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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:

You Tube

You Tube

[Jingchun Zhao]

Thanks. I am tring it now. But I can not find the menu forbutton with action in M/TAv Mode or Tv SHIFT mode. My Vivitar lens f3.5 135 mm works without I change any settings.

[beebs]

I, like other K-30 users earlier, was perplexed when it said the setting for the Green Button was under "Button Customization"...on the K-30, it is not there.

On the K-30, the Green Button settings are part of the E-DIAL PROGRAMMING settings. Go to the second page of the E-DIAL PROGRAMMING settings, and you'll see a line with this:

M (dial) Tv (dial) AV and then a green dot.

Navigate to the green dot, and choose "TvSHIFT, hit OK.

It took me about an hour just now to figure that out.

Again, K-30 "Green Button" settings are part of the E-DIAL PROGRAMMING settings, not "Button Customization".

Hope this helps the other K-30 folks out.

I've been experimenting with my M50mm all evening. I'm trying to take enough shots that the procedure becomes "habit": Set to "M", hit 4-way controller "UP" to set ISO, focus, press shutter halfway, press green button, take the shot.

[Fluke]

It needs to be stated in this thread that, at the time or writing, K30 and K50 will not meter correctly with an M42 lens in M mode unless in Live view.


Again, at the time of writing, Pentax/Ricoh don't seem to understand this.

[MJSfoto1956]

not sure which way to proceed with my unusual setup.

What I have:

• K-3 + Chinese painted aluminum adapter (no optics) + Nikkor 180mm f/2.8 (to be used for macro work)

What I want to do:

• CIF macro shots

Tests so far:

With paint on adapter:

• I can specify AF-S or AF-C.
• Camera asks for focal length and I type in 180mm.
• Exposes fine.
• SR works too.
• But CIF doesn't work (Use Aperture Ring and CIF is set to true in menu)
• AF confirmation doesn't work either.

With paint removed from adapter (i.e. bare aluminum, i.e. pins are being shorted):

• I CANNOT specify any AF mode: neither AF-S or AF-C.
• AF confirmation works! (I can hear a beep and see the focus point blink in the VF)
• Exposes fine.
• CIF still doesn't work (Use Aperture Ring and CIF is set to true in menu)

Any ideas how to trick this puppy into allowing CIF for my given setup?

Michael

[moth_luna]

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-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), 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 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. Also, avoid auto ISO.

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).
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!

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

thanks for all the info! very helpful! just one question, we aply the same steps (from the ''important!'' note and below) for any manual focus lens? for example samyang?

[alexk99]

Adam

Thanks for this . I think I've now managed to work out how this applies to my set up

[RedneckPictureTaker]

So helpful - thanks.

[ausmoose]

Thanks Adam - I didn't know how to use the green button for this before. It was already set in my camera for the green button to measure the light - I'm not sure how you change it?

Also, this is a helpful link you might want to include in the description:

You Tube

You Tube

.
Since it's so hard to acquire actual pentax mounts these days, third party mounts are very common and some of them get stuck on your DSLR. I got my mount stuck on my camera yesterday and was quite worried until I found this youtube clip which explains why the mount is stuck and how to remove. The tool that comes with the mount and the mount itself are made so that it is very hard to remove the mount - but it can be done!

[haviet]

Could anyone suggest a good quality third party M42 to K mount adapter? Thanks

[Pepe Guitarra]

Could anyone suggest a good quality third party M42 to K mount adapter? Thanks

There is no such think IMHO. I tried many. However, Pentax poduced the original Pentax couple of years ago, and I bough about 6 for $28 each, I think. Pentax may do that again. However, I have seen the original for sale in many places.

---------- Post added 05-29-14 at 08:42 AM ----------

Here is one on the auction site.

---------- Post added 05-29-14 at 08:43 AM ----------

Here (another) is one on the auction site.

And another.

[haviet]

There is no such think IMHO. I tried many. However, Pentax poduced the original Pentax couple of years ago, and I bough about 6 for $28 each, I think. Pentax may do that again. However, I have seen the original for sale in many places.

---------- Post added 05-29-14 at 08:42 AM ----------

Here is one on the auction site.

---------- Post added 05-29-14 at 08:43 AM ----------

Here (another) is one on the auction site.

And another.

Interesting. I see many generic M42 to K adapters on ebay. You're saying none of those work?

[D1N0]

Interesting. I see many generic M42 to K adapters on ebay. You're saying none of those work?

The flanged ones (flange on top of mount) will not give you infinity focus, since they act as a little macro extender. The ones that fit inside the mount will work, but you run the risk of getting it stuck in your mount. When you unscrew the little spring on them you won't have that problem, but the adapter won't lock. Not a real problem, but with some lenses you might turn de lens out of the mount while focussing. You just need to be careful.

[Pepe Guitarra]

Interesting. I see many generic M42 to K adapters on ebay. You're saying none of those work?

I damaged my Kx when the lens got stuck and could not retrieve it. I threw all those away. Another thing: The original adapter goes on the camera, not on the lens. Keep that in mind. It is very easy to remove. You need not tool to remove it. I remove it with my fingernail, pushing the little spring inside. Althugh the manual that comes with it says that you can use a ball point pen to do that. See how easy is to use? I use my K3 now mostly with M42 lenses.

[haviet]

I see. So there's some risk with those generic adapters. Thanks for the heads up. I'll keep an eye out for a genuine adapter made by Pentax.

[Tall Guy]

I damaged my Kx when the lens got stuck and could not retrieve it. I threw all those away. Another thing: The original adapter goes on the camera, not on the lens. Keep that in mind. It is very easy to remove. You need not tool to remove it. I remove it with my fingernail, pushing the little spring inside. Althugh the manual that comes with it says that you can use a ball point pen to do that. See how easy is to use? I use my K3 now mostly with M42 lenses.

Same here with the Pentax original on my K10.