Go Back   Steve's Digicams Forums > Digital SLR and Interchangeable Lens Cameras > Pentax Lenses

Thread Tools Search this Thread
Old Sep 17, 2008, 7:08 AM   #1
Senior Member
Join Date: Jun 2007
Posts: 179

One of my most-used lenses is a Pentax SMC 50mm f/1.4 that I bought new in about 1976. It has been superceded by similar Pentax lenses bearing appelations suc as "M", "A", "F", "FA", etc. It was preceded by "Takumar" lenses, possibly of several types. This lens is almost as new, regardless of its age, and, since it is kind of an old buddy, I will keep it in any case.

My question: are the optics in all of these essentially the same? If not, what is considered to be better? I am used to shooting manually. I might replace the lens I now have if I can get an alike one which is greatly better.

I hope someone reading this has had experience enough in this matter to asdvise me.

Old Engineer
Old Engineer is offline   Reply With Quote
Sponsored Links
Old Sep 17, 2008, 11:11 AM   #2
Senior Member
bilybianca's Avatar
Join Date: Nov 2005
Location: Hassleholm, Sweden
Posts: 3,436

As far as I know, and can see on Bojidar Dimitrov's fantastic site http://www.bdimitrov.de/kmp/ the optical design of all Pentax 50mm 1.4 (K, M, A, F, FA) is the same. But apparently there was some tweaking of the lens elements when the A version was introduced, to get (even) better resolution in the corners. This should be of less importance when used on a digital body, due to the smaller sensor. Maybe there is a difference/improvmentin the SMCcoating. Some say one is better, some say another. Myself I think differences are rather due to the individual lens or batch of lenses.

For a thorough discussion on the topic, check Stan's page: http://stans-photography.info/. Click "normal prime lenses", scroll to "50 mm Lenses - They are all good; which is better", click the headline to get the extended discussion. Then enjoy the reading, after that you will enjoy and appreciate your recent lens even more.

bilybianca is offline   Reply With Quote
Old Sep 17, 2008, 2:34 PM   #3
Senior Member
mtngal's Avatar
Join Date: Nov 2005
Location: Frazier Park, CA
Posts: 16,087

An interesting question. My own personal experience is that my M 50mm 1.4 lens is really soft at 1.4, softer than my M 50mmm 1.7 is at 1.7. If you stop both lenses down to f2, they are exactly the same. It's seemed to me that the pictures posted around here taken with either the A or FA versions of the 1.4 are better than what my M 1.4 is capable of, so I always assumed that Pentax tweaked the design when they came out with the A version, making it sharper wide open. But Kjell is probably right - my softness could be due to the particular lens I happen to have, rather than a design change.
mtngal is offline   Reply With Quote
Old Sep 17, 2008, 7:34 PM   #4
Senior Member
robar's Avatar
Join Date: Mar 2005
Location: D/FW area Texas
Posts: 7,590

i've used both the M and the FA and i have to say that i miss my M even tho it was perfectly usable(i've got great shots) wide open i've got to say the FA is a tad bit better IQ and is AF to boot.. it's one of 2 AF lenses i have out of 11 i use..

robar is offline   Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

All times are GMT -5. The time now is 1:03 PM.