iris goes up when zooming?

[johnsolos]

hello hpx250 world! I just bought my first video camera today.. so if this question is noobish forgive me.. im trying to use full manual options..

when i zoom in from wide angle all the way to the macro on the lens, the iris i set initially when i was in wide ange increases when zooming in..

for example lets say when im on wide angle on at 1.8 and when i zoom in all the way it automatically goes into 3.8.. is this normal? or is there something to disable this from happening..

thank you

[TheDingo]

Aperture ramping is pretty normal for prosumer zoom lenses. If you want one F-Stop throughout the full zoom range with the HPX250/AC160/AC130, then set the lens to f/3.2 ( or higher ) at the wide-angle setting, then zoom and the lens will keep one F-Stop.

[LiamR]

It's not a constant aperture lens, as said previously, it will 'close' down the aperture when zooming in.

Just a handy HPX250 tip, keep the aperture around 3 or 4 stops, as this is when the picture will be at it's sharpest, easiest way to achieve this on the run, is to set the IRIS to AUTO, and if you're in an outdoor setting, throw ND filters on until it automatically goes to around 3.5 then flick it back over to manual so it doesn't go wild and change when panning, etc... this is how I do it at least.