Kenko Teleconverter's , any good ?

[acidhouse]

Kenko Pro 300 DG 2x Teleconverter, has anyone seen or used any of these ?

http://cgi.ebay.co.uk/Kenko-Pro-300-DG-2x-Teleconverter-for-Canon-NEW-8P_W0QQitemZ7609480264QQcategoryZ4687QQrdZ1QQcmdZV iewItem

yes i know their cheep, but do they work and with what limitations?

[blonde]

it is actually a fantastic TC that is regarded very highly.. i would say that i did not notice any difference between this one and the canon one..

[roli_bark]

See here for many tele lens performance with various types of TeleConverters:

http://www.eospix.com/content-cat-10.html

[Andy_T]

And, of course, re-read the Teleconverter FAQ (on top of the forum)

Best regards,
Andy

[jediforce4ever]

Any 2xTC, regardless of brand degrades the Imgae quality of the lens by quite a big margin.
I have heard and tested that the Kenko TC gives faster AF on the lenses than the Canon ones...1.4x and 2X

[Andy_T]

Anoter issue is that with some TC's (the 'standard' Kenko & Tamron ones) you can use AF with lenses that are slower than f/4 (this feature is normally deactivated by the camera). Note ... this can lead to damage to your lens if the light is too low and the motor continuously tries to re-focus ... so be sure to pay attention to how the lens behaves!

The Pro300 models do the same thing as the Canon TC's, they pass on the information to the camera that a TC was added and the max aperture of the lens was thus changed. So you can only AF with a lens faster than f/4.0 (or f/2.8 in case of a 2x t-con) with these.

Best regards,
Andy

[Juan Zas]

The Pro300 models do the same thing as the Canon TC's, they pass on the information to the camera that a TC was added and the max aperture of the lens was thus changed. So you can only AF with a lens faster than f/4.0 (or f/2.8 in case of a 2x t-con) with these.

Best regards,
Andy

Unless you tape the three famous pins, then the camera believes has f/0, as manual lens (F/stop not reported) and AF still works, slower but works.

BTW. The x1.4 Kenko TC performs very well, at least over my 70-200 f/4.

I have just ordered yesterday a x2 Kenko Pro 300 DG for $118 + S&H.

As I am going also to buy a EF 300 f/4 L IS USM in two weeks in NYC, and I have readen several good reviews of the x2 TC with this prime, So I have decided to give a try and see what happens,

[Andy_T]

Good point, Juan. Thanks for pointing it out!

Best regards,
Andy

[acidhouse]

thanks for that , i just thought for the price they were some cheap con.
for the amount of times i'll probably use it then this seems to do what i was looking for.

[FlashZebra]

Unless you tape the three famous pins, then the camera believes has f/0, as manual lens (F/stop not reported) and AF still works, slower but works.

BTW. The x1.4 Kenko TC performs very well, at least over my 70-200 f/4.

I have just ordered yesterday a x2 Kenko Pro 300 DG for $118 + S&H.

As I am going also to buy a EF 300 f/4 L IS USM in two weeks in NYC, and I have readen several good reviews of the x2 TC with this prime, So I have decided to give a try and see what happens,
This test seems to indicate to me that you should not expect very much edge sharpness from the combo you intend to try.

http://www.eospix.com/content-20.html

Enjoy! Lon

[FlashZebra]

Kenko Pro 300 DG 2x Teleconverter, has anyone seen or used any of these ?

http://cgi.ebay.co.uk/Kenko-Pro-300-DG-2x-Teleconverter-for-Canon-NEW-8P_W0QQitemZ7609480264QQcategoryZ4687QQrdZ1QQcmdZV iewItem

yes i know their cheep, but do they work and with what limitations?
Unless you are using a 2X converter on the absolutely sharpest lenses available, the performance may be substandard.

See this report to see what happens to sharpness, especially edge sharpness, on a very highly regarded lens (with regard to sharpness).

If you are using a more pedestrian lens with the converter the image degradation will be even more pronounced.

Many feel that the 1.4X converter typically provides reasonable performance, but the 2X converters really gouge into image resolution, especially at the corners and especially if you are not using them on extremely sharp lenses.

http://www.eospix.com/content-20.html

Enjoy! Lon

[Juan Zas]

This test seems to indicate to me that you should not expect very much edge sharpness from the combo you intend to try.

http://www.eospix.com/content-20.html

Enjoy! Lon

I know that test, thank you. But for the price I have paid for the Kenko if I can get some decent shots is more than I can expect. The real thing is that I don´t know the Canon x1,4 more expensive than the Kenko), but the Kenko with my 70-200 f/4 gives me excelent results. Let´s see ...

test shoots it will be with the moon at 600 mm ....

[FlashZebra]

I know that test, thank you. But for the price I have paid for the Kenko if I can get some decent shots is more than I can expect. The real thing is that I don´t know the Canon x1,4 more expensive than the Kenko), but the Kenko with my 70-200 f/4 gives me excelent results. Let´s see ...

test shoots it will be with the moon at 600 mm ....
Even with a 1.6 crop digital, your "moon" test will not really challenge the teleconverter, even at 600mm the moon will fill less than half of your frame. My ballpark estimate is that you will get about 800 X 800 pixels with an 8MP 1.6 crop digital. The center sharpness on the 2X teleconverter (either Kenko or Canon) is reasonable, it is the edges that really get funky.

Since you moon shot will only be at the center of the frame you will never see the possible weakness of the edge detail.

Enjoy! Lon

[Juan Zas]

Since you moon shot will only be at the center of the frame you will never see the possible weakness of the edge detail.

Enjoy! Lon

That´s I try to see, if it´s OK in the center, then it could be useful. I know, borders are the weakness, I shall try to test also afterwards, to know where are the limits.

Thank you, Lon

[Kether]

Hi,
i've tried read every thread about TC but still cannot find clear answer for my basic question :) At this moment I have 5D with 70-200 f/2.8L (24-70 f/2.8L also but really don't want to use TC on that :)) In Czech Republic is Kenko about 1/3 - 1/2 cheaper than Canon so what advantage is in Canon 2x than Kenko 2x (Pro300) ?

[FlashZebra]

The Canon is optically better. Read the test reports cited above to see this difference in measurments.

The Kenko is less expensive, and since it does no have any protruding elements, fits more lenses.

Enjoy! Lon

[evandavies]

I use the Kenko Pro300DG x1.4 with the Canon 100-400 on a 350D and using the tape trick on the pins DOES KEEP AF.
I read the Canon produces only slightly better quality.

[jrsforums]

See here for many tele lens performance with various types of TeleConverters:

http://www.eospix.com/content-cat-10.html

Thanks for the good pointer....

....makes one think that the Canon's may be worth the add'l cost.

[Acc]

I have the Kenko PRO 1.4 TC and it works for me. It costs 1/3 of the Canon TC ...

Alb