Hello,

 

does anyone have experience using Sigma MC-11 with a Milvus lens? Am interested to know if the metadata from the lens is communicated, and naturally, that the aperture is controlled correctly from the camera.

 

Thanks.

OK, let me answer my own questions.

 

Metadata is communicated, Lens shows as "DT 50mm F2 SAM", aperture is included. Seems that the Steadyshot is picking up the focal length too. So that is all great!

 

Aperture control, it seems that the aperture is adjusted when the shot is taken, so at least for now I have to focus at f2. Have to see if that will be a problem ... perhaps there is some setting for DOF Preview? Anyway ...

 

 

The Milvus lens itself is wonderful, really well built, and the adapter was very well packaged too. The combined size of lens and adapter is somewhere between a Batis 25 and 85, however the weight is a hefty 836g. Still, its all metal and really impressive. Here is how it looks ...

 

 

 

 

I've assigned Aperture Preview to the centre button, for a DOF Preview. That works.

 

Probably the only thing missing is Automatic MF-Assist ... I guess that the Zeiss Lens does not signal changes in focus. Will take it for a walk tomorrow, try to find some butterflies ....

I have my 7-II set to use something beyond just 

aperture preview. Can't recall it's feature name, 

some sort of "image preview". It INCLUDES iris 

stop down but also WB, exposure etc. Might as 

well preview how your DoF looks on your actual

shot with the color, contrast, brightness, etc, etc 

cuz some of that does affect the impression of 

sharpness as well as "real" DoF :-)  

   

FWIW I put it on the C3 button next to the EVF. 

Yes, I have to do that too I think, "image preview" rather than "aperture preview".

 

What I find is that the exposure is metered at f2 (lens is normally wide open, actually a useful thing), and then calculated for the target aperture based on that reading, and that calculation is influenced by the natural vignetting of the lens ... so ... the shots at smaller apertures are over-exposed. The smaller the aperture the greater the error, due to compounding, naturally.

I just bought the Milvus 50 1.4. Im happy with the results I get, despite the under-exposed preview at smaller apertures. This is a quite dramatic effect with apertures from F4 and below.

Does anyone have a work-around in mind? 

Does the aperture iris of you lens stay wide open when you adjust the f-stop? And then stop down only when you press shutter?

Yep.. exactly that way. It stays wide open and only adjusts the aperture during the shot. I guess its due to the vignetting, but the effect is quite dramatic. In the german sonyuserforum a member has the milvus 85 on the metabones and has no such issues.

you mean that with the metabones adapter the aperture is _not_ staying wide open all the time? That would be interesting, since as you mention, I too think the vignetting is causing the problem - the camera is metering at wide open, calculating the end exposure, and then setting the aperture based on that ... so the vignetting impacts on that calculations accuracy.

 

So far I got used to dialling in some exposure compensation ... trial and error at first ... but now its just about automatic.

I found an easy workaround. Just set aperture preview on c3 and press it before shooting.This for sure only makes sense in M mode.

I have it (aperture preview) on the centre button   

 

Actually, having the lens normally wide open is _really_ useful for getting exact focus ... so I like that part a lot!

 

I'm using the Milvus 2/50M, its wonderful, really great.

Still strange that the 85 on the metabones doesnt underexpose. Maybe it doesnt vignette that strong.

I have the problem the other way, wide open exposure is OK, as you would expect, stopped down I get over-exposure and need to apply -ve exposure compensation. The metering (centre, spot, and what_ever_the_other_one_is_called) probably has an impact too.

 

Perhaps there are other factors. For sure, with my camera, the metering is being measured with the lens wide open and then calculated to the target aperture ... OK ... perhaps if I update the firmware of my camera that changes.

 

Anyway, not much to do about that ...