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wolffman
10-10-2010, 11:35pm
Im Thinking about getting the 300mm f4 which is afs. I have an older kenko teleconverter which is afd. I'm assuming that if I use this I will lose af but should still meter ok with the d90
Any ideas?

jaimedormer
14-10-2010, 10:52pm
Wolffman,

What magnification factor teleconverter do you have, x1.4, x1.7, x2 ??

This will be the first thing that will determine AF, the other is the amount of light that is present on the day, what is to be your main subject?

kiwi
14-10-2010, 11:05pm
I'd say it should be ok....there Is a nikon teleconverter compatability chart that I have posted before, I can easily search on my iPad, but it's around

jaimedormer
15-10-2010, 4:44pm
Wolffman,

What teleconverter do you have, it is relevant to the question ??

wolffman
15-10-2010, 6:23pm
It's a kenko 2x and it is n-afs. I had a go with the 35mm f1.8 dx and it certainly was able to drive the afs but would barely lock onto something stationary so my expectations are not high.
In hind sight I should have tried that first

arthurking83
15-10-2010, 8:59pm
hey wolffman. the easiest way to determine if the lens or TC is AF-S capable is that it wil have the full complement of (either) 9 or 10 CPU pins.

older AF-D lenses (and TC's) have either 5 or 7 pins(can't remember exactly which again :p)

kenko's are thirdparty material so they try to mimic genuine Nikon stuff.. they could have any number of pins, but if it is AF-S then to be fully compatible it'll have 10.

Just because the 35mm lens and TC hunt for AF, doesn't mean that it will do the same on another lens too. take into account contrast. wide lenses usually offer very little contrast naturally, so if you add a TC which has to pass the image onto the AF sensor.. if the image is even lower contrast then it could be the issue.. not the type of AF issue you're expecting it to be. AF @ f/8(on that 300/4) will be hard tho... so don't expect miracles.
The beauty of Nikon gear tho is that it's not deliberately disabled(some lower end Canon's deliberately disable AF at apertures smaller than f/5.6) The Nikon will just try to achieve focus. they obviously recommend not to try tho.

The only real way you will ever find out for sure, is: if someone with that exact same combo posts their experience, or of you go to a camera shop and ask to try it out. You won't be forced to purchase the lens.. it'll be fun doing so and just be sure to tell them you want to try it out with your camera and TC.. to be sure.

As jaimedomer pointed out.... you're going to need plenty of light with that combo, and the viewfinder will be dark.

note too: that 300AF-S works impressively with the Nikon TC-14EII... gives you an almost 400/5.6 with impressive ability going by sample images I've seen :th3
if I ever replace my 300mm and 500mm, it will be for that combo plus a TC-17EII I reckon.

kiwi
15-10-2010, 9:01pm
The 1.4 kenko pro dg is about as optically good as the nikon

I have one for sale on camera market at the mo

The 2x ones are pretty bad

jaimedormer
15-10-2010, 9:04pm
You may want to think about upgrading your teleconverter to the current pro 300 series model, you should be able to get great photos with the 1.4 & 1.7 series, with full AF, on your D90 with the 1.4 you will have the equivalent of a 675mm f/5.6 and with the 2x a 900mm f/8, I have both the nikon & kenko verions of both of these and the 2x is pretty good, and the 1.4x is better, I am told from research that the 1.7x is very good, have not got these yet.

Hope this help, cheers

wolffman
15-10-2010, 9:24pm
Thanks all. I still have another couple of things to sell before I can get the 300mm f4, so there is some time. The fact that it drove the 35mm lens means that it will at least drive the AFS system so I will be able to use it to start with and then move to the 1.4 if the IQ is no good.
I have phoned around adelaide and no one is stocking it