Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
09-14-2012, 10:37 AM   #196
Veteran Member




Join Date: Jul 2012
Posts: 376
QuoteOriginally posted by cwood Quote
a re-designed 300mm F2.8 with a matched new set of teleconverters would have made far more sense. Pentax fails once again for me.

Many Pentax shooters may not realize this because Pentax has been unable to keep up with the market. But the new telephotos and the new teleconverters produced by Canon and Nikon do NOT suck when combined and shot wide open. The historical "loss of quality" when shooting teleconverters is hardly worth discussing. Typically the only "problem" I notice when I use my long Canon lenses plus teleconverters is that AF performance drops slightly (but not too bad).

My current favorite long-lens is a 200mm F1.8 which I can stack using my 1.4x plus 2x teleconverters for a superb 560mm F5. Basically I get 4 lenses for the price of one (200mm, 280mm, 400mm, 560mm). The thought of spending $7k for this lens would not even enter my thought process. I'd rather pick up a Sigma with a set of TC's.
Even the glorious Sigma 120-300/2.8 works great with a 2x.

I can only hope that the 560 was the last screwup from the dark Hoya ages.

09-14-2012, 11:18 AM   #197
Pentaxian




Join Date: Apr 2007
Location: Romania
Posts: 8,414
QuoteOriginally posted by cwood Quote
a re-designed 300mm F2.8 with a matched new set of teleconverters would have made far more sense. Pentax fails once again for me.
Reality check: BHPhotovideo (street) prices for 300mm f/2.8 OEM lenses:
Nikon: $5,799.00
Canon: $7,249.00
Sony: $6,998.00
Olympus: $6,999.00
Do you honestly think a Pentax version would be much cheaper?

(Please, don't tell me how Pentax must be below the $3,399.00 Sigma)

LamyTax, I see you already have a strong opinion on how the 560mm will perform. I'm afraid there isn't anything left to discuss, until we'll have real data and your opinion will either be confirmed, or disproved.

Last edited by Kunzite; 09-14-2012 at 11:31 AM.
09-14-2012, 11:33 AM   #198
Pentaxian




Join Date: Dec 2011
Posts: 1,150
[deleted]

Last edited by beholder3; 08-11-2013 at 07:19 AM. Reason: [deleted]
09-14-2012, 03:16 PM   #199
Pentaxian
Pål Jensen's Avatar

Join Date: Dec 2007
Location: Norway
Photos: Albums
Posts: 3,064
QuoteOriginally posted by cwood Quote
.

My current favorite long-lens is a 200mm F1.8 which I can stack using my 1.4x plus 2x teleconverters for a superb 560mm F5.
Fantastic for you. Canon discontinued this lens beacuse they could not make a profit on it; it should cost about .......$7000. Any lens with a 2X convrter would not be anywhere near as sharp as a prime lens with the same focal lenght as the lens in question + a 2X converter...

09-14-2012, 03:58 PM   #200
Veteran Member




Join Date: Aug 2008
Location: California
Posts: 851
QuoteOriginally posted by beholder3 Quote
That might be an eyesight issue.

This here shows the actual loss of resolutions:
http://www.traumflieger.de/objektivtest/open_test/telekonverter/ueberblick.gif

For the best converter (Kenko x1,4) that still is 10% loss. Many including the Canon x2 loose a massive 25% of resolution (here some samples (Traumflieger-Telekonverter-Test: Teil 2). For many lenses that is how much difference you have between the worst and the best aperture settings and also the difference between a poor and a good lens. Even the thought of stacking these makes me shudder.

The only really good pictures I every saw using two teleconverters stacked are the Sigma 500/4.5 plus Kenkos x1,4 and x2 on a Pentax K-5 to get an FF equivalent of 2,100 mm :
http://pentaxians.cwsurf.de/forumimages/2012/2012033157_img13785mondklarf5p61500mm.jpg
And even that lost quite some resolution.
These are shot wide open as JPG in camera (sorry for the cloudy WB setting... )

If you want to do pixel analysis there is definitely a case for the stacked TC's causing trouble. But in my world (where I am not taking photos of fine-print text) these are more than usable. And of course... don't forget that ALL lenses benefit from being stopped down a bit while these were shot at MAX aperture.

200mm F1.8 plus 2x TC = 400mm F3.5


100% crop


200mm F2.8 plus 2x plus 1.4x = 560mm F5
100% crop
09-14-2012, 05:30 PM   #201
Veteran Member
borno's Avatar

Join Date: Nov 2006
Location: md-usa
Photos: Gallery | Albums
Posts: 2,580
I thought I'd post a 100% crop of the canon 300mm f2.8 IS (version 1) with a 2x tc,wide open, certainly useable. I paid 4K for it a couple years ago, brand new. I would say it is as fast as the DA300 even with the 2x, and of course much faster with none. I wonder if the new lens is so long and slow because they can't seem to get a TC to work with the SDM? They promised one a long time ago, and even had a mock-up when they were coming out with the 60-250mm.Hand held, of course.

09-14-2012, 08:20 PM   #202
Veteran Member




Join Date: Aug 2008
Location: California
Posts: 851
QuoteOriginally posted by Pål Jensen Quote
Fantastic for you. Canon discontinued this lens beacuse they could not make a profit on it; it should cost about .......$7000. Any lens with a 2X convrter would not be anywhere near as sharp as a prime lens with the same focal lenght as the lens in question + a 2X converter...
Canon actually discontinued that lens due to lead tooling in the manufacturing process - it was a self-imposed environmental upgrade to their manufacturing plant. For a few short years there was a hole in their lineup until they redesigned it as a 200mm F2 (IS).
09-15-2012, 09:21 AM   #203
Moderator
Site Supporter
Blue's Avatar

Join Date: Jun 2008
Location: Florida Hill Country
Photos: Gallery | Albums
Posts: 17,166
QuoteOriginally posted by borno Quote
I thought I'd post a 100% crop of the canon 300mm f2.8 IS (version 1) with a 2x tc,wide open, certainly useable. I paid 4K for it a couple years ago, brand new. I would say it is as fast as the DA300 even with the 2x, and of course much faster with none. I wonder if the new lens is so long and slow because they can't seem to get a TC to work with the SDM? They promised one a long time ago, and even had a mock-up when they were coming out with the 60-250mm.Hand held, of course.

Pentax had working prototypes a few years back of the 1.4x TC.

09-15-2012, 11:37 AM   #204
Veteran Member
borno's Avatar

Join Date: Nov 2006
Location: md-usa
Photos: Gallery | Albums
Posts: 2,580
QuoteOriginally posted by Blue Quote
Pentax had working prototypes a few years back of the 1.4x TC.
I do remember seeing pictures of it at a show, and wondered why they never came up with it. They certainly would have sold quite a few.
09-15-2012, 11:43 AM   #205
Moderator
Site Supporter
Blue's Avatar

Join Date: Jun 2008
Location: Florida Hill Country
Photos: Gallery | Albums
Posts: 17,166
QuoteOriginally posted by borno Quote
I do remember seeing pictures of it at a show, and wondered why they never came up with it. They certainly would have sold quite a few.
A couple of members got to actually play with them at one of the shows. Its one of the big Pentax mysteries.
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!
da, lens, pentax, pentax da, pentax news, pentax rumors, photokina
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
The Pentax DA 560/5.6 will indeed be collapsible...I think... Pål Jensen Pentax News and Rumors 28 09-06-2012 11:48 AM
Pentax K-5 + YN 560 II X-Sync striker_ Flashes, Lighting, and Studio 2 08-03-2012 11:47 AM
Pentax 540 and Yongnuo 560 - if they flash together? pich Flashes, Lighting, and Studio 3 10-29-2011 04:49 AM
yn-560 flash +pentax k-5 Purusam Pentax K-5 2 03-12-2011 05:02 PM
Pentax Expected at Las Vegas CES January 6-9 2011 bobell69 Pentax News and Rumors 26 01-12-2011 02:19 PM



All times are GMT -7. The time now is 05:33 PM. | 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