Many Pentax DSLR owners want to use M42 screwmount (Takumar) lenses, or M or K manual lenses, on their cameras because of the low cost and relatively high image quality of these lenses.

If you're wondering whether or not these lenses can be used with Pentax DSLRs (or the K-01), then the answer is yes! Pentax as well as third-party manual and screwmount lenses can easily be mounted on any Pentax DSLR (such as the K-1 series, KP, K-3 series, K-70, K-S2, K-S1, K-50, K-500, K-30, K-5 series, K-r, K-x, K-7, K10D, K100D, K200D, *ist D, etc.) Just follow this guide!



Modern Pentax DSLRs use the Pentax "K-mount", which employs a bayonet and therefore differs significantly from the M42 screw mount. The older manual M and K (SMC Pentax-M, SMC Pentax) lenses actually use the bayonet, so they will not need an adapter - you can skip straight to the lower portion of this article (starting at "Important!") for information on how to meter with those lenses. Screwmount lenses usually have "Takumar" in their names, and in order to mount screwmount lenses on your k-mount body, you'll need a Pentax k to m42 adapter. Pictured above is the genuine Pentax adapter, which is ideally the one you want to get. Similar third-party adapters are also available. Caution: Many third-party adapters, such as this one, have a protruding flange which will prevent you from focusing all the way to infinity. If you want to buy a third-party adapter (they're generally cheaper), make sure that they don't have this flange. Here's an example of a good third-party adapter.

Once you have your adapter, the next step is to install it on your camera (it can easily be put on and removed on-the-fly). Check out the m42 to k adapter manual.

After you've installed the adapter, you'll want to mount the lens. This is done by screwing it into the camera until the lens feels firmly attached. The focusing window and lens ring should line up with the camera just like any other lens. Now that your lens is mounted, let's talk about how to take photos with it.

Important! The hard part is to get the camera to actually fire when a manual lens is mounted. In order to accomplish this, enter your camera's custom function menu, select the "Using Aperture Ring" setting (usually at the end of the menu, #21 on the K-7, #27 on the K-5, #27 on the K-3, #26 on the K-1), and set it to 2 (allowed). Once you do this, the shutter will at least fire, as it wouldn't have with this setting disabled (you would simply have seen an F-- indication on the top LCD/info screen). The setting description should read: 'Shutter will release when aperture ring is not set to the "A" position' when "allowed" is selected. Also note that the mount on the lens must be conductive for electrical current so that it shorts the electrical contacts on the camera body. All Pentax manufactured lenses have a conductive mount, but some third party lenses do not in which case the area of the mount touching the contacts must be sanded down.

K-30, K-50, K-500, K-70, K-S1, K-S2 and K-01 users: make sure you also set your green button "action in M/TAv Mode" to Tv SHIFT. This is found under the button customization menu (page 3 of the main menu) on the K-01 or as a custom function on the K-30, K-50 and K-500. On the K-S2 and K-70, look under the e-dial programming sub-menu under button customization in the record menu.

Finally, ensure that auto ISO is disabled.

At startup, if your camera asks you for the focal length, enter the actual focal length as labeled on the lens. This will ensure optimal Shake Reduction performance. For zooms, you can use the lower end of the zoom range (this ensures that there will be no over-compensation), or the focal length that you shoot at most often.

Now, let's discuss metering. Since manual lenses don't feed aperture data to the camera, the only way for the camera to check how much light is being passed through the lens is to measure the light while the lens is stopped down. Follow this procedure to properly meter with a screwmount, M, or K lens:

___0. Ensure that the "Using Aperture Ring" custom function is set to "2 (allowed)" (K-30/50/500/01 users must also ensure that the green button is configured to Tv Shift in M/TAv Mode) as described above

1. Set your camera to M mode using the mode dial (your camera won't fire in other modes*)
2. Compose and focus your image.
3. Using the aperture ring (the ring at the very back of your lens; it will have numbers such as 2.8, 4, 5.6, 8 written on it), select your desired aperture setting. Note that the smaller the aperture number is, the more light passes through the lens, and the blurrier the out of focus areas of your photograph will be (and vice-versa). Note your lens will not stop down until step 5.
4. [Screwmount lenses only] Switch the diaphragm clutch on your lens to "Manual" (you can leave it on Auto when composing and focusing if you don't want a dark viewfinder).
5. Measure the light by either pressing the "Green Button" (older bodies may use the Av button), or pushing your power button to DOF preview mode (only available on high-end bodies). Your camera will automatically set the shutter speed for you.

All that's left now is for you to press the shutter release button to take your photo. Congratulations- you've now learned how to use M42 and M & K manual lenses with Pentax DSLRs!

*Screwmount lenses may also be used in Av mode since they are always stopped down to the aperture you will be shooting at (unlike M&K lenses, which are stopped down only when the shutter is released or when you meter as described above).

Note: if your aperture ring has an "A" on it, instead of doing stop-down metering as per this guide, you'll want to set the ring to "A" and use the camera's scrollweel to adjust the aperture via Av mode.

Click here if you found this article helpful!

Video version:

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[KX-Digital]

Hi

I have been reading this thread the past days and notices two things
1) it keeps attracting new postst
2) it seems behaviour is different with different models and even firmwares. Especially the K30 and K50 behave weird and unreliable.

My first camera was a then 5 years old Ricoh KR-10 super with Rikenon 50/2.0 and Osawa 70-150mm 3.8 which was soon supplemented with a Sigma 28mm 2.8 and later with a Vivitar 400mm 5.6 later. After breakdown of the 28, selling the 50 for a Sigma 35-70mm 2.8, which also broke down, and replacing that with an pentax-m 50mm 1.7 (which i still have), for a wide-angle i settled for an Aus Jena Flektogon 20mm 2.8 for ƒ250 which was at that time one fifth of the price of a Pentax 20mm. The Flektogon being an M42-lens of course needed an adapter to be used on the Ricoh and the one sold to me was the genuine Pentax version. Later i bought a 24mm K-mount Panagor and some other M-lenses.

Missing AE-lock, depth-of-field-preview, shutter-speed-priority (for use with the 400mm) and having read about the zone sytem (spotmetering) in 1993 i purchased a Z-1 which had all of that and to which i bought the A 35-105mm 3.5 as AF lenses were not build as tough, especially not the FA-types. My need for fast available-light lenses was filled with a Jupiter-8 85mm and a Panagor 35mm both 2.0. I also got me an S1a with a 55mm 1.8.

These lenses I have used on my Z-1 and on my 2008 K200D using the M42-adapter. In fact the first thing i did when purchasing the K200D was to set the custom function 'Allow using aperture ring' and some other custom functions (as i did on the Z-1). I deem myself lucky these lenses work on the K200D as described in Adams opening post. There are however a few details i'd like to mention.

AF-confirmation works on the Z-1 with M-lenses but not with M42-lenses. It does not work with my Vivitar 1.5x TC (anodized mount) but it does work if i use a K-mount extention/macro ring.
AF-confirmation works on the K200d with both M-lenses and M42-lenses.
Having extended experience of manual focusing with both the Z-1 and the K200D i have also come to the conclusion that this is not possible with the standard focusing screens. One really needs the AF-confirmation-led to blink or...
use another focusing screen. For several years i fitted into my K200D an Ec-L screen from focusingscreen.com. Recently i also discovered the screens of the Pentax MX (and LX) also fit in the Z-1 although that might affect light-metering.
I do need to thest the latter. I also discovered manual focusing is perfectly possible with the screen of a Minolta Dynax 300si and i wonder why the screens of Pentax are so much worse.

For me the easiest way to use the adapter is to screw it onto the lens and then mount the lens as if it were a K-mount. When removing the lens the adapter stays in the camera and has to be removed by pushing the spring with a fingernail. This is done easily provided one has long-enough fingernails. I have only one adapter and never dared to drill a hole in the lenses mount for the pin to lock them.

I have found that M42-lenses are generally cheap as long as it concerns third-party-brand lenses. This was already true in the nineties when M42-lenses were costed next to nothing but third-party bayonet-mount lenses were higher priced whether Pentax, Olympus, Minolta, Canon or Nikon mount. Nowadays third-party K-mount lenses are as cheap. Takumar lenses were not cheap then and still are asked more for than for third-party brands and the same goes for M42 lenses by Tomioka or by German manufacturers like Carl Zeiss*, Meyer Görlitz, Alpa, Schneider Kreuznach or the like.
(* with exception of Aus Jena 50mm 2.8 and 3.5, all Jena lenses are generally a bit lower priced than the others though)

Regards

[180pilot]

New to forum, so if I missed this already being revealed please excuse me. Back in the late 60's when in Vietnam I purchased a Spotmatic and many prime lenses, from the standard Super Tak. 50mm to a 300 mm. Very,very, cheap then, even at a Corporals wages. I used these for many years with film. These lenses sat in a case for many years, after going digital with some point and shoots. I was waiting for prices of a full frame Pentax DSLR to become reasonable. I did purchase a original Pentax M42 adaptor. Well, couldn't wait any longer just bought a K70. I really am now amazed how sharp and fast these Super Takumars really are.. After setting up camera to above settings, finding the Tv-shift under the e-dial programing was the most difficult. I use the Av mode and the ISO locked at 400. That way when I rotate the aperture ring I can watch the shutter speed change in the viewfinder. And, do not have to use the green button. So merely, focus, press shutter to see speed then rotate to 1/500 and take pix. In normal daylight this is around f5.6, a good sweet spot for the f2.5 135 mm. I use most, with the 1.5 conversion, this equals a 200 mm telephoto.
Some thing I have not come across yet, is the anti-shake setting for a M42 should it be the full frame mm or the 1.5 compensation? I have been setting it at 200mm, and doesn't seem a problem.

Super Takumars; f4 17mm, f3.5 24mm, f1.4 50mm, f4 50mm macro, f2.5 135mm, f4 300mm.

[Not a Number]

Some thing I have not come across yet, is the anti-shake setting for a M42 should it be the full frame mm or the 1.5 compensation? I have been setting it at 200mm, and doesn't seem a problem.

Super Takumars; f4 17mm, f3.5 24mm, f1.4 50mm, f4 50mm macro, f2.5 135mm, f4 300mm.

Enter the nearest setting to the actual focal length of the lens, e.g. 50mm for the 50mm.

[greynimlet]

I’ve just bought a petri SMC 28mm f2 lens to go with my K-3ii. I’ve missed manual lenses and am keen to get back to them.

I’ve tried following the advice on this forum to get the lens working but am a bit stumped, can someone help? (Apologies if I’ve missed something obvious, or not followed the advice correctly, I’ve a lot to learn!).

I’ve attached the lens and the aperture springs wide open.

I’ve changed setting C26 in the menu to enable the aperture ring.

Up to this point, the screen shows F--. If I short the 6th pin then the back of the camera changes to an F number which I can change via the dial (the F number on the top screen still shows F--).

I’ve tried configuring the green button to TvShift (the only option I can find on the K-3ii which is close to the M/TAv mode shown on this thread is on E-Dial programming screen 2 M: TV / AV to TV Shift).

The aperture still stays wide open regardless of whether I turn the lens to F2 or F16. Am I missing the point somewhere?

[rjbrett]

Does the aperture ring have an "A" setting on it?

[marcusBMG]

The aperture still stays wide open regardless of whether I turn the lens to F2 or F16.

The petri is like an "M" series lens. You need to use M manual mode. The green button is then your means of metering but personally I just chimp a couple of shots and then adjust exposure (shutter) according to the aperture set.
Lenses without the electrical contacts of the "A" and later lenses will not stop down in Av or TAv on a dslr, the dslr's lack the aperture simulator connection of the film cameras. The only hack around is to not fully mount the lens - at the risk of the lens falling off!

[Rvtazz]

Many Pentax DSLR owners want to use M42 screwmount (Takumar) lenses, or M or K manual lenses, on their cameras because of the low cost and relatively high image quality of these lenses.


If you're wondering whether or not these lenses can be used with Pentax DSLRs (or the K-01), then the answer is yes! Pentax as well as third-party manual and screwmount lenses can easily be mounted on any Pentax DSLR (such as the K-1, KP, K-3, K-70, K-S2, K-S1, K-50, K-500, K-30, K-5 series, K-r, K-x, K-7, K10D, K100D, K200D, *ist D, etc.) Just follow this guide!



Modern Pentax DSLRs use the Pentax "K-mount", which employs a bayonet and therefore differs significantly from the M42 screw mount. The older manual M and K (SMC Pentax-M, SMC Pentax) lenses actually use the bayonet, so they will not need an adapter - you can skip straight to the lower portion of this article (starting at "Important!") for information on how to meter with those lenses. Screwmount lenses usually have "Takumar" in their names, and in order to mount screwmount lenses on your k-mount body, you'll need a Pentax k to m42 adapter. Pictured above is the genuine Pentax adapter, which is ideally the one you want to get. Unfortunately, it has been discontinued and can only be purchased second-hand. However, similar third-party adapters are also available. Caution: Many third-party adapters, such as this one, have a protruding flange which will prevent you from focusing all the way to infinity. If you want to buy a third-party adapter (they're generally cheaper), make sure that they don't have this flange. Here's an example of a good third-party adapter.

Once you have your adapter, the next step is to install it on your camera (it can easily be put on and removed on-the-fly). Check out the m42 to k adapter manual. After you've installed the adapter, you'll want to mount the lens. This is done by screwing it into the camera until the lens feels firmly attached. The focusing window and lens ring should line up with the camera just like any other lens. Now that your lens is mounted, let's talk about how to take photos with it.

Important! The hard part is to get the camera to actually fire when a manual lens is mounted. In order to accomplish this, enter your camera's custom function menu, select the "Using Aperture Ring" setting (usually at the end of the menu, #21 on the K-7, #27 on the K-5, #27 on the K-3, #26 on the K-1), and set it to 2 (allowed). Once you do this, the shutter will at least fire, as it wouldn't have with this setting disabled (you would simply have seen an F-- indication on the top LCD/info screen). The setting description should read: 'Shutter will release when aperture ring is not set to the "A" position' when "allowed" is selected. Also note that the mount on the lens must be conductive for electrical current so that it shorts the electrical contacts on the camera body. All Pentax manufactured lenses have a conductive mount, but some third party lenses do not in which case the area of the mount touching the contacts must be sanded down.

K-30, K-50, K-500, K-70, K-S1, K-S2 and K-01 users: make sure you also set your green button "action in M/TAv Mode" to Tv SHIFT. This is found under the button customization menu (page 3 of the main menu) on the K-01 or as a custom function on the K-30, K-50 and K-500. On the K-S2 and K-70, look under the e-dial programming sub-menu under button customization in the record menu.

Finally, ensure that auto ISO is disabled.

At startup, if your camera asks you for the focal length, enter the actual focal length as labeled on the lens. This will ensure optimal Shake Reduction performance. For zooms, you can use the lower end of the zoom range (this ensures that there will be no over-compensation), or the focal length that you shoot at most often.

Now, let's discuss metering. Since manual lenses don't feed aperture data to the camera, the only way for the camera to check how much light is being passed through the lens is to measure the light while the lens is stopped down. Follow this procedure to properly meter with a screwmount, M, or K lens:

___0. Ensure that the "Using Aperture Ring" custom function is set to "2 (allowed)" (K-30/50/500/01 users must also ensure that the green button is configured to Tv Shift in M/TAv Mode) as described above

1. Set your camera to M mode using the mode dial (your camera won't fire in other modes*)
2. Compose and focus your image.
3. Using the aperture ring (the ring at the very back of your lens; it will have numbers such as 2.8, 4, 5.6, 8 written on it), select your desired aperture setting. Note that the smaller the aperture number is, the more light passes through the lens, and the blurrier the out of focus areas of your photograph will be (and vice-versa). Note your lens will not stop down until step 5.
4. [Screwmount lenses only] Switch the diaphragm clutch on your lens to "Manual" (you can leave it on Auto when composing and focusing if you don't want a dark viewfinder).
5. Measure the light by either pressing the "Green Button" (older bodies may use the Av button), or pushing your power button to DOF preview mode (only available on high-end bodies). Your camera will automatically set the shutter speed for you.

All that's left now is for you to press the shutter release button to take your photo. Congratulations- you've now learned how to use M42 and M & K manual lenses with Pentax DSLRs!

*Screwmount lenses may also be used in Av mode since they are always stopped down to the aperture you will be shooting at (unlike M&K lenses, which are stopped down only when the shutter is released or when you meter as described above).

Note: if your aperture ring has an "A" on it, instead of doing stop-down metering as per this guide, you'll want to set the ring to "A" and use the camera's scrollweel to adjust the aperture via Av mode.

Click here if you found this article helpful!

Video version:
How to use a manual lens (M, K, or M42) on a Pentax DSLR - YouTube

I would just like to add that M-lenses can be used in AV-mode if you don't mount them all the way till they click in : set the aperture fully closed and mount the lens while looking at the aperture tru the front element , when you see the aperture opening up (because the aperture lever gets moved aside) stop mounting the lens and return until the aperture is fully closed again . You can now use AV-mode by setting the aperturering to your desired f-stop and the camera will automatically adjust to the correct shutterspeed just like with M42 lenses. You can always psysically remove the aperture lever for the same effect and then you can mount the lens till it clicks into place . Only disadvantage is focussing because of the darkness of the ovf at smal apertures . As a more sophisticated hack you can make a shallow "hole" in the lensmount so it clicks in in a position before the aperturelever gets moved aside .

[reh321]

I would just like to add that M-lenses can be used in AV-mode if you don't mount them all the way till they click in : set the aperture fully closed and mount the lens while looking at the aperture tru the front element , when you see the aperture opening up (because the aperture lever gets moved aside) stop mounting the lens and return until the aperture is fully closed again . You can now use AV-mode by setting the aperturering to your desired f-stop and the camera will automatically adjust to the correct shutterspeed just like with M42 lenses. You can always psysically remove the aperture lever for the same effect and then you can mount the lens till it clicks into place . Only disadvantage is focussing because of the darkness of the ovf at smal apertures . As a more sophisticated hack you can make a shallow "hole" in the lensmount so it clicks in in a position before the aperturelever gets moved aside .

So much carefulness to avoid green-button metering ...... which is not that difficult at all.

[Rvtazz]

So much carefulness to avoid green-button metering ...... which is not that difficult at all.

I'm not avoiding it , i'm just adding an alternative that could be usefull in some occasions. I actually prefer green button metering because it's much easier to focus with small apertures. All roads lead to Rome lol

[Mercifulfate]

I have never once heard an M42 lens, "click" when "screwing" it on the camera. There is nothing on the lens that would "click". The only clicks I hear are from the aperture ring or my shutter.

What do people mean by hearing a click on a screw thread?

Maybe I lost the hearing in my three ears.

[Thagomizer]

I think the reference to "clicking" you are referring to is Rvtazz talking about mounting a K mount M series lens (rather than an M42 lens) in such a way that the camera's spring loaded lens locking pin does not engage the slot in the lens mount rear face. This keeps the aperture lever from operating, allowing the K mount M lens to be used in AV mode like a screwmount lens, thereby avoiding green button metering and saving a step when shooting. At the risk of having your lens fall off the camera...

[dadengler]

I can only speak for the K-50:

Using K-mount lenses with no "A" setting, you follow the information above, set the camera's mode button to "M", use the green button to stop down the lens and get a meter reading before shooting. It's usually within a stop or two of being correct, but I find adjustment is necessary almost every time to get a proper exposure. Regardless of the aperture setting, the iris remains open for focusing, and only closes down when the actual shot is taken or the green button is pushed.

Using M-42 mount lenses, you do NOT use the green button. Set the camera's mode dial to "AV" (or "TAV", but limit your ISO), choose the aperture you want on the lens, and the camera does the rest—well, you have to compose and focus, of course. With M-42 lenses, the aperture opens and closes as you turn the aperture dial. Focusing at f/8 and smaller apertures (higher numbers) can be a challenge, but exposure is usually right on the money—it's a bit like shooting with an automatic lens. Therefore, I actually prefer my M-42 lenses to my K-mount. Exposure is more accurate, and there's no futzing about with the green button.

I'm late to the party with this. I have a K-50 and recently picked up a Spotmatic for that great 50mm M-42 lens. This forum is a great source of info but this thread is out of date and confusing. I spent a couple of hours wading through the thread and stupidly trying to change the green button settings and then to get the button to work and on and on...

Maybe separate instructions for the types of lens mounts would help. Don't get me wrong, I really appreciate all the hard work the moderators do. Thanks!

[Dan James]

Finally, ensure that auto ISO is disabled.

Thank you so much for this part especially! I've been shooting with K lenses fine on my K100D using M mode and using the optical depth of field preview to take a meter reading, but couldn't figure it out with my K-30 as when I put it on M mode it kept saying it was still on Av mode and was only meter for the lens being wide open. It's because I use auto ISO fixed between 100 and 400 by default. Now I've switched to fixed ISO of 100 and it all works a treat, and is a slightly more fluid process than with the K100D as the K30 takes a reading and then adjusts the shutter speed too, whereas the K100D takes the reading but then you have to adjust the shutter speed manually still. I have a new Auto Chinon 50/1.4 to play with - the 50/1.7 versions have given me lovely results in the past...

[abcasada]

I just got a Takumar 200mm f/3.5 and found that its rear is so narrow that it does not reach the contacts on the K-50's lens mount, and because they are not shorted by a lens, the camera will not perform stop-down metering unless I hold a piece of foil or something on the contacts. (It does work wonderfully in Av mode, of course, when an automatic mode is desired.) I suppose this narrow rear end is somewhat uncommon among m42 lenses, since this article never mentions being unable to stop down a lens due to the contacts not being shorted?

[marcusBMG]

I just got a Takumar 200mm f/3.5 and found that its rear is so narrow that it does not reach the contacts on the K-50's lens mount, and because they are not shorted by a lens, the camera will not perform stop-down metering unless I hold a piece of foil or something on the contacts. (It does work wonderfully in Av mode, of course, when an automatic mode is desired.) I suppose this narrow rear end is somewhat uncommon among m42 lenses, since this article never mentions being unable to stop down a lens due to the contacts not being shorted?

As long as you're not distant focusing, use one of the flanged adapters - the better quality plated brass ones, not the cheap black anodised ones..