Aperture Range

[downcrash]

Hi all,

I am a beginner photographer. I'm using a Pentax K2000 with a MC Pentax-DA 18-55mm 1:3.5-5.6 AL Lens.

So, according to that the range of the lens would be f/3.5 - f/5.6?

I'm wondering why, when I adjust the f stop on the camera body, I can range the settings from 4.0 - 38?

I know that I'm failing to understand something here. Can anyone help explain this to me? Thanks!

 

[belial]

Hi all,

I am a beginner photographer. I'm using a Pentax K2000 with a MC Pentax-DA 18-55mm 1:3.5-5.6 AL Lens.

So, according to that the range of the lens would be f/3.5 - f/5.6?

I'm wondering why, when I adjust the f stop on the camera body, I can range the settings from 4.0 - 38?

I know that I'm failing to understand something here. Can anyone help explain this to me? Thanks!

3.5-5.6 is telling you the widest the lens can open to. At the lenses widest focal length (18mm)you will range from about 3.5-22 or so. And at it's longest (55mm)you will get a range from f/5.6 all the way into the 30's

 

[mfdrookie516]

I understand that to mean that the maximum aperture is f/3.5 at 18mm and 5.6 at 55mm.

EDIT: Looks like someone beat me to it.

 

[downcrash]

Wow. I get it. Thank you so much.

 

[downcrash]

While I'm asking questions... I've noticed some lenses provide a ranged number for aperture, while other just list one number. For example:

Canon EF Zoom lens - 24 mm - 105 mm - F/4.0

as opposed to

Pentax-DA 18-55mm 1:3.5-5.6

Is there a reason why some cameras provide a ranged number and others don't?

 

[Mach0]

While I'm asking questions... I've noticed some lenses provide a ranged number for aperture, while other just list one number. For example:

Canon EF Zoom lens - 24 mm - 105 mm - F/4.0

as opposed to

Pentax-DA 18-55mm 1:3.5-5.6

Is there a reason why some cameras provide a ranged number and others don't?

Different lenses. Its a constant aperture vs variable aperture. Constant aperture zooms often cost more than variable aperture zooms of the same focal range.

 

[proberok]

Edit. Answered.

 

[downcrash]

I see. Thank you so much guys!

 

[Tiberius47]

Lenses with the constant aperture are generally better quality lenses too. And faster.

 

[o hey tyler]

I understand that to mean that the maximum aperture is f/3.5 at 18mm and 5.6 at 55mm.

Why do you keep copying posts (not quoting) from other members when the question had been answered by the post you copied? It's starting to look a lot like spam.

 

[downcrash]

Lenses with the constant aperture are generally better quality lenses too. And faster.

Right. I had to look up the difference between constant and variable aperture, but I've noticed this. Also that the prime lenses are generally faster as well. I think I'm slowly learning.

 

[DiskoJoe]

Its helpful to remember that the smaller the aperture number the wider the opening and thus the more light you can let in and take pictures faster. It all comes in waves.