Why can't I open my aperture more?

OfMikeandMen

TPF Noob!
Joined
Mar 12, 2013
Messages
48
Reaction score
1
Location
United States
Can others edit my Photos
Photos OK to edit
I am using a Nikon D40X with the kit (18-55mm) lens. It states that the f/stop should go to f/3.5. In various circumstances it will let me open it to a 3.5, but it's usually stuck around f/4.x. I've tried researching this, but can't figure out why. I figured it might be an ISO/SS combination, but even if I change those, it STILL won't let me open it any larger.
 
I had trouble figuring out what was going on with my Canon 18-135 f3.5-5.6 until I read online somewhere that the f3.5 was only at 18mm focal length and it quickly reduced to f5.6 as I zoomed.

The variable f-stop is a method used by lens makers to reduce the size and weight of the lens. It's also less costly to produce and buy.

On the other side of the coin is the fixed-aperture zoom lenses, which are anything but low price. They are typically 'faster' (lower f-stop number, wider aperture) and maintain that f-stop throughout the zoom range. But to do that, there are generally more glass elements inside the lens as well as a larger diameter overall, adding to their weight. Maybe they're priced by the ounce like gold and other precious metals? :(
 

Most reactions

New Topics

Back
Top