Can anyone recommend an M42 to K-mount adapter?

jeryst · 12-14-2017, 07:16 PM

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I bought an M42 screw mount lens and want to use it on my k5.
I see cheap ones on ebay for like $5, but they are not rated very highly,
and even though they say that they allow infinity focus, the reviews
Say that is not true. Then I can find genuine Pentax adapters, but they
run around $50. Does anyone know of an adapter brand that works correctly
and allows infinity focus but is in the $20 range?

**twilhelm** · 12-14-2017, 07:22 PM - **1 Like**

Fotodiox. I have two, paid $12 for one $10 for the other. They work exactly like my Pentax adapter, but I did remove the lock which is held on by a small screw because there is the possibility of the adapter jamming (though it never happened to me).

You can find them on eBay, Amazon, B&H or Adorama.

**boriscleto** · 12-14-2017, 07:48 PM

Keep searching eBay. You can get a genuine adapter for less than $30...for example...with shipping a little over $30...

Genuine Asahi Pentax K / M42 Mount Adapter | eBay

It amazes me that anyone would pay $50 or more for one...

Not a Number · 12-14-2017, 11:22 PM

It's funny - 6 or 7 years ago when the genuine adapters were going new for $25-30 they were going for around $50 on the used market (eBay). Of course this was when they would show up in stock once or twice a year and sell out rapidly. Now that the price for new is around $50 the used market is around $25-30. They always seem to be in stock (new) now.

disconnekt · 12-15-2017, 12:28 AM

Keh currently has a couple on their site for sale: Pentax Adapter Screw Mount To K-Mount at KEH Camera Store

Cabessius · 12-15-2017, 01:25 AM

If you are patient enough, you will get a genuine one for a good price.
Check every day for new listings, I do it and every time I see one for less than 20 €/$ I buy it.
Now I have 4 of them, all genuine. Apart from LBA do I suffer ABA?

Jonathan Mac · 12-15-2017, 02:03 AM

I'd stick to the genuine ones, they're not that hard to find. I bought two then got another as part of a bunch of film gear I bought. People have had bad experiences with some third-party ones, especially them getting stuck on cameras.

**savoche** · 12-15-2017, 02:50 AM

Originally posted by jeryst

I bought an M42 screw mount lens and want to use it on my k5.
I see cheap ones on ebay for like $5, but they are not rated very highly,
and even though they say that they allow infinity focus

As long as you buy the kind without a flange they will allow infinity focus. The main problem with the cheap ones is that the alignment of the threading seems to be completely random. At least two of my cheapo adapters will leave the lens upside down on the camera. Not that it bothers me too much.

And I always, always, always remove the locking spring on those adapters.

pathdoc · 12-15-2017, 06:37 AM

If not the genuine Asahi ones, I've found the higher quality third party ones to say things like "Body mount P/K M42" or things like that, rather than to be completely devoid of information. The best third-party adapters seem to be from the era when the real thing was commonly available in stores; the third-party companies knew their product had to be quality stuff. Now they know they have a more or less captive market.

photoptimist · 12-15-2017, 06:51 AM

Originally posted by twilhelm

Fotodiox. I have two, paid $12 for one $10 for the other. They work exactly like my Pentax adapter, but I did remove the lock which is held on by a small screw because there is the possibility of the adapter jamming (though it never happened to me).

You can find them on eBay, Amazon, B&H or Adorama.

I also have the Fotodiox adapter -- it seems decently made, it works at infinity focus, the price was good ($12) and mine came with the little lock/unlock spanner key. I've left the little lock tab in place and had no problems although it sometimes seems a bit fidgety to get the adapter into the mount.

I don't know if the genuine adapter is better but the Fotodiox is good enough.

Kozlok · 12-15-2017, 09:06 AM - **1 Like**

+1 for fotodiox. I remove the spring latch also. I slightly over tighten the lens on the adapter and just leave them together so it acts kind of like a K lens.

Not a Number · 12-15-2017, 09:56 AM

You can always on eBay do an advanced search and include terms like "original" or "genuine" and the price range. Once you get a search that gives the results you want you can save it and set it to send you email updates on hits.

My advice for bidding on eBay is to ask you self honestly what the most you are willing to (and can afford) to pay for an item. Enter that as your proxy bid or into a sniping program/service and don't even bother following the auction until it is done. If someone outbids you before, walk away. Unless it is a truly one of a kind item another of the same item will be listed again in time. And your saved search will notify you.

12-14-2017, 07:16 PM	#1
jeryst Senior Member Join Date: Sep 2009 Location: Western PA Posts: 136	Can anyone recommend an M42 to K-mount adapter? Staff note: This post may contain affiliate links, which means Pentax Forums may earn a small commission if a visitor clicks through and makes a purchase. If you would like to support the forum directly, you may also make a donation here. I bought an M42 screw mount lens and want to use it on my k5. I see cheap ones on ebay for like $5, but they are not rated very highly, and even though they say that they allow infinity focus, the reviews Say that is not true. Then I can find genuine Pentax adapters, but they run around $50. Does anyone know of an adapter brand that works correctly and allows infinity focus but is in the $20 range?

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12-14-2017, 07:22 PM - 1 Like	#2
twilhelm Loyal Site Supporter Join Date: Feb 2009 Location: Florida Photos: Gallery \| Albums Posts: 2,369	Fotodiox. I have two, paid $12 for one $10 for the other. They work exactly like my Pentax adapter, but I did remove the lock which is held on by a small screw because there is the possibility of the adapter jamming (though it never happened to me). You can find them on eBay, Amazon, B&H or Adorama.

12-14-2017, 07:48 PM	#3
boriscleto Loyal Site Supporter Join Date: Dec 2009 Location: North Syracuse, NY Photos: Gallery Posts: 16,475	Keep searching eBay. You can get a genuine adapter for less than $30...for example...with shipping a little over $30... Genuine Asahi Pentax K / M42 Mount Adapter \| eBay It amazes me that anyone would pay $50 or more for one...

12-14-2017, 11:22 PM	#4
Not a Number Moderator Join Date: Mar 2012 Location: Venice, CA Posts: 10,526	It's funny - 6 or 7 years ago when the genuine adapters were going new for $25-30 they were going for around $50 on the used market (eBay). Of course this was when they would show up in stock once or twice a year and sell out rapidly. Now that the price for new is around $50 the used market is around $25-30. They always seem to be in stock (new) now.

12-15-2017, 12:28 AM	#5
disconnekt Pentaxian Join Date: Oct 2011 Location: SoCal/I.E. Photos: Albums Posts: 1,700	Keh currently has a couple on their site for sale: Pentax Adapter Screw Mount To K-Mount at KEH Camera Store

12-15-2017, 01:25 AM	#6
Cabessius Veteran Member Join Date: Jun 2013 Location: Ibiza, Spain Posts: 471	If you are patient enough, you will get a genuine one for a good price. Check every day for new listings, I do it and every time I see one for less than 20 €/$ I buy it. Now I have 4 of them, all genuine. Apart from LBA do I suffer ABA?

12-15-2017, 02:03 AM	#7
Jonathan Mac Pentaxian Join Date: Apr 2009 Location: Madrid, Spain Posts: 10,902	I'd stick to the genuine ones, they're not that hard to find. I bought two then got another as part of a bunch of film gear I bought. People have had bad experiences with some third-party ones, especially them getting stuck on cameras.

12-15-2017, 02:50 AM	#8
savoche Master of the obvious Join Date: Jun 2011 Location: Lowlands of Norway Posts: 18,311	Originally posted by jeryst I bought an M42 screw mount lens and want to use it on my k5. I see cheap ones on ebay for like $5, but they are not rated very highly, and even though they say that they allow infinity focus As long as you buy the kind without a flange they will allow infinity focus. The main problem with the cheap ones is that the alignment of the threading seems to be completely random. At least two of my cheapo adapters will leave the lens upside down on the camera. Not that it bothers me too much. And I always, always, always remove the locking spring on those adapters.

12-15-2017, 06:37 AM	#9
pathdoc Pentaxian Join Date: Mar 2015 Photos: Gallery \| Albums Posts: 6,381	If not the genuine Asahi ones, I've found the higher quality third party ones to say things like "Body mount P/K M42" or things like that, rather than to be completely devoid of information. The best third-party adapters seem to be from the era when the real thing was commonly available in stores; the third-party companies knew their product had to be quality stuff. Now they know they have a more or less captive market.

12-15-2017, 06:51 AM	#10
photoptimist Pentaxian Join Date: Jul 2016 Photos: Albums Posts: 5,127	Originally posted by twilhelm Fotodiox. I have two, paid $12 for one $10 for the other. They work exactly like my Pentax adapter, but I did remove the lock which is held on by a small screw because there is the possibility of the adapter jamming (though it never happened to me). You can find them on eBay, Amazon, B&H or Adorama. I also have the Fotodiox adapter -- it seems decently made, it works at infinity focus, the price was good ($12) and mine came with the little lock/unlock spanner key. I've left the little lock tab in place and had no problems although it sometimes seems a bit fidgety to get the adapter into the mount. I don't know if the genuine adapter is better but the Fotodiox is good enough.

12-15-2017, 09:06 AM - 1 Like	#11
Kozlok Pentaxian Join Date: Jun 2012 Location: Albuquerque Photos: Gallery Posts: 3,148	+1 for fotodiox. I remove the spring latch also. I slightly over tighten the lens on the adapter and just leave them together so it acts kind of like a K lens.

12-15-2017, 09:56 AM	#12
Not a Number Moderator Join Date: Mar 2012 Location: Venice, CA Posts: 10,526	You can always on eBay do an advanced search and include terms like "original" or "genuine" and the price range. Once you get a search that gives the results you want you can save it and set it to send you email updates on hits. My advice for bidding on eBay is to ask you self honestly what the most you are willing to (and can afford) to pay for an item. Enter that as your proxy bid or into a sniping program/service and don't even bother following the auction until it is done. If someone outbids you before, walk away. Unless it is a truly one of a kind item another of the same item will be listed again in time. And your saved search will notify you.