Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
05-20-2011, 12:50 PM   #16
Veteran Member
dgaies's Avatar

Join Date: Oct 2009
Location: Maryland / Washington DC
Posts: 3,917
QuoteOriginally posted by Mike.P Quote
I got hold of a Kenko 1.5x teleconverter the other day just to see how it performed with my DA* 200mm and DA* 60-250mm.

Here is a quick test shot with the 60-250mm and TC hand held @ 250mm (375mm) .. I didn't think it was actually that bad.
I didn't think the combo was that bad optically; my main issue was the effect it had on AF performance.

05-21-2011, 05:39 AM   #17
Site Supporter




Join Date: Oct 2009
Location: Philadelphia, Pa
Photos: Gallery
Posts: 763
QuoteOriginally posted by dgaies Quote
I didn't think the combo was that bad optically; my main issue was the effect it had on AF performance.
Hey Dan, do you find the AF performance virtually identical (good or bad ) with the Kenko and the Tamron Tc's? I have the Kenko and AF is pretty good with the 60-250 and pretty bad with the DA*300.
05-21-2011, 06:05 AM   #18
Veteran Member
dgaies's Avatar

Join Date: Oct 2009
Location: Maryland / Washington DC
Posts: 3,917
QuoteOriginally posted by GaryH Quote
Hey Dan, do you find the AF performance virtually identical (good or bad ) with the Kenko and the Tamron Tc's? I have the Kenko and AF is pretty good with the 60-250 and pretty bad with the DA*300.
Gary, I don't think I've ever used a Kenko TC so I can't really comment on whether there might be a difference. I had always been under the assumption that the 1.4x Tamron and 1.5x Kenko were pretty similar in design and performance.

Just to clarify, the combo of the DA*60-250 + 1.4x wasn't terrible or anything. In fact of all the DA* lenses that I tried the 1.4x on, the DA*60-250 (surprisingly) behaved the best despite the fact that it's a zoom and f/4. I don't have a 1.4x TC anymore (sold my last one recently), but as I recall this is how I would rank the AF performance of the different DA* lenses with the 1.4x TC attached:

best to worst in terms of AF performance: DA*60-250/4, DA*300/4, DA*200/2.8, DA*50-135/2.8

With the 60-250, the AF worked almost normally, although occasionally it would take a second try to lock focus. It was a little slower to find the focus, but again not terrible all things considered. The DA*300 worked ok, but would often require a second try to lock. Manually focusing close and then engaging the AF would help in terms of locking on the first try. The DA*200 was similar to the DA*300, although I felt like the performance was a little less consistent. Not sure why, as the 200 was a full stop faster, but that's just subjectively how I remember it. The DA*50-135 was the worst performer of the bunch and would almost always require a second or third try to lock focus with the 1.4x attached.

Last edited by dgaies; 05-21-2011 at 07:35 AM.
05-21-2011, 07:33 AM   #19
Site Supporter




Join Date: Oct 2009
Location: Philadelphia, Pa
Photos: Gallery
Posts: 763
I am sort of finding the same thing with the Kenko. Image quality is as good as the Tamron I used to have but I am using it on different lenses and find too that the 60-250 focuses best while the 300 is a little iffy most of the time.
Still gotta find a 1.7 I guess.

05-21-2011, 07:39 PM   #20
Pentaxian
Digitalis's Avatar

Join Date: Mar 2009
Location: Adelaide.
Posts: 8,535
QuoteOriginally posted by nater Quote
The 70-200mm works well for people pictures in a way that the 100-300mm just wouldn't, so it ends up being a more versatile lens for me I think.
then buy a 100-300mm f/4 and a DA70mm f/2.4 and zoom with your feet. I really don't get people's obsession with having every conceivable focal length their zoom lenses cannot fill in. There isn't a huge difference between 70 and 100mm - I use the sigma 100-300mm f/4 and for shorter focal lengths than 100mm, I use the FA77 f/1.8 and it outperforms any 70-200 f/2.8 lens @ 70mm.
05-21-2011, 10:47 PM   #21
Site Supporter




Join Date: Aug 2009
Location: New England
Photos: Albums
Posts: 686
QuoteOriginally posted by Digitalis Quote
then buy a 100-300mm f/4 and a DA70mm f/2.4 and zoom with your feet. I really don't get people's obsession with having every conceivable focal length their zoom lenses cannot fill in. There isn't a huge difference between 70 and 100mm - I use the sigma 100-300mm f/4 and for shorter focal lengths than 100mm, I use the FA77 f/1.8 and it outperforms any 70-200 f/2.8 lens @ 70mm.
For fun the last two years I've photographed the HONK! Festival in Somerville/Cambridge, MA. The 70-200mm focal length is perfect for most of the parade shots and I absolutely need a zoom to photograph dynamic events like that (especially since I have only one digital camera body), and the f/2.8 is great for subject isolation. I don't think a 100-300 f/4 would serve me well there. (At an airshow that's a different story, and while I certainly enjoy photographing airshows, I don't enjoy it nearly as much as photographing something like HONK!)

It's also worth noting that the Sigma 100-300m f/4 has been discontinued, and replaced with the $3,200 120-300mm F2.8 EX DG OS APO HSM. I paid $730 for my Tamron 70-200mm f/2.8 (new, with a 7-year warranty).

Last edited by nater; 05-21-2011 at 10:57 PM.
05-21-2011, 11:21 PM   #22
Pentaxian
Digitalis's Avatar

Join Date: Mar 2009
Location: Adelaide.
Posts: 8,535
QuoteOriginally posted by nater Quote
It's also worth noting that the Sigma 100-300m f/4 has been discontinued, and replaced with the $3,200 120-300mm F2.8 EX DG OS APO HSM
the 120-300mm f/2.8 isn't a replacement for the 100-300 f/4 - sigma wouldn't do anything that stupid* I'm betting they will eventually release an optically stabilized version of the 100-300mm f/4 APO EX DG


*considering their pricing of the SD1 perhaps they would.
05-22-2011, 02:10 PM   #23
Site Supporter




Join Date: Aug 2009
Location: New England
Photos: Albums
Posts: 686
QuoteOriginally posted by Digitalis Quote
the 120-300mm f/2.8 isn't a replacement for the 100-300 f/4 - sigma wouldn't do anything that stupid* I'm betting they will eventually release an optically stabilized version of the 100-300mm f/4 APO EX DG


*considering their pricing of the SD1 perhaps they would.
Have you checked out Sigma's site? The official product info page on the 100-300mm F4 EX DG APO HSM says "We're sorry, this product is discontinued. Please consider using this product instead: 120-300mm F2.8 EX DG APO HSM #135110" but then when you go that page, it says "We're sorry, this product is discontinued. Please consider using this product instead: 120-300mm F2.8 EX DG OS APO HSM #136110" so it looks to me like they've already discontinued the replacement for the discontinued 100-300mm, which I'd think would make the chances that they're still working on a new 100-300mm f/4 about zero (and notice the new 120-300mm f/2.8 got OS).

05-24-2011, 01:15 AM   #24
Pentaxian
Digitalis's Avatar

Join Date: Mar 2009
Location: Adelaide.
Posts: 8,535
QuoteOriginally posted by nater Quote
which I'd think would make the chances that they're still working on a new 100-300mm f/4 about zero
I don't think so, the 100-300mm f/4 APO EX DG has been a very popular product from sigma - who if you recall, also discontinued the 150mm f/2.8 APO EX DG Macro and recently released an OS version of it...same goes for their 70-200mm f/2.8 lens - they discontinued it...then released an OS version, are you seeing the pattern here?

I think it's only a matter of time to see what they will do but I'm banking on that they will release an OS version of the 100-300mm f/4 APO EX DG eventually.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
k-mount, pentax, pentax lens, sigma, slr lens, teleconverter, terms
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
K-x & Sigma 150-500 focusing problems davesofnj Troubleshooting and Beginner Help 11 05-21-2011 03:53 AM
What has better resolution Sigma 120-400 or 150-500? PixleFish Pentax SLR Lens Discussion 5 03-18-2011 01:57 AM
Marrying a KX to a Sigma 150-500 Al_in_the_Shire Pentax DSLR Discussion 4 03-19-2010 07:29 AM
Sigma 50-500 vs 150-500 vs 170-500 juanraortiz Pentax SLR Lens Discussion 19 10-30-2009 03:32 PM
Sigma lenses 150-500, 50-500 ? lesmore49 Pentax SLR Lens Discussion 19 03-21-2009 06:49 AM



All times are GMT -7. The time now is 12:10 AM. | See also: NikonForums.com, part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top