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.

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[sai]

Great guide, point by point explanation, started taking good pictures with Helios 44M 58/2 lens on my Pentax K-x.

[sany]

I've read comments such as 'use your nails to remove the adapter' or things like 'using a normal screwdriver' to remove it. All this has left me confused.
Are these adapters that complicated to remove or it is easy as fixing like a normal clockwise rotating mechanism (as described in the manual link provided in the article).

Secondly, instead of removing lens first and adapter > is it possible to leave the adapter fixed with the lens so that we can fix the lens/adapter set whenever required straight into the body as a normal bayonet lens?

[sany]

bumping this up!

[i_trax]

Hi Sany, I will try to explain, it is not as simple as that.
The Pentax adaptor is the best, perfectly manufactured to fit K mount.
It has little black spring attached to the ring which locks the adaptor in place.

This is my first attempt to attach pictures, hopefully it will work.
To remove it just simply push the spring with your finger nail, turn it and remove it.
the location of the spring while inserted:

Some people just glue adaptor permanently to the camera body, I did have Helios lens modified like that and I did not like it.
Glued lens completely covers the access to the spring so it has to be removed otherwise you would not be able to remove the lens from the body.
Consequently the lens can not securely lock into the body, it is just inserted so you need to be very careful while turning focusing etc rings.
This kind of ( focus to infinity) adaptors does not and can not use the small pin which is utilised to lock all standard K lenses.
There are some other adaptors which will focus to infinity but most of them are not as precise as Pentax and are much harder to unlock and remove.
Some of them actually come with dedicated removal tool:

if you can not see images look at:
Pentax K to M42 - a set on Flickr

---

Last edited by i_trax; 07-24-2011 at 09:44 AM. Reason: mistake

[i_trax]

No, picture insert from my ( just created ) album did not work?
I will try the different option.

[i_trax]

Looks like this one did work,
It is definitely worth investigating and utilising M42 lenses.
Like obviously Super-Takumars but also other brands, Mamiya-Secor 55/1.4 , Rikenon 50/1.7 ,
Cosinon 50/1.8 , Pentacon 30/3.5 just to list some of my favorites.
They are all beautifully made, all metal , fast ( easy in manual focusing ) just pure pleasure to use.

[i_trax]

Hey BSandu, it looks like you have the "black base lens syndrome" case.
you need to get some aluminium foil and short all contacts on your camera body before mounting your black based lens.
Some people scratch the base so it becomes nice silvery shiny , I personally would not do it.
this syndrome could also cause problems with AF

[sany]

Looks like this one did work,
It is definitely worth investigating and utilising M42 lenses.
Like obviously Super-Takumars but also other brands, Mamiya-Secor 55/1.4 , Rikenon 50/1.7 ,
Cosinon 50/1.8 , Pentacon 30/3.5 just to list some of my favorites.
They are all beautifully made, all metal , fast ( easy in manual focusing ) just pure pleasure to use.

thanks i_trax for taking time to explain.

[sany]

Question moved into DSLR lens discussion section for more visibility: Apologies

[vlad2304]

When I got my Pentax KR I immediately bought 2 lenses from Ebay:

Chinon 50mm/1.9 and Porst 28mm/2.8, both for K mount. I paid around $70 for both incl. delivery to Moscow and received them in perfect shape.

And here I faced the same problem using both of them:
while using on close distance they produced the good images but when I tried to shoot landscapes or distant images they were out of focus (not as sharp as I expected).

I knew that some M42 lenses when using them with adapter for Canon EOS had the same problem with focus to infinity but it is strange that this happened with the ones that are for native Pentax mount.

That's why I am sure that I am doing something wrong or not doing something right.

So, I will appreciate if somebody can help me with this problem.

[i_trax]

"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."

On my K7 Green Button - YES , works perfectly but my nose is in the way ( I am left eyed
photographer) but DOF does not automatically set the shutter speed for me.
It stops down the aperture and shows EV bar and then I have to manually adjust with e-dial the shutter speed while holding DOF switch pushed on.
Am I missing something, looked through all menus and can not find anything relevant to it , or am I doing something wrong?

[i_trax]

Hey vlad2304,

I purchased recently the exactly same lens.
It is very plasticky, I did use it indoors , close-up and portrait - it was fine.
I never tried landscapes, I know those lenses need good light and F5.6 or 8 to get reasonable sharpness and contrast.
I will take some outdoor photos with mine within next few days and will post back

[vlad2304]

I tried to use it outdoors without shake reduction and it produced much sharper images.

[Pepe Guitarra]

I read this whole thread years ago and also went through the stuck problems with the screw-mount lenses and the adapters until I got the Genuine Pentax adapter. The problems were solved not because the adapter was genuine, but because it came with instructions. I found out that I was doing the whole thing wrong. THE ADAPTER IS PLACED IN THE CAMERA, NEVER ON THE LENS. THE GENUINE PENTAX ADAPTER INSTRUCTIONS bring photos on how to do it. With a ball-point pen you place the adapter IN THE CAMERA and rotate until the spring clicks. Then you screw the lens and done. When done, you unscrew the lens to remove the lens FIRST. Then take the ball-point pen and push the spring counter-clockwise and teh adapter is removed. I tried my Bower (recommended at the beginning of this thread) adapter, and it works just fine. The Bower comes with a tool to remove the adapter frm the camera, no need of ball-point pens. The chines adapters with a flange are OK to install on the lens, but will not provide infinite focussing (because they add a small lenght to the focal distance --the thickness of the flange --- the genuine adapter has no flange, it is flush with the camera). If you can live with that,you are welcome. Remember, THE ADAPTER GOES IN THE CAMERA BODY, NOT ON THE LENS.

[Pepe Guitarra]

I've read comments such as 'use your nails to remove the adapter' or things like 'using a normal screwdriver' to remove it. All this has left me confused.
Are these adapters that complicated to remove or it is easy as fixing like a normal clockwise rotating mechanism (as described in the manual link provided in the article).

Secondly, instead of removing lens first and adapter > is it possible to leave the adapter fixed with the lens so that we can fix the lens/adapter set whenever required straight into the body as a normal bayonet lens?

See my post above. The only way to leave an adapter ON the lens is to buy the cheap adapter on ebay (from China) that come wtih a flange. Those can be placed on the lens and left there, but will not provide infinite focussing because they change the focal lenght the lens was designed for.