thanks for clarifying this. i am afraid the tamron 1.4x will behave just like the sigma 1.4x. will know soon when i get my hands on the tc.
On Fri, 17 Aug 2018 12:12:34 -0400 Mark C <[email protected]> wrote: > I just tried my 1.7x adapter with K3 and DA16-45. It does ask for > focal length when starting up. The 1.7x adapter adjusts aperture > info, however, adding 1.5 stops. > > My Sigma 1.4x (an older, pre-EX model) just passes the actual focal > length and aperture on to the body. > > Mark > > On 8/17/2018 1:19 AM, Subash Jeyan wrote: > > i had the 1.7x AF TC long back (used with the A*300/4) but as far > > as i remember there was no way to set the focal length manually in > > the body. of course i may remember wrong.... > > > > On Fri, Aug 17, 2018 at 9:55 AM Alan C <[email protected]> wrote: > > > >> That is a very interesting point. I'll try setting the focal length > >> manually using the 1.7x AF converter to see if there is any > >> improvement. > >> > >> Alan C > >> > >> On 16-Aug-18 08:28 PM, Mark C wrote: > >>> If you have both you can test them out. My experience has been > >>> that unless the teleconverter and lens are designed to be used > >>> together, results can be unpredictable. Sometimes great, > >>> sometimes not. > >>> > >>> If you are planning on using the setup with shake reduction > >>> enabled, check to see of the TC sends adjusted focal length info > >>> to the camera, or if just passes through the the lens focal > >>> length. I think that for image stabilization to work optimally > >>> the camera should be set to the adjusted focal length (lens focal > >>> length X teleconverter power), so you may nee to manually set it. > >>> > >>> Mark > >>> > >>> On 8/15/2018 11:02 PM, Subash Jeyan wrote: > >>>> i'm going on a winter trek to the himalayas in november. > >>>> planning to do some birding also along the way and since the > >>>> sigma 150-500, at almost 2kg, is too heavy for that i was > >>>> looking at alternatives. > >>>> > >>>> i have a tamron 1.4x pz-af (af works with sdm too) and i was > >>>> wondering if i could use that with the da 55-300. i did some > >>>> googling and the results surprised me. it looks, in spite of all > >>>> the conventional wisdom that TCs can only be used with a sharp > >>>> prime lens, people have got good results. see the (old) thread > >>>> here: https://www.dpreview.com/forums/thread/3680410 > >>>> > >>>> have any of you used 55-300, or any other zoom, with a tc? if so > >>>> i'll be interested in how that went... -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
