tele converter

So what do people regard as the best available 1.4 converter on the market?

Hi Donovan

I am a newbie at this but I suspect you are bound to hear from one of the experienced people here immediately asking you "attached to what lens?"

As there are different criteria for choosing TCs.

But I might be wrong and may be there is something such as a gem. Well, there is one in fact that is like gold dust amongst TCs, the Pentax 1.7x adapter. Its very sought after and if you check a few threads you will come across some comments about it.

But like I said, to choose a good TC might be dependent on what lens you want to use it with.

You are bound to get a response from one of the very helpful people here shortly, so I might be wrong, let's wait and see

Thanks

Amin

The tamron 1.4 or the Kenko 1.5, there simply isn't anything else, there was an pentax 1.4 on the roadmap but not anymore.

The newest version of the tammy and the kenko can be used with SDM so the newer KAF3 lenses (DA 17-70 + newer DA*) would still have autofocus, the Pentax 1.7 has his own autofocus but is mighty expensive.

ps. it's been said that the tammy and thee kenko are the same, but tamron is hard to come by these days.

Edit: I see you have the sigma 50-500 if you planned to use it on that you will have limitations with those named above and you need to use Sigma I believe. I'm sure that somone here can explain that.

I second the Kenko 1.5, though it does cause focus hunting on my DA* 50-135. Better on the DA* 16-50. Works a dream on my Sigma 18-200!

I have the Kenko 1.5 and was disappointed that it doesn't appear to work at all on my DA* 300 mm/K10D. You have to manual focus since the lens seems to think that it is still in SDM mode. Also, with the combination attached to the camera, when you press the menu button it flashes off immediately and you cannot get into the menus. Remove just the lens leaving the convertor atached, and the Menu button functions as normal! Strange.

John

Have the Tamron 1.4x, Sigma 1.4x EX DG and Pentax 1.7x converters.
The Pentax knocks the spots off all of them even with the extra magnification. If it's for the Bigma though non of them will AF.

Interesting, I'm considering a Kenko 1.5x for use on my Sigma 18-200, looking at the aperture settings it should also work on my Tamron70-300.

Anybody tried this combo?

Very strange indeed, SDM should simply work though the Tamron and the Kenko are the same in design.
You do have a TC with the SDM/powerzoom connections right?

The DA* 300 still has the camera driven focus spigot. so you would think that it would use that system on a none SDM Kenko 1.5x with Auto Focus, but it will only manual focus

Yes since the camera gets the info that the lens can do SDM so it won't use the camera driven focus but is trying to use the SDM to focus, if the TC doens't have the contacts the signal doesn't come trhough of course.

I don't believe there is away around it, for camera driven AF the camera also wants the lens information so covering up contacts wouldn't work I think.

The latest Kenko 1.5x DG TC's don't have the power connections wired through, you need to have the version with the suffix/prefix Pz (Power zoom).

I had the Tamron 1.4x Pz-AF TC and that worked fine with no hunting on my new DA*60-250, but the previous generation SDM DA* lenses used to hunt and then give up.

I agreed to sell it before I tried it out on my 60-250, so asked the boys at SRS to try their stock of Kenko converters, sadly no go.

If that is the case then Pentax fitting the Drive Spigot to the DA*300 would be pointless.

Richard The Kenko ones you are looking for are Pz-AF 1.5X Teleplus SHQ these work on SDM. Pz-AF 1.5X Teleplus MC do NOT

No it isn't pointless beacuse the older models Pentax DSLR can't use the SDM but will use the Drive Spigot to auto focus. The newer Pentax's like the DA*55 and the DA17-70 are KAF3 and don't have a drive spigot anymore but KAF2 still has.

If the camera sees it's an SDM lens it will use that of course and not the drive spigot, you would get troubles I believe if the camera tries to use both. It also doesn't make sense that the camera doesn't use the SDM but the drive spigot if the lens has both.

If you have a K10D you can use the firmware version 1.02, that one isn't SDM capable so it will use the drive spigot but you will lose SDM support of course.

edit:Typos

I understand what you mean now Stefan. What i do not understand is, if a TC with no SDM contacts is placed between a SDM camera and a SDM lens, how does the the fact it's a SDM lens get transmitted?