-type TCs and remove the glass from them. My 2x TCs averaged US$15 each (shipped). These are both about 25mm thick; I've seen M-types as much as 30mm thick. If a 100mm macro will reach 1:1 magnification by itself, then with four such deglassed TCs, each 25mm thick, you can reach 2:1. And four TCs will probably cost rather less than 100mm of A-type extension tubes. EDIT: Clarification highlighted above. But I just checked the DFA100WR specs and it DOES go to 1:1, right? So the numbers are correct. If you're handy with a soldering iron, there's another trick: Get just one A-type TC, and almost any used bayonet bellows. Doesn't matter if the bellows are for Pentax, Nikon, Exakta, OM, whatever, as long as the mounting plates are held on by screws. Remove the mounts from the TC. Pull the mounts from the bellows and replace them with the PK-TC mounts. Solder wires to connect the contacts of the front and rear mounts. Now you have an A-type bellows! Last edited by RioRico; 12-26-2011 at 11:26 AM.

12-25-2011, 11:34 PM	#5
ivoire Veteran Member Join Date: Mar 2007 Photos: Gallery Posts: 3,381	https://www.pentaxforums.com/forums/photographic-equipment-sale/167877-sale-k...sion-tube.html The Kenko 25mm Uniplus Tube DG (extension ring) is an accessory exclusively designed for use with standard AF lenses to shoot subjects at closer distance with higher magnification. Magnification ratio for the Uniplus Tube 25 is about 1/2 when used with a 50mm standard lens. Provides perfect coupling with automatic aperture, TTL metering and AE mechanism. AF support is dependent on your lens' maximum aperture. As a rule, the lens has to be set to f/5.6 or brighter in order for the camera's AF system to work. This DG Extension tube has upgraded "Gate-Array IC" circuitry to work better with digital SLR's and some of the digital SLR lenses.

12-26-2011, 12:06 AM	#6
LightSpeed Banned Join Date: Dec 2011 Posts: 639 Original Poster	PM SENT. This will be for my K5 by the way

12-26-2011, 12:13 AM	#7
Bruce Veteran Member Join Date: Oct 2009 Location: Sydney Photos: Gallery \| Albums Posts: 448	Originally posted by RioRico If you're handy with a soldering iron, there's another trick: Get just one A-type TC, and almost any used bayonet bellows. Doesn't matter if the bellows are for Pentax, Nikon, Exakta, OM, whatever, as long as the mounting plates are held on by screws. Remove the mounts from the TC. Pull the mounts from the bellows and replace them with the PK-TC mounts. Solder wires to connect the contacts of the front and rear mounts. Now you have an A-type bellows! One vote for the MacGyver Award for Rico!

12-26-2011, 08:57 AM	#8
mattt Site Supporter Join Date: Feb 2011 Location: Niagara Photos: Gallery \| Albums Posts: 3,907	Originally posted by Bruce One vote for the MacGyver Award for Rico! +1 to that!

12-26-2011, 09:36 AM	#10
creampuff Veteran Member Join Date: May 2007 Location: Singapore Photos: Gallery Posts: 3,953	Originally posted by bluestringer With a Pentax 100mm F4 Macro, which does 1:2 on it's own, how much tube do I need to get 1:1? Thanks. You'll need another 50mm extension.

12-26-2011, 11:35 AM	#11
RioRico Veteran Member Join Date: Jun 2008 Location: Limbo, California Posts: 11,263	Originally posted by bluestringer With a Pentax 100mm F4 Macro, which does 1:2 on it's own, how much tube do I need to get 1:1? Thanks. Originally posted by creampuff You'll need another 50mm extension. Quite right. Be aware that adding extension means the lens will not focus to infinity. (That should be obvious, right?) Far-focus drops to about 31cm / 12in.

12-26-2011, 12:23 PM	#12
bluestringer Veteran Member Join Date: Nov 2011 Location: Cotton fields of South Georgia Photos: Gallery Posts: 2,748	Ok. Thanks. I've found a 3x TC that may be just about right after removing the glass.

12-26-2011, 02:04 PM	#13
RioRico Veteran Member Join Date: Jun 2008 Location: Limbo, California Posts: 11,263	Originally posted by bluestringer Ok. Thanks. I've found a 3x TC that may be just about right after removing the glass. You'll want to measure the thickness. The 3x TCs I've seen are about 40mm thick. The closer you get to 50mm thickness, the closer you'll get to 1:1 magnification.

12-29-2011, 02:12 AM	#14
zapp Pentaxian Join Date: Jul 2011 Posts: 2,385	Originally posted by bluestringer Ok. Thanks. I've found a 3x TC that may be just about right after removing the glass. There may also be some mechanical parts in the way... Anyways, I can see a need for macro tubes and extensio tube from PENTAX.