Teleconverters - again!
There is the Sigma above and recently I hired a DA* 300mm from SRS and found it worked well with my 1.5x Kenko teleconverter, including autofocus.
Were you using SDM or Screw drive for the auto focus on the DA300. The reason I ask is that I was using the the same combination with SDM and found it slowed down the AF by a noticeable amount
https://pentaxphotogallery.com/artists/barrieforbes
https://www.flickr.com/photos/189482630@N03/
The result - there is no doubt that this lens hits all the highs in relation to IQ, but boy oh boy is it heavy, and if only l could catch the little guy who kept adding bags of cement to the lens as the day wore on ! Fortunately l had packed a monopod, so on day three that became a fixture on the lens, and it is fair to say that the weight problem diminished noticeably.
My view - it's a stunning lens, but if using as l did, then a monopod is an absolute necessity.
with the Pentax 60-250 f/4 provided there was a teleconverter that would work with the 60-250 and still give me fast auto focus. Is there such a teleconverter or am I asking too much? Or can anyone recommend a 200-400 or similar with a Pentax fit?
60-250 is a very slow focusing lens alone (SDM is like a tortoise), this invalidates your first question.
Also I remember Mike-P saying some time ago on this forum, that 60-250 with TC wasn't a good combination due to drop in IQ for some reason, while *300 was much better.
As for 200-400, unfortunately Pentax still doesn't have any (that much needed) telephoto like Canon/Nikon/Sony have (so something like 80-400, 100-400, etc).
I had the previous non-OS 150-500mm and loved it, but moved up to the 50-500mm for the Lens OS function which I think is superb, especially when using handheld. Just need to make sure you have a couple of spare fully charged batteries if you are going to use it a lot as it does drain them quite quickly.
Previously I had the Sigma 150-500 but was never really happy with it. When I first had it, it was mounted on a K-7 and I was not satisfied with the quality of almost all the images that I took. I did send the K-7 back to Pentax on 2 occassions as I believed that the auto-focus was not correct but eventually lost confidence in both the K-7 and the 150-500 so sold both to upgrade to the K-5 and the DA*300.
I think that I will get a Tenko as this will be a very much lighter that the Bigma and will see what happens then and will report back
Many thanks to all who replied - any other suggestions gratefully received.
Regards
Eoin Hanley
It works well with the Sigma 400mm and my Sigma 100-300 f/4.0, as this recent test shot (K20D at f/4.0; cropped) shows:
Sigma 100-300 f/4.0 EX DG plus Tamron 2X Pz-AF BBAR MC7 by Dr 'B ', on Flickr">[img]http://farm8.staticflickr.com/7006/6629090803_ee2827635a_b.jpg" class="comment_image" />
Sigma 100-300 f/4.0 EX DG plus Tamron 2X Pz-AF BBAR MC7 by Dr 'B ', on Flickr" class="comment_image" />
In good light, AF is possible, but slow with a degree of 'hunting' on both lenses (100-300 f/4.0 < 400 f/5.6), but my preference when using the TC is MF. Should prove more reliable/consistent with the 70-200 f/2.8.
Don't have a lens with SDM so I can't comment, but others have reported variable degrees of success dependent on the lens used (search on the forum at the 'other place').
Jon
There is the Sigma above and recently I hired a DA* 300mm from SRS and found it worked well with my 1.5x Kenko teleconverter, including autofocus.
Hi, its me again
I have just had a long discussion with SRS who were very helpful to the extent of getting a Kenko 1.4 (no 1.5 in stock), K-5 and DA*300 together and the combination drove the K-5 mad. Their advice is that there is NO teleconverter that works with the SDM DA*300 to give AF.
I appear to be back at the beginning!
Comments anyone?
Eoin Hanley
I have the Teleplus 2X Pz-AF MC7 as well, this will not work with SDM, at least my sample won't.
John
I am no expert - but can share my experiences, which will hopefully help.
The currently manufactured Kenko TC's (1.4 and 2x) do NOT have the SDM/HSM contacts (the two square gold contacts on the inner of the lens/camera body - some distance from the outer bunch of standard contacts).
They will therefore NEVER give AF on SDM/HSM lenses. They will give AF on screw drive lenses.
They CAN be used on SDM/HSM lenses in MF - BUT, you have to set the metering mode switch to single point and the focus switch to MF otherwise the camera just goes crazy (as SRS stated). If you use these settings you can use the new TC's with SDM/HSM lenses in MF and achieve correct exposure etc.
To get AF with the newer lenses - you need to get an OLDER TC (strange, but true!).
I was fortunate enough to bump into a Tamron 2x converter with these contacts (only available 2nd hand).
This works fine with Sigma HSM lenses, providing AF (even the 150-500mm F5-6.3 which is fun!).
With Pentax SDM lenses, all camera functions work - you do not have to fiddle with metering modes etc. - BUT - as John says above, AF still does not work - the display automatically switches to MF no matter what you set!
I am told that either the Kenko 1.4x SHQ of Tamron 1.5x Pz DO work with Pentax lenses (again, both only available 2nd hand).
Hope that helps.
I wonder if any of the experts know why the Tamron 2x TC only provides AF with Sigma HSM lenses and not Pentax SDM lenses? Does the SDM require more power (the only thing I can think of)?
Is there a way to force the Pentax SDM lenses to use screw drive?
Thanks
Lloyd
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25 posts
12 years
Near Barnstaple
I am in the fortunate position of being able to spoil myself. I currently have a K5- and a K-r for backup with a variety of lenses (see below). I am delighted with both the Sigma 70-200 f/2.8 and the Pentax DA* 300 f/4 but need that extra bit of reach as most of my photography is wildlife - I have just loaded on the Gallery some shots taken in Galapagos September 2011.
My camera case weighs about 10kg already and I do not want to increase this by much. I am tempted to replace both the 2 lenses above with the Pentax 60-250 f/4 provided there was a teleconverter that would work with the 60-250 and still give me fast auto focus. Is there such a teleconverter or am I asking too much? Or can anyone recommend a 200-400 or similar with a Pentax fit?
Whilst writing, what experience have people got about the Pentax 60-250?
Many thanks
Eoin Hanley in Devon
K-5, K-r, Sigma 10-20, Sigma 24-70 f/2.8, Sigma 70-200 f/2.8, Pentax DA* 300 f/4