Forgot Password
Pentax Camera Forums Home

Show Printable Version Search this Thread
02-20-2008, 03:06 PM - 1 Like   #1
Veteran Member
bc_the_path's Avatar

Join Date: Mar 2007
Location: Ankara, Turkey
Photos: Gallery
Posts: 399
Pentax FA 28-70mm f/4 vs Tamron 28-75mm f/2.8

These two lenses share about the same range. Tamron is faster; Pentax is cheaper!
So what? you may ask! I have the Pentax 28-70mm on my MZ-3 and I have tried it on my K10D comparing it with Sigma 17-70mm. After a casual test (at 35mm), I have failed to see much difference between them, color-wise and resolution-wise.
Since it is a full frame lens, I expect better (than Sigma 17-70mm) performance at the edges on my APS-C sensor (not tested).

Is there anyone saying that Tamron 28-75mm is a FAR BETTER lens than my Pentax 28-70mm? (Yes, this question is a sign of my LBA). Is it true that Pentax is sufficiently sharp at f/4 throughout its range?

Can I justify selling my Pentax for about €50, and buying Tamron for about €400? (My wife will send her regards to those who will say "no").

And, why do I ask? Because there have been too much praise of the Tamron recently in this forum. That is why

02-20-2008, 03:09 PM   #2
Inactive Account

Join Date: Dec 2006
Location: Outside of Philly
Posts: 1,561
Well the Tamron is sufficiently sharp at f/2.8 throughout it's range. I've never tried the FA f/4, but I absolutely loved my Tamron. I say go for it!
02-20-2008, 05:10 PM   #3
Veteran Member
creampuff's Avatar

Join Date: May 2007
Location: Singapore
Photos: Gallery
Posts: 3,953
As a FA 28-70 f/4 user, I would say get the Pentax, save the money and make your wife happy.

I have had 2 copies of the Pentax. It is a very compact lens and seriously, with the 1.5x crop factor, the 28-70 focal length simply doesn't go wide enough. I have no doubt the Tamron 28-75mm is a good lens, it's just that the focal range isn't too versatile for me.

The Pentax has a decent performance. Certainly one of the better consumer grade Pentax zooms. The price difference for a gain of 1 stop isn't very significant in my opinion. Another reason why I have kept my DA 16-45 f/4 instead of the newer DA* 16-50 f/2.8.

Here's a stray cat taken with the Pentax FA 28-70 f/4. Nice colour and good detail. Cropped left ear indicates the cat has been neutered.

Last edited by creampuff; 02-20-2008 at 11:29 PM.
02-20-2008, 08:20 PM   #4
Senior Member

Join Date: Jul 2007
Location: Quezon City, Philippines
Photos: Gallery | Albums
Posts: 143
wow! that's tack sharp!

02-20-2008, 08:26 PM   #5
Veteran Member

Join Date: Mar 2007
Location: Boston, PRofMA
Photos: Albums
Posts: 3,026
QuoteOriginally posted by creampuff Quote
Cropped left ear indicates the cat has been neutered if snipping something else weren't enough :-P
02-20-2008, 09:14 PM   #6
Veteran Member
hinman's Avatar

Join Date: Oct 2006
Location: Fremont, CA
Photos: Albums
Posts: 3,473
Keep the Pentax

I don't have the Pentax FA 28-70 f/4.0 but if I were you, I would keep the Pentax and use the money for a good prime or zoom not overlapping the range that you have. That is of course, if you like the Pentax lens for the range and aperture that it performs for you. After trying out many lens, I have to say that a lot of f/3.5 and f/4.0 lens are just as good in daylight shooting.

The LBA cracks up on me really bad that I got both Tamron 28-75 f/2.8 and Pentax 28-105 f/3.2-4.5, along with a good SMC FA 28-80 f/3.5-4.5 power zoom. There is no doubt in my mind that the Tamron is a superb lens for image quality, build quality, and fast and sharp lens at wide open aperture. But having 2+ lens in similar range would make your life tougher when you have to decide which one to sell.

My life is miserable after having all good lens in that same range and I hesitate to sell one over the other. It is a good problem to have with too many lens but if I can do it all over again, I will always prioritize with less is better and go with prime for longer term and keep usable zooms around such as your Pentax.

After test shots with Pentax SMC FA 28-105, I decide to keep it longer along with the Tamron. One thing that I especially like about the Pentax 28-105 is on its small weight and size and in terms of traveling needs and walk around needs, I will pick the Pentax FA 28-105 any day over the Tamron. Tamron's fans, please don't flame me as I do love the Tamron but not in its weight. And you have to compare the weight of your current Pentax with that in the Tamron if weight is a factor in your consideration for highly used zoom.

Just a thought from someone having a hard time to decide which lens in repeated focal range to sell.
02-21-2008, 05:09 AM   #7
New Member

Join Date: Feb 2008
Location: Meltham, West Yorkshire
Posts: 1
As a long-time Tammy user, I'd say go for it, especially considering that it can be got for around 240 EUR new from e-bay.

The Tamron is an extremely good performer and of comparable quality to the FA and M 50mm primes at that focal distance.

A sample from the lens:


02-21-2008, 01:03 PM   #8
Veteran Member
bc_the_path's Avatar

Join Date: Mar 2007
Location: Ankara, Turkey
Photos: Gallery
Posts: 399
Original Poster
Thank you!

Thank you all, my friends...
I have decided to give a serious try to my Pentax FA 28-70mm f/4.
Thanks also for the nice photos you submitted.
02-21-2008, 01:36 PM   #9
Veteran Member

Join Date: Jul 2007
Location: Florida Gulfer
Photos: Albums
Posts: 3,054
This is the Sigma 28-70 f2.8


  • 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!
28-70mm, f/4, fa 28-70mm f/4, k-mount, pentax, pentax fa 28-70mm, pentax lens, sigma, slr lens, tamron
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Similar Threads
Thread Thread Starter Forum Replies Last Post
Tamron 17-50mm, Tamron 28-75mm, Sigma 17-70mm, which lens for my trip to Greece? macky112 Pentax SLR Lens Discussion 15 11-20-2011 03:08 PM
Pentax FA* 28-70mm/2.8 VS Tamron 28-75mm/2.8 at 50mm pcarfan Pentax SLR Lens Discussion 27 05-30-2010 06:14 AM
Tamron 28-75mm f2.8 or Sigma 24-70mm f2.8? bfo Pentax SLR Lens Discussion 15 05-01-2010 03:47 AM
Wanted - Acquired: sigma 17-70mm or tamron 28-75mm f/2.8 kjfaust Sold Items 1 01-26-2010 07:25 PM
For Sale - Sold: Pentax DA50-200mm, FA50mm, M50mm f2, Sigma 24-70mm, Tamron 28-75mm ndy4eva Sold Items 9 09-04-2009 09:20 AM

All times are GMT -7. The time now is 03:10 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]