[slackercruster]

Was trying to track down a Pentax 1.7 converter. 2 were on ebay for near $500 each...that was all I could find. I did run accross an interetsing thread on them. wonder if the lead in the glass issue is for real?

http://www.birdforum.net/showthread.php?p=2028198

[Adam]

I don't think there's lead in the glass- but yeah, these things get really pricey

[slackercruster]

You got any contacts in Japan to order some for us?

[kenafein]

One was for sale on the market for 380. It was hard to pass up.

[mattt]

I believe there was one for sale in the marketplace here less than a week ago...

HEh - What he said beat me by a moment Kenafein

[pearsaab]

i checked with japan and they said they had new ones for over 600

[pxpaulx]

Yep the 1.7x TC, at the moment, is a steal at a price anywhere around $400. I'll say it is worth every penny!

[slackercruster]

I have a rare Sigma 1.4x 'NON APO' AF TC. If I could find a non apo Sigma 1.7 or 2x I'd like to try one. (Don't even know if they made them?)

1.4X is great, just a little low magnification for somethings. Pentax crazy prices for their 1.7 TC is out of line. I'd go $325 for one snd that is high enough for what it is. Just another example of Pentax's crazy lens prices.

[icywindow]

Pentax crazy prices for their 1.7 TC is out of line. I'd go $325 for one snd that is high enough for what it is. Just another example of Pentax's crazy lens prices.

While I don't disagree with you on the pricing, the Pentax AF TC is kind of special - it turns MF lenses into AF lenses. That is something I personally haven't seen other AF TCs do.
The only reason the 1.7x is not on my LBA list is that it makes bokeh a bit hard edged for my tastes.

[RobA_Oz]

I have a rare Sigma 1.4x 'NON APO' AF TC. If I could find a non apo Sigma 1.7 or 2x I'd like to try one. (Don't even know if they made them?)

1.4X is great, just a little low magnification for somethings. Pentax crazy prices for their 1.7 TC is out of line. I'd go $325 for one snd that is high enough for what it is. Just another example of Pentax's crazy lens prices.

I don't think Pentax is to blame here - AFAIK, this teleconverter has been out of production for some time, which probably accounts for its current 2nd-hand pricing. Bojidar's listing suggests production ceased in 1999, but I'm sure some must have been made since then. I have one, bought new for $350US in October 2009, and I've watched their asking price rise since then, with some incredulity. Pentax could do worse than re-release this unit, perhaps as a "Limited" special, with appropriate casing mods to justify it, though the price needn't change significantly.

[rvannatta]

I have a rare Sigma 1.4x 'NON APO' AF TC. If I could find a non apo Sigma 1.7 or 2x I'd like to try one. (Don't even know if they made them?)

1.4X is great, just a little low magnification for somethings. Pentax crazy prices for their 1.7 TC is out of line. I'd go $325 for one snd that is high enough for what it is. Just another example of Pentax's crazy lens prices.

over priced TC's are reason to buy a lens long enough to start with. but my issue with the AF 1.7x is that it needs a pretty fast lens
to start with. For example it's very happy with an f2.8 lens, but I'd never recommend it for use with say an A*600 f/5.6. There is just too much
of the time that there isn't enough light to make AF feature work. I suppose it would be different if you lived in arizona and took lots of photos
in direct sunlight, but where I am it's pretty dreary most of the time.

I'm really looking forward to the pentax promised 1.4x SDM TC (which I assume will support the screw drive as well.) I think it will have a better chance of protecting the AF function of AF lenses, although it won't have the nifty ability to take fast Pentax A lenses and effectively
make them AF.

[Greyser]

I have a rare Sigma 1.4x 'NON APO' AF TC. If I could find a non apo Sigma 1.7 or 2x I'd like to try one. (Don't even know if they made them?)

That's very interesting. Some time ago I bought older Sigma 1.4X non-APO, non-EX, non-DG. It did not AF with my FA*300 and other lenses. I sent it back. I do have two other 1.4X Sigmas: EX non-DG and EX DG versions. They are fine, but non DG provides better IQ then the latest APO EX DG.
What are you using yours with?

[oeriies]

I own 3 TCs: the Pentax 1.7; a Tamron 1.4 1.4x Pz-AF MC4; and a Sigma 2.0 APO DG EG. For whatever it is worth, I prefer the Tamron. It preserves all the features of the lens it is mounted behind, including autofocus on SDM lenses; it doesn't degrade the resulting images very much; it will autofocus in lower light than the other TCs; and it is the least expensive. The Tamron is out of production but shows up with some frequency on eBay. Note that only the Pz-AF version works with SDM.

The Pentax 1.7 is a useful piece of equipment, and essential if you want to autofocus a manual lens. However the range in which it will autofocus is very thin with long glass. At 500mm, for example, you have to manual focus within a dozen feet or so of the target before the autofocus on the 1.7 will work. So forget moving targets. I used mine yesterday for some distant egrets. They were grazing and moving slowly so it was fine, but I missed a couple of birds in flight that I could have gotten without the TC. I paid $450 for mine, new old stock, about a year and a half ago.

[slackercruster]

While I don't disagree with you on the pricing, the Pentax AF TC is kind of special - it turns MF lenses into AF lenses. That is something I personally haven't seen other AF TCs do.
The only reason the 1.7x is not on my LBA list is that it makes bokeh a bit hard edged for my tastes.

My Sigma 1.4 non apo is AF. Was pretty cheap used...$60. Works great. Just wish I had a 2nd copy in 1.7 or 2x like this Sigma.

[slackercruster]

I own 3 TCs: the Pentax 1.7; a Tamron 1.4 1.4x Pz-AF MC4; and a Sigma 2.0 APO DG EG. For whatever it is worth, I prefer the Tamron. It preserves all the features of the lens it is mounted behind, including autofocus on SDM lenses; it doesn't degrade the resulting images very much; it will autofocus in lower light than the other TCs; and it is the least expensive. The Tamron is out of production but shows up with some frequency on eBay. Note that only the Pz-AF version works with SDM.

The Pentax 1.7 is a useful piece of equipment, and essential if you want to autofocus a manual lens. However the range in which it will autofocus is very thin with long glass. At 500mm, for example, you have to manual focus within a dozen feet or so of the target before the autofocus on the 1.7 will work. So forget moving targets. I used mine yesterday for some distant egrets. They were grazing and moving slowly so it was fine, but I missed a couple of birds in flight that I could have gotten without the TC. I paid $450 for mine, new old stock, about a year and a half ago.

Thanks, will check out the Tammy TC. Do they make it in 1.7 or 2x?