Teleconverter magnification comparison. (5 imgs)

Started Aug 25, 2013 | Photos
Nicols Contributing Member • Posts: 865
Re: Klaus...Groups and Elements...

brandrx wrote:

Everything looks identical except for one thing. In your first image it appears that the rear element sticks out a couple of milimeters. Mine is completely level with that black ring with the lines (grooves) around it and has three screws in it.

Yes, it sticks out about 2mm.

EDIT: Another quick look at my Promaster Spectrum 7 1.7X Pz_AF shows that it too sticks out a couple of millimeters and looks identical to your image below. I also think that if you measured the diameter of the glass that can be seen in the rear of your's, you will find it is probably 25mm, which is the same as the Promaster (my Kenko measures about 27mm).

That is as you suppose: 25mm diameter

It seems that my Kenko is identical with the version that has been sold as Promaster 1.7x: Same scale increase, same diameter and position of the back element. Maybe for some time it was sold with this brand, and later they changed. Who knows…

The reflections are hard to count. One appears only approaching the eye to very close distances, and I suspect that some of them are probably two, but I am not able to distinguish clearly the two images…

Thank's a lot, Ron, for your help.

Cheers - Klaus

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Greyser Veteran Member • Posts: 6,380
Re: Dave...

brandrx wrote:

DaveJC wrote:

I bought the lens from group member Fleafly who recommended a Sigma over the Kenko. IQ is the main thing for me. Birds are small enough to start with so the better IQ is worth the price for me. Also waiting for a used IIs to come into my price range. Should not be too long after September announcements.--

There is no Sigma teleconverter that I am aware of that will fit the Pentax-F*300mm f4.5 lens. The protruding front element of the Sigma will hit the rear element of the Pentax and cannot even be mounted.

Hi Ron,

I'd like to understand for myself and resolve this issue what we've been clashing over and over again once and for all.

First. The rear element of my FA*300/4.5 (and F*300/4.5 as well I assume) is recessed way deep down in the lens body.

Second. Both Sigma 1.4x TCs: APO EX non-DG and APO EX DG fit well with my FA*300 and do not harm anything. Yes it's true that the EX DG front element protrudes about 0.5mm or 0.020"-0.025" (I'm lazy to measure it exactly) over the the mount edge. However it doesn't interfere with anything in the lens.

From our previous discussions I know that your Sigma TC K-mounts do not lock with your F*FA*300 lenses. Mine do without any trouble. I see no mechanical issue with using the Sigmas with FA*300/4.5.

Long time ago, pairing most of available 1.4x TCs with FA*300, I found the Tamron Pz-AF (and Vivitar Series-1, which is re-branded Tamron with no Pz contacts anyway) to be superior (by small margin) to both Sigmas. However, playing recently with my Sigma 500/4.5 I discovered that both Sigma TCs do require different than for the lens itself AF micro adjustment when they are installed. I did not take it in account when I was testing them with FA*300. Now I believe that for the 500/4.5 Sigma at least 1.4x EX non-DG and EX DG resolve a bit better than my Tamron. However, I did not test this thing with FA*300. Due to inconvenience of constant changing of AF micro adjustment settings I still prefer using the Tamron Pz-AF over sigmas with my FA*300.

it would be nice, if someone else with F*FA300/4.5 and Sigma 1.4x TC, especially EX DG, experience would elaborate on the issue as well. Please do. I'd like to know the ultimate truth.

My warmest regards,

SG

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Nicols Contributing Member • Posts: 865
Re: Klaus...

brandrx wrote:

BTW: The writing on my Kenko reads "Pz-Af TELEPLUS 1.5X SHQ". This is the same as what you indicated in an earlier post of your's.

Yes, that's funny. Same label, but it seems there is a Promaster type TC inside. Marketing of these enterprises seems to have been special. Maybe they thought that writing 1.5x on it simplifies things as they can sell with this label both their 1.35 and 1.7 models :-D.

Cheers - Klaus

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OP brandrx Forum Pro • Posts: 28,337
Re: Dave...

Greyser wrote:

brandrx wrote:

DaveJC wrote:

I bought the lens from group member Fleafly who recommended a Sigma over the Kenko. IQ is the main thing for me. Birds are small enough to start with so the better IQ is worth the price for me. Also waiting for a used IIs to come into my price range. Should not be too long after September announcements.--

There is no Sigma teleconverter that I am aware of that will fit the Pentax-F*300mm f4.5 lens. The protruding front element of the Sigma will hit the rear element of the Pentax and cannot even be mounted.

Hi Ron,

I'd like to understand for myself and resolve this issue what we've been clashing over and over again once and for all.

First. The rear element of my FA*300/4.5 (and F*300/4.5 as well I assume) is recessed way deep down in the lens body.

Second. Both Sigma 1.4x TCs: APO EX non-DG and APO EX DG fit well with my FA*300 and do not harm anything. Yes it's true that the EX DG front element protrudes about 0.5mm or 0.020"-0.025" (I'm lazy to measure it exactly) over the the mount edge. However it doesn't interfere with anything in the lens.

From our previous discussions I know that your Sigma TC K-mounts do not lock with your F*FA*300 lenses. Mine do without any trouble. I see no mechanical issue with using the Sigmas with FA*300/4.5.

Long time ago, pairing most of available 1.4x TCs with FA*300, I found the Tamron Pz-AF (and Vivitar Series-1, which is re-branded Tamron with no Pz contacts anyway) to be superior (by small margin) to both Sigmas. However, playing recently with my Sigma 500/4.5 I discovered that both Sigma TCs do require different than for the lens itself AF micro adjustment when they are installed. I did not take it in account when I was testing them with FA*300. Now I believe that for the 500/4.5 Sigma at least 1.4x EX non-DG and EX DG resolve a bit better than my Tamron. However, I did not test this thing with FA*300. Due to inconvenience of constant changing of AF micro adjustment settings I still prefer using the Tamron Pz-AF over sigmas with my FA*300.

it would be nice, if someone else with F*FA300/4.5 and Sigma 1.4x TC, especially EX DG, experience would elaborate on the issue as well. Please do. I'd like to know the ultimate truth.

Greyser,

I was slightly wrong about the Sigma 1.4X + Pentax-F*300/4.5 lens. I can mount it but it will not autofocus. As far as the FA* lenses go...the elements do not hit but the lens will not lock into place with the Sigma teleconverter. For some strange reason I did get an FA*300/4.5 lens to lock onto a Sigma teleconverter one time but it would not autofocus.

Eveything else...there is nothing for me to resolve. My Sigma teleconverters do not work with any of my F* or FA* lenses and that is all there is to it. If your's does then that's fine. I am happy for you.

I have stopped even trying to mount any F* or FA* lenses on to any Sigma teleconverter. Instead, I reach for a Tamron. Kenko, Vivitar, or Promaster teleconverter.

This makes about the tenth time we have gone through this Greyser. You say your's works. I say mine does not work. Let it go now. I don't want to be going through this everytime I post something about teleconverters.

Cheers.

Ron

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Ron - 'We don't have time to go take pics this afternoon Carl.'
Carl - 'What do you mean? It will only take 1/1000s.'
'Keep your eyes looking forward. However, glance back now and then to see where you've come from. It will put a smile on your face.' ~ brandrx

Greyser Veteran Member • Posts: 6,380
Re: Dave...

brandrx wrote:

This makes about the tenth time we have gone through this Greyser. You say your's works. I say mine does not work. Let it go now. I don't want to be going through this everytime I post something about teleconverters.

I agree. However, that's what it is:

  • Yours - do not lock and do not AF
  • Mine - do lock and do AF

We need at least someone else to confirm either one statement. Otherwise we cannot continue making a bold statements that Sigma 1.4X EX APO or Sigma 1.4X EX DG APO TCs do or do not work with Pentax FA* lenses. People ask questions and want the answers that they can rely upon.

Please no offense, Ron. I respect you big way. And you know that. I just want to learn the truth.

My warmest regards again,

SG

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OP brandrx Forum Pro • Posts: 28,337
Greyser...

Greyser wrote:

brandrx wrote:

This makes about the tenth time we have gone through this Greyser. You say your's works. I say mine does not work. Let it go now. I don't want to be going through this everytime I post something about teleconverters.

I agree. However, that's what it is:

  • Yours - do not lock and do not AF
  • Mine - do lock and do AF

We need at least someone else to confirm either one statement. Otherwise we cannot continue making a bold statements that Sigma 1.4X EX APO or Sigma 1.4X EX DG APO TCs do or do not work with Pentax FA* lenses. People ask questions and want the answers that they can count on.

Please no offense, Ron. I respect you big way. And you know that. I just want to learn the truth.

Here's the deal Greyser. As far as i know you own the FA*300mm f4.5 and you say your Sigma teleconverter works on that lens. I do not doubt that what you say is true.

I own the FA*200/2.8, F*300/4.5, FA*300/4.5, FA*400/5.6, and FA*250-600/5.6 and the Sigma 1.4X APO EX, Sigma 1.4X APO EX DG, Sigma 2X APO EX, and Sigma 2X APO EX DG. None of those Sigma teleconverters will work on any of the F* or FA* lenses that I own. I do not need anyone to confirm this for me and I will continue making the same bold statement whether or not you believe, or anyone else believes what I say or not. People can count on or not count on any statement that I make. That is their choice.

Cheers.

Ron

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Ron - 'We don't have time to go take pics this afternoon Carl.'
Carl - 'What do you mean? It will only take 1/1000s.'
'Keep your eyes looking forward. However, glance back now and then to see where you've come from. It will put a smile on your face.' ~ brandrx

Greyser Veteran Member • Posts: 6,380
Re: Greyser...

brandrx wrote:

Greyser wrote:

brandrx wrote:

This makes about the tenth time we have gone through this Greyser. You say your's works. I say mine does not work. Let it go now. I don't want to be going through this everytime I post something about teleconverters.

I agree. However, that's what it is:

  • Yours - do not lock and do not AF
  • Mine - do lock and do AF

We need at least someone else to confirm either one statement. Otherwise we cannot continue making a bold statements that Sigma 1.4X EX APO or Sigma 1.4X EX DG APO TCs do or do not work with Pentax FA* lenses. People ask questions and want the answers that they can count on.

Please no offense, Ron. I respect you big way. And you know that. I just want to learn the truth.

Here's the deal Greyser. As far as i know you own the FA*300mm f4.5 and you say your Sigma teleconverter works on that lens. I do not doubt that what you say is true.

I own the FA*200/2.8, F*300/4.5, FA*300/4.5, FA*400/5.6, and FA*250-600/5.6 and the Sigma 1.4X APO EX, Sigma 1.4X APO EX DG, Sigma 2X APO EX, and Sigma 2X APO EX DG. None of those Sigma teleconverters will work on any of the F* or FA* lenses that I own. I do not need anyone to confirm this for me and I will continue making the same bold statement whether or not you believe, or anyone else believes what I say or not. People can count on or not count on any statement that I make. That is their choice.

No problem, Ron. Just give them the choice.

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OP brandrx Forum Pro • Posts: 28,337
Dave again...

brandrx wrote:

DaveJC wrote:

I bought the lens from group member Fleafly who recommended a Sigma over the Kenko. IQ is the main thing for me. Birds are small enough to start with so the better IQ is worth the price for me. Also waiting for a used IIs to come into my price range. Should not be too long after September announcements.--

There is no Sigma teleconverter that I am aware of that will fit the Pentax-F*300mm f4.5 lens. The protruding front element of the Sigma will hit the rear element of the Pentax and cannot even be mounted.

Hi again Dave,

So after exchanging pleasantries with Greyser, I have decided to retract my statement above. As far as I am concerned you can waste your money buying a Sigma teleconverter if that is what you want to do. According to Greyser, it might work on your F*300/4.5 lens. According to me the chance of it working is slim to none. You will have to decide for yourself. 

Cheers.

Ron

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Ron - 'We don't have time to go take pics this afternoon Carl.'
Carl - 'What do you mean? It will only take 1/1000s.'
'Keep your eyes looking forward. However, glance back now and then to see where you've come from. It will put a smile on your face.' ~ brandrx

KentG Veteran Member • Posts: 4,712
Re: Is Kenko 1.5 a Rebranded Tamron?

Its the other way around. The Tamron is a rebadged Kenko. Kenko makes most of the worlds TCs that are not made by the camera makers (except the current Sigmas, as they did make a few of the older pre-EX ones I think). Or I should say that most are likely made in a factory belonging to their partner Tokina. Kenko is the "K" in THK (Tokina Hoya Kenko) a company that markets all their products.

Kent Gittings

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KentG Veteran Member • Posts: 4,712
Re: Klaus...Groups and Elements...

Seven reflections is not possible with any combination of 4-5 elements regardless of the number of groups (except with no coatings because then you will get reflections of reflections). The same number of groups will produce the same number of internal reflections regardless of the number of elements. Only the number of air-to-glass surfaces count in that. However depending on the coatings some IRs will be suppressed more than others.

Kent Gittings

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OP brandrx Forum Pro • Posts: 28,337
Kent...

KentG wrote:

Seven reflections is not possible with any combination of 4-5 elements regardless of the number of groups (except with no coatings because then you will get reflections of reflections). The same number of groups will produce the same number of internal reflections regardless of the number of elements. Only the number of air-to-glass surfaces count in that. However depending on the coatings some IRs will be suppressed more than others.

Kent,

Whether it is possible or not, I counted seven. So, I guess I need to go back to school and learn how to count again? Or, perhaps I have double vision all of a sudden. Maybe I was dreaming.

I have no explanation other than the fact that there were seven reflections of the light that was directed into the lens staring back at me. These reflections were yellow, orange and bluish or greenish.

Cheers.

Ron

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Ron - 'We don't have time to go take pics this afternoon Carl.'
Carl - 'What do you mean? It will only take 1/1000s.'
'Keep your eyes looking forward. However, glance back now and then to see where you've come from. It will put a smile on your face.' ~ brandrx

KentG Veteran Member • Posts: 4,712
Re: Dave...

Too bad Kenko does not make the Pro 300 DGX series TCs in Pentax mount. That is considered the poor man's Canon II TCs. Way better than anything available for Pentax except the non-AF -L and -S Pentax series (but they lack digital friendly coatings). In my estimation the Kenko Pro 300 DGX 2x is better than the Pentax 1.7x AF TC. However the Pro 300 like the Canon II and III series will shut down AF electronically if the combo is more than F5.6. You can make it AF by taping one of the Canon contact points just like you can for the Canon II TC (but not the Canon III, because it can't be fooled by that). The Pro 300 TCs are 1.4x 5E-4G and 2x 7E-4G. They actually make a Pro 300 DG 3.0x also ( Kenko/Teleplus has always made a 3x all the way back to the M42 era).

Officially since the 2011 merger the combined company is now called HKT Imaging (HKT is Hoya- KenkoTokina, and it is KenkoTokina because that merger happened first and apparently Kenko was larger than Tokina). They also own Slik, Tasco-Japan, and Sightron.

Kent Gittings

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OP brandrx Forum Pro • Posts: 28,337
Twists and turns...

Wow! This thread has sure taken some twists and turns. All I was trying to do was show a visual representation of the differences between four teleconverters and the fact that what you read on the side of the telconverter might not be what the actual magnification is.

I don't think I should do this type of thing anymore.

Cheers.

Ron

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Ron - 'We don't have time to go take pics this afternoon Carl.'
Carl - 'What do you mean? It will only take 1/1000s.'
'Keep your eyes looking forward. However, glance back now and then to see where you've come from. It will put a smile on your face.' ~ brandrx

KentG Veteran Member • Posts: 4,712
Re: Greyser...

You do realize, Ron, that the TCs, like the lenses I think can be rechipped (reflashed) as far as I know also, so it is possible your TCs may need upgrading to work. In the case of Sigma when I see one item that doesn't work while another of the same series does that one needs an electronic update.

Kent Gittings

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OP brandrx Forum Pro • Posts: 28,337
Kent...

KentG wrote:

You do realize, Ron, that the TCs, like the lenses I think can be rechipped (reflashed) as far as I know also, so it is possible your TCs may need upgrading to work. In the case of Sigma when I see one item that doesn't work while another of the same series does that one needs an electronic update.

Kent,

It has nothing to do with electronics.

It is the fact that the Sigma lenses will not mount, will not lock into place, and if by chance it does lock into place it will not autofocus because the screwdrive from the camera just does not turn the teleconverter screwdrive.

Cheers.

Ron

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Ron - 'We don't have time to go take pics this afternoon Carl.'
Carl - 'What do you mean? It will only take 1/1000s.'
'Keep your eyes looking forward. However, glance back now and then to see where you've come from. It will put a smile on your face.' ~ brandrx

OP brandrx Forum Pro • Posts: 28,337
Correction...

brandrx wrote:

KentG wrote:

You do realize, Ron, that the TCs, like the lenses I think can be rechipped (reflashed) as far as I know also, so it is possible your TCs may need upgrading to work. In the case of Sigma when I see one item that doesn't work while another of the same series does that one needs an electronic update.

Kent,

It has nothing to do with electronics.

It is the fact that the Sigma lenses will not mount, will not lock into place, and if by chance it does lock into place it will not autofocus because the screwdrive from the camera just does not turn the teleconverter screwdrive.

Correction - I should have written that if by chance it does lock into place it will not autofocus because the screwdrive from the camera will turn the screwdrive of the teleconverter but the screwdrive of the teleconverter will not turn the screwdrive of the lens.

And...now I have a freeking headache from explaining this over and over again for the last four years.

Ron

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Ron - 'We don't have time to go take pics this afternoon Carl.'
Carl - 'What do you mean? It will only take 1/1000s.'
'Keep your eyes looking forward. However, glance back now and then to see where you've come from. It will put a smile on your face.' ~ brandrx

KentG Veteran Member • Posts: 4,712
Re: Kent...

Well It still seems strange to me. While I do not have any of those particular lenses right now I have used Sigma TCs almost exclusively regardless of what brand of camera I was using at the time and have yet to have an issue with any of them not working. And it could very well be electronic. From my own experience I know that sometimes when newer cameras come out Sigma lenses do not work. This is an electronic issue usually caused by the camera company making a change that affects the "code responce" from the lens.  All EX and EX DG lenses and TCs have electronics that "intercepts" the code response sequence from the lens to the camera. This is done in many cases to cause the camera's AF drive to work at a slower rate if the F-ratio of the combo is close or at the F5.6 limit for that brand. Did not exist in the pre-EX era as they were all mechanical. However Sigma went from imbedded ROM chips (EX series) to flash memory (EX DG series). They don't update EX anymore, as the memory chips don't exist any longer.

As for the mechanical issue about not locking up that has me stumped as I have never seen a Sigma TC fail to do that on any lens regardless of brand that I used on a Pentax camera. But here is something to note, sort of a Twilight Zone thing. A Sigma optical product with a Sigma camera mount will do just that because they use a PKA mount that twists CCW instead of CW like the Pentax. All the way back to their first non-AF cameras, thru their AF ones to the current SD and DP line. Anyway skipping that if they do not lock up how can you know whether the electronic contacts are even lining up. If they don't the AF screwdrive will not work because the camera will not know a lens is attached. I mean I have a Tamron Pz-AF 1.4x that I never used because I only bought it to use or try to use with SDM lenses. I use a Sigma 1.4x EX TC exclusively on all my Pentax and 3rd party lenses, primarily on my K20D as I have not updated to a newer body (except the K-01).

Has to be something more to this. Sigma sold their TCs right thru the F and FA years and I never heard any complaints during those years when I was big on the old Pentax backed Pentax-Discuss forum.

K

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KentG Veteran Member • Posts: 4,712
Re: Correction...

I used a Sigma TC in my ZX-5n days with FA and other lenses and never had an issue. That covered about 8 years until I switched to the Minolta Maxxum 9. And I am pretty sure it was the same Sigma 1.4x EX TC I have now although I may have had a non-EX version in the early part of those 8 years.

Kent Gittings

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OP brandrx Forum Pro • Posts: 28,337
Re: Kent...

KentG wrote:

Well It still seems strange to me. While I do not have any of those particular lenses right now I have used Sigma TCs almost exclusively regardless of what brand of camera I was using at the time and have yet to have an issue with any of them not working. And it could very well be electronic. From my own experience I know that sometimes when newer cameras come out Sigma lenses do not work. This is an electronic issue usually caused by the camera company making a change that affects the "code responce" from the lens.  All EX and EX DG lenses and TCs have electronics that "intercepts" the code response sequence from the lens to the camera. This is done in many cases to cause the camera's AF drive to work at a slower rate if the F-ratio of the combo is close or at the F5.6 limit for that brand. Did not exist in the pre-EX era as they were all mechanical. However Sigma went from imbedded ROM chips (EX series) to flash memory (EX DG series). They don't update EX anymore, as the memory chips don't exist any longer.

As for the mechanical issue about not locking up that has me stumped as I have never seen a Sigma TC fail to do that on any lens regardless of brand that I used on a Pentax camera. But here is something to note, sort of a Twilight Zone thing. A Sigma optical product with a Sigma camera mount will do just that because they use a PKA mount that twists CCW instead of CW like the Pentax. All the way back to their first non-AF cameras, thru their AF ones to the current SD and DP line. Anyway skipping that if they do not lock up how can you know whether the electronic contacts are even lining up. If they don't the AF screwdrive will not work because the camera will not know a lens is attached. I mean I have a Tamron Pz-AF 1.4x that I never used because I only bought it to use or try to use with SDM lenses. I use a Sigma 1.4x EX TC exclusively on all my Pentax and 3rd party lenses, primarily on my K20D as I have not updated to a newer body (except the K-01).

Has to be something more to this. Sigma sold their TCs right thru the F and FA years and I never heard any complaints during those years when I was big on the old Pentax backed Pentax-Discuss forum.

Ok Kent. I give up. You are trying to do the same thing that Greyser does. You are trying to say in so many words that I don't know what the heck I am talking about. No use in discussing this anymore with you. I have four of the very latest Sigma teleconverters that will not mount properly to five of my Pentax lenses. Those lenses being F*300/4.5, FA*200/2.8, FA*300/4.5, FA*400/5.6, and FA*250-600/5.6. It has NOTHING to do with the electronics no matter how much you try to make it have something to do with the electronics.

By the way, I do know how to mount a teleconverter. I have been doing it for many years.

Cheers.

Ron

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Ron - 'We don't have time to go take pics this afternoon Carl.'
Carl - 'What do you mean? It will only take 1/1000s.'
'Keep your eyes looking forward. However, glance back now and then to see where you've come from. It will put a smile on your face.' ~ brandrx

KentG Veteran Member • Posts: 4,712
Re: Kent...

Not saying that, Ron. I'm sure each of us is seeing what we are reporting. Like 3 blind men trying to describe an elephant when each is touching a different part. I went back this morning and dug a couple of FA lenses out, hooked each one to my Sigma 1.4x EX TC and tested it on the *ist D, K20D, and K-01. They all locked up and they all AF'd fine. I also realize if the mount can't rotate far enough to lockup the possibility is the contacts don't line up and the electronics won't work. But without being able to see one that doesn't lock up myself I can't know if yours are going all the way around to the stop or not. If it is and the only mechanical part is the pin does not lock into the hole but the contacts line up, that is an electronic issue. The only issue I ever had with a Sigma product was a 300/2.8 APO on a Minolta Maxxum 9. The camera showed screwy info and the lens appeared to be dead, it would not do anything. Sent it back to Sigma, they replaced the ROM memory chip in the lens and it ran fine after that.

Kent Gittings

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