Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
02-03-2010, 05:48 AM   #1
Veteran Member
philippe's Avatar

Join Date: Apr 2008
Location: Flanders Fields
Posts: 463
Difference

Amazing how lenses (FF) of the same focal distance can be different...


Last edited by philippe; 01-14-2011 at 01:08 AM.
02-03-2010, 05:55 AM   #2
Pentaxian
Lowell Goudge's Avatar

Join Date: Jan 2007
Location: Toronto
Photos: Gallery | Albums
Posts: 15,312
we had a similar observation a while back where people thought that a lens designed for ASP=C should be smaller than full frame,

turns out the DA 300F4 is bigger and heavier than the SMC-300mm F4

you need to consider the space for the motor, and difference in design between the two. the sigma is internal focusing, the SMC-A is a classical lens where the entire group moves forward on the focusing helix

Internal focusing is somewhat necessary to keep the mass of the focusing elements down to a minimum,

if you look at lens development overall, you can actually link lens advances to camera developments.

wide open metering was possible with aperture feedback, variable apertures were viable with TTL flash metering, internal focusing permitted AF, and slow wide to normal zooms were all permitted with AF and bright viewfinders, where they would have darkened out a split image
02-03-2010, 05:59 AM   #3
Pentaxian
bdery's Avatar

Join Date: Mar 2008
Location: Quebec city, Canada
Photos: Gallery
Posts: 5,657
Nice pic, why B&W ?
02-03-2010, 08:48 AM   #4
Veteran Member
philippe's Avatar

Join Date: Apr 2008
Location: Flanders Fields
Posts: 463
Original Poster
QuoteOriginally posted by bdery Quote
Nice pic, why B&W ?
B&W is always better, except when it does not…

Philippe

02-03-2010, 09:56 AM   #5
Veteran Member




Join Date: Jan 2009
Location: Canada
Posts: 1,255
QuoteOriginally posted by Lowell Goudge Quote
we had a similar observation a while back where people thought that a lens designed for ASP=C should be smaller than full frame,

turns out the DA 300F4 is bigger and heavier than the SMC-300mm F4
Sorry to ruin your joke, but DA 300 f/4 is a "full frame" lens.
02-03-2010, 10:20 AM   #6
Veteran Member




Join Date: Nov 2008
Location: The Untied States
Photos: Albums
Posts: 1,882
QuoteOriginally posted by asdf Quote
Sorry to ruin your joke, but DA 300 f/4 is a "full frame" lens.
And, by all accounts, the same exact thing as the FA version.
02-03-2010, 10:22 AM   #7
Pentaxian




Join Date: Sep 2007
Location: Boston, MA
Posts: 7,411
QuoteOriginally posted by wallyb Quote
And, by all accounts, the same exact thing as the FA version.
Yeah, the difference in size is probably down to the SDM.
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!
k-mount, pentax lens, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
IQ difference between FA and A 50mm/1.4? kpp80202 Pentax SLR Lens Discussion 12 11-27-2010 07:19 AM
What's the difference Dxn2 Troubleshooting and Beginner Help 6 12-26-2009 06:55 PM
FA vs. F? What's the difference? PentaxForums-User Pentax SLR Lens Discussion 3 12-23-2009 08:37 AM
the difference between BARCUD Pentax SLR Lens Discussion 5 07-26-2008 01:11 AM
K and A difference JCSullivan Pentax SLR Lens Discussion 15 03-04-2008 01:02 AM



All times are GMT -7. The time now is 08:54 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