Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
09-02-2011, 06:46 PM   #1
New Member




Join Date: Aug 2011
Posts: 6
Pentax-M lens -- trouble stopping down

I was testing my new Pentax-M 50mm f1.7 lens today. It's my first manual lens (have it mounted on my K-x), so I was testing out different apertures to get a feel for corresponding shutters speeds in various light conditions.

When I focused on a bright, sunlit area on the side of my house (has pretty light colored, yellow shingles), set the aperture to wide-open (f1.7) then pressed the green button to stop down, the shutter speed went up to .3 of a sec. It was the same for the next couple F-stops, until finally, around 4 or so, the shutter speed went back up to 1/400 or something thereabouts.

Has anyone had this experience before? Was there just too much light getting to the sensor with lens wide-open that everything went wacko? I really don't understand it.

Thanks,
Brian

09-02-2011, 06:50 PM   #2
Veteran Member
JinDesu's Avatar

Join Date: Jun 2011
Location: New York City
Photos: Gallery
Posts: 5,638
Yes, there was too much light. When the shutter speed required to get the correct exposure is greater than 1/6000 in the k-x, it automatically shows 0.3.
09-02-2011, 07:59 PM   #3
Site Supporter
Site Supporter
jatrax's Avatar

Join Date: May 2010
Location: Washington Cascades
Photos: Gallery | Albums
Posts: 12,991
Not wacko, this is intended behavior. The amount of light is more than the camera can handle at it's fastest speed so it shows .3. I personally think it should show something else like 'OL' or an up arrow or anything except an answer that can be confused as both an expected exposure and an out of bounds reading.

But as Jindesu says it is just too much light. Adjust ISO or aperture until you get within the capabilities of the camera.
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!
f1.7, k-mount, lens, light, pentax lens, pentax-m, pentax-m lens, shutter, slr lens, wide-open
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Please help stopping/cleaning lens fungus Rafalas Pentax SLR Lens Discussion 32 11-06-2011 08:43 AM
K-R trouble focusing in low light with Live View using Pentax 18-55 kit lens sportv Pentax K-r 8 01-02-2011 06:42 PM
Stopping down fekish Troubleshooting and Beginner Help 21 10-08-2010 01:24 AM
still having trouble with this lens Deiberson Troubleshooting and Beginner Help 4 12-27-2009 02:44 PM
Auto Revuenon 135mm lens not stopping down pszilard Pentax SLR Lens Discussion 8 02-12-2009 05:26 PM



All times are GMT -7. The time now is 11:22 PM. | 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