Forgot Password
Pentax Camera Forums Home

Show Printable Version Search this Thread
05-27-2016, 06:20 PM   #1
Site Supporter
Site Supporter
jeffreybehr's Avatar

Join Date: Feb 2016
Location: Phoenix, Arizona USA
Photos: Gallery | Albums
Posts: 59
Pntax 24-90, 28-105, 100-300/4.7..., Tamron 28-300, Sigma 70-300...and new 15-30

Having lots more money than good sense, I've purchased and tested these lenses, among others, with my K-1:
SMC Pentax-FA 24-90mm F3.5-4.5 AL [IF] ... SMC Pentax-FA 24-90mm F3.5-4.5 AL [IF] Reviews - FA Zoom Lenses - Pentax Lens Reviews & Lens Database
HD Pentax-D FA 28-105mm F3.5-5.6 ED DC WR ... HD Pentax-D FA 28-105mm F3.5-5.6 ED DC WR Reviews - D FA Zoom Lenses - Pentax Lens Reviews & Lens Database
SMC PENTAX-FA 100-300mm f/4.7-5.8 ... SMC Pentax-FA 100-300mm F4.7-5.8 Reviews - FA Zoom Lenses - Pentax Lens Reviews & Lens Database
Sigma 70-300mm F4-5.6 APO DG Macro ... Sigma 70-300mm F4-5.6 APO DG Macro Lens Reviews - Sigma Lenses - Pentax Lens Review Database
Tamron 28-300mm F3.5-6.3 XR Di AF ... Tamron 28-300mm F3.5-6.3 XR Di AF Lens Reviews - Tamron Lenses - Pentax Lens Review Database

The 24-90, 28-105, and 28-300 are competing at being my one walkabout lens. Overall, I liked the range to 24 but wanted more on the longer end but don't 'need' range to 200-300mm. I was satisfied, overall, with the 24-90 but wanted to see if the NEW 28-105 was better. The answer is yes and no. The 24-90 is sharper at the shorter lengths and the 28-105 was sharper at the longer lengths. The 28-105 'feels' better while the 24-90 is lighter and less expensive, as in c. U$500 v. c. U$250. No advantage here.

The Tamron surprised me...positively! It feels about the same (=good) as the 28-105, both feeling more solid (and heavier) than the 24-90. At lengths thru c. 100mm, the Tamron is sharper than either the 24-90 or 28-105 and its images look quite good. For $350 v. $500, it's a 'no-brainer' choice over the more-expensive 28-105. And one gets the flexibility of much-longer reach. For MY walkabout lens, the Tamron 28-300 is the winner, the 24-90 is the bargain winner AND it's lighter, and the new 28-105 is a bit of a disappointment to me; mine's going back.

I bought the 100-300/4.7-5.8 for about $60 delivered. Over my last 16 years as a fotog I haven't shot much with long lenses so I wasn't willing to spend much money on one. The 100-300 is better than its price indicates and is actually good...or at least adequate. But recently I bought the Sigma for $199 at B&H, and after the Tamron 28-300 arrived I compared their images. The 100-300 is bettered clearly by the relatively-bargain-priced Sigma (U$199 delivered for a 300mm lens! And I paid about $1500 for the Canon L-series 70-300 I used with my various Canon 5Dany bodies!) The Sigma's images were still sharper than the Tamron's at 100 - 300mm, so the Sigma will be my 'serious' telezoom while the Tamron will still be my casual-carry lens with more reach than I bargained for. I'm very happy I found this Tamron.

After buying Zeiss ZKs in 28/2, 35/2, and 85/1.4 and being VERY happy with their results, I decided not to pursue the apparently-even-rarer (and sometimes-FAR-more-expensive) ZKs shorter than 28. That left me looking for an excellent ultrawide and I decided to try the new Pentax HD 15-30/2.8 ... HD Pentax-D FA 15-30mm F2.8 ED SDM WR Reviews - D FA Zoom Lenses - Pentax Lens Reviews & Lens Database
First, it's big and heavy.

L-to-R, 15-30, ZK 35/2, Limited 43/1.9, ZK 85/1.4, and Sigma 70-300.

Secondly, the U$170 Fotodiox WonderPana66 filterholder spec'd for the Tamron 15-30 fits perfectly. ...

With adapters for the 6.6"/150mm slide-in filters.

Thirdly, it performs very well so far in my limited testing, so I'm keeping all that stuff.

Last edited by jeffreybehr; 05-27-2016 at 06:40 PM.
05-27-2016, 08:42 PM   #2
Loyal Site Supporter
Loyal Site Supporter
UncleVanya's Avatar

Join Date: Jul 2014
Photos: Gallery | Albums
Posts: 16,980
Did you consider testing the FA 28-200 or the third party version?

I'm frankly stunned that the 28-300 performed this well. Pictures showing your points would be fantastic.
10-05-2016, 03:46 PM   #3
Loyal Site Supporter
Loyal Site Supporter

Join Date: Feb 2010
Location: Maryland
Posts: 467
Interesting comparison, I also own the 28-300 Tamron, the Pentax 24-90, the Pentax 28-70 FA and tested them against prime lenses (FA 50 1.4, and FA 50 Macro 2.8). Agree about the Pentax 24-90 being pretty good considering its aging design. It really is pretty flimsy mechanically.
I tested these lenses on a solid pier examining a solid building in the distance. Mirror lockup and remote shutter release at F11 to minimize focusing inaccuracies. I also tested image shift resolution for each lens.

My analysis of IQ suggested the following rough order for sharpness at F11:

FA 50 1.4 = FA 28-70 2.8 >FA 50 2.8 macro=Pentax 24-90 >>28-300 Tamron.

For contrast:

FA 50 1.4=FA 28-70 2.8=FA 50 2.8 macro=Pentax 24-90 >>28-300 Tamron

For image shift resolution:

FA 50 1.4=FA 28-70 2.8=FA 50 2.8 macro=Pentax 24-90 showed obvious improvement with pixel shift.
28-300 Tamron showed no improvement.

My conclusion was that the FA 28-70 (at 50) was superb, the 24-90 was really good and the Tamron.....not so much. The pixel shift resolution test was interesting. Is it possible that the former lenses are still out-resolving the 36 megapixel sensor?

Your mileage may vary of course.

Last edited by Pentax Syntax; 10-05-2016 at 03:50 PM. Reason: added information
10-19-2016, 04:26 AM   #4
Forum Member

Join Date: Apr 2007
Location: Hamburg
Posts: 99
there is a difference between the 2 Versions of the Tamron 28-300 and Version II. !

In the german has someone tested the different versions....

I have the II. myself and I'm quite satisfied with it's results!


  • 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!
database, fa, k-mount, lens, lenses, pentax, pentax lens, pentax-fa, reviews, sigma, slr lens, smc, tamron
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Similar Threads
Thread Thread Starter Forum Replies Last Post
For Sale - Sold: Pentax FA 100-300, FA 70-200, M 28mm; Sigma EX 28-70, Apo 70-300; Tamron Di LD 70-300 stillnk Sold Items 17 04-08-2012 11:39 AM

All times are GMT -7. The time now is 08:31 PM. | See also:, 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?
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]