Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
03-27-2010, 05:02 PM   #1
Site Supporter
Clinton's Avatar

Join Date: Feb 2010
Location: Salt Lake City, UT
Photos: Gallery | Albums
Posts: 1,826
Found a Pentax Sears A 75-300mm F4.5 for $40 and a 50mm M/1.4 for $30

In an adventure today, I stopped by some pawn shops here in Salt Lake and spent the time to dig through their lenses when I happened upon a like new Sears K mount lens with an A setting on the aperture ring. It was closed away in a padded leather hard case, and looks as though it's never even been used.

When they told me they wanted $40 for it, I rushed out to my car, got my K-7, hooked it up and was astounded that it was working flawlessly.

On the lens, it reports 1:4.5-5.6; therefore the next surprise was when I zoomed it out to 300mm the lens still reported it was F4.5. Is this a mistake on the lens's reporting to the camera or is it really F4.5 through the whole range? The metering doesn't appear to underexpose at 300mm F4.5.

I'll try to post some pics of the lens and with the lens tomorrow. Right now I need to hook our 1.7x tc to it and see what it looks like.

On this same trip at a later pawn shop, I picked up a Pentax-M 50mm F1.4 for $30!

03-27-2010, 05:10 PM   #2
Site Supporter
forensicscientist's Avatar

Join Date: Jun 2008
Location: DFW Texas and Maine - I commute :)
Posts: 889
Nice....

Nice find. I've visited many a pawn shop in search of a "find". Never found any photo gear...but once found a carbon frame bike (cycling is my other passion), complete with exceedingly high end wheels, and other parts for only $300. I quickly paid and left....all the while feeling like I had just robbed them......and basically I did.
03-27-2010, 06:30 PM   #3
Pentaxian
Just1MoreDave's Avatar

Join Date: Feb 2007
Location: Aurora, CO
Photos: Gallery | Albums
Posts: 4,858
QuoteOriginally posted by cgoudie Quote
...On the lens, it reports 1:4.5-5.6; therefore the next surprise was when I zoomed it out to 300mm the lens still reported it was F4.5. Is this a mistake on the lens's reporting to the camera or is it really F4.5 through the whole range? The metering doesn't appear to underexpose at 300mm F4.5.
The original method for A series lenses to tell the camera their maximum aperture could only handle one aperture value. So all variable-aperture A-type zooms behave this way. The method uses a pattern of contacts on the mount to communicate with the camera. Besides telling only one aperture to the camera, they can only say whether the aperture ring is in the A position or not.

Autofocus lenses like the F series have a chip and communicate more data digitally. Variable aperture zooms work in this system, which can also send focal length for SR to work and the lens name. The FA chips added more capacity so FA lenses have more data, and DA lenses even more. Third party lenses may have less information, either because they did not license the mount from Pentax or Pentax added more data without officially changing the published specs.
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!
300mm, 50mm, f4.5, k-mount, lens, pawn, pentax lens, sears, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Found a Pentax-F 50mm f1.7 Tom in Delaware Pentax SLR Lens Discussion 7 05-28-2010 08:51 PM
test Sears 300mm nupentaxian Post Your Photos! 3 06-12-2008 02:52 PM
Found a rare-ish lens...Pentax 24-50mm ryan s Pentax SLR Lens Discussion 3 03-30-2008 03:11 PM



All times are GMT -7. The time now is 11:36 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