Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
05-23-2016, 10:00 PM   #1
Senior Member




Join Date: Apr 2015
Location: Western Washington
Posts: 204
D FA 28-105 better IQ than D FA 24-70

I'm planning on getting a K-1 when they are available again and am considering a general purpose (and good quality) lens to start with. I'm getting the impression after reading online reviews of both lens that the IQ of the less expensive actually has better IQ than the more expensive D FA 24-70. Is this the general impression in comparing these two lens?

I'm aware that the 24-70 has more to offer in terms of providing f2.8 at all focal lengths. The weight of the lens is OK with me. I'm a bit disappointed that the 24-70 isn't manufactured by Pentax - just relabeled, or whatever Pentax does to it.

What's the general opinion concerning these two?

05-23-2016, 10:18 PM   #2
Administrator
Site Webmaster
Adam's Avatar

Join Date: Sep 2006
Location: Arizona
Photos: Gallery | Albums
Posts: 51,584
QuoteOriginally posted by PhilRich Quote
I'm a bit disappointed that the 24-70 isn't manufactured by Pentax
But hey, it's "Made in Japan", unlike Pentax lenses Same with the 15-30mm.

I was actually planning to do a detailed test comparing the two lenses tomorrow. I'll post my results once I have them!

Adam
PentaxForums.com Webmaster (Site Usage Guide | Site Help | My Photography)



PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:
05-23-2016, 10:26 PM   #3
Pentaxian
Paul the Sunman's Avatar

Join Date: Aug 2011
Location: Melbourne
Photos: Gallery
Posts: 4,836
My impression is that the 28-105 is great in the centre, but may lag the 24-70 at the edges. I will await Adam's comparison with interest.
05-23-2016, 11:53 PM   #4
Site Supporter
Site Supporter
jatrax's Avatar

Join Date: May 2010
Location: Washington Cascades
Photos: Gallery | Albums
Posts: 12,991
I debated a long time between the two and finally got the 24-70 which I am happy with. But I hear good things about the 28-105 as well. Also looking forward to Adam's review.

05-24-2016, 12:41 AM   #5
Veteran Member




Join Date: Jul 2007
Location: Sweden
Posts: 845
It's not a simple relabeling. The optics are the same as the Tamron versions plus the added bonus of Pentax own coating. The Pentax versions are weather sealed, the Tamron labels not. There's also Pentax electronics and chip inside the Pentax versions.
05-24-2016, 12:54 AM   #6
Site Supporter
Site Supporter
acoufap's Avatar

Join Date: Jan 2011
Location: Munich, Germany
Photos: Gallery | Albums
Posts: 4,161
QuoteOriginally posted by Adam Quote
But hey, it's "Made in Japan", unlike Pentax lenses Same with the 15-30mm.

I was actually planning to do a detailed test comparing the two lenses tomorrow. I'll post my results once I have them!
Great, thanks!
05-24-2016, 01:31 AM   #7
Forum Member




Join Date: Jun 2013
Location: Otradnoe, Moscow
Posts: 65
I was initially disappointed with the 24-70 as I was getting soft results at f2.8. However, I discovered that I needed some AF adjustment. I'm now incredibly happy with this lens.

05-24-2016, 01:40 AM   #8
Site Supporter
Site Supporter
Papa Lazarou's Avatar

Join Date: Mar 2013
Location: Bletchley, Buckinghamshire, UK
Posts: 340
I haven't tried the 28-105, but am another very pleased 24-70 user. It's brilliant on the K-1.
05-24-2016, 03:20 AM   #9
Veteran Member
FantasticMrFox's Avatar

Join Date: Oct 2014
Location: Munich
Posts: 2,339
QuoteOriginally posted by RMabo Quote
The Pentax versions are weather sealed, the Tamron labels not.
The Tamron 24-70 f/2.8 has always been weather sealed
05-24-2016, 03:32 AM   #10
Veteran Member
robjmitchell's Avatar

Join Date: Oct 2007
Location: Melbourne Aus
Posts: 1,776
From all accounts the 24-70 is a superb lens, with the pentax version seeming to have improved performance over the Tamron VC version due to removal of VC elements (increased corner sharpness) plus the improved contrast and flare control from the pentax coating. It was also designed by a famous ex pentax employee and comes with a fast ring type USM motor.
The 28-105 on the other hand is simply exceptional for the price point. Its main weakness is that it is not that wide and has weaker corners on the long end, along with the obvious limitations of a slower aperture. If you plan on buying a wider lens or like using some of the great pentax primes then it makes sense. If you want the best zoom performance and 24mm is wide enough then I'd go the 24-70. Of course personal rendering preference comes in to it too. I love the rendering of DA*16-50 for instance despite all its optical weaknesses.
ephotozine has reviews up.
https://www.ephotozine.com/article/pentax-hd-pentax-d-fa-24-70mm-f-2-8-ed-sdm-wr-review-29349
https://www.ephotozine.com/article/tamron-sp-24-70mm-f-2-8-vc-usd-lens-review-19056
https://www.ephotozine.com/article/hd-pentax-d-fa-28-105mm-f-3-5-5-6-ed-dc-wr-lens-review-29352
05-24-2016, 06:32 AM   #11
Veteran Member




Join Date: Jun 2013
Location: Nevada, USA
Photos: Albums
Posts: 3,348
I don't have the 28-105 but I do have the 24-70. K-3 is my body. The 24-70 is exceptional for sure. My system seems to have a hard time nailing focus. Sometimes it's front focused. Sometimes its back focused. It's like the lens overshoots the focus point. I don't know if that's the K-3 commanding it incorrectly or if the lens is wonky. It could also be shake reduction just not having settled down either. That's happens a minority of the time. When proper focus is achieved I think the performance is prime-like.
05-24-2016, 11:54 AM   #12
Senior Member




Join Date: Apr 2015
Location: Western Washington
Posts: 204
Original Poster
It is good to hear that those who have the 24-70 really like it - helps my decision on which one I'll purchase. Thanks.
05-24-2016, 12:44 PM   #13
Loyal Site Supporter
Loyal Site Supporter
boriscleto's Avatar

Join Date: Dec 2009
Location: North Syracuse, NY
Photos: Gallery
Posts: 16,464
QuoteOriginally posted by RMabo Quote
The Pentax versions are weather sealed, the Tamron labels not.
Tamron calls the 24-70 'drip-proof'. That's pretty much what Pentax calls 'Weather Resitant'. The main difference is the Tamron has VC and the Pentax does not.
05-24-2016, 03:57 PM   #14
Site Supporter
Site Supporter
jatrax's Avatar

Join Date: May 2010
Location: Washington Cascades
Photos: Gallery | Albums
Posts: 12,991
QuoteOriginally posted by 6BQ5 Quote
I don't know if that's the K-3 commanding it incorrectly or if the lens is wonky.
Boris, do you have the latest k-3 firmware?
05-25-2016, 02:03 AM - 2 Likes   #15
Administrator
Site Webmaster
Adam's Avatar

Join Date: Sep 2006
Location: Arizona
Photos: Gallery | Albums
Posts: 51,584
I shot some comparisons as promised and the results are quite interesting. For this post, I only compared the lenses at 28mm and 70mm and used unedited raw files.

Sharpness

The short version is that both lenses are great. In the center, at 28mm, the 24-70mm is sharper by a hair at F2.8 compared to the 28-105mm at F3.5, but the difference is negligible. In the corner, the lenses are about the same, though the 28-105mm exhibits more fringing.

At 70mm, again the two lenses are neck-and-neck in the center, even wide-open. Out in the corner, though, the 28-105mm actually pulls a little bit ahead of the 24-70mm, which is softer and shows more fringing wide-open. Given the 1.5 stop difference, though, this is to be expected. When the 24-70mm is stopped down, it catches up to the 28-105mm.

Stopped down, I'd say that both lenses are sharp "corner to corner". So, in practice, the difference between sharpness between the two is negligible.

Vignetting

Both lenses vignette significantly when wide-open at the wide end. At 70mm, the 28-105mm vignettes noticeably more, however, as it has visible falloff near the center of the frame when wide-open. Things clear up nicely after being stopped down to F4/5.6.

For wide-open shots, some vignetting remains visible even after running in-camera corrections. All in all, the 24-70mm is the winner in this category, but you can still see dark corners in the viewfinder with it. The vignetting just isn't as bad at the tele end.

Field of View

This is another area of practical significance. The 24-70mm gives you a field of view that's 8 degrees wider than the 28-105mm. On the other hand, the 28-105mm gives you plenty more reach.

Size and Weight

The 24-70mm is almost twice as heavy as the 28-105mm, and its barrel is some 2cm wider in diameter. I didn't find the larger size to be an issue, but you can certainly feel the difference in weight. Both lenses handle well, though I prefer the tactile feel/distance scale of the 24-70mm's focusing ring.

Conclusion

Both area great lenses! At the end of the day I think it boils down to features and size. The 24-70mm is fast and heavy, the 28-105mm is slow and light, but the lenses' overall optical performance is otherwise similar.

The 28-105mm certainly exceeds expectations given its $499 price tag. While it looks similar to the APS-C 18-135mm, it's considerably sharper.

Adam
PentaxForums.com Webmaster (Site Usage Guide | Site Help | My Photography)



PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:
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!
fa, impression, iq, k-mount, lens, pentax, pentax lens, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
IQ Difference between the DA 16-85 and the D FA 24-70 F2.8 Driline Pentax SLR Lens Discussion 10 05-16-2016 09:59 AM
How is FA* 28-70mm/f.8 vs HD PENTAX-D FA 24-70mmF2.8ED? henryzhou Pentax DSLR Discussion 4 05-15-2016 10:48 PM
FA Limiteds vs. the new D-FA 24-70 zoom 6BQ5 Pentax SLR Lens Discussion 31 09-27-2015 11:38 AM
D FA* 70-200 and D FA 150 - 450 samples davidsladek Pentax SLR Lens Discussion 54 03-28-2015 09:56 PM
D-FA* 70-200mm and D-FA 150-450mm Announced PF Staff Homepage & Official Pentax News 7 02-08-2015 03:10 PM



All times are GMT -7. The time now is 07:18 AM. | See also: NikonForums.com, CanonForums.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