Lenses couple with the rangefinder only from 0.7m or 1m

Even if you want to shoot a subject on the table, you can't get close to it. Don't worry. It's not out of order. If you want to get closer, don't bother and just add a compact digital or DSLR camera. By the way, it's wonderfully philosophical when we talk about what it means to shoot a subject at a distance of 1m or further.

That cosine error

You want to shoot wide open for no reason, don't you? But, you may be worried about the cosine error because with a rangefinder you can only focus in the center of the frame. In such a case, I recommend a film Leica because you can't check the results right after shooting and you will even forget what you focused on. Instead, you will learn to stop down because you will realize you don't have to shoot wide open 24/7. In a sense, you become more adult. Of course, this paragraph is meant to caution myself as well.

Hard to photograph in the center

It's about the viewfinder rather than rangefinder, yet it's an important issue. For example, there's a flowerpot in front of a wall. A little flower looks pretty and you want to photograph it in the center of the frame. But, this is difficult and the subject always gets out of the center because you are not looking at the subject through the lens. One way to overcome this issue is to master "camera shifting" that corrects this off-centeredness, but it's all right because you can also use a digital camera like one of these.

Can't frame accurately

Again, it's about the viewfinder. The bright-line frame is in fact loose. This can't be helped because of the mechanism. So, it's best to get a digital rangefinder because you can take as many shots as you want. Some people say, "I shoot solely with 50mm!" but even Henri Cartier-Bresson trimmed his pictures, so you can deal with the looseness and everything is gonna be all right. And, once you get used to shoot with a rangefinder, you'll be able to complement the looseness to some extent. In other words, it's not the instrument that evolves, but the photographer does. That's what a rangefinder teaches.

The Noctilux f1.0's 2m limit

The Noctilux f1.0 has become incredibly expensive, but the lens doesn't focus well in a distance somewhere between its minimum focus distance and 2m. But, don't worry because it's made that way. I once sent mine back to Germany, but they said it was in perfect working order and asked me if it was OK to "modify" to increase the accuracy in that range of distance. The focus depth is already extremely shallow, so sometimes you may worry about the lens, focusing shift, or your own handshake, and then you don't know which standard you should use. Therefore, in order to use an ultra fast lens, you have to take things philosophically as they are. It's unhealthy if you worry too much. Think this way. You need to be lucky to get subjects in focus as wanted.

Tidbit by one of our photographers

Our photographer A obtained the Noctilux in fair condition. It had serious back focus issues, but he was skilled enough to compensate the focus difference by turning the focus ring accordingly. One day, he altered the rangefinder coupling cam and "optimized" it for focusing on to 20 meters by making it unable to focus at infinity. I said to him, "Look what you've done!" But, he said "I don't focus at infinity with the Noctilux and only shoot wide open anyway." Is he afflicted with paranoia? No, he just practiced the manner to use an ultra fast lens on a rangefinder.

Focusing with the eye. No need for rangefinder

The minimum focus distance for a rangefinder is 0.7m to 1m. It's shorter with some wide lenses and altered lenses, but you have to focus with the eye because it exceeds the rangefinder coupling range. Once you get used to it, you'll be able to handle lenses with some rangefinder coupling issues. If you take one step further, you'll be able to take macro photography by unscrewing the L mount lenses just before it falls off, making an "extension tube." Of course, there's no rangefinder coupling either and there's always a risk of lens falling. Using a rangefinder makes people unserious and irresponsible. If there're more such people, the world would become more peaceful. The end.