GH4 No Aperture Control - Just One Lens!

R

recordrevolution

New member
Hey wise ones of the forum, I'm hoping to get some feedback on a weird issue I've encountered. Also it's my first post so be gentle.

I'm using my GH4 with an XL Speedbooster (EF), and finding that I'm unable to adjust the aperture of one of my lenses. The lens is a Tamron 17-50, and though the display shows aperture swinging from f1.7 to 19 while I turn the wheel, my image doesn't brighten or darken at all.

I checked the electronic sensors, as it seems like a communication issue between lens & body, and they seem to be clean. Unfortunately, I don't have a second body to try the lens on.

I also popped a different lens on the GH4 (+Speedbooster) and had no issues changing aperture when on a 50mm prime.

Has anyone encountered something like this before? Common fix? Obvious issue that I'm missing?
 
You might want to contact Metabones to see if this lens is supported or if it is going to be supported in the future. Metabones seems to be pretty active with updating the firmware on their electronic SpeedBoosters.
( I checked the Metabones website and could not find anything listed about compatibility with the Tamrom 17-50mm lens )
 
Hey Dingo, thanks for the reply.
Your post got me thinking and I just finished testing the VC (image stabilization) on the lens. It functions properly, which I think means that the electronic sensors are in fact interfacing as they should be. Kind of makes the makes the aperture inability even more confusing...
 
recordrevolution said:
Hey Dingo, thanks for the reply.
Your post got me thinking and I just finished testing the VC (image stabilization) on the lens. It functions properly, which I think means that the electronic sensors are in fact interfacing as they should be. Kind of makes the makes the aperture inability even more confusing...
Click to expand...

I think that may only mean that power is reaching the stabilization motors, which it should. Aperture control would be something else. Just speculating…..
 
From my experience Tamron communicates a bit differently.
We had the same issue with our adapters and Tamrons.
Iris displays the change but nothing happens.
We had to modify the program.
I think Red has the same issue with Tamrons although the other brands work fine.
 
This happens to me occasionally with my Sigma 18-35..take off the lens and there is a small metal spring in the Meta bones, just tap or depress to reset it....I have to do this every few months..no big deal..only happens when I switch lens..may be a defect, but easy to remedy.YMMV
 
You must log in or register to reply here.
Back
Top