EOS M6 aperture closing on itself in manual mode

[Chased]

My aperture keep closing on itself on manual mode, is the problem in the setting or in the lense hardware?

[shadowsports]

Greetings,

Can you please provide the following information. 

Model of your camera, model of your lens?  Does this problem happen with other lenses or just one? 

The initial step we would recommend is resetting the camera to factory defaults and retesting.  

Testing with a second lens and resetting the camera should help narrow down the source of the issue or give you a definitive answer.  

[Chased]

Hi! Model of the camera is Eos m6, this problem happens when I'm using the efs 55-250mm lens with adapter. I haven't tried using another lense yet. But the problem seems to happen only on daylight or outdoor because when I test it again during the night and indoor, it did not happen again, and keep reappearing during the day outdoor.

[deebatman316]

You have a variable aperture lens. The more you zoom the smaller the aperture gets. For instance wide open at 55mm is F/3.5 but at 250mm wide open is F/5.6. So what you're seeing is completely normal in this case. Only constant aperture lenses maintain the same aperture throughout the entire zoom range.

[Chased]

Thanks for sharing this info! One more question, is the aperture supposed to narrow that far every time the zoom range changes? Because in my case it will got to the narrowest every time.

[deebatman316]

What focal length are you at. Every variable aperture lens wide open changes at different focal lengths. Your lens is working correctly. An example at 150mm wide open is F/5.6. So it won't take that much for your aperture to become narrow. I also don't know the Full model name of your lens in question. So please post the Full Name of it. 3 versions of this lens were released. With the last version using an STM AF motor.

[ebiggs1]

Whether the reply above is correct or not can easily be determined if you do the reset as Rick asks you to do and after set the camera to P mode and the lens to AF. Try it outside on a sunny day. If it works as it is supposed to there isn't anything wrong with the lens and either the above reply is accurate or you as the user are doing something wrong.

Unless you have a specific need for manual mode you are well better off letting the camera do its thing. Most of the time P mode is your friend. Cameras like the M6 and the ef-s 55-250mm zoom lens although they both do manual mode, that is really not their best use.