eos 5d changes iris

[xha1dude]

Shot a test today, with a canon 24-85 zoom lense.
everytime i zoom in or out, eos changes my iris (even if i am in M mode and have an iris of 8)

is there any function to change that?

 

[PerroneFord]

I thought the 24-85 was not a constant aperture zoom? So it's not the camera that's changing it, it's the lens.

 

[xha1dude]

yes its 3.5-4.5
so there is no way to stop that?

 

[PerroneFord]

yes its 3.5-4.5
so there is no way to stop that?

No, that's why people pay more for constant aperture lenses...

 

[buelusa]

Same issue here. How can you tell a lens has a constant aperture before you buy it?

 

[PerroneFord]

Same issue here. How can you tell a lens has a constant aperture before you buy it?

It only lists one F-Stop on it. So instead of saying F3.5-F5.6 it will say F3.5.

It will also cost about $300 more than the "cheaper lens" with the same focal lengths.

 

[xha1dude]

hm at my eos 400d the iris stays the same when i zoom... :/