Forgot Password
Pentax Camera Forums Home

Show Printable Version Search this Thread
04-15-2012, 09:50 PM   #1
Senior Member

Join Date: Jan 2010
Location: HCMC
Posts: 271
50-55-58mm Subjective Sharpness Rating

Hi all,

I’ve been searching for the sharpest 50-55-58mm lens wide open or up to f2.8 (with the exception of the macros at f4) in pentax or m42 mounts with a pleasing background that goes with it. I am sure am not the only one searching for this info and I would like to do something about it...

We all know that we can never compare specific lenses due to endless differences in characteristics, that’s why I am mainly focusing on the sharpness without considering all the other characteristics (except for the background blur or bokeh) in order for us to have a more accurate data.

With this in mind, I will try to gather all the information I could get with your help... for us to create a compilation of individual user/lens experience ratings for these FL’s (the 50-55-58mm) to once and for all address the issue of sharpness…

This data is all Subjective that’s why I need to set a rule on rating a specific lens…

 Pentax (most modern) to the oldest M42 mounts (or any other mounts that can be adapted/fitted on our Pentax bodies without the need for surgeries)
 50mm, 55mm or 58mm only (or any other unusual focal lengths if there are still any within the range of 50-58mm)
 A Subjective data compilation for all of your lenses within these focal lengths
 Subjective Sharpness rating only combined with a pleasing Bokeh (A)
 Write the complete lens name (Optional / if you deemed necessary for future information you can also include the Serials)
 Lens settings from Wide open up to f2.8 only (with the exception of macros at f4)
 Rate from 1-10 (10 being the highest)(B)
 Subjective Bokeh rating: A, B or C (Some prefer smooth and buttery, others swirly or busy)
 Sample Rating info for a lens in its simplest form: Lens Name – Aperture – Bokeh:
Sample: SMC FA 50 1.7 – f1.7 - 10A

With this information, I will decode each and every lens rating by username and create a file (in pdf form to secure and protect the original file) that I will update here in Pentaxforums (exclusively) on a regular basis.

You can update lens rating if you have acquired another lens…
Ex) Original Rating (2 lenses)
SMC FA 50 1.7 – f1.7 – 2A
SMC M 50 2 – f2 – 1C

Updated Rating (3 lenses): You only need to update the 3rd lens and the lens you want to give a higher rating to (highest for 3 lenses)
SMC FA 50 1.7 – f1.7 – 3A
Super Takumar 55 1.8 – f1.8 – 2A

I hope this data will pave the way for us to have a concrete information on all of our old and modern lens sharpness in these focal lengths…

Thanks to all in advance

(A): Pleasing Bokeh is a very wide topic as well, so we will need to rate the bokeh subjectively as well from (A, B or C) in the simplest possible way…
 A: Smooth and Buttery Bokeh
 B: Swirly Bokeh
 C: Busy or Distracting Bokeh

(B): 1-10 Rating… (Based on the number of lenses you own or used in order for me to control any bias ratings)
 1 lens – 1 is the highest rating, 2 lenses – 2 is the highest rating, 3 lenses – 3 is the highest rating and so on….

04-15-2012, 10:04 PM   #2
Senior Member

Join Date: Jan 2010
Location: HCMC
Posts: 271
Original Poster
Let me start this one...

SMC FA 50 1.7 - f1.7 - 8A
SMC K 55 1.8 - f1.8 - 8A
Super Takumar 55 1.8 - f1.8 - 8A
SMC M 50 1.7 - f1.7 - 8A
Fujinon 50 1.9 - f1.9 - 7A
Helios 44-2 - f2 - 7B
Super Takumar 50 1.4 - f1.4 - 6A
SMC M 50 2 - f2 - 6C
Chinon 50 1.7 -f1.7 - 4A
Revuenon 55 1.2 - f1.2 - 4A
SMC A 50 1.4 -f1.4 - 4A
Helios 44M-4 - f2 - 4A
Helios 44M - f2 -4A

I will update my other lenses if i missed them...
04-15-2012, 10:05 PM   #3
Senior Member

Join Date: Jan 2010
Location: HCMC
Posts: 271
Original Poster
I am wondering about the IQ of Pancolar 50 1.8...
04-16-2012, 12:42 AM   #4
Veteran Member
hoanpham's Avatar

Join Date: Nov 2009
Location: Strand
Photos: Gallery | Albums
Posts: 1,366
Thanks for your effort.

I have several comments:
(1) I have too many lenses, mapping bokeh and sharpness in each f-stop will take forever.
(2) Bokeh is highly personal preferences. Some dislike the round ring from mirror lenses, some doesnt like the harsh, swirly, glow ring but I think they all are unique and can be used with excellent result from case to case. During the mapping process, one will find out that at some distances, the bokeh is distracting, but acceptable otherwise, given condition the same f-stop, same focal, same lens - the background pattern/edges affects the bokeh result.
(3) Copy variation, especially sharpness - also a highly personal preference. I like my Petri 28/2.8 which is sharp but with soft/glow wide open for it's own character, but razor sharp one click down. Or the tamron 70-150/2.8 soft focus, which is compact and has a bonus of razor sharp at all f-stop when soft focus is not used.

No offense from me - please understand that I am appreciate your work here.
I am not fan of testing lenses infront of a chart. I shot mostly portrait, and interested in properties of a lens for my use: distances, f-stop, sharpness, bokeh, CA/PF, distortion, focus throw.
If you have data of 40 lenses in 50/55/58, what purpose can these data serve us? You may end up keeping one of each. I also got the bad bokeh lenses after I read bad reviews - they turn out to be not so bad anyway.

04-16-2012, 11:28 AM   #5
Veteran Member
RioRico's Avatar

Join Date: Jun 2008
Location: Limbo, California
Posts: 11,264
I agree with @hoanpham that copy variation and individual preference make this an impossible chore. It would indeed be possible (and tedious) to test sharpness+resolution+contrast+etc for individual lenses at all apertures. But those numbers would only apply to those specific copies. Different users would interpret them differently, as well as having their own tastes in bokeh, rendering, character. The many versions of the Helios-44 alone would be difficult to qualify. Good luck!
04-16-2012, 11:08 PM   #6
Otis Memorial Pentaxian
Loyal Site Supporter
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 42,007
What they said...It is enough to say that most lenses have a definite flavor. This is usually evident by looking at example photos.


  • 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!
bokeh, data, f1.7, information, k-mount, lens, lenses, pentax, pentax lens, sharpness, slr lens, smc
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Similar Threads
Thread Thread Starter Forum Replies Last Post
Sharpness, Fine Sharpness, Extra Sharpness Taviali Pentax K-5 & K-5 II 8 03-31-2012 12:56 PM
For Sale - Sold: M42 lenses: Helios 44-2 (58mm/f2) and Carl Zeiss 58mm/f2 (Worldwide) geauxpez Sold Items 6 03-17-2011 04:54 PM
For Sale - Sold: Two Hoya R72 Infrared Filters - 52mm & 58mm (with 49-58mm step-up ring) (US/CA LowVoltage Sold Items 4 12-05-2010 06:05 PM
Advice needed: subjective experience with a battery grip TysonG Pentax Camera and Field Accessories 16 07-21-2009 01:35 AM

All times are GMT -7. The time now is 03:13 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]