1.4x or 2x Teleconverter

i have a K10 with DA 18/55mm lens and DA 55-300mm F4.5 lens im looking to get a teleconverter to give me that bit extra on the 55-300mm lens are these worth giving a go or buying and what whould be the best choice any help would be good
thanks paul

A TC is worth buying if its a good one. You can expect to pay around £200 for the SMCP-F 1.7x AF teleconverter, which is the best I've ever tried.

Whilst a TC will add a bit of reach, one major point to remember is the light attenuation that occurs. A 1.4x will lose 1.4 stops of exposure and a 2x will lose 2 stops. If you combine it with a slow lens your shooting opportunities can be a bit limited.

Please forgive the selling opportunity, but if you want to try a 2x TC without much expense, I have a Takumar-A 2x for sale here. It will not allow AF, but it has the electrical contacts for metering.

thanks for the help had a look at the takumar will consider it thanks

I Have tried quite a few Tc's The one i have settled on, is the Kenco 1.4 dg from SRS and at £89 inc postage for members of the forum not bad
I do have a shot taken with it on the camera in my gallery if you want to look.

If it's the Pz-AF version you talking about, this converter was discussed in another recent thread. Some said theirs worked with SDM focus others not. So it might be worth checking first with SRS if you need SDM focus.

The Sigma 1.4 DG does not work (Auto focus) with the 70-200HSM MK11 and won’t fit the Tamron 70-200 f2.8.
It Is about time Pentax bought one out for use on SDM lenses.
PS the newKenko one I am using is the P/AF DG With my Tamron 70-200 f2.8.
Another PS, I did buy it from SRS?

I bought a promaster spectrum 7 1.7x teleconverter which works with every lens I have attached to it, it has SDM contacts and powers my Sigma 50-150mm HSM very well and also has a screw AF drive pass through - so all my lenses have auto focus when attached to it.

I ordered it from a fleabay store about 5 months ago but cant remember which it was, worked out about £68 after import duty had been added.

Strangely, that's not right. You lose just 1 stop with a 1.4x teleconverter.

In effect, you multiply the aperture value by the converter power (f/4 with a 1.4x TC becomes f/5.6, or f/8 with the 2x TC, for example).

Dan

2x would be too much for decent results with your 55-300. The higher the magnification of the converter, the darker the image and the poorer the quality. Hand-holding would be very shaky indeed as well.

A 1.5x Kenko would be better, though you'd still need a tripod (or a lot of luck) to get properly sharp shots.

Hi folks

I have a 1.4x Pz-AF, and it does not give very good results with my DA55-300mm - you could see the difference on the edge of the review screen when you magnify the image, and that was at about F8-F11 in bright light in Egypt. Maybe the latest versions are better?

Seems to work OK with a Sigma 70-200F2.8 though (and I have just bought the Sigma APO version for use at airshows - but that won't fit the 55-300mm)