kenko teleplus DG pro 300

[gio67]

this arrived today and it,s the 2x converter,
it does not autofocus with my 70-200 2.8 sigma and only sometimes on my tamron 90mm macro 2.8, the little levers inside the lens housing (theres one at either end) are swinging free ,but do go solid when i fit it to a lens, on all my lenses they are solid could this be a faulty converter

[David Kilpatrick]

The levers are the aperture linkage and should show normal spring resistance. The current Kenko 300DG will not focus any SSM or HSM lens, for that, the new Kenko 300 DGX appearing next month will be needed. I don't know why it does not work with the Tamron though.

David

[gio67]

thanks for the reply david, i,ve tried it again with the tamron and it does autofocus and also i tried it with my 50mm 1.7 minolta and no problems, i should have waited till next month, but it,s not a big deal to manual focus

thanks again

[WaltKnapp]

The levers are the aperture linkage and should show normal spring resistance. The current Kenko 300DG will not focus any SSM or HSM lens, for that, the new Kenko 300 DGX appearing next month will be needed. I don't know why it does not work with the Tamron though.

David

I've used the Kenko 300DG with the 70-400G and AF does work surprisingly well with the 1.4x version, but not with the 2x version.

Walt

[David Kilpatrick]

The 1.4X does work, but fails to report the correct aperture or focal length. That will be corrected, I am told, in the DGX versions. That's why I sold both my 1.4X Pro 300 models - original and DG (which, for the record, were absolutely identical including the coatings - Kenko literally just stuck a new label on the box).

David

[WaltKnapp]

The 1.4X does work, but fails to report the correct aperture or focal length. That will be corrected, I am told, in the DGX versions. That's why I sold both my 1.4X Pro 300 models - original and DG (which, for the record, were absolutely identical including the coatings - Kenko literally just stuck a new label on the box).

David

I look more at does it work, and it does. What goes into the exif is not important to me and I don't depend on SSS at such long focal lengths. (actually I don't need to depend on AF either) Since the DGX are not here it's kind of a moot point if shooting today.

Walt

[Jasper_D]

It´s kind of hard to find though, even the US stores exporting abroad (B&H for one!) have it ´Discontinued´ or don´t list it. There is a small remote possibility I might get one from a local retailer in Switzerland, but that one didn´t update his website for ages now, it might not be available at all (stock says: ´1´)...
So I´m getting a bit sick of searching, and of waiting, Sony might be pleased, I´m ready to spend twice as much for the SAL14TC. I´ll probably only use it with the 70-400G anyway and I don´t care that much about retaining AF. My only point of concern would be IQ... Is it better - I´d hope so at twice the price, but then it´s Sony - equal, worse??? Somebody with inside info on release of the 1.4 DGX for Sony, if ever?

[David Kilpatrick]

I don't believe the Sony 1.4X converter works with the 70-400mm SAL G SSM. If anyone can advise me otherwise, please do. I thought it could not be fitted physically. The main reason for using the Kenko 1.4X is that is does fit, even if it does not work perfectly.

David

[Jasper_D]

It depends a bit on what Sony website you visit, but at least Sony Japan says you can...

http://www.sony.jp/dslr/products/SAL14T ... html#L1_10

[David Kilpatrick]

That's good enough for me. I have here the Sigma HSM 1.4X and 2X - I own the 2X, the 1.4X was sent to see whether the physical fit would allow use with the 70-300mm SSM (it does not). If the Sony 1.4X fits the 70-400mm, then the Sigma new HSM type (not the older one) will almost certainly fit the 70-400mm and provide a lower cost alternative.

Someone with a 70-400mm SSM in the UK - pm me if you can test the converter for me.

David

[WaltKnapp]

I don't believe the Sony 1.4X converter works with the 70-400mm SAL G SSM. If anyone can advise me otherwise, please do. I thought it could not be fitted physically. The main reason for using the Kenko 1.4X is that is does fit, even if it does not work perfectly.

David

I don't have the Sony version of the 1.4x, but the Minolta equivalent does work with the 70-400G. No AF, of course.

Walt

[Jasper_D]

That´s confirmed, a few here seem to have the Sony mounted: http://forums.dpreview.com/forums/read. ... e=34538467
I might not have a choice anyway, it´s either a positive reply before the end of this week from the only retailer I found, or I will have to purchase the Sony. Unless Kenko beats them with an announcement very soon... Spring has started, I´d like to shoot some new born animals soon.

[David Kilpatrick]

No AF Walt? Is that because it is not the final version SSM compatible of the Minolta converter, or because Minolta built in a disabling function for f/8? I know that the Kenko converter will attempt to use AF, but the SSM protocol is not perfectly handled and the result is overshoot/undershoot hunting - which can damage the lens.

The new DGX Kenko is supposed to: a) transmit the correct aperture and focal length information to the camera, to enabled proper flash and SSS functions and record correct EXIF data
b) Transmit the correct SSM protocol, slowing the focus motor down to ensure the system can lock focus reliably

What we do not know until it appears is whether it will also disable AF (which the existing one does not) despite the fact that with the A700, A900 and A850 an f/8 lens will successfully AF in daylight conditions, unless disabled deliberately.

David

[WaltKnapp]

No AF Walt? Is that because it is not the final version SSM compatible of the Minolta converter, or because Minolta built in a disabling function for f/8? I know that the Kenko converter will attempt to use AF, but the SSM protocol is not perfectly handled and the result is overshoot/undershoot hunting - which can damage the lens.

The new DGX Kenko is supposed to: a) transmit the correct aperture and focal length information to the camera, to enabled proper flash and SSS functions and record correct EXIF data
b) Transmit the correct SSM protocol, slowing the focus motor down to ensure the system can lock focus reliably

What we do not know until it appears is whether it will also disable AF (which the existing one does not) despite the fact that with the A700, A900 and A850 an f/8 lens will successfully AF in daylight conditions, unless disabled deliberately.

David

With the Minolta 1.4x TC the 70-400G makes no attempt at all to AF. As if it's switched off. I think it's the final version of that TC. Sony is erratic about reporting their 1.4x TC working with the 70-400G because they say it won't AF with the TC, unlike some other SSM lenses that will AF.

With the Kenko 1.4x TC the 70-400G does AF with little hunting. And the focusing uses the same methods as without TC. And those are very similar to how I manually focus a lens as far as the motions involved. I have used it even at Sunset (not shooting at the sunset) with little hunting. I do not see how this could damage the SSM. Since SSM is a direct drive motor there is no linkage to deal with or wear.

Here's a shot at sunset with the 70-400G with the Kenko 1.4x TC. AF was not hunting here.
http://madranis.home.mindspring.com/DSC00376.jpg

Note I'm using all this on my a700s. I usually run them with the slower AF for better accuracy. If that has anything to do with it. I also don't use the TC all that much. I cannot speak for other Sony DSLRs.

Walt

[motor]

I have both the sony 1.4x and the 2x and have tried them on the 70-400G. I was under the assumption that NO teleconverters would work on af because the 1.4x take it to F8 and 2x is F11 on the A700. Are you saying the kenko versions do work af on the 70-400? I was looking at the new dgx models. I called THK and they said that they will be for sale at the end of April in the US. For $99 that would be worth trying so I could use it on other lenses. The sony telecoverters only works on my 70-200 and 70-400G and nothing else. I'd love to try the new kenko on the 50 1.4 and even the 85 1.4 at times.

Motor