Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
333 Likes  
How to use/meter Manual & M42 Lenses on all Pentax DSLRs (K-1, K-3, K-5, K-30, etc)
Posted By: Adam, 08-12-2010, 04:24 AM

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, #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.

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 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:


Last edited by Ole; 02-12-2011 at 11:46 AM.
Views: 258,711
11-22-2014, 08:04 PM   #256
Site Supporter




Join Date: Apr 2012
Location: Colorado
Posts: 74
QuoteOriginally posted by Not a Number Quote
Different models handle non-conductive lens mounts differently - it may also be a matter of the firmware version too. The easiest way to check this is to put a piece of metal foil over the the contacts and mount the lens.
Ok, I tried this and it seemed to work (most of the time). I didn't like the bits of foil left behind, so is there another method to address this? I tried to search, but must not have the right index words...thanks.

Also interesting in that the Vivitar 50mm 2.0 Auto works in all modes on the K-01 but stays fully open on the K-3. Annoying.

Z


Last edited by HomeMadeSin; 11-22-2014 at 08:05 PM. Reason: spelling
11-23-2014, 12:00 AM   #257
Pentaxian
Not a Number's Avatar

Join Date: Mar 2012
Location: Venice, CA
Posts: 4,072
QuoteOriginally posted by HomeMadeSin Quote
I didn't like the bits of foil left behind, so is there another method to address this?
If the foil solves the problem then the alternatives are to use some metallic tape on the lens mount (which will eventually wear or peel off) or remove some of the non-conductive coating.
11-27-2014, 06:50 AM   #258
Pentaxian
Rimfiredude's Avatar

Join Date: Oct 2014
Location: Washington
Photos: Gallery
Posts: 2,177
I just bought a 135 and 300 SMC Takumars with the lever on them. Will they meter like an M or K lens or like all the other Takumars?
https://www.flickr.com/photos/24877856@N00/15890520921/

Last edited by Rimfiredude; 11-27-2014 at 10:58 AM.
11-27-2014, 11:42 AM   #259
Pentaxian
Not a Number's Avatar

Join Date: Mar 2012
Location: Venice, CA
Posts: 4,072
QuoteOriginally posted by Rimfiredude Quote
Will they meter like an M or K lens or like all the other Takumars?
By all the other Takumars I take it you mean screwmount lenses. Asahi Optical/Pentax did resurrect the Takumar name for budget K-mount lenses for a time. You would meter as you would with any other screwmount lens. The difference is you can leave the f-stup setting and open or stop-down the diaphragm by setting the switch to auto or manual respectively.

11-27-2014, 11:51 AM   #260
Pentaxian
Rimfiredude's Avatar

Join Date: Oct 2014
Location: Washington
Photos: Gallery
Posts: 2,177
QuoteOriginally posted by Not a Number Quote
By all the other Takumars I take it you mean screwmount lenses. Asahi Optical/Pentax did resurrect the Takumar name for budget K-mount lenses for a time. You would meter as you would with any other screwmount lens. The difference is you can leave the f-stup setting and open or stop-down the diaphragm by setting the switch to auto or manual respectively.
In other words...I can set my fstop at f8, leave the lens open on auto, hit the green button, it will stop down to take a reading and expose at f8?
11-27-2014, 12:08 PM   #261
Pentaxian
Not a Number's Avatar

Join Date: Mar 2012
Location: Venice, CA
Posts: 4,072
QuoteOriginally posted by Rimfiredude Quote
In other words...I can set my fstop at f8, leave the lens open on auto, hit the green button, it will stop down to take a reading and expose at f8?
Correct. An improvement on the preset lenses You would set both rings to the desired f-stop, turn the aperture ring to wide open to focus and compose then close down the aperture ring until it hit the preset stop. The advantage is that you don't have to count the f-stop clicks or look at the ring to reach the preset.

And if the light doesn't change significantly you can skip using the green button until the the lighting does change.
12-08-2014, 08:38 AM   #262
New Member




Join Date: Nov 2014
Posts: 1
QuoteOriginally posted by Adam Quote
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, K-S1 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 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 bought the General Brand M42 adapter that is shown in the link at the end of the first paragraph. It did not work at all for the Takumar 50mm lens. This adapter has an inner flange, compare a photo of this adapter to an original Pentax adapter, it can be plainly seen. I had to put the adapter on a lathe and cut away the inner flange so it would not interfere with the f stop lever or the long pin on the base of the lens and so it would seat fully. Now it works fine. Also there is a link on you tube which explains how to get these adapters out without being rough on your camera, don't have it handy. Just do a search on you tube "How to remove M42 lens adapter", should be an esay find.
12-08-2014, 09:14 AM   #263
Pentaxian
Not a Number's Avatar

Join Date: Mar 2012
Location: Venice, CA
Posts: 4,072
QuoteOriginally posted by steve523 Quote
I bought the General Brand M42 adapter that is shown in the link at the end of the first paragraph. It did not work at all for the Takumar 50mm lens. This adapter has an inner flange, compare a photo of this adapter to an original Pentax adapter, it can be plainly seen
The function of the inner flange is to depress the auto aperture stop down pin. On auto lenses without an auto/manual switch this is the only way to stop them down. Some people modify their lenses by gluing down the pin or replacing the pin with something to actuate the stop-down mechanism.

This is the first I've heard of such adapters causing a problem. It is good that it works for you now.

12-22-2014, 10:52 AM   #264
Forum Member
KatPal's Avatar

Join Date: Nov 2014
Location: Northern NJ
Photos: Albums
Posts: 63
Thank you for this guide!
12-24-2014, 05:19 AM   #265
Senior Member
malenisjaj's Avatar

Join Date: Dec 2013
Posts: 166
As wirrah said here, I also discovered that the quickiest way to use m42 on my K-5 II is like this:

You can also use Av with M42 lenses on the *ist D. This is how I always use them on my *ist D. It obviates the need to press the green button. I am assuming this works for later models.

Set the lens A/M switch to manual. Set the camera to Av. The camera will continuously set the shutter speed based on the aperture setting on the lens. You should do your focussing at maximum aperture first for a brighter image.


Is it possible to use SMC-K lenses like m42 lenses in AV mode on K-5 II? I know that camera can control aperture on this [SMC-K] lenses, but is it possible to disable that function so I could use aperture ring like I do with m42 (preset) lenses. For me, it's much quicker than pushing the green button all the time.
12-24-2014, 07:12 AM   #266
Pentaxian
D1N0's Avatar

Join Date: May 2012
Location: ---
Photos: Gallery
Posts: 3,975
It's possible but awkward. Just don't lock the lens al the way in. The aperture lever won't get pressed in. This needs a smooth aperture and focus ring, so you won't turn the lens in the mount while operating the lens and you have to take care not to turn it out anyway.
12-24-2014, 03:13 PM   #267
Senior Member
malenisjaj's Avatar

Join Date: Dec 2013
Posts: 166
So there is only mechanical solution and not something which include settings in K5 II software/firmware?
12-24-2014, 03:24 PM   #268
Pentaxian
Not a Number's Avatar

Join Date: Mar 2012
Location: Venice, CA
Posts: 4,072
QuoteOriginally posted by malenisjaj Quote
So there is only mechanical solution and not something which include settings in K5 II software/firmware?
Pretty much so. You can modify the lens by removing the auto stop down lever. This can probably be done in a non-destructive and reversible manner rather than simply cutting it off.

I suppose you could drill another lock notch so you can lock the lens into a position where the stop down lever is not being pushed.
12-25-2014, 12:12 AM   #269
Senior Member
malenisjaj's Avatar

Join Date: Dec 2013
Posts: 166
I think I'll stay away from any mechanical modifications. Thanks.
01-06-2015, 10:46 AM   #270
Senior Member




Join Date: Jul 2010
Posts: 238
Is there any thread on this forum concerning M42 lenses and flash metering? As far as I learned one cannot work in P-TTL with M42 glass, right? So what's the choice for Sigma EF-610 DG Super (no external auto-mode sensor) + K-5 IIs body (or K-3 body) + M42 lens besides full manual flash mode?
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!
act, adapter, aperture, auction, body, button, camera, d100, dof, f-stop, focus, im, iso, k-50, lens, lenses, lever, m42, mode, mount, pentax, post, press, preview, screwmount, series, shutter, site, third-party
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
For Sale: Instantly download your Pentax eBook! (K-1, K-70,K-3, K-5, K-50, K-S2 and more DSLRs) ebooks4pentax Photographic Equipment for Sale 101 05-31-2017 11:52 PM
For Sale - Sold: NIB KatzEye Focusing Screen for K-3, K-5, K-5ll, K-30, K-50, O-ME53 Magnifying Eyecup monochrome Sold Items 8 08-03-2016 06:34 PM
Wanted - Acquired: KatzEye Focus Screen for K-3 (K-3, K-5, K-5II, K-7, K-30, K-50, K-500), New or LN fwcetus Sold Items 15 05-07-2016 08:01 PM
For Sale - Sold: Focusingscreens.com EE-S Screen for K-3, K-5, K-5II, K-7, K-30, K-50 & K-500 Aperturae Sold Items 6 10-06-2014 06:49 AM
For Sale - Sold: KatzEye Split-Prism Focusing Screen - for K-3, K-5, K-5II, K-7, K-30, K-50 & K-500 chickentender Sold Items 7 04-15-2014 08:35 PM



All times are GMT -7. The time now is 10:29 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