Black stripe when adapting vintage lens

[Yaeli]

Maybe the camera is thinking that no lens is attached -- and "hallucinates"?????

Hello everyone,
My apologies for the delayed answer.
Xkaes, I doubt it : it works on certain speeds, so I don't see why it would think that no lens is attached. It also registers the shutter speeds and everything. Besides, I often use freelensing / lens whacking and it works just fine, so...

I was going to say maybe there is an obstruction in the lens that causes the strange vignetting, but it apparently it is ok.

It doesn't make sense that the shutter would misbehave only with one lens. The best explanation is that the issue is intermittent and that you've been "lucky".

I guess it's possible that I've been lucky, but it doesn't seem very likely to me : all the shots above 1/2000 of a second showed the black stripe with the Helios 44, and none of the shots at the same speeds, taken a few minutes apart with the EF lenses, showed any stripe whatsoever.

I have a camera that only shutter caps in certain cases. Like yours, it's more common at the highest speeds and in vertical orientation. I'm sure the orientation part has to do with gravity. The EOS R is a relatively new camera for that to be happening to though, unless maybe some grime got into the shutter somehow.

I just got back from a wedding and shot 1000 photos. I'm going to review them all, see if I can spot anything on the EF lenses (I chose not to use the Helios 44, just in case). I will also take the time to inspect the adapters, the Helios, and also see if there's any (even slight) wobbling on the side of the adapter.

 

[Yaeli]

Hello everyone,

So, I inspected the lens and both adapters, and I found nothing that seems out of place or could explain the dark stripe. I cleaned them, just in case, and did other tests today, and it's still there. As for the wedding photos with the EF lenses, no sign of the dark stripe on any of them, no matter how I shot of what settings I used. So it's definitely coming from the Helios lens or adapters, but I still have no idea how.

 

[joe bosak]

I suppose this could not be some kind of light path issue (maybe dependent on direction of light). If it's at fast shutter speeds does that mean wide aperture? Maybe try lining the extension tube/adapter with something light-absorbing.

 

[Yaeli]

I suppose this could not be some kind of light path issue (maybe dependent on direction of light). If it's at fast shutter speeds does that mean wide aperture? Maybe try lining the extension tube/adapter with something light-absorbing.

Usually yes, the fast shutter speed is linked to a wide aperture (generally wide open, at F/2).
I wonder if lining the extension tube would really help : it's already black, and so is the adapter. So...

 

[joe bosak]

So nothing ventured nothing gained... have fun....