[chickenandavocado]

hi

does anyone have any experience with using a tc with the tamron 70-200 2.8?

i am wondering
-what options are available?
-what is your experience with each tc (i want to know the best one works without degrading iq too much)

thanks!

[nater]

I have tried the following Pz-AF teleconverters with the Tamron 70-200mm f/2.8 lens when shooting outdoors in a mix of sun and overcast clouds:

Kenko 1.5x - works without much impact on quality or AF speed, and what I ended up using most.

Promaster 1.7x - AF speed was inconsistent enough that I didn't enjoy using it for action photography, so I didn't take many pictures with it.

Kenko 2.0x - AF speed was even more affected than it was with the 1.7x, so I've used it even less so far.

I've owned them a bit over a year... other people on the forum might have more experience, but if I had to have just one, it would be the Kenko 1.5x.

[Ash]

Tamron 1.4x TC - excellent quality, works perfectly with the Tamron 70-200, slows down AF slightly, but not appreciably if focus is already near the correct position.

[chickenandavocado]

thank you for your responses

any one have experience using the pentax 1.7 tc?

[nater]

thank you for your responses

any one have experience using the pentax 1.7 tc?

The Pentax-F 1.7x AF Adapter is a whole other kettle of fish. It will make the Tamron lens a manual focus lens and it will take over autofocus duties itself (its elements will move inside the adapter), and you'll have to manual focus the Tamron to approximately the right place and then let the AF Adapter do the AF. On the used market they go for $250-$350 these days, so it's also the most expensive option (and frankly I think it's most useful with SDM or HSM lenses because there are no SDM or HSM teleconverters, whereas with your Tamron you can use an teleconverter that passes through the AF drive to the lens and retain lens AF capability). People do tend to be very happy with the optical quality of Pentax teleconverters.

[chickenandavocado]

thanks for your insight, much appreciated

i will look around for a kenko or tamron tc in such a case

[mikeSF]

i have the Tamron 70-200 and use it with the Tamron F 1.4 TC which works great.

Here is a handheld bug shot at max zoom...unfortunately i didnt dial a fast enough shutter speed to cover the 280mm focal length, but shake reduction was apparently my friend, even at 1/125th sec.

[chickenandavocado]

excellent! and lovely picture

[OrenMc]

I personally don't have any experience with the 70-200 either, however I can vouch for the quallity of the Tamron MC4 1.4X and the Pz-AF MC7 2X. If the quality of the lens is good they will retain IQ very well.