[cyberjunkie]

Recently I checked if I could find PKA tubes on Ebay. I hoped some Chinese company made them. I didn't find any, new or second hand.
I guess the only way would be to deglass some cheap four-elements converter.
If I remember I even have one with pass-through screwdriver AF...
I'll keep the Pentax ones, a 7-elements PKA Macro converter, and a Kenko Pz-AF 1.5x. All the others could be sacrificed, but I'm not sure the extension would be enough to make a real difference with my 1:2 90mm and 180mm macro lenses.
I'd like to hear from people who have actually done this kind of modifications.
It's a true pity P-TTL needs objectives with electric contacts.
Unfortunately the new standard works much worse than the old TTL in my aged LX ...
I still have an *ist D for this sole reason.
My dual-flash TTL system worked great for macro hunting, and I remember Pentax sold specific accessories for wired multi-flash

Cheers

Paolo

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Last edited by cyberjunkie; 12-07-2017 at 10:07 AM.

[disconnekt]

There are these extension tubes on Amazon: amazon.com : Movo MT-P56 2-Piece AF Chrome Macro Extension Tube Set for Pentax K DSLR Camera with 20mm, & 36mm Tubes : Camera & Photo?tag=pentaxforums-20&

No experience with them though, but it's nice to see that there's a company that made extension tubes for Kmount

[pathdoc]

I still have an *ist D for this sole reason.

I bought an *istDS secondhand for that reason. (It was under $100 and in perfect working order). It works great with the AF080C ringflash I bought here in the forums.

I have the K-1 and I have used it with a deglassed 2X teleconverter with A contacts, no AF, so I don't think it is passing the full information that DA and D-FA lenses can send through. This is not its fault; it simply predates that time and doesn't have all the required electrical passthroughs. Your T/C with pass-through screw-drive is at least from the Pentax-F and possibly the Pentax-FA lens era, and may not suffer from this problem.

The extension will be enough, but what you will probably find with long-focal-length macro lenses and longer (deglassed) teleconverters, especially if joined together, is that the combination vignettes on full frame. I have seen this happen with my D-FA100/2.8 WR Macro.

[BrianR]

There are these extension tubes on Amazon: amazon.com : Movo MT-P56 2-Piece AF Chrome Macro Extension Tube Set for Pentax K DSLR Camera with 20mm, & 36mm Tubes : Camera & Photo?tag=pentaxforums-20&

No experience with them though, but it's nice to see that there's a company that made extension tubes for Kmount

Thanks for the link! I'll be waiting to reviews from anyone brave enough to buy a set. Their product photo does not inspire confidence, but hopefully they are decent.

Kooka was another option, but reviews were terrible Kooka KOOKA KK-P25 Copper Macro Extension Tubes reviews - Pentax Camera Accessory Review Database

[Thagomizer]

There are these extension tubes on Amazon: amazon.com : Movo MT-P56 2-Piece AF Chrome Macro Extension Tube Set for Pentax K DSLR Camera with 20mm, & 36mm Tubes : Camera & Photo?tag=pentaxforums-20&

No experience with them though, but it's nice to see that there's a company that made extension tubes for Kmount

The tubes in the picture don't look like they have the correct contacts for K mount. The contacts should look like this:

https://arhc.callcut.net/ebay-image/580f4f0d5cc36/large/vivitar-mc-tele-conv...ith-case-4.jpg

[pathdoc]

The product photo does not look like a KAF mount at all, which makes me fervently hope they are just reusing a stock photo from some other system (a worrying sign in itself). Interestingly, their length makes them seem suspiciously like new-old-stock teleconverters in 1.4X and 2X that never received their glass, or whose glass was possibly outsourced and either was simply never delivered or failed QC so badly it had to be scrapped.

Most extension tube sets are three-piece and have a 12mm or other short tube, but we do not see that here, strengthening my suspicion about them being T/C shells.

I personally see nothing wrong with that, because I use a deglassed teleconverter for this very purpose, and if you have the outer parts and are looking to make good on a disaster, why not repurpose them for what the rest is best at? I am merely curious as to their true nature and origin.

So I too will be interested to see what happens if anyone buys a set.

[disconnekt]

The product photo does not look like a KAF mount at all, which makes me fervently hope they are just reusing a stock photo from some other system (a worrying sign in itself). Interestingly, their length makes them seem suspiciously like new-old-stock teleconverters in 1.4X and 2X that never received their glass, or whose glass was possibly outsourced and either was simply never delivered or failed QC so badly it had to be scrapped.

Most extension tube sets are three-piece and have a 12mm or other short tube, but we do not see that here, strengthening my suspicion about them being T/C shells.

I personally see nothing wrong with that, because I use a deglassed teleconverter for this very purpose, and if you have the outer parts and are looking to make good on a disaster, why not repurpose them for what the rest is best at? I am merely curious as to their true nature and origin.

So I too will be interested to see what happens if anyone buys a set.

If anything looking at the reviews for the extension tubes they have for other mounts could give us a general idea on how good (or bad) they are

[Not a Number]

The tubes pictured on Amazon are for Canon. If you go to the Movophoto website the Pentax tubes have the correct contacts and screwdrive.

Movo Photo AF Pentax DSLR Macro Extension Tube Set

[JensE]

Most extension tube sets are three-piece and have a 12mm or other short tube, but we do not see that here, strengthening my suspicion about them being T/C shells.

On ebay, you find "new old stock" Vivitar tubes from the Pentax-M era with exactly the same 36mm plus 20mm two tube configuration.

I think I'll give them a try - have been looking for the Kenko Uniplus for a long time without success.

[Not a Number]

On ebay, you find "new old stock" Vivitar tubes from the Pentax-M era with exactly the same 36mm plus 20mm two tube configuration.

I think I'll give them a try - have been looking for the Kenko Uniplus for a long time without success.

You won't be able to use P-TTL unless the tubes have "A" contacts.

[JensE]

You won't be able to use P-TTL unless the tubes have "A" contacts.

Sorry, I should have been more clear. I meant that those 20mm+35mm set were also not uncommon in the past, so the Movo Tubes are likely not deglassed converters. And, I may give the Movo Af Tubes a try. I have some Jessops on the way first though.

Flash isn't much of a concern to me as my only PTTL flash is the AF201FG, but being able to use the DFA100WR (no aperture ring) and recording aperture in EXIF are.

[pathdoc]

IIRC my A-lens-era deglassed TC will pass aperture data but not focal length, so you should be right to go. Thanks for the info on the likely ancestry of the Movo tubes.

Rarely I have had interesting things happen, like the DA50/1.8 being reported by my deglassed T/C as an f/1.7 at full aperture, as if the T/C were somehow remembering the olden days when it had a 50/1.7 A, F, or FA lens on it. Sort of touching yet creepy at the same time.

[Just1MoreDave]

IIRC my A-lens-era deglassed TC will pass aperture data but not focal length, so you should be right to go. Thanks for the info on the likely ancestry of the Movo tubes.

Rarely I have had interesting things happen, like the DA50/1.8 being reported by my deglassed T/C as an f/1.7 at full aperture, as if the T/C were somehow remembering the olden days when it had a 50/1.7 A, F, or FA lens on it. Sort of touching yet creepy at the same time.

There isn't a code for the six contact system that represents f1.8. The contact pattern only does half-stops.

[pathdoc]

So that's why it's happening. I see now! Can I assume that the current Pentax DA teleconverter, were I to use that deglassed, would actually pass the 1.8?

[Just1MoreDave]

Probably. I think the 7th data pin carries the correct aperture information and focal length too. But I haven't done it, so proceed at your own risk.