Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
04-03-2009, 12:35 PM   #1
Pentaxian
jimH's Avatar

Join Date: Apr 2009
Location: South Central Nebraska - USA
Photos: Gallery | Albums
Posts: 1,413
Pentax-M f1.4 50mm lens & K-10D

I have a several Pentax-M, bayonet mount series lens; an f3.5 28mm that works fine on my K-10D at all distances in the AV mode, I've also got a SMC Pentax 135 f2 lens that works OK with my K10-D. But I also have a very nice SMC Pentax-M f1.4 50mm that seems to focus OK at relatively close ranges but I can't get it to fall into focus at distances at or around infinity.

I'd love to use my 50mm f1.4 as a prime lens with my K10-D especially in low light but I can't use it until I figure out why it won't focus properly.

Can anyone shed some light on what my problem could be? Could there possibly be a loose element in the lens? When shaking the lens I don't detect any internal movement, so I don't know what the problem could be. Any help on this issue would certainly be appreciated.

Thanks

04-03-2009, 01:15 PM   #2
Veteran Member
Robert S Donovan's Avatar

Join Date: Mar 2009
Location: Anderson, SC
Photos: Gallery
Posts: 361
Sounds like it might not have been indexed correctly after disassembly. That's just something I've heard but I don't have any direct experience with.
04-03-2009, 02:55 PM   #3
Pentaxian
jimH's Avatar

Join Date: Apr 2009
Location: South Central Nebraska - USA
Photos: Gallery | Albums
Posts: 1,413
Original Poster
QuoteOriginally posted by Robert S Donovan Quote
Sounds like it might not have been indexed correctly after disassembly. That's just something I've heard but I don't have any direct experience with.
Thanks for your reply. I see that you're a fan of Ansel Adams too.
04-03-2009, 05:01 PM   #4
Veteran Member
Robert S Donovan's Avatar

Join Date: Mar 2009
Location: Anderson, SC
Photos: Gallery
Posts: 361
QuoteOriginally posted by jimH Quote
Thanks for your reply. I see that you're a fan of Ansel Adams too.
Hard not to be.

I'm sure that will create some kind of Ansel Adams debate here

04-03-2009, 05:12 PM   #5
Pentaxian




Join Date: Feb 2009
Location: Alameda, CA
Posts: 3,194
I can't help you with the 50mm f/1.4 lens. But I'm curious about this:

QuoteOriginally posted by jimH Quote
I have a several Pentax-M, bayonet mount series lens; an f3.5 28mm that works fine on my K-10D at all distances in the AV mode,...
Is it a bayonet (PK) mount? How do you use it in Av mode with the K10D?

As far as I know, unless you don't rotate the lens all the way until it's locked in, in Av mode, the photo is taken with the aperture wide open (in this case, f/3.5).
04-04-2009, 09:45 AM   #6
Site Supporter
pschlute's Avatar

Join Date: Mar 2007
Location: Surrey, UK
Photos: Gallery
Posts: 701
Thats is correct.... M lens on Digital body in Av mode = all pictures are taken at the lens' widest aperture, irrespective of what f-stop the aperture ring is set to.
04-04-2009, 10:34 AM   #7
Veteran Member
OregonJim's Avatar

Join Date: Mar 2009
Location: Willamette Valley, Oregon
Posts: 1,329
QuoteOriginally posted by jimH Quote
But I also have a very nice SMC Pentax-M f1.4 50mm that seems to focus OK at relatively close ranges but I can't get it to fall into focus at distances at or around infinity.
Are you able to turn the focus ring all the way to the infinity mark? Does the lens wobble at all when properly mounted (bent flange ears)? Are there any loose screws on the lens' base mount?
04-04-2009, 12:52 PM   #8
Pentaxian
jimH's Avatar

Join Date: Apr 2009
Location: South Central Nebraska - USA
Photos: Gallery | Albums
Posts: 1,413
Original Poster
QuoteOriginally posted by SOldBear Quote
I can't help you with the 50mm f/1.4 lens. But I'm curious about this:



Is it a bayonet (PK) mount? How do you use it in Av mode with the K10D?

As far as I know, unless you don't rotate the lens all the way until it's locked in, in Av mode, the photo is taken with the aperture wide open (in this case, f/3.5).
The camera automatically selects the AV mode when the Allow Aperture ring allowed is set in the setup menu, that is unless the camera is set in the Manual mode.

Thanks to some of your comments concerning the "AV" mode, I moved to the Manual mode and did some experimenting. While in the manual mode, I found that after setting the aperature ring to the selected setting and then using the green button, the camera will close the aperature to the position to where it is set, take a meter reading and then set the shutter speed.

The result is a perfect exposure with the proper depth of field. Focus also seems a little better at a distance than it was before. I don't know if that information is in the manual or not, but I've not run accross it in the past.

I've done some experimenting with my legacy glass and had kind of given up being able to use it. I think that with the information that you folks have given me, I might be able to use some of my glass again in the manual mode with available light. I've not tried any of this with the flash yet but intend to see if I can make it work. I have really missed having a "fast" prime lens to use in available light photography, now possibly, I'll be able to use my f1.4 50mm.

My lens are normal "K" bayonet mount, as are all of my Pentax lenses. They would fit any Pentax from at least the K-1000 on forward. When mounting the lenses They all rotate until completely seated and locked. The lens focus ring turns all the way from lock to lock, no problem. The issue is only evident when the lens is mounted on the K-10D. While mounted on the ME Super or the MX, no problem.

Thanks for all your comments folks, I appreciate them.

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!
50mm, f1.4, focus, k-10d, k-mount, lens, light, pentax lens, pentax-m, slr lens, smc
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
For Sale - Sold: (AUS) SMC Pentax-M 50mm/1.4 & A35-105mm/3.5 & MV1 body & DB1 Grip (AUS) ddhytz Sold Items 4 04-22-2010 03:28 AM
For Sale - Sold: Pentax K1000 & 50mm f2 lens KmountShooter Sold Items 0 06-08-2009 07:51 AM
Pentax-M f1.4 50mm lens & K-10D jimH Pentax SLR Lens Discussion 8 05-19-2009 06:59 AM



All times are GMT -7. The time now is 09:48 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