F-Stops

[Partsrept]

Hi. Can some one explain this pleese ?

On lens it says F-Stops 3.5 - 5.6 BUT cameras can still allow you to go up to 32. Why ?
What do i change when i do more than lens supports ??? Is that kind of fake simulation of small apertures?

A zoom lens will list both Minimal (or largest, just to add some confusion to the matter) f-stops that are relative to the focal length range.

Example: a 55-200 Zoom lens will have a minimal f-stop of 3.5 at 55mm but the f-stop changes to 5.6 while at 200mm focal length.

Hope this clarifys it a bit.

[Partsrept]

Originally Posted by Bakeys

A zoom lens will list both Minimal (or largest, just to add some confusion to the matter) f-stops that are relative to the focal length range.

Example: a 55-200 Zoom lens will have a minimal f-stop of 3.5 at 55mm but the f-stop changes to 5.6 while at 200mm focal length.

Hope this clarifys it a bit.

My lens can physically do only 3.5-5.6. Why camera still allow me to change it to 32 with dial ?

[dalmorloson]

Your camera will physically operate with the numbers listed plus any f/stop that is larger (smaller opening). The lens lists the smallest number (largest aperature) for a given focal legnth. You can always "stop down", but can't open the aperature any bigger than the numbers listed.

[inkista]

Originally Posted by Partsrept

My lens can physically do only 3.5-5.6. Why camera still allow me to change it to 32 with dial ?

Because that's not your aperture range; it's your max. aperture. And f/32 is smaller than f/3.5 or f/5.6.



These are ratios/fractions. Just as 1/8 is smaller than 1/2, f/8 is smaller than f/2.

Suggest you read this: What is Maximum Aperture?

[OsmosisStudios]

Originally Posted by Partsrept

My lens can physically do only 3.5-5.6. Why camera still allow me to change it to 32 with dial ?

It can physically do a MAXIMUM of f/3.5 at one end and f/5.6 at the other. It can do anything smaller (ie a higher number).

FYI: If you're gonna be a smart-ass trying to correct people, then at least know what you;re talking about

[autofocus]

The numbers you are referring to are the largest opening apertures the lens will do at over the various zoom range settings of the lens. Small F number=large opening, large number=small opening of the aperture. Again, that's only the largest aperture opening capable on your lens..those numbers have nothing to do with how small the aperture could potentially close down...possibly to F/16, or /f/22, etc. If you make a fraction out of those F numbers by putting a number 1 above the number you will see that F8 expressed as 1/8 is smaller than F4, or 1/4. Hope this clears it up for you

[Partsrept]

I am not asking to explain me what F-stop is and how it works.

Question was technical: according to spec 3.5-5.6 is what lens can do: aperture is a "physical hole" that can be open and close at 3.5-5.6.

If spec says 5.6 smallest i can do (says on lens) then why camera still go to 32 ? Will it also change "physical hole" size or is it going to be electrical emulation of that aperture (not hardware) ?

[autofocus]

Originally Posted by Partsrept

I am not asking to explain me what F-stop is and how it works.

Question was technical: according to spec 3.5-5.6 is what lens can do: aperture is a "physical hole" that can be open and close at 3.5-5.6.

If spec says 5.6 smallest i can do (says on lens) then why camera still go to 32 ? Will it also change "physical hole" size or is it going to be electrical emulation of that aperture (not hardware) ?

I think the answer is already here for you..just go back and read all the previous posts. For starters, the camera doesn't go to F/32, the lens does, and that would be the smallest aperture opening. So, if you already know about F/Stops, you already should know that!

[Partsrept]

is there a tech person here to answer it ?