Profiling aperture across long exposure

[Mikeysing]

I would like to do daytime shots that show moving objects with a fading tail. I think I could achieve this with a suitable ND filter and a long exposure, where the aperuture opens up during the course of the exposure. 

It seems that this should be readily achievable on an a6400 with the remote control app (Android Imaging Edge) where an aperture profile across the shot could be set up. So can this be done in any way, and if not is it something Sony could do something about?

[IamNic]

Hello @Mikeysing,

depending on how long your exposure time will be, you should be able to achieve that without an ND-filter (unless you want to achieve shallow depth of field).

Simply close the iris as far as possible F-Value as high as possible (e.g. F22), set the ISO as low as possible (ISO 100) and expose long enough (e.g. 8 seconds) that the object "smears" across the image, creating the "trail" you want to see.

Also you MUST use a tripod.

Not really sure what you are trying to achieve by opening the aperture during the exposure of the image... could you please elaborate on that? Also no, not possible to do that during the exposure of an image unless you use a third party lens where you can adjust the iris on the lens manually/motor controlled.

- Nic

[darkframe]

Hi @Mikeysing,

what you are looking for is normally achieved by a lower shutter speed.

You should be able to adjust the shutter speed as described here. Lower shutter speed and, if necessary, adjust exposure and aperture.

Cheers

darkframe