Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
05-09-2022, 05:53 PM - 25 Likes   #1
Site Supporter
Site Supporter




Join Date: Jun 2020
Posts: 77
SMC Pentax 20mm 1.4

So here is what I've learned about the lens and some pictures.

For the Lens database:
Regular K-mount with the newer M-style font and lens speed format. Since it doesn't say "Pentax-M", I would list it as a K-mount prime.
Weight is 465 grams
Diaphragm is 8 blades
Front lens cap is a 77mm, same as the k-mount 300mm and 400mm lenses.
Minimum focus is .8 ft / .25m

Compared to the brand new 21mm Limited lens, the 20mm is a little shorter but is also lacking the 21mm's built in lens hood.

As you can see in the pictures the speed of the lens comes from one oversized front element, the rest of the lens is a normal size. Also you can see that unlike most of the old wide angle lenses Pentax made from this time period, the 20mm lens has a full size rear element.

I will post some image tests in another post.

Attached Images
View Picture EXIF
Surface Duo  Photo 
View Picture EXIF
Surface Duo  Photo 
View Picture EXIF
Surface Duo  Photo 
View Picture EXIF
PENTAX K-1 Mark II  Photo 
View Picture EXIF
PENTAX K-1 Mark II  Photo 
View Picture EXIF
PENTAX K-1 Mark II  Photo 
View Picture EXIF
PENTAX K-1 Mark II  Photo 
View Picture EXIF
PENTAX K-1 Mark II  Photo 
View Picture EXIF
PENTAX K-1 Mark II  Photo 
05-09-2022, 06:55 PM   #2
Pentaxian




Join Date: Dec 2016
Location: Southeastern Michigan
Posts: 3,774
Very interesting. I knew of the M 20mm f/4 MF lens, but not one of f/1.4 which is a remarkable achievement in a FF lens this compact. It makes one wonder how well it performs wide open or close to it.
05-09-2022, 08:37 PM   #3
Loyal Site Supporter
Loyal Site Supporter
kiwi_jono's Avatar

Join Date: Dec 2009
Location: Christchurch, New Zealand
Photos: Gallery | Albums
Posts: 2,407
Wow, thats interesting. Never heard of that one.
Look forward to seeing the tests!
05-09-2022, 09:04 PM   #4
Unoriginal Poster
Loyal Site Supporter
iheiramo's Avatar

Join Date: Nov 2016
Location: Espoo
Photos: Albums
Posts: 2,782
So it is in the hands of a member. Superb! Very interested to see the shots it can produce and how it compares to new 21ltd. Rendering most likely won't be flawless as it didn't get into production.

05-09-2022, 10:29 PM - 7 Likes   #5
Moderator
Site Supporter
Loyal Site Supporter
Sandy Hancock's Avatar

Join Date: Feb 2012
Location: Adelaide Hills, South Australia
Photos: Gallery | Albums
Posts: 10,174
You outbid me, you bastard

But seriously, congratulations on acquiring a true unicorn of the photographic world. I can't wait to see some sample images.
05-09-2022, 11:20 PM   #6
Administrator
Site Webmaster
Adam's Avatar

Join Date: Sep 2006
Location: Arizona
Photos: Gallery | Albums
Posts: 50,633
What is the origin of the lens itself- it is a prototype that ultimately went on to go up for auction?

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, 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:

05-10-2022, 12:08 AM   #7
Loyal Site Supporter
Loyal Site Supporter
pschlute's Avatar

Join Date: Mar 2007
Location: Surrey, UK
Photos: Gallery
Posts: 5,581
A true rarity. Thanks for posting.

05-10-2022, 12:33 AM   #8
pid
Pentaxian




Join Date: Jan 2010
Photos: Gallery
Posts: 509
wow! Never saw one, always wanted it and never had the chance to get one. Congratulation. How much was it and where did you find it?

Saw it my first time on this site: http://kmp.pentaxians.eu/lenses/_prototype/k20f1-4/
May be you want to support them with the missing Infos:


K 20/1.4 AL

Product Information
Exact Name: SMC PENTAX 1:1.4 20mm
Color: black
Year of Introduction: 1976

Technical Specifications
OpticsOptical Formula: 11 elements in 10 groups
Aperture Range: f/1.4 ~ f/22
Number of Aperture Blades: unknown
Minimum Focusing Distance: 0.25 m
Maximum Magnification: unknown
Special Features: aspherical element(s)

Mechanics
Filter Diamete: r77 mm
Maximum Diameter: 80 mm
Length: 65 mm
Weight: 445 g

Accessories
Cap: unknown
Fitting Hood(s): unknown
Fitting Case(s): unknown

Last edited by pid; 05-10-2022 at 12:45 AM.
05-10-2022, 01:01 AM   #9
Site Supporter
Site Supporter




Join Date: Mar 2019
Location: Merano (BZ)
Photos: Gallery | Albums
Posts: 94
Interesting, I would like to see some photos take with that lens.
05-10-2022, 01:42 AM   #10
Pentaxian
LennyBloke's Avatar

Join Date: Aug 2008
Location: Worcestershire, UK
Photos: Gallery
Posts: 602
Thank you for sharing the images and information - it'll be great to see some images taken with the lens when you get a chance
05-10-2022, 02:58 AM   #11
Pentaxian




Join Date: Apr 2016
Location: Tirana
Posts: 727
Oh wow, you really did catch a unicorn!
Cant wait to see some samples taken with it.
I guess this gives us hopes of seeing the 35mm/1.4 in the wild too.
05-10-2022, 03:35 AM   #12
Pentaxian
Jonathan Mac's Avatar

Join Date: Apr 2009
Location: Madrid, Spain
Posts: 9,020
For those who didn't see it, this thread tells the story of this lens since it first popped up on the forum radar in May 2019: SMC Pentax K 20mm f/1.4? - PentaxForums.com

I'm very glad it was bought by a forum member. Can't wait to see some sample shots with it.
05-10-2022, 03:35 AM   #13
Loyal Site Supporter
Loyal Site Supporter




Join Date: Aug 2016
Location: Leura NSW
Posts: 168
I just don't understand how you ended up in possession of my lense?????
Super green with envy.😁
05-10-2022, 03:45 AM   #14
Moderator
Site Supporter
Loyal Site Supporter
Sandy Hancock's Avatar

Join Date: Feb 2012
Location: Adelaide Hills, South Australia
Photos: Gallery | Albums
Posts: 10,174
QuoteOriginally posted by Adam Quote
What is the origin of the lens itself- it is a prototype that ultimately went on to go up for auction?
My understanding is that something like seven prototypes were made, and that's it.
The K 20/1.4 never made it to sale. Of course
05-10-2022, 08:06 AM - 1 Like   #15
Site Supporter
Site Supporter
Digitalis's Avatar

Join Date: Mar 2009
Location: Adelaide,South Australia.
Posts: 10,933
Interesting, the rear element looks almost exactly like the one found on the SMCP-K 50mm f/1.2
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!
20mm, element, front, k-mount, lens, pentax, pentax lens, pictures, post, size, slr lens, smc pentax 20mm
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
For Sale - Sold: SMC Pentax-A 20mm F2.8, SMC Pentax-M 20mm F4(sold) ChatMechant Sold Items 5 08-19-2019 01:23 PM
Wanted - Acquired: Pentax SMC-M 20mm f4 or SMC Pentax-FA 20mm F2.8 abdalian Sold Items 1 05-30-2016 01:28 PM
Wanted - Acquired: Pentax FA 20mm or Pentax A 20mm loveisageless Sold Items 2 01-13-2011 12:00 PM
For Sale - Sold: SMC 85mm f/2.2 Soft, SMC-M 50mm f/4 Macro, SMC-M 135 3.5, SMC-M 85mm 2, SMC-M jgmankos Sold Items 3 06-14-2010 06:48 PM



All times are GMT -7. The time now is 11:51 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