I heard so much from others on the ability of this Pentax F-1.7x AF TC that can turn a manual focus lens into a auto focus lens. It is partly true when I test it. The manual focus has the ability to partial focus when the focusing target is close to the focal point. When the current focal point is farther away from the target, I only see blinking from the focus lock confirmation that requires intervention on my part to turn focusing ring to close to target to get the AF in the TC to engage.
Impressions & Notes:
- This is a magical TC to get if price is reasonable. It cost twice more than Tamron 1.4x Pz-AF TC but for the ability for it to turn a manual focus lens to have the ability to AF at close target, it is something I am willing to pay money for
- When used with my Komine 200mm f/3.5 manual focus lens, I can use the combination to photo hummingbirds in flight. The AF part comes as a great tool when it comes to birds.
- There are times I find the partial focusing doubtful and I need to train myself to refrain from hitting the shutter fast but rather check to confirm is focus is nailed.
- PF and CA seems to be a concern as I see more CA in using Tamron 1.4x Pz-AF.