Forgot Password
Pentax Camera Forums Home

Show Printable Version Search this Thread
10-28-2014, 04:12 PM   #1
New Member

Join Date: Sep 2014
Location: WA
Posts: 5
Yashica ML 50mm f2 to K-5

Hello Pentaxians,

I have been searching through the forums to the answer of my question, but have not found it so I will ask the question once again.

I recently purchased a Yashica ML 50m f2 lens for $5 and was wondering what route would be best for adapting it to my K-5.

1. Use an adapter off the internet: : Neewer Black Metal Lens Mount Adapter with Optical Glass for Contax/Yashica C/Y lens to Pentax PK / K Mount Camera Body, fits Pentax K7 K5 K3 K50 K30 K2 km kx kr K1000 k100d k100ds k200d k10d k20d : Camera & Photo

2. Try the PK+MM:

3. Or do a "Frankenlens" mod :

I don't mind modding the lens. It doesn't seem overly rare and I have the tools to do it. My only question with the mod is: do you grind down the under side of the three locking lugs or grind completely around the ring that sits against the DSLR mount?

Attached Images
View Picture EXIF
PENTAX K-5  Photo 
View Picture EXIF
PENTAX K-5  Photo 
10-28-2014, 07:32 PM   #2
Loyal Site Supporter

Join Date: Jun 2009
Location: Tumbleweed, Arizona
Photos: Gallery | Albums
Posts: 5,091
Good Evening Brian and Welcome to the Forum,

I have two Contax Zeiss lenses that I have swapped mounts on - from the C/Y to the PK mount. I used the kit. You would not want to go this route for a couple of reasons. First the parts run about $100 and only make economic sense on a Contax Zeiss lens. Second, the parts are machined to match the Contax Zeiss rear parts as a replacement, and probably would not have the correct thickness for Yachica's version of the C/Y mount, in order to match the PK mount's exact registration distance. In terms of your list of options -
  1. Use an adapter off the internet: - This adapter will not work as it is waaaay toooo thick. The difference between the C/Y and PK mount registration distance is nearly 0mm and this will only provide you the ability to never focus to infinity.
  2. Try the PK+MM: - This may be an option, I have read about it but I was waiting for their weather sealed version of the mount.
  3. Or do a "Frankenlens" mod : - For a $5 lens, this may be the best approach. I would buy a cheap set of Pentax PK mount extension tubes. This way the lens would try to mount on to the tubes, and thus you can "see" inside the mount from the camera's perspective in order to determine where and how much to grind off the flange tabs. Rio Rico was a master at modding lenses. I really miss his posts.
Macro Extension Tube Ring for Pentax DSLR K20D K200D KR KX KM K5 K7 K30 K3 K5IIS | eBay
Hope that helps...

Last edited by interested_observer; 10-28-2014 at 07:38 PM.
10-29-2014, 10:51 AM   #3
New Member

Join Date: Sep 2014
Location: WA
Posts: 5
Original Poster
Thanks for the quick reply. I am leaning towards the modification just because how cheap I got the lens and I am pretty happy with Pentax cameras (and their mounts). I agree with you that paying more for adapters than the lens itself is counter-productive. Thank you again for the advice!

Last edited by nitrousneal; 10-31-2014 at 11:14 PM.
01-23-2015, 06:31 PM   #4
Forum Member

Join Date: Nov 2014
Photos: Albums
Posts: 56
The mod requires removing metal from the leading edges of all three mounting flanges and also shaving down the step ring on the mount. It is best to have an old camera mount or an extension ring handy so you can insert the lens and see what interferes. I use the lens mount from a dead Pentax A3000. It's not difficult, but is tedious getting the step ring down to size because there is a lot of brass to remove.

Ideally this would be done on a metal lathe. I started with a thin hand file from a needle file set and that got so old so fast. Dremel with the 426 bit that RioRico recomienda. The ML50 1.9 is hardly worth doing, but the ML50/1.4 and ML28/2.8 are good.

In the end, you can pick up an M42 DS Yashinon lens for less money, so ... what the heck are we doing this for? I guess if you already have the lenses, it might make sense.


  • 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!
adapter, camera, f2, lens, ml, ml 50mm f2, mod, pentax help, photography, pk, question, troubleshooting, yashica ml 50mm
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Similar Threads
Thread Thread Starter Forum Replies Last Post
For Sale - Sold: Pentax K-5 IIs with Pentax DA 35mm f2.4 and Tamron 17-50mm f2.8 artloie Sold Items 8 05-26-2014 07:07 AM
For Sale - Sold: Prices lowered!!--- 'K' series primes: 30mm f2.8, 50mm f1.4, 55mm f1.8, 135mm f2.5 lightsleuth Sold Items 5 11-15-2013 07:23 PM
Nature Franken-lens la RioRico - Yashica ML 50/1.4 Jean Poitiers Post Your Photos! 12 05-25-2012 02:22 PM
Rico's mod on a Yashica ML 50 f1.4 - any photos or input Jean Poitiers Pentax SLR Lens Discussion 12 05-25-2012 04:37 AM
For Sale - Sold: Pentax Lenses F2 50mm, F4 75-150mm, F1.7 50mm, F4 200mm, F2.5 135mm, F4.5 80-2 hangu Sold Items 10 03-27-2010 07:51 PM

All times are GMT -7. The time now is 04:16 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]