I shot a frame at f22 last week with the 1.4x and 60-250. It focused quickly.
Paul via phone > On Mar 26, 2014, at 7:01 PM, Stanley Halpin <s...@stans-photography.info> > wrote: > > I’ll further explore that question tomorrow. > > stan > >> On Mar 26, 2014, at 2:59 PM, Ken Waller <kwal...@peoplepc.com> wrote: >> >> 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. > > > -- > 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. -- 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.
