[Rokka]

Hello Guys,
Here is Marco and I'm brand new here.

I wrote down this post because I wanted to ask you about K3's compatibility issues.

I just got the pentax smc 50mm 1.4 but when I locked into my K3, basically nothing happened and no info got shown on the display but the ISO, I couldn't focus, shoot or do anything else.
So now the question is where is the problem? Is it in the lens or in the camera?

Thank you very much in advance for the replies,
hope to find a solution to this.

[photolady95]

First thing you need to do is set the option in the Custom menu to allow aperture ring. In the menu just set it to number 2. I don't have a K3 but so can't say which number it is on your camera. Someone will know and will respond soon.

[Rokka]

First thing you need to do is set the option in the Custom menu to allow aperture ring. In the menu just set it to number 2. I don't have a K3 but so can't say which number it is on your camera. Someone will know and will respond soon.

Thank you for the tip, I'll take a look.

[twilhelm]

Under the Custom menu, it's option 27. Set it to 2 and you'll be able to use the aperture ring on the lens.

[jatrax]

You should read this article first: Using Manual Lenses (M42 Screwmount, M , K) on Pentax DSLRs F-- - PentaxForums.com

[stevebrot]

Welcome to the Pentax Forums!

Your lens is:

• Manual focus, so you have to focus it using the focus ring
• Has aperture that cannot be controlled by the body, so you have to set it on the aperture ring. For this to work, make sure that the Aperture Enabled setting is set to true (instructions above).
• Will only stop down for exposure and DOF preview in M, X, and B modes
• Requires fully manual exposure settings for shutter, aperture, and ISO (no exposure automation)
• No P-TTL flash automation

To help you with focus and exposure tasks:

• There is a feature called 'focus confirm" where the AF system will tell you when the subject is in focus. There is also something called catch-in-focus that will release the shutter when the subject is in focus. Instructions are in user guide. Unfortunately you are limited to the center AF point only.
• Stop-down metering (similar in many ways to working with a vintage Pentax Spotmatic camera) is available for metering using either the green button or the DOF preview feature. The flow goes like this:
  1. Camera in M mode
  2. Set your desired aperture using the ring on the lens
  3. Set your desired ISO on the camera
  4. Frame and focus on your subject and press the green button. The camera will set the appropriate shutter speed using your choice of center-weighted or spot metering.
  5. Keep those settings and shoot at will until either your light or subject changes. There is no need to meter for each shot.
  As an alternative to the green button, you may use the DOF preview lever to manually stop down the lens and use the viewfinder EV scale to adjust proper exposure using either the aperture ring or shutter speed wheel. I prefer to set the desired shutter speed first when using this method and move the aperture ring or ISO to center the pointer. This method is flexible and worth playing with. Exposure compensation is available for both methods for stop-down metering.

Note that all of the above is specific to K-mount lenses having electrically conductive mounts (no paint or anodizing). Adapted M42 lenses have a similar flow, but with a few quirks thrown in to make it more interesting.

If you encounter problems, the users on this site are incredibly helpful in troubleshooting and helping you get success.


Steve

[Rokka]

Welcome to the Pentax Forums!

Your lens is:

• Manual focus, so you have to focus it using the focus ring
• Has aperture that cannot be controlled by the body, so you have to set it on the aperture ring. For this to work, make sure that the Aperture Enabled setting is set to true (instructions above).
• Will only stop down for exposure and DOF preview in M, X, and B modes
• Requires fully manual exposure settings for shutter, aperture, and ISO (no exposure automation)
• No P-TTL flash automation

To help you with focus and exposure tasks:

• There is a feature called 'focus confirm" where the AF system will tell you when the subject is in focus. There is also something called catch-in-focus that will release the shutter when the subject is in focus. Instructions are in user guide. Unfortunately you are limited to the center AF point only.
• Stop-down metering (similar in many ways to working with a vintage Pentax Spotmatic camera) is available for metering using either the green button or the DOF preview feature. The flow goes like this:
  1. Camera in M mode
  2. Set your desired aperture using the ring on the lens
  3. Set your desired ISO on the camera
  4. Frame and focus on your subject and press the green button. The camera will set the appropriate shutter speed using your choice of center-weighted or spot metering.
  5. Keep those settings and shoot at will until either your light or subject changes. There is no need to meter for each shot.
  As an alternative to the green button, you may use the DOF preview lever to manually stop down the lens and use the viewfinder EV scale to adjust proper exposure using either the aperture ring or shutter speed wheel. I prefer to set the desired shutter speed first when using this method and move the aperture ring or ISO to center the pointer. This method is flexible and worth playing with. Exposure compensation is available for both methods for stop-down metering.

Note that all of the above is specific to K-mount lenses having electrically conductive mounts (no paint or anodizing). Adapted M42 lenses have a similar flow, but with a few quirks thrown in to make it more interesting.

If you encounter problems, the users on this site are incredibly helpful in troubleshooting and helping you get success.


Steve

Thank you very much,
I will try to fix as soon as I can.

Very helpful reply!

[benie]

Marco, you may want to read through this article.
Pentax K-3 Review - Recommended Settings | PentaxForums.com Reviews
Among many useful suggestions, it also touches on the problem you encountered and tells you what setup is required.
Hope this helps

[demondata]

Is the lens an F or FA lens, or is it the M or K version? Asking because you didn't specify, and everyone is assuming it's not an F or FA lens and therefore all instructions are for older, manual-focus lenses. It probably is, but on the off chance that it is an F or FA with issues, you may have to get it repaired. Hoping that it's not and that everyone has it correct that it's manual focus only.

[Rokka]

Sorry for not specifying that...
The lens is an FA, but I already solved the problem