Hi and welcome. I'll put this into the lenses section in a moment.

You can use your lens in M and Av modes. If you set any other auto mode such as Tv it will still be in Av mode. Set the aperture ring to a desired value and use the stop down lever (round the shutter release) or the green button to stop down the lens and take a meter reading. Then when you release the shutter it will work.

The reason for all this is that M series lenses do not have any electronic contacts on the mount, so the camera cannot control the lens. It is more convenient to use an A series or later lens that has an "A" on the aperture ring.

However, the lens will work. If you don't follow the procedure above the shutter speed will vary with the light if you use Av, but the lens will always be at maximum aperture. As you're doing portraits you just might try this as well, but don't forget to focus very carefully on the eyes!

I've corrected the title spelling of Voigtlander, which might assist anyone doing a search.

If you have four cards instead of one, each card will only get 25% of the use. If one card fails then only 25% of the images are compromised, and if it's a long time since they were new that might be a timely warning to replace them all.

That is absolutely fantastic news. What a relief for you after such a dreadful few days.

What remarkable phone calls you get Ken!

That is a bit harsh! You mean the ones that proudly claim to have an "Optical Lens"?

Actually as I wrote that I had a nasty feeling that the future may bring us non-optical lenses, perhaps light bent by a ring of adjustable gravity fields? Hmm...

You could override the Auto ISO and set a fixed value at a lower setting.

Shaky, yes, you can. Anywhere that can process black and white film can "push" a film for you. All you need to do is make the instruction to do so. Just tell then +1, +2 stops or whatever you want.

There's nothing specialist in this, photo labs do it routinely. I am assuming that you have never used film as an enthusiast and are therefore unaware of the origins of much of the digital technique that is used today.

Photoshop is effectively a digital darkroom, based on traditional darkroom techniques.

No, they looked to see what was in the frame. Nobody thought much of all this technical stuff till much, much later!

Mind you, I wonder what you mean by "the early days"? I'm referring to the days when a photographer might reach for "the twelve inch lens" before his head disappeared under the black hood.

I'm not that old, Stefan....