Forgot Password
Pentax Camera Forums Home

Pentax Accessory Reviews » Lens Accessories » Miscellaneous Adapters
Pentax Mount Adapter K (M42 Screwmount to K Mount) Review RSS Feed

Pentax Mount Adapter K (M42 Screwmount to K Mount)

Reviews Views Date of last review
12 24,686 Sat September 22, 2018
Recommended By Average Price Average User Rating
100% of reviewers $29.60 9.50
Pentax Mount Adapter K (M42 Screwmount to K Mount)

Pentax Mount Adapter K (M42 Screwmount to K Mount) Pentax Mount Adapter K (M42 Screwmount to K Mount)

Adapter to allow the use of M42 screwmount lenses on K-mount bodies.

Step-by-step camera settings guide
In Production: Buy the Pentax Mount Adapter K (M42 Screwmount to K Mount)
Price History:

Add Review of Pentax Mount Adapter K (M42 Screwmount to K Mount) Buy the Pentax Mount Adapter K (M42 Screwmount to K Mount)
Sort Reviews by: Date | Author | Rating | Recommendation | Likes (Descending) Showing Reviews 1-12 of 12
New Member

Registered: March, 2013
Location: Highlands, Scotland
Posts: 3
Review Date: September 22, 2018 I can recommend this item: Yes | Price: $15.00 | Rating: 10 

Pros: Build quality, Pentax (!)
Cons: None

This is a 'must have' piece of equipment if you use M42 mount lenses with a modern K mount SLR/DSLR. There are plenty of third party adapters out there, but it's always hit or miss as to their working properly or at worst damaging your camera mount. The Pentax item works flawlessly every time. A brilliant item for mounting classic glass onto a modern camera like the KP. Well worth paying a little more for the actual 'Pentax' made piece of kit..........
Site Supporter

Registered: August, 2009
Location: Elko, Nevada
Posts: 1,289

1 user found this helpful
Review Date: October 1, 2016 I can recommend this item: Yes | Price: $40.00 | Rating: 10 

Pros: Works perfectly on every Pentax camera I have tried.
Cons: None.

I purchased both of mine direct from Pentax so the price was a little high. But, considering that they work perfectly, while other I have tried do not, the price is definitely secondary.

If you own M42 lenses that you would like to try with your K-mount cameras, digital or film, don't waste your time fiddling with the other types. Buy this one.

It just works.
Site Supporter

Registered: February, 2012
Location: Albuquerque, NM
Posts: 450
Review Date: September 26, 2013 I can recommend this item: Yes | Price: $37.00 | Rating: 9 

Pros: Build Quality!!!
Cons: a little bit pricey

I took 1 score off because of its costly price (i paid $33+$4S/H)
However it totally worth the price. Just before this one I got a offbrand one, it looks fine, but serious build problem. Even finally I negotiated with the seller I still feel bad cuz it hurs lens' mount.
Although this problem has been discussed a lot, but what I want to say here
NO THIRD PARTY ADAPTER. Never, ever. Just stick with the origin Pentax one.
Site Supporter

Registered: April, 2011
Location: Lost in translation ...
Posts: 17,675
Review Date: April 22, 2013 I can recommend this item: Yes | Price: $40.00 | Rating: 9 

Pros: Well built, easy installation and removal
Cons: None really ... wobbles with a Helios 44-2 lens


Great item that I bought a while back and that stays in the camera bag all the time.

Easy installation and removal via a fingernail.

No problems for infinity focus ... it's just great!

Salut, J
Site Supporter

Registered: January, 2013
Location: Ottawa, Canada
Posts: 1,965
Review Date: March 7, 2013 I can recommend this item: Yes | Price: None indicated | Rating: 9 

Pros: Precise fit, ease of use, infinity focus.
Cons: Price, availability

I have had very good success with the genuine Pentax adapter, but have not used any of the 'after-market' brands.

The Pentax Mount Adapter K installs very smoothly; fits precisely, positively, and cleanly; and removes equally easily. It provides for convenient and trouble-free use in the field. It is machined to close tolerance, and mates well to the body mount. The threads provide for a close and wobble-free mounting of the lens. Needless to say, it allows the M42 lens to focus to infinity, which certain 'flanged' adapters do not. Finally, the adapter requires no modification for effective operation and no additional tool is required to dismount it - certain after-market varieties come with a small device that is used to dislocate the securing spring latch.

Concerning the availability and price: In 2011, I paid the full 'Canadian' retail price over the counter at a local dealer who had several on the shelf. I originally thought it was a steep price to pay for a small piece of metal; later, however, I appreciated its quality and ease of use and have not had any remorse. Recently, I bought another (second-hand) for a good price to provide more convenience and to serve as a back-up in case of loss or damage.

Highly recommended.

Registered: May, 2010
Location: Hong Kong / Irvine, CA
Posts: 601
Review Date: January 18, 2013 I can recommend this item: Yes | Price: $38.00 | Rating: 10 

Pros: easy, good build
Cons: pricy

Buy one and use it forever.
It is highly recommended to buy the genuine one at the first time.

Don't waste the money on a ebay/3rd party one or whatever and get all those problem.
They are hard to remove and may cause problem to your DSLR.
I had a few of these to compare.

The genuine one is very good and it is worth to spend the money.
Veteran Member

Registered: February, 2012
Location: Fredericton, New Brunswick
Posts: 631
Review Date: May 10, 2012 I can recommend this item: Yes | Price: $40.00 | Rating: 10 

Pros: Infinity Focus, Solid Build, Easy(And safe) to remove
Cons: Wish it had some way to make the lens release button work...

Don't waste time with the Non-Pentax adapters, get the real thing.

Side note: M42 Extension Tubes+Macro M42 Adapter+M42 Lens=K Mount Macro Lens? The macro adapter works better for this, as you can remove it from your camera in a hurry.

Registered: October, 2010
Posts: 4,266
Review Date: May 9, 2012 I can recommend this item: Yes | Price: $15.00 | Rating: 10 

Pros: Easy to use, works well.
Cons: None so far.

It work as I would think. My M 42 lenses works well. Only gripe is that you have to remove adapter for using your K-mount lenses like unscrewing lens and then removing that ring, and it is not fast...but that is not really bad thing, since with manual lenses at your hand you are not usually in hurry. And you can have one body for AF lenses if you want to have one at hands...
Loyal Site Supporter

Registered: June, 2009
Location: Tumbleweed, Arizona
Posts: 5,458
Review Date: July 25, 2011 I can recommend this item: Yes | Price: $30.00 | Rating: 9 

Pros: Works very well
Cons: extraction at night

I have one, and it works very well. The only down side - if any, is using it at night and then changing lenses to a K mount. In the dark I have to extract it. Its just part of using M42 lenses. So what I have done, is to limit myself to K mount lenses at night to eliminate the problem. I could just semi-permanently attach it, but I have not gone that far yet.

Veteran Member

Registered: June, 2010
Posts: 737
Review Date: July 23, 2011 I can recommend this item: Yes | Price: None indicated | Rating: 8 

Pros: easy to use, locks when mounted on dslr

Apparently better quality than other adapters I used, however even with this genuine adpater I wasn't able to get my Takumar 50/1.4 to focus on longer distances and infinity. Since the adapter seemed to be perfectly flash with the mount i suppose that somebody must have adjusted Takumar's focusing ring then. Unfortunately...
Loyal Site Supporter

Registered: February, 2011
Location: Vancouver
Posts: 4,544

2 users found this helpful
Review Date: April 6, 2011 I can recommend this item: Yes | Price: $10.00 | Rating: 10 

Pros: Great for using old lenses, works as intended
Cons: None

My first Pentax camera is a K-5. In researching my purchase, besides all of the great features of the K-5, one of the outstanding benefits to the Pentax system is the availability of old lenses. The price of my Takumar lenses (28, 50, 85 and 135) allowed me to get a range of glass that was cheaper than one DA L lens, with little loss of quality. As well, I am enjoying trying to learn to properly control light and focus.

So, about the adapter. Having read of some people’s problems with non-Pentax adapters, I knew I wanted a genuine Pentax ring. I got lucky - my adapter came in the proverbial $100 box of lenses! It has worked perfectly for all of my screwmounts.

The adapter easily screws onto a lens, which then mounts just like any K mount lens. To change lenses, I only have to unscrew the one lens, and screw in another, rather than removing the adapter. The adapter is easy to remove by pressing the spring, and rotating.
New Member

Registered: March, 2010
Location: Texas
Posts: 5

2 users found this helpful
Review Date: March 8, 2011 I can recommend this item: Yes | Price: $31.00 | Rating: 10 

Pros: Fits perfectly.

For many years, my primary "good" camera was a Pentax Spotmatic. Just last year, I finally made the leap to a digital SLR with a Pentax K-x. I was, and am, quite pleased with the camera and the two lenses that came with it, but time and again I'd catch myself reaching for my screwmount specialty lenses to get just the look I wanted.

After doing some research, I ordered the Pentax Mount Adapter K. There are a lot of off-brand adapters out there for about half the price, but I read too many horror stories of damaged bodies and fallen lenses to feel safe using anything but the genuine article.

The adapter installs easily and after learning how to set up the camera to work most effectively with the old lenses, I was back in business without having to buy all-new lenses. (Though there are a bunch that I still want to buy when I have the cash...)

If you have a hoard of old screwmount lenses gathering dust in a closet, I heartily recommend that you get this accessory.
Add Review of Pentax Mount Adapter K (M42 Screwmount to K Mount) Buy the Pentax Mount Adapter K (M42 Screwmount to K Mount)

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]