Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
07-15-2007, 12:24 PM   #1
Inactive Account




Join Date: Jun 2007
Location: Baltimore, Maryland USA
Posts: 162
A-Series Pentax Lens Quality

Do all A-series lenses possess superior optical quality compared to the M & Kseries lenses that preceded them??

For instance, is the A 15mm f3.5 lens better than the K 15mm f3.5??

I realise that all of the lenses with a * in the designation were designed to be optically superior..

I have seen mentioned that you have to "set the focal length" when using A-series lenses with the K100 & K10D cameras..

What exactly does this mean, & how is it accomplished??

I've recently acquired an A 50mm f1.4 lens & would like to be able to use it with confidence on my K10D..

Thanks for any & all help concerning this matter..

Bruce

07-15-2007, 12:45 PM   #2
Inactive Account




Join Date: Jun 2007
Posts: 264
QuoteOriginally posted by baltochef920 Quote
Do all A-series lenses possess superior optical quality compared to the M & Kseries lenses that preceded them??
No, not all. The A-series were a later line with added electronic functions... this does not mean they were all optically superior. Best to compare the lenses on an individual basis (or simply don't bother, and just buy one safe in the knowledge that none will be bad ) But there are various sites where people have run tests or present their own opinions of which are better. Sites like this which lists results of resolution tests (not including either 15mm though).

QuoteOriginally posted by baltochef920 Quote
I have seen mentioned that you have to "set the focal length" when using A-series lenses with the K100 & K10D cameras..
It has no significance at all for normal shooting, except when using Shake Reduction... the SR system needs to know the focal length of the lens.

QuoteOriginally posted by baltochef920 Quote
I've recently acquired an A 50mm f1.4 lens & would like to be able to use it with confidence on my K10D..
You can - some might be better than others, but any Pentax 50mm f/1.4 is a good lens.
07-15-2007, 01:40 PM   #3
Veteran Member
creampuff's Avatar

Join Date: May 2007
Location: Singapore
Photos: Gallery
Posts: 3,955
Optically, I have found the older M & K lenses to be cooler in tone (bluer) when compared to equivalent focal length A versions. This I attribute to possible differences in the lens coating. The A lenses differ because of the electronic contacts that allow the camera to set the aperture, hence the A setting on the aperture ring. Yes the A* lenses are very good but not every A lens is necessarily optically better than the earlier M & K lenses - eg the A 135mm f2.8 is only so-so.
07-15-2007, 02:01 PM   #4
Administrator
Site Webmaster
Adam's Avatar

Join Date: Sep 2006
Location: Arizona
Photos: Gallery | Albums
Posts: 43,281
Specifically speaking, the A 15mm has only 5 aperture blades, while the K version has 6. The A series contains many lenses faster than their M or K counterparts, but in general, the series does not denote any superior optical quality. It all depends on what lenses you're comparing!

I'm moving this thread to the lens forum since it doesn't belong here- please always remember to post in the correct category!


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



PentaxForums.com's high server and development costs are user-supported. You can help cover those costs by donating. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

07-15-2007, 02:37 PM   #5
Veteran Member
FotoPete's Avatar

Join Date: Feb 2007
Location: Toronto
Photos: Gallery
Posts: 1,710
The A series saw the introduction of more plastic. I like metal bodies better.

It bothers me that it seems only the Limited are built to last nowadays. I mean how many of today's lenses where build like they were decades ago. Even something as cheap as the M 50/2.

Last edited by FotoPete; 07-15-2007 at 09:09 PM.
07-16-2007, 03:12 PM   #6
Site Supporter
Site Supporter
jamesk8752's Avatar

Join Date: Dec 2006
Location: Suburban Detroit, MI, USA
Posts: 226
[QUOTE=baltochef920;76573]Do all A-series lenses possess superior optical quality compared to the M & Kseries lenses that preceded them??

For instance, is the A 15mm f3.5 lens better than the K 15mm f3.5??

(snip)

/QUOTE]

For what it's worth, I own copies of both the K and A versions of the 15/3.5, and I have found my K version to be sharper in the corners than my A version. Of course, this may be due to sample varriation, as the optical design is said to be identical. IMO neither is particularly good on digital - my DA14/2.8 blows both of them away for sharpness and contrast.

Note that I think that individual lens comparisons are often questionable because of lens-to-lens production variations or misalignment due to age and rough treatment. Unfortunately few if any of us can afford to acquire multiple copies to use for lens tests!
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!
15mm, a-series, k-mount, lens, lenses, pentax lens, quality, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
K or M Series - Which has the best image quality 8540tomg Pentax SLR Lens Discussion 20 10-05-2009 07:53 AM
Which K-series lenses equal * quality? Rorschach Pentax SLR Lens Discussion 31 09-01-2009 06:39 AM
Cokin P Series, Z-Pro Series and quality filters max11 Pentax Camera and Field Accessories 2 06-08-2009 04:00 PM
A Series Build Quality tux08902 Pentax SLR Lens Discussion 10 01-25-2008 07:46 PM



All times are GMT -7. The time now is 12:05 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