Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
01-11-2015, 01:01 AM   #1
New Member




Join Date: Sep 2014
Posts: 4
K-3 lens compatability

Hello gurus, I hope you can help me with a problem. Thanking you in advance!

I have a new K3 but some of my lenses arent working with it - the lenses that worked with my Kr.

In particular this lens is not working with the K-3: Sigma 18-125 F3.5-5.6 DC

A Pentax legacy lens doesnt work with it either: 50mm f1.7 SMC
Two other lenses also don't work:
An MF legacy ricoh rikonon lens
Another sigma MF lens
All of the above lenses work with my Kr.


All the aperture blades are working on the lenses & they all work with my Kr.

TESTING:
Set to M (manual)

MF lenses set to MF and aperture ring enabled
The result i get with the lenses that arent working is that no matter what aperture i set the exposure comes out the same.




Can you tell me why the lenses don't work on the K3 or how I could fix the problem?

Thank you!

01-11-2015, 01:41 AM   #2
Administrator
Site Webmaster
Adam's Avatar

Join Date: Sep 2006
Location: Arizona
Photos: Gallery | Albums
Posts: 43,226
QuoteOriginally posted by pandora Quote
The result i get with the lenses that arent working is that no matter what aperture i set the exposure comes out the same.
Isn't that what you'd normally want?

The procedure for using manual lenses on the K-3 is that same as on the K-r. Also, the Sigma 18-125mm isn't a manual lens, so do you think something else (like an exposure setting) might be causing the problem?

Sample pics / more info would be great!

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:

01-12-2015, 02:03 AM   #3
New Member




Join Date: Sep 2014
Posts: 4
Original Poster
hey Adam, thanks a lot for your response.

it's an unusual problem. Posting pics won't help. Basically the result with the lenses in question is this: no matter what aperture i set with the SAME shutter speed the pics come out with the same exposure. That's with the camera set on manual.

so....if i set f3.5 at 1/60th the picture comes out the same exposure as if i set at f22 at 1/60th.

Weird right?
01-12-2015, 02:44 AM   #4
Administrator
Site Webmaster
Adam's Avatar

Join Date: Sep 2006
Location: Arizona
Photos: Gallery | Albums
Posts: 43,226
QuoteOriginally posted by pandora Quote
hey Adam, thanks a lot for your response.

it's an unusual problem. Posting pics won't help. Basically the result with the lenses in question is this: no matter what aperture i set with the SAME shutter speed the pics come out with the same exposure. That's with the camera set on manual.

so....if i set f3.5 at 1/60th the picture comes out the same exposure as if i set at f22 at 1/60th.

Weird right?
Do you see the lenses stopping down at all when you look at them? See if the aperture level in the camera is stuck in the wrong position.


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:

01-12-2015, 03:36 AM   #5
New Member




Join Date: Sep 2014
Posts: 4
Original Poster
Cheers Adam.

When I take the manual lenses of the camera i can see that they are fully functional when i operate the aperture ring. This being the case, i can only assume that the camera is somehow operating in aperture priority mode as the exposure is consitent no matter what aperture i set it to.

for example: if i set f3.5 at 1/60th the picture comes out the same exposure as if i set at f22 at 1/60th.

i'm not sure what the case is with the modern lens that doesnt have a manual aperture ring, but the outcome is the same from the same settings.


01-12-2015, 03:46 AM   #6
Pentaxian
Tjompen1968's Avatar

Join Date: May 2012
Location: Norrköping, Sweden
Photos: Gallery | Albums
Posts: 1,329
I remember having the same issue. It may have something to do with the contacts on the camera body that needs to be shortened to make older lenses stop down or something along those lines... I will get back later to tell you my findings.

---------- Post added 01-12-15 at 11:48 AM ----------

Also the 50mm f1.7 SMC has to be set to A on the aperture ring if I am not mistaken.

---------- Post added 01-12-15 at 11:51 AM ----------

And also I should mention that all the lenses should work. That is the beauty of Pentax.
01-12-2015, 07:55 AM   #7
Pentaxian




Join Date: Jul 2013
Posts: 1,457
I use some of the exact same lenses.....NO problem at all.
Im wondering if you need to disable or enable a setting in M or TV mode for "P-Line"..................?
The 50 1.7 can be set to any position to work in M mode.
01-12-2015, 08:01 AM   #8
Veteran Member
crewl1's Avatar

Join Date: Jul 2010
Location: Los Angeles, CA
Photos: Gallery | Albums
Posts: 9,797
Is the K-3 in M mode and the ISO setting on a fixed value ie not in Auto?

---------- Post added 01-12-15 at 07:03 AM ----------

You say posting pics won't help but if we could see the EXIF data from both pics we could tell if it is a user error or camera problem.

01-12-2015, 10:06 AM - 1 Like   #9
Pentaxian
Tjompen1968's Avatar

Join Date: May 2012
Location: Norrköping, Sweden
Photos: Gallery | Albums
Posts: 1,329
Well now I have tried my Auto Chinon 50 mm f/1.9 that has a aperture lever and a Meyer Optik Lydith 30mm f/3.5

Scenario 1: Lens with aperture lever. The contacts on the camera has to get shorted with the lens or it will not stop down. I have the Green Button set to P-line in M-mode.

Then I put the camera in Manual mode, I set my aperture and press the Green Button to make it stop down and measure a appropriate shutter speed.
It will stop down if I use the optical depth of field preview on the On/Off-button.

Scenario 2: M42 lens that does not short the contacts, i.e a cone shaped lens. Meyer Optik Lydith 30mm f/3.5

Manual mode, set focus, set aperture, press Green button and shoot OR use Av-mode, set focus, set aperture and shoot. The shutter speed will automatically change when in Av.
IF IN LV, you have to use Av. Green Button will NOT give you a mesurement when in Manual mode and Live View.

Scenario 3: M42 lens that short the contacts.

Same as above with the difference that it will try to fysically stop down so you hear the stop down sound. Now Green Button works in Live view


Also Catch in Focus needs the contacts to be shortened to work. I use aluminum foil if needed.



I think I tested what I can test and I think what I had problems with was that it would not stop down due to not having the contacts shortened on a lens that have a lever. This way it will have the aperture fully open at all times.
01-15-2015, 03:48 PM   #10
Veteran Member




Join Date: Aug 2011
Location: Austin, Texas
Photos: Albums
Posts: 302
You need to enable the aperture ring in the camera menu (Operating Manual page 82) C-4 Menu item 27.
01-18-2015, 01:31 AM   #11
New Member




Join Date: Sep 2014
Posts: 4
Original Poster
Hi Tjompen, i just tried to work through your notes.

I cannot for the life of me get my sigma AF to work, which is my main concern because it's my only AF lens and my general work horse.

i tried various things with P-line and green button. I don't usually use any "fancy settings" as i said, i just use DSLRs as if they were a K1000!

I feel like a nong not being able to work this out.

Can i ask you what you mean by using aluminium foil?

Thanks again for all your help.
01-18-2015, 04:43 AM   #12
Pentaxian
Tjompen1968's Avatar

Join Date: May 2012
Location: Norrköping, Sweden
Photos: Gallery | Albums
Posts: 1,329
The Sigma lens should work without any special treatment since it is a modern lens. If it is the lens I googled... Try cleaning the contacts on the lens and body. The contacts you see on the mount, down to the left, sometimes needs to be shortened as stated in my earlier post. I then put some aluminum foil between the lens and body on that position. Carefully...



File:K-mount-late-(Pentax-MZ3).jpg - Wikimedia Commons
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!
aperture, dslr, enable aperture ring, k-3, k-3 lens, k3, kr, legacy, legacy lenses, lens, lens compatability, lenses, mf, pentax k-3, pics, post, sigma
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Flash Compatability with Pentax K-3 Pentax Bob Ask B&H Photo! 1 02-16-2014 01:15 PM
Lens compatability squigglytwigs Pentax DSLR Discussion 5 10-16-2010 12:23 AM
Lens Compatability georgesherlock Pentax SLR Lens Discussion 2 08-18-2010 02:58 PM
lens compatability lorne-ranger Pentax SLR Lens Discussion 3 09-13-2008 08:03 AM
Lens compatability flashman77 Pentax SLR Lens Discussion 2 01-16-2008 10:54 AM



All times are GMT -7. The time now is 02:18 AM. | 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