Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
327 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: 249,827
06-17-2014, 12:51 PM   #196
New Member




Join Date: Oct 2013
Posts: 2
QuoteOriginally posted by Fluke Quote
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.
Fluke:

Forget about using manual mode when using M42 lenses with the lens switch set to M.

True, with an M42 lens set to M, the K-30, K-50 won't meter in manual mode unless in live mode, but why would you want to meter this way when you can use Av mode? It's not necessary to use manual mode at all unless you want to set things manually. (that's what it's for.) Setting the camera to manual mode and pressing the green button is the only way k-mount manual lenses can be metered since this is the way the camera stops down the lens to meter (you can't manually stop down the lens). Av mode can't be used with these k-mount manual lenses. This is not necessary with an M42 lens with the lens switch set to M as the lens is already stopped down and Av mode works fine.

(Camera still has to have aperture ring enabled and green button set to Tv Shift)


Last edited by smoldman; 06-19-2014 at 08:54 AM. Reason: typed k-3 instead of K-30, added TV Shift note
06-17-2014, 01:47 PM   #197
Pentaxian
Not a Number's Avatar

Join Date: Mar 2012
Location: Venice, CA
Posts: 3,896
The support pages on the Pentax - Ricoh site for both the K-30 and K-50 say to enable use of aperture ring, and to set the green button for manual mode in the eDial programming menu to Tv Shift. The default is P-line. If left as P-line the CPU will try to set both aperture and shutter speed. Since the body has no control over the aperture on K, M, M42 and "A" lenses off the A-mode you get incorrect exposures.

Using Older Lenses on the PENTAX K-50 | Ricoh Imaging Support
Using K-30 With Older Lenses | Ricoh Imaging Support
07-08-2014, 09:43 AM - 1 Like   #198
Loyal Site Supporter
UncleVanya's Avatar

Join Date: Jul 2014
Photos: Gallery | Albums
Posts: 9,495
K50 - Not supported PER Pentax for M Mode lenses

I'm having a lot of heartburn. I bought my K-50 with the expectation that I could use it with my manual lenses when desired. However it doesn't seem to work. I have set the green button to do TV Shift and enabled the use of the aperture ring as described but when I push the green button I get a quick stop down and then it opens again. When I contacted Pentax they replied in a support email that it wasn't supported - that the K-30, K-50, and K-500 only worked with A series lenses if you wanted to meter.

I reached out to them and showed them their own website info and they said it was wrong.

Is Pentax/Ricoh right? That doesn't seem to match up with the experiences reported on the forums and elsewhere. What firmware version do you have installed if you have a K-50 and it works as expected? I upgraded mine and now I'm wondering if I downgraded it by upgrading - if you know what I mean.

I would swear that before the firmware upgrade this was working on my two manual (non-A series) lenses.
07-08-2014, 12:45 PM   #199
Loyal Site Supporter
UncleVanya's Avatar

Join Date: Jul 2014
Photos: Gallery | Albums
Posts: 9,495
My Firmware...

My K-50 Firmware is 1.02 which is NOT what this forum lists as the latest for the K-50. This forum shows 1.01 as the latest but the Pentax official site shows 1.02 - has anyone tried this since 1.02 was released on their K-50???? I swear the M series lens metering worked on my original firmware - it doesn't anymore and Pentax says the K-30, K-50, and K-500 don't support M series lenses for metering.

Please someone tell me I'm not crazy.

07-08-2014, 01:02 PM   #200
Pentaxian
Not a Number's Avatar

Join Date: Mar 2012
Location: Venice, CA
Posts: 3,896
What was it doing before the upgrade? The way the green button works on my K10D in manual mode on non-A non-M42 lenses is that the iris briefly closes down, sets the shutter speed and opens again. With the DOF preview set to optical, when I operate the DOF preview lever, the diaphragm closes down and remains closed as long as I hold the lever in the preview mode. This turns on the EV bars and I can adjust the exposure via the edial (shutter speed) and from the aperture ring on the lens.
07-08-2014, 01:12 PM   #201
Loyal Site Supporter
UncleVanya's Avatar

Join Date: Jul 2014
Photos: Gallery | Albums
Posts: 9,495
1.01 Firmware doesn't work either on my K-50

On my K-50 I'm not having any luck using my two lenses that are manual even after downgrading firmware. Can someone please confirm this works - despite what Pentax is now claiming?

---------- Post added 07-08-14 at 04:55 PM ----------

QuoteOriginally posted by Not a Number Quote
What was it doing before the upgrade? The way the green button works on my K10D in manual mode on non-A non-M42 lenses is that the iris briefly closes down, sets the shutter speed and opens again. With the DOF preview set to optical, when I operate the DOF preview lever, the diaphragm closes down and remains closed as long as I hold the lever in the preview mode. This turns on the EV bars and I can adjust the exposure via the edial (shutter speed) and from the aperture ring on the lens.
I was just plain confused. You are right the Green Button works as you describe and it is working. The DOF option provides the optical preview but there is no manual metering bar displayed. I think I was confusing my D100 Super experience with my K-50 one - and the DOF on D100 Super with the green button on the K-50... sorry folks.

What worries me is the crazy response from Pentax saying you can't use the M series lenses and get metering from them on the K-30/50/500 series. Crazy.
07-08-2014, 02:03 PM   #202
Senior Member




Join Date: Jan 2013
Photos: Gallery | Albums
Posts: 134
QuoteOriginally posted by bradshea Quote
I bought my K-50 with the expectation that I could use it with my manual lenses when desired. However it doesn't seem to work. I have set the green button to do TV Shift and enabled the use of the aperture ring as described but when I push the green button I get a quick stop down and then it opens again. When I contacted Pentax they replied in a support email that it wasn't supported - that the K-30, K-50, and K-500 only worked with A series lenses if you wanted to meter.

I reached out to them and showed them their own website info and they said it was wrong.

Is Pentax/Ricoh right? That doesn't seem to match up with the experiences reported on the forums and elsewhere. What firmware version do you have installed if you have a K-50 and it works as expected? I upgraded mine and now I'm wondering if I downgraded it by upgrading - if you know what I mean.

I would swear that before the firmware upgrade this was working on my two manual (non-A series) lenses.

This is an interesting thing to read. The way how you describe the metering to work is how all (best to my knowledge) Pentaxes have worked since the istD. It would be a big surprise if suddenly metering on K- and M-lenses wasn't supported anymore.

I just tried with a SMC M 75-150 f:4. When pointing to the light nearby and pressing the green button, the camera closes down the iris and gives sensible readings: 1/2500 for f:4, 1/250 for f:11 and 1/25 for f:32. With the lens cap on, it suggests times between 2" and 8". So everything is just like how one would expect the camera to operate with a manual lens.

I'm having a K-30 running firmware 1.05.

There seems to be 1.06 firmware at Ricoh site. Is it so that in the change list the "Improved stability for general performance" item includes the removed support for manual lens metering?


I happened to stumble upon this thread because I'm having some problems with a Vivitar K-mount lens (35mm f2.8 VMC), where the bayonet is probably not conductive. For this reason, as documented in this thread, the body doesn't recognize the lens, but instead thinks that it is a M42-lens. So the camera thinks that I'll manage my aperture in the lens only, and pushes the lens to wide open, regardless of aperture setting in the lens. Because it is a K-mount lens, there obviously isn't auto/manual setting as in M-42 lenses, so I've been shooting wide open the latest days.

In live view the lens' aperture setting seems to be honored.

So in conclusion: using a K- or M-series lens on a K-30 should allow you to meter with the green button. That's the way it has always worked. That's the way it should always work.
07-08-2014, 03:05 PM   #203
Pentaxian
Not a Number's Avatar

Join Date: Mar 2012
Location: Venice, CA
Posts: 3,896
Not all the bodies support the meter bars with DOF preview in manual mode. From what I can determine it seems like only the "flagship" models seem to have this feature. I'm not sure if the K-3 has this feature.

07-08-2014, 03:15 PM   #204
Lens Buying Addict
monochrome's Avatar

Join Date: Mar 2008
Location: Kirkwood (St. Louis) MO
Photos: Gallery | Albums
Posts: 19,453
QuoteOriginally posted by Not a Number Quote
Not all the bodies support the meter bars with DOF preview in manual mode. From what I can determine it seems like only the "flagship" models seem to have this feature. I'm not sure if the K-3 has this feature.
K-3 has the feature and of all my digital Pentax cameras meters manual lenses with the highest accuracy.

Recent mid-range cameras (K-01/K-30/K-50/K-500) have a somewhat less robust feature and Modeset and a slightly different process then the flagships.
07-20-2014, 05:59 PM   #205
Site Supporter




Join Date: Dec 2012
Posts: 71
Just a note some m42 lenses are auto only. When you set the aperture to say 5.6 the lens stays wide open unless the camera compresses the pin on the m42 mount. This is the case fore example on some of my old fujica and vivitar tx lenses. With the Pentax converter you need to disable the pin to make the manual apertures work on those. Others like my mamiya sekor or vivitar fix lenes have switches that disable the pin and make the manual aperture setting work without the pin being compressed.

After taking the mount off of a few of these and disabling the pins, I found that some of the third party converters have an inner rim (bower versions) that compress the pin so you don't need to modify the lenses to make them work. However, because of the sticking risk on these third party units ( noted in other replies) I take the locking springs off of the mount converter ... Lens won't lock but I never had one fall off and I have never had a problem removing the lens.
07-23-2014, 11:27 PM   #206
Junior Member




Join Date: Jan 2014
Posts: 36
Well, I've read through all 14 pages of this thread and I am now more confused than when I started. "M" lenses either will or won't meter properly because they either will or won't stop down when the green button is pressed depending on (or regardless of) the manual clutch setting...and it all depends on which K camera you own.

I have a K-5IIs with fully updated firmware. Can anyone definitively comment, through personal experience, on the following?
Let's assume I have already set my camera to enable shooting with the aperture not set to "A" (which would include all lenses with an aperture ring), programmed the green button per the OP, and set the metering mode to "manual".

1. With a screw-mount lens having a manual clutch, I need to use it to stop down the lens and then press the green button for the camera to set the proper shutter speed for the manually set aperture. I must keep the aperture stopped down when I shoot because the camera, through the adapter, has no ability to stop down the lens automatically.

2. With an "M"-style K-mount (or an "A"-style K-mount) set to a specific aperture value (using the aperture ring on the lens), I may meter using the green button to get the camera to set the proper shutter speed. However, as this is a K-mount, the lens will be stopped down automatically to the set aperture both when I meter and then, again, when I shoot. (I tried this earlier today and it appears to work.) (see Using Older Lenses on the PENTAX K-5 II and K-5 IIs | Ricoh Imaging Support)

3. Apparently, some "auto" M42 lenses that do not have a manual clutch require a modification to the pin assembly in order to permit the lens to stop down at all once it's mounted to the camera. (see this).

Do I have the above summarized correctly? Assistance is welcomed.

Thanks,
Barry
08-10-2014, 07:14 AM   #207
New Member




Join Date: Apr 2014
Photos: Albums
Posts: 4
I know this is an old thread but am new to the forum. I started with a Pentax ME Super 35 mm film camera and it used M lenses in aperture-priority. I don't understand why the Pentax K DSLRS cannot use M lenses in Av mode (aperture-priority). What is the issue? I have the Pentax D100 and Pentax K-7. I thought I would be able to use my M lenses in Av mode and not have to bother with the extra step of the green button.
08-10-2014, 08:56 AM   #208
Pentaxian
Not a Number's Avatar

Join Date: Mar 2012
Location: Venice, CA
Posts: 3,896
The issue is the "crippled" mount on DSLR and the design of pre-A series lenses. The crippled K mount lacks the aperture control lever so the camera has no way of determining what the aperture is set to on the lens without taking a stopped down reading through the lens. In A lenses the iris closes down to the proper f-stop from the position of the auto-aperture diaphragm lever.

Pre-A series lenses lack the contacts that give the min and max f-stop capability of the lens. Pre-A lenses also do not have the linear relationship between the position of the auto diaphragm stop down lever and f-stop (some of the later production M series lenses may have the linear relationship). Without the min-max aperture information the camera cannot calculate the relative position to move the diaphragm control lever to set the f-stop. Without a linear relationship of the lever position to iris opening the f-stop cannot be set accurately.

You can modify the mounts on your M series lenses and short out the "A" pin on the camera body and simulate an A series lens. WIthout the linear relationship of the aperture settings though you will have to run tests on each lens to determine how much exposure compensation to apply to each f-stop.

It's probably a whole lot simpler just to get used to the extra button press.
08-10-2014, 10:06 AM   #209
New Member




Join Date: Apr 2014
Photos: Albums
Posts: 4
So my old ME Super from the 80's has this aperture control lever and as sophisticated as the new K DSLRs are they do not behave as an aperture-priority camera when in Av mode? I figured putting it in Av mode meant it would work like my old ME Super, the way Manual mode works like a manual camera. So I should be looking for A lenses then or M42s. I prefer manual focus so not planning to buy any more DA/FA lenses. Just bought a bunch of M lenses, darn.
08-10-2014, 10:09 AM   #210
Administrator
Site Webmaster
Adam's Avatar

Join Date: Sep 2006
Location: Arizona
Photos: Gallery | Albums
Posts: 40,957
Original Poster
QuoteOriginally posted by spnny1 Quote
So my old ME Super from the 80's has this aperture control lever and as sophisticated as the new K DSLRs are they do not behave as an aperture-priority camera when in Av mode? I figured putting it in Av mode meant it would work like my old ME Super, the way Manual mode works like a manual camera. So I should be looking for A lenses then or M42s. I prefer manual focus so not planning to buy any more DA/FA lenses. Just bought a bunch of M lenses, darn.
The ME super relied on the aperture ring- since the digital age, Pentax has decided to drop full support for the aperture ring, so you have to stop-down meter with M, K, and screwmount lenses. On modern lenses setting the aperture is done electronically.

Adam
PentaxForums.com Webmaster (Site Usage Guide | Site Help | My Photography)



PentaxForums.com's high server and development costs are user-supported. You can help cover those costs by donating. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

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 100 3 Days Ago 11:12 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 07:32 AM. | See also: NikonForums.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