Do we still need a TC?

Started Nov 11, 2013 | Discussions thread
Anastigmat Forum Pro • Posts: 12,663
Re: Do we still need a TC?

awaldram wrote:

Anastigmat wrote:

Exactly, the light is the problem. If you have a bright light with good contrast like that a f5.6 lens and a 2x teleconverter will still autofocus. Point the same combination at a hawk sitting in a tree outdoors even when there is sunlight, and the autofocus will still hunt back and forth. Hawks are not like lamps. They don't come with LED or tungsten bulbs. With a f5.6 lens, a 1.4x teleconverter will still allow autofocus in real world situations with real world subjects, but not a 2x.

I don't recognise anything your saying re Pentax cameras, Do you have any experience with Pentax AF 2x converters and decent lens ?

From a boat hence the camera shake

This is an easy subject with bright illumination and high contrast subject. Try photographing a red tailed hawk sitting in a tree in the shade, with the same combination of lens and teleconverter and report to us the results. BTW, why do you use ISO 100? Only a beginner would do that sort of thing, unless of course your camera is so nosiy at high ISO settings that you dare not use ISO 400 or above. BTW, it looks out of focus as well, which is precisely my point. Manufacturers of 2xTCs all have instruction sheets that advise against using a combination of f5.6 and 2x teleconverters.  They don't want irate customers calling them and complaining that the combination does not work.

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