Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
07-09-2010, 04:55 AM   #1
Inactive Account




Join Date: Nov 2008
Location: Stavanger, Norway
Posts: 150
Screwmount? Bayonet? K-mount? What is what?

I'm surfing eBay for _cheap_ lenses and I just don't understand the mounts. I know the new pentaxes are k mount. Is the k-mount equivalent to Screwmount? Or bayonet?

07-09-2010, 04:58 AM   #2
Pentaxian
Asahiflex's Avatar

Join Date: Jan 2008
Location: Netherlands
Photos: Gallery
Posts: 2,754
QuoteOriginally posted by Nimrad Quote
I'm surfing eBay for _cheap_ lenses and I just don't understand the mounts. I know the new pentaxes are k mount. Is the k-mount equivalent to Screwmount? Or bayonet?
As the name implies, the screwmount has a screwmount (i.e. a screw-in thread). The k-mount is a bayonet mount with 3 tabs.
07-09-2010, 05:11 AM   #3
Inactive Account




Join Date: Nov 2008
Location: Stavanger, Norway
Posts: 150
Original Poster
Hmm.. How can I spot the difference at eBay when people say "Pentax mount", "P/K Mount" "Pentax M Mount" etc?

For instance this one:
07-09-2010, 05:16 AM   #4
Pentaxian
Asahiflex's Avatar

Join Date: Jan 2008
Location: Netherlands
Photos: Gallery
Posts: 2,754
Well, that's a Pentax K-mount, so here you go

However, please note the long flange (for protecting the diaphragm lever). From the look of things this flange needs to be removed otherwise it cannot be mounted.

See Flange Fix for Vivitar Lenses - Mark Roberts Photography for more information.

As for your other mount questions; you should ask the seller if you aren't sure. Usually PK P/KA R-P/K Pentax-M means a K-mount lens, but the seller can easily come up with other fantasy names to make it more difficult for buyers.

07-09-2010, 05:26 AM   #5
Ira
Inactive Account




Join Date: Mar 2009
Location: Coral Springs, FL
Photos: Gallery | Albums
Posts: 5,218
Nim, when you come across any brand of lens that says M42, that will work with a Pentax that has the m42 to k adapter mounted on the body. M42 is a universal screw size.
07-09-2010, 05:35 AM   #6
Pentaxian
Lowell Goudge's Avatar

Join Date: Jan 2007
Location: Toronto
Photos: Gallery | Albums
Posts: 15,352
a simple word of caution

the lens shown is a third party lens and the shield around the aperture activation lever is larger than necessary and will foul on the DSLR body internally.'

it needs to be trimmed, which is a simple operation, described in detail in the lens forum
07-09-2010, 05:51 AM   #7
Administrator
Site Webmaster
Adam's Avatar

Join Date: Sep 2006
Location: Arizona
Photos: Gallery | Albums
Posts: 41,421
Screwmount = any lens which you screw-in rather than latch-on. Typical sizes are M39 (early Pentax "Takumars") and M42 (later lenses, most of which resemble the M series).

K mount lenses are bayonet lenses and are very plentiful. There are many different series, but all of these lenses are compatible with Pentax DSLRs. Here's a page explaining the different series: Pentax K-Mount Lenses Explained
07-09-2010, 06:02 AM   #8
Pentaxian
Asahiflex's Avatar

Join Date: Jan 2008
Location: Netherlands
Photos: Gallery
Posts: 2,754
QuoteOriginally posted by Adam Quote
Screwmount = any lens which you screw-in rather than latch-on. Typical sizes are M39 (early Pentax "Takumars") and M42 (later lenses, most of which resemble the M series).
I need to correct you here, Adam. The early Asahiflex Takumars had a M37 screwmount. All other Takumars have the M42 screwmount. M39 is the Leica screwmount. Leica screwmount lenses can only be used as close-up/macro due to the different flange distance.

07-09-2010, 08:14 AM   #9
Site Supporter
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 26,487
QuoteOriginally posted by Asahiflex Quote
I need to correct you here, Adam. The early Asahiflex Takumars had a M37 screwmount. All other Takumars have the M42 screwmount. M39 is the Leica screwmount. Leica screwmount lenses can only be used as close-up/macro due to the different flange distance.
There are also M39 Zenit (Russian) SLR lenses with the same registration as the M42.

On the K-mount end of things, there is also the Ricoh-P variant originally made to fit Ricoh cameras with program exposure modes. These have a pin that may jam into the AF drive on Pentax AF camera bodies.

To summarize Pentax/Asahi brand lenses (in historic order):
  • M37 Takumar screw (relatively rare)
  • M42 Takumar screw (common, may be adapted to fit all K-mount bodies)
  • Pentax-K, Pentax-M, Takumar Bayonet (all bayonet lenses lacking the "A" position on aperture ring...note that Takumar bayonet lenses were a bargain brand and are not worth much)
  • Pentax-AF (early AF lens, lacks "A" position)
  • Pentax-A, Takumar-A(have "A" position on aperture ring...see above note regarding non-screwmount Takumar lenses)
  • Pentax-F, Pentax-FA, Pentax-FAJ, Pentax-DA, Pentax-D FA (auto-focus lenses)

A comprehensive summary of all Pentax mount variants and the lenses that fit them (including a functionality matrix for cross-compatibility) may be found at:

http://kmp.bdimitrov.de/technology/summary/index.html

Steve


(Are we confused yet?)

Last edited by stevebrot; 07-09-2010 at 11:58 AM. Reason: Forgot Takumar-A on first try...Thank you to drougge for the heads up!!!
07-09-2010, 08:47 AM   #10
Loyal Site Supporter
drougge's Avatar

Join Date: Jan 2010
Location: Malmö
Photos: Gallery
Posts: 787
QuoteOriginally posted by stevebrot Quote
  • Pentax-A, Takumar Bayonet (have "A" position on aperture ring...note that Takumar bayonet lenses were a bargain brand and are not worth much)
I think that's wrong, Takumar Bayonet doesn't have an A position, Takumar-A does. (At least for lenses I have seen.)
07-09-2010, 11:55 AM   #11
Site Supporter
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 26,487
QuoteOriginally posted by drougge Quote
I think that's wrong, Takumar Bayonet doesn't have an A position, Takumar-A does. (At least for lenses I have seen.)
You are correct. I will edit my post...


Steve

(Tend to avoid even thinking about the K-mount Takumars...)
07-09-2010, 12:19 PM - 1 Like   #12
Veteran Member
mickeyobe's Avatar

Join Date: Dec 2006
Location: Toronto, Ontario, Canada
Posts: 1,762
Pentax lens mounts

Nimrad,

We photographers should know that a picture is worth 1000 words.

See this for pictures.

SLR Lens Mount Identification Guide

There are more than just Pentax lenses here but I think all Pentax mounts are covered.

Mickey
07-09-2010, 01:13 PM   #13
Pentaxian
Lowell Goudge's Avatar

Join Date: Jan 2007
Location: Toronto
Photos: Gallery | Albums
Posts: 15,352
as stevebot indicated, there are many different mounts both bayonet and screw mount, so caution is needed.

If, however, the use of the term bayonet or screw mount is used along with with pentax, then in general terms, you are discussing some form or K mount, or the M42 x 1 thread per mm Screw mount. (Yes I know the origonal asahiflex used an M37 thread, but those are rare)

Once you go outside of pentax mounts there are tons of non compatible bayonet or screw mounts. All current production SLRS (All makers) use bayonet mounts. Canon did make breach mount (the bayonet is on the camera not the lens) as did others but these are now obsolete

In screw mounts, you have the T mount which is M42 by .75 mm/ thread, the M39 mount, Miranda's M44 mount, and the list goes on and on.

ALso note that unless the lens is specifically made for pentax or other cameras with the 45.46mm regestry distance, you may or may not achieve infinity focus, even if you can get a thread adaptor.
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!
bayonet, k-mount, pentax lens, screwmount, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Utilizing Old K mount and Bayonet Mount Lenses jk333 Pentax SLR Lens Discussion 11 08-15-2010 01:30 AM
nikon to pentax bayonet mount jdub Non-Pentax Cameras: Canon, Nikon, etc. 4 02-22-2010 01:42 PM
Screwmount vs. K-mount zoeybird Pentax SLR Lens Discussion 20 02-03-2009 02:20 AM
Takumar Bayonet 28mm f2.8 reverse mount wilkin Pentax SLR Lens Discussion 7 01-26-2009 02:17 AM



All times are GMT -7. The time now is 04:04 PM. | 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