Aperture changing constantly

I've searched the web for an answer to this, but no definitive answer. Pre-AF OFF, AF-S, not touching any buttons, the aperture changes constantly as the light entering the lens changes: https://youtu.be/OqaF87utnlM

My questions:

Why is this required?

How will this affect the life of the aperture mechanism?

Can I turn it off.

I'm guessing here but try turning off exposure/effect preview (whatever it's called), perhaps set natural view to on as well if your cam has it. I also think it wouldn't do that if you select EVF-only+eye-detect view mode, not until you put the camera to your eye at least.

I think if the lens diafragm (apertutre ring) is in position" a " (automatic) so the aperture changes with the change of light entering the lens

this is a normal working mode of the camera - no harm

nex55 wrote:

I think if the lens diafragm (apertutre ring) is in position" a " (automatic) so the aperture changes with the change of light entering the lens

this is a normal working mode of the camera - no harm

Lens was set to F2.

imagei wrote:

I'm guessing here but try turning off exposure/effect preview (whatever it's called), perhaps set natural view to on as well if your cam has it. I also think it wouldn't do that if you select EVF-only+eye-detect view mode, not until you put the camera to your eye at least.

Thanks. I toggled Viewmode and Natural View and that makes no difference. Is "Exposure/effect preview" referring to the "Preview exposure in manual mode" setting? I think that only applies to manual mode, but I tried that too.

The camera is maintaining a usable exposure setting in order to get proper images to display on the EVF or LCD.

It's part and parcel of the mirrorless experience. Exposure control is no longer a "when the shutter is released" kind of thing -- it's continuous whenever the viewfinder is active. There's nothing you can do about it.

When you half-press, the camera will adjust to your shooting parameters, which means it'll stop down to your designated aperture and will stay there until the picture is taken or you release the shutter button.

vhimste wrote:

So why they constantly change it when you do not half press the shutter and point the camera to brighter/darker areas is still a mystery to me.

It appears the camera doesn't like running the electronic shutter at a very fast setting during the "no-press" image framing time. It's still forced to go a bit high in full daylight -- my X-T10 won't stop down beyond f/5.6 during framing, and at a framing ISO of 200 (its minimum) the camera would need 1/1600 in Sunny 16 conditions.

You could ask Fujifilm why it matters, but I doubt they'd tell you. Modern "smart" cameras are based on a lot of secret-sauce logic that the manufacturers keep to themselves.

User1107598218 wrote:

AndreM365 wrote:

I've searched the web for an answer to this, but no definitive answer. Pre-AF OFF, AF-S, not touching any buttons, the aperture changes constantly as the light entering the lens changes: https://youtu.be/OqaF87utnlM

My questions:

Why is this required?

How will this affect the life of the aperture mechanism?

Can I turn it off.

It's a known issue. Fujifilm website has explanations, but in Japanese only. To avoid it, just manually set shutter speed. Meanwhile, please make sure "PREVIEW EXP./WB IN MANUAL MODE” in the camera menu is set to "ON".

Very interesting. I have not been able to find that "known issue" mentioned anywhere. I did notice that switching to manual shutter stops the aperture stuttering.

User1107598218 wrote:

Try this if you can read Japanese: http://digitalcamera.support.fujifilm.jp/app/answers/detail/a_id/17361/~/%E9%9B%BB%E6%BA%90%E3%82%92%E5%85%A5%E3%82%8C%E3%82%8B%E3%81%A8%E7%B5%9E%E3%82%8A%E7%BE%BD%E3%81%8B%E3%82%89%E9%9F%B3%E3%81%8C%E3%81%99%E3%82%8B%E3%80%82

Google Translate renders that as follows:

With the FUJIFILM X-Pro1, the diaphragm blades are automatically switched according to the brightness of the subject when the power is turned on to display the LCD with the appropriate brightness.
Therefore, if the amount of light transmitted through the lens changes, for example, by tilting the camera, you may hear the sound of the diaphragm blades moving.
If you press the shutter button halfway, the aperture value will change.

Which doesn't really say anything we didn't already discuss.

I've gotten around this by using non-electronic manual lenses such as Rokinon 21mm F1.4.  The camera can't change the aperture or focus so it figures out how to make the EVF and LCD deliver usable imagery so you can take a picture.  This works well on my X-E1, X-T100, and X-T3.

Fuji could easily fix it with a menu item that says "set aperture full-time in aperture priority mode" but years have gone by and they won't do it.  This is my pet beef regarding the use of Fuji electronic lenses.  At present I own only one Fuji lens!

But Fuji is not the only one doing this.  I believe the Nikon D800 series allows you to set Nikon electronic lenses to fixed aperture full-time, but I have only heard this and I don't know of any others.

Thanks for the replies. The workaround doesn't work for me as I mostly shoot Aperture priority. In manual mode the aperture stays wide open and display adjusts if you change SS, so I don't understand why they can't do the same in Av. They could easily fix it with firmware

I've the same issue on my X-H2, and can't find any setting how to disable this. Also it seems for me that this behavior started randomly without any real change to the settings...