Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
08-07-2013, 05:40 PM   #31
Site Supporter
boriscleto's Avatar

Join Date: Dec 2009
Location: Liverpool, NY
Photos: Gallery
Posts: 12,297
QuoteOriginally posted by Kalki Quote
I think i am posting this in the right place. I have been experimenting with film photography and learning along the way for a nearly a year now, mainly with a K100 and an ME Su albeit with varied results. I believe i have managed to grasp the fundamentals such as exposure, metering, f stops, iso, aperture etc.

However i still wave no idea what makes a decent lens or what the benefits are of different lenses past wid angle, tele macro etc. Could somboady please explain to me what all this f1.8 business means and why an f1.8 lens might e better to use in certain situations rather than an f2 etc.

Excuse my ignorance and thanks in advance.
https://en.wikipedia.org/wiki/F-number#Standard_full-stop_f-number_scale

The difference between f/1.8 & f/2 is 1/3 of a stop. One full stop would be f/1.4.

A stop is a unit of measurement used to quantify ratios of light. Each added stop is a factor of two, each subtracted stop is a factor of one-half. So changing one stop, ie from f/2 to f/4, is a halving of the light intensity.

F stops also have an effect on Depth of Field.

https://en.wikipedia.org/wiki/F-number#Effects_on_image_sharpness

In addition to DoF there are the effects of diffraction to be concerned with above f/11 or so. But in some situations you have to bite the bullet and accept diffraction for the added DoF.

Lens speed - Wikipedia, the free encyclopedia

Aperture - Wikipedia, the free encyclopedia

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, f/1.7, lenses, mx, pentax, smc
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Which lenses are your using for startrails and night sky Conqueror Pentax SLR Lens Discussion 25 12-15-2012 06:05 AM
Which teleconverter for Pentax and Sigma lenses? Sten Pentax Camera and Field Accessories 11 05-09-2012 01:11 AM
For Sale - Sold: For sale two K1000 bodies with 50mm lenses and flash sagiboy Sold Items 8 08-13-2011 07:57 PM
For Sale - Sold: K1000 lenses and flash (Worldwide) sagiboy Sold Items 2 07-11-2011 10:09 AM



All times are GMT -7. The time now is 12:14 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