I'm more interested in the smaller aperatures at which it fails to focus. It
would be nice to be able to use it on my 600. I have both the A-1.4X-L &
A2.0X-L but of course I lose AF with those.
Kenneth Waller
http://www.pentaxphotogallery.com/kennethwaller
----- Original Message -----
From: "Rob Studdert" <distudio.p...@gmail.com>
Subject: Re: Because inquiring minds want to know (more on the 1.4x)
Thanks for the report Stan, it does look useful, but I will have to
sell a K5 body to afford it :(
On 21 March 2014 02:38, Stanley Halpin <s...@stans-photography.info>
wrote:
I just did a couple of focus "tests" with my two slowest lenses. I won't
post any results - I was just handholding on random twigs, turkeys, lawn
sculptures, trees, etc. The images would tell you nothing about
sharpness. All of the following using center-point focus, K-3.
1. Sigma DG 150-500mm f5-6.3 APO HSM + Pentax 1.4x TC
With the Sigma at 150mm zoom (presumably f/5.0)
- Sigma AF OFF: nothing happens - no AF.
- Sigma AF ON: snappy AF, no searching or other bad
behaviors
With the Sigma at 500mm zoom (presumably f/6.3)
- Sigma AF ON: Quite a bit of searching on low contrast
targets (e.g., tree trunks.) Fairly quick "snap" to focus on a weed seed
head 20 feet away against a backdrop of the river ice 150 feet away.
Quick "snap" to focus on tree trunks across the river.
- Probably usable at 500mm/6.3 when tripod mounted,
looking at a stationary target with reasonably high contrast. Not sure I
would try to handhold this combination to pick out flying birds above. If
nothing else, the motor noise as it searched would get on my nerves.
2. Pentax FA 28-105/4-5.6 PZ (the original model of this lens)
With the lens at 28mm (presumably f/4.0)
- Quick albeit noisy focus on pretty much everything I
looked at.
(I had forgotten how noisy the AF is on non-SDM
lenses! It has been awhile.)
With the lens at 105mm (presumably f/5.6) [AV, dialed to "wide
open", f/8.0 indicated on the display]
- Same results. Quick lock in on whatever targets.
If anyone wants to try this on a different lens, let me know and I'll
send you my shipping address and return the results to you soonest. Or
stop by and play with it yourself.
I will have this with me on an upcoming trip to Sweden/Norway/Denmark and
any Pentaxians I encounter along the way are welcome to do a try out of
the 1.4x.
stan
--
PDML Pentax-Discuss Mail List
PDML@pdml.net
http://pdml.net/mailman/listinfo/pdml_pdml.net
to UNSUBSCRIBE from the PDML, please visit the link directly above and
follow the directions.
--
Rob Studdert (Digital Image Studio)
Tel: +61-418-166-870 UTC +10 Hours
Gmail, eBay, Skype, Twitter, Facebook, Picasa: distudio
--
PDML Pentax-Discuss Mail List
PDML@pdml.net
http://pdml.net/mailman/listinfo/pdml_pdml.net
to UNSUBSCRIBE from the PDML, please visit the link directly above and follow
the directions.
