Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
05-15-2008, 06:18 AM   #1
New Member




Join Date: Sep 2007
Location: Menifee, CA
Photos: Gallery
Posts: 8
Getting f------ with certain lenses

I know I have seen this before but I can't remember the remedy. When I use certain lenses I get f------ in the top screen. These lenses are pentax lenses or at least fit pentax.......Help!

Brian

05-15-2008, 06:24 AM   #2
Senior Member
bnishanth's Avatar

Join Date: May 2008
Location: Bangalore, KA
Photos: Gallery
Posts: 223
The title of this article is very misleading..

Can you give us more information on the lens ? Is it a 'M' lens ?

If the Aperture ring on the lens cannot be set to 'A' then the camera fails to determine the aperture setting and flashes on the LCD. However this does not prevent you from exposing a shot as you can set the appropriate shutter (in Hyper-Manual mode) by clicking the green button.

Cheers
Nish
05-15-2008, 06:26 AM   #3
Forum Member
smokey's Avatar

Join Date: Sep 2007
Location: Salina, KS
Posts: 92
Do the lenses have the 'A' setting on the aperture ring? If not, you need to change your camera settings. Using aperture ring to Permitted in the custom settings menu.
If the lens does, then make sure it is set on 'A'.
05-15-2008, 06:29 AM   #4
Senior Member
Peacekeeper's Avatar

Join Date: Jul 2007
Location: Back at work :(
Photos: Gallery
Posts: 169
Dirty lens/camera contacts can make the Av display -- as well

05-15-2008, 06:31 AM   #5
Banned




Join Date: Oct 2007
Location: Savannah, U.S./Baguio City, P.H.
Posts: 5,979
any lens that doesn't have the 'A' setting on the aperture ring will do that because the lens is not communicating with the camera. essentially any lens before the A series will do that unless you have a newer lens and don't select the 'A'. there are also plenty of 3rd part lenses that have the 'A' setting as well. so in pentax land that means M,K & m42 lenses will do this.



The KA mount is derived from the original K mount. It allows the lens' aperture to be set by the body, and thus permits shutter priority and program auto exposure modes. It was introduced in 1983, and is supported by A-series and P-series bodies; Pentax lenses that support it are marked 'SMC Pentax-A'. It is completely backward-compatible with the original K mount.
The aperture on the lens is set from the body by the same stop-down lever found on the original K mount, but on KA lenses this lever is proportional to the area of the aperture opening, rather than the diameter as on previous lenses. This allows the body to easily set a specific aperture, since the relationship to F stops is linear. The lenses add an 'A' setting on the aperture dial, which gives the body control of the aperture. Other, numeric settings are used for manual aperture modes—aperture priority and full manual mode.
Six electrical contacts are added to the bayonet ring. One is slightly recessed and allows the lens to indicate whether the aperture ring is set at 'A' or not. If it is, a pin on the lens extends slightly and makes contact, while if the lens is at any other setting the pin is retracted and does not make contact. The other five contacts are used to encode the lens' aperture range. Each contact on the lens is either conducting or non-conducting, providing a binary 1 or 0, respectively. Two contacts encode the lens' minimum aperture—f/16, f/22, f/32 or f/45; although no Pentax K-mount lens has ever had an f/16 minimum aperture, OEM lenses often have. The other three contacts encode the lens' maximum aperture; their meaning is dependent on the minimum aperture indicated by the lens.
05-15-2008, 08:01 AM   #6
New Member




Join Date: Sep 2007
Location: Menifee, CA
Photos: Gallery
Posts: 8
Original Poster
one lens is a m42 with an adapter, the other is a 50mm I took off of my Pentax ME. Both do not have an A on the aperture ring. Contacts are clean....
Is it possible to get these lenses to work on my K10? How? mainly shoot manual mode.
05-15-2008, 08:08 AM   #7
Banned




Join Date: Oct 2007
Location: Savannah, U.S./Baguio City, P.H.
Posts: 5,979
is it an M 50mm? I would assume so. either way with the K10 you first have to make sure and 'allow aperture ring' in the menu. (check the manual if you need to know how to do that)

mount the lens
select the M 'manual' mode
select desired aperture
compose and frame your shot
push the 'green button'
the camera will then stop down the lens, meter the light and select the appropriate shutter speed for proper exposure
take the picture.

the same goes for the m42 lens except you can use an m42 in Av mode to simplify things. M, an K series bayonet lenses ( or any A series or later not in 'A' mode) however will not get proper exposure on your K10 (except at widest aperture) due to the 'crippled' mount.
05-15-2008, 08:12 AM   #8
Inactive Account




Join Date: May 2007
Location: Uppsala, Sweden
Photos: Gallery
Posts: 46
QuoteOriginally posted by noleysdad Quote
one lens is a m42 with an adapter, the other is a 50mm I took off of my Pentax ME. Both do not have an A on the aperture ring. Contacts are clean....
Is it possible to get these lenses to work on my K10? How? mainly shoot manual mode.
If they don't have an "A", the lens can't tell the body what aperture it is set to.
You get the "f----" on the display. You have to measure stopped down, with the green button or AE-L.

-- MW

05-15-2008, 08:14 AM   #9
New Member




Join Date: Sep 2007
Location: Menifee, CA
Photos: Gallery
Posts: 8
Original Poster
Thank you all for you input........its much appreciated.

B
05-15-2008, 09:43 AM   #10
Senior Member
bnishanth's Avatar

Join Date: May 2008
Location: Bangalore, KA
Photos: Gallery
Posts: 223
QuoteOriginally posted by séamuis Quote

mount the lens
select the M 'manual' mode
select desired aperture
compose and frame your shot
push the 'green button'
the camera will then stop down the lens, meter the light and select the appropriate shutter speed for proper exposure
take the picture.
One more thing...
Change 'Use Aperture Ring' to permitted in Custom menu to use the Green Button if you are not able to do the above..

Cheers
Nish
05-15-2008, 09:52 AM   #11
Banned




Join Date: Oct 2007
Location: Savannah, U.S./Baguio City, P.H.
Posts: 5,979
ahem, I covered that

QuoteQuote:
either way with the K10 you first have to make sure and 'allow aperture ring' in the menu.
05-16-2008, 05:44 AM   #12
New Member




Join Date: Sep 2007
Location: Menifee, CA
Photos: Gallery
Posts: 8
Original Poster
Thanks alot.........got it figured out.

B
05-16-2008, 12:25 PM   #13
Senior Member
bnishanth's Avatar

Join Date: May 2008
Location: Bangalore, KA
Photos: Gallery
Posts: 223
Sorry..!!

Sorry séamuis, I missed that....
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!
camera, dslr, lenses, photography
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Pentax Km and old manual lenses: SMC Takumars & Tamron Adaptall 2 lenses Kendrick Troubleshooting and Beginner Help 10 04-14-2010 03:23 AM
For Sale - Sold: Yard sale: M lenses, K 300mm, DA 14mm, ME film body, Nikkor lenses and more Nachodog Sold Items 24 12-26-2009 12:03 AM
For Sale - Sold: Lenses, lenses, lenses... and a flash! pbo Sold Items 18 05-28-2009 04:35 PM
For Sale - Sold: M42 / K / KA / FA Lenses Grab bag of Vintage to Current lenses. 50mm FA f/1.4 MikeDubU Sold Items 10 02-09-2009 12:45 PM



All times are GMT -7. The time now is 11:54 PM. | 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