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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[ankh]

Pentax brand adapters are "back ordered" at Adorama

B'n'H has: http://www.bhphotovideo.com/c/search?Ntt=K+to+M42+adapter&N=0&InitialSearch=yes
but the reviews are not encouraging

[pippin65]

so my question is do I bite the bullet and pay the exorbitant price of a real pentax adapter or can one of my fellow pentaxians direct me to solid 3rd party ones? The "general" one hyperlinked in the text of the article did not have very good reviews. I just purchased a 50mm super tak 1.4 and am excited to throw it on my k30, or does someone wanna sell me an extra real one for like 40 shipped???
UPDATE: bit the bullet....and am $49 poorer

[timmijo]

I believe a genuine Pentax adapter can be had for around $25 either here on the forum or from someone on EBay. $49 seems a bit steep.

[ankh]

> a genuine Pentax adapter can be had

Pointer welcome. Don't all rush in at once, I'm looking for one too.

Pentax Webstore via email insists that Pentax USA still sells them but only via 800 number. Pentax USA 800 number guy says no, they don't sell anything directly, would I be interested in a third party product. I said nope. Then he said Pentax Philippines gets a few every few months and releases them to Adorama, B'n'H, KEH, and "some little stores you've never heard of" but then he said he'd checked and they're backordered; he says keep phoning around.

EDIT April 16th -- I'm still looking

---

Last edited by ankh; 04-16-2013 at 11:14 AM.

[Randolph Arends]

No, M and K lenses cannot be stopped down when the camera is in Av mode (or any other mode than M). So M42 lenses are actually more convenient to use from that aspect. Overall the M/K lenses are easier to use, though, because you have no adapter to fiddle with.

I have two M lenses. 50 and 135mmt and a zoom that I can use. All in AV mode. I tried Manual but it did not work all that great. I have set up my camera to detect the lenses and it asks for the focal length. However what do I do with the zoom or should I just forget it? I also have the 2X converter that comes handy in a pinch.

Set your custom setting 4 option 22 to permit the use of aperture ring. If you are inserting a M lens like in my case and you turn on the camera it will ask you for the focal length. You can assign the metering to the green button to get the correct exposure and get great shots with the manual lenses. I hope this helps.

[Randolph Arends]

No, M and K lenses cannot be stopped down when the camera is in Av mode (or any other mode than M). So M42 lenses are actually more convenient to use from that aspect. Overall the M/K lenses are easier to use, though, because you have no adapter to fiddle with.

I have two M lenses. 50 and 135mmt and a zoom that I can use. All in AV mode. I tried Manual but it did not work all that great. I have set up my camera to detect the lenses and it asks for the focal length. However what do I do with the zoom or should I just forget it? I also have the 2X converter that comes handy in a pinch.

Set your custom setting 4 option 22 to permit the use of aperture ring. If you are inserting a M lens like in my case and you turn on the camera it will ask you for the focal length. You can assign the metering to the green button to get the correct exposure and get great shots with the manual lenses. I hope this helps.

[D1N0]

I find it hard to use shutter priority with a takumar lens on my K-5. Mode does not work. With my 135mm it seems to want to shoot at 1/125 (in P mode or super AV when you use a tak). I want it to shoot at at least 1/160. It does not react to program lines. The only way to do it is to manually set a higher iso value. I don't want to use the cumbersome m-mode for my taks. Is there a way to manually set shutterspeed at say 1/250 with the camera automatically adjusting the iso to that speed.

[Randolph Arends]

If you happen to have the A setting on your Aperture ring, you might be able to get better control over the shutter speed if you use the manual f-stop mode. In the AV mode you can still get auto exposure. Also if you use the digital zoom to bring in your subject you can get better focus. If you use the A mode you need to go to the Manual setting. I do not know how similar the K-5 and K-x are but that is how I use the manual lenses.

[D1N0]

If you happen to have the A setting on your Aperture ring, you might be able to get better control over the shutter speed if you use the manual f-stop mode. In the AV mode you can still get auto exposure. Also if you use the digital zoom to bring in your subject you can get better focus. If you use the A mode you need to go to the Manual setting. I do not know how similar the K-5 and K-x are but that is how I use the manual lenses.

This thread is about manual lenses, so m42 takumars pentax-k and pentax-m lenses. They don't have an (a)utomatic mode.

[altopiet]

Manual lenses can only be used in M and AV modes. If you put it in TAv, Tv or Sv modes it will revert to Av mode. In K, M and M42 lenses in Auto mode, will always be wide open in Av mode. If you put them in M mode you first manually set your aperture on the ring to the desired aperture and the desired ISO, then press the green button while aiming toward the target, which will stop down to the aperture setting picked by you, take a light measurement and taking into account the ISO setting you picked, decide on a suitable shutter speed to capture a correctly exposed image. Using a pre-set or M42 lens in manual mode, you can use Av mode. As there is no aperture lever to be stopped down, what you see through the VF, or live view, is what you get. When you stop down on the aperture ring you'll see it get darker and the shutter speed changing accordingly, adapting to the aperture getting smaller. You can change the shutter speed, but will not get a correctly exposed image

[D1N0]

I know, just wish there were some setting to configure the minimum shuttertime. it always picks 1/125 independend from focal length.(unless there is more light or very little light at the top of the iso range) I could limit the auto iso range for higher shuttertimes, but that would leave me without the low iso. I've now configured the front wheel to change iso in av-mode (green button restores auto iso) shuttertime goes up automatically. 1/125 is fine with most lenses, but from 135mm upwards it's kind of slow.

[altopiet]

Have a look at the shots I took with this beast, the ISO, Shutter speed and f stop is indicated. With Pentax cameras you can comfortably let the ISO go up a bit and still get clear shots, and if you shoot RAW and do a bit of PP you'll still get reasonable results.

https://www.pentaxforums.com/forums/lens-sample-photo-archive/216174-noflexar...m-samples.html

EDIT: This was done in M with green button.

[mike_berger]

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-30, K-5, 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 (#21 on the K-7, #27 on the K-5), 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.

K-30 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.

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:

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).
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", or pushing your power button to DOF preview mode (only available on select 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!

Thanks for the tips!

[ivanvernon]

Thanks for a great explanation Adam. However, I will really appreciate one clarification. You state the following:

"K-30 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."
From PentaxForums.com: https://www.pentaxforums.com/forums/pentax-lens-articles/110657-how-use-meter...#ixzz2RsPT6FIa

However, when I navigate my menu to Button Customization, I find these five options: (1) One Push File Format, (2) Preview, (3) Focus Peaking, (4) Custom Image, and (5) Digital Filter. I cannot find anything about "action in m/TAvMode" to Tv SHIFT.

I wonder what I am missing?

Thanks,

ivan

[hypernotactive]

As far as I can rememer its in an other part of the menu. I'm at work at the moment but I will check it out when I'm home