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LEicA m

Rangefinder focus
and view of field

In this article I will take you through the benefits and practical ways of working with a rangefinder camera, to make it easy to handle.

At the end of the article, you will find a VIDEO about Zone focusing. Read the article first and expand with the video afterwards.

The years of autofocus cameras surely have caused many photographers to miss the skills of manual focus. The manual focusing techniques have been lost for some, and they may have a harder time doing manual focus than it is.

The EVF (Electronic View Finder) cameras also make some uneasy about looking through clear glass instead of a monitor in front of their eyes. Or they look on a flip screen like an iPhone. 

The blessing of manual focus

 

Manual focus needs a little practice, but when you get used to it, it’s a blessing to be in control. Autofocus is limited by seeking what it thinks must be in focus and doesn’t know what the photographer wants to be in focus. Autofocus often takes the nearest subject and the subject with the clearest contrast or lines which may not be the wanted effect.

With manual focus, the photographer decides. Not the camera.

Keeping your rangefinder viewfinder and focus window clean helps keep a clear vision immensely and is important for the best result.

So how to approach manual focus? First of all, there is a difference between capturing moving subjects in the street or a model sitting on a chair where you have time to find focus. I will get back to that, but first, it´s good to know how the rangefinder camera operates.

(There are three windows on a Leica M8 and M9 range finder camera. The biggest one is the clear window which is the viewfinder.  The second one is opaque and provides illumination for the framelines (on newer M this is exchanged with  battery powered illuminated frame lines, at the M10 and onwards). The third one is the focusing spot.

The disadvantage of a naturally lit frame line from a small window catching light is that you may block the incoming light with your fingers, making the frame lines disappear. This can also happen in low-light situations or camera angles where light is hindered from going in. Electronic illumination solves this.

The rangefinder mechanism is the second and third window acting together. There is a small movable disk that changes the angle of a mirror sitting a bit more than a 45-degree angle to the third window. The movement of the mirror moves the point at which the viewfinder image and the view from the rangefinder spot intersect. The larger the angle the closer the focal point. 

Due to its design, a Leica M camera cannot focus on objects closer than about three feet. When the focus mechanism is engaged, the lens corrects for parallax by moving the entire set of frame lines and the rangefinder patch diagonally across the frame. This adjustment ensures that the frame lines accurately represent what is being captured, even when focusing on close objects.

How to focus – three different methods

The best one is to look for a broken line like on the edge of a chair, or the frame of a window. Frame and look for any vertical line in the image and bring the broken line together in the rangefinder patch.

Secondly look for any clear pattern in the image, like patterns on a jacket, and bring it together to coincide. This may lead to errors with repeating patterns because it can be confusing to overview. Reframe to check if there is a clear pattern for more accurate focusing.

Thirdly there is the possibility of contrast for focusing. If you have focused using the first two methods a small adjustment will make the rangefinder patch slip into optimum contrast. Now the most precise focussing adjustment is achieved.

It might sound like a lot of things to consider for a single picture, but it will very quickly be a routine and not feel like that. With a little training, you are on the right path.

Remember, all photos with a rangefinder have been done similarly for many years, and it worked well. Only laziness from autofocusing cameras causes photographers to miss the skills of focusing. 

First learned, you can nail focus through windows with reflections, people in the middle of a crowd, or an object partly hidden by the leaves of a tree, without being misguided by accidental autofocus.

There are a few errors possible. Please notice that when focussing on a subject reflecting polarized light it can happen that this polarizing effect of the prism system in the rangefinder will blot out the contrast in the rangefinder patch. this may lead to focussing difficulties in are cases.
To overcome this, as well as if you can’t find good lines in the right direction to focus on, you can turn your camera 90 degrees to focus and then reframe and take the picture.

Framelines move when the focusing ring is turned because the lens and the viewfinder are in different places. This resulting parallax is compensated by a shifting of the frame lines for compensation.

Note that when one focusses in a vertical camera position, and afterwards recomposes in the wanted horizontal position, for geometrical reasons, one must bend slightly backwards or forwards to keep the focussing distance because of the move.

Pre-focus


In the streets, you can select pre-focus and pre-set your aperture for enough depth of field (DOF) to cover the area you expect to aim at. Using a 35mm or 50mm lens at f11, you can have from 4′ / 1,2 metres to infinity in focus depending on the lens.

In most cases, you are safe in focusing in that distance, and with a 35mm focal length, you are better off than with 50mm and above. That is one way to deal with it, but there is more to the aesthetical and practical way of focusing.

This way of shooting demands great care of composition because every little detail and distracting background will be sharp and clear. 

Shallow depth of field

 

To separate a subject from the background, we need to open up the aperture to decrease the DOF. This narrow depth of field will be helped on the way with a 50mm compared to a 35mm lens. The speed of the lens also is an important factor. A Summilux 50mm lens with an aperture opening at f1.4 will have a more narrow DOF than a lens where the widest opening is f2.8.

I practise this micro-focusing always and I am therefore constantly ready. Before I go out the door, I set my camera up, ready to shoot. Fresh batteries, a clean memory card, and my lens set at the expected aperture, shutter speed and ISO where I am.
I set my lens at infinity so I can easily narrow in, instead of having to search one way to realise I have to turn the focus the opposite way and lose time and miss my target.

It comes down to practice and some habits making it all easy. I mostly have the aperture wide open to have this intimate feeling and separate my main objects from disturbing back or foregrounds. I describe my movement around a subject I want to photograph as a dance. 

Body focus

 

When I focus I also do a bit of movement with my body towards or away from the subject. This dancing with my subject and camera, and it’s just small micro-movements of the body, become micro-focus movements. This way I change the focus point without turning the focus ring when I have first set it as close as I can to the subject.

Zone focusing


In street photography nailing people moving around can be a challenge. Not only for manual focusing but also for auto-focus cameras. Zone focus is a technique where I pre-focus on an area and wait for the moving subject to pass the zone. Then I hit the shutter button when people, dogs or whatever it may be, pass through the predefined focus spot.
At f1.4 it can be a good idea to shoot on burst mode so you have a short series of pictures, and one of them will be nailed at the right time. If you open up to  f2.8 or f4 there will be a wider depth of field in focus and better chances of nailing it. It all comes down to practice.

If you wear glasses

 
If you need glasses to focus as I do, be sure you have a current prescription and a diopter correction lens if needed to help you see better through the viewfinder without glasses on. Glasses can be a bit annoying to wear but for now, I have kept mine and live with the slightly worse view in the viewfinder.
To ensure things are crystal clear ensure your camera and lenses are well calibrated, and then add an additional diopter correction if you prefer to have your glasses off when taking a photo.

diaopter ring leica

A diopter lens to mount on your camera.

Framing and edges 

 

The Leica M cameras work as any other rangefinder camera, with the central patch in the viewfinder as the focussing tool. When aligning the two fields so they overlap and are aligned, it will be in focus on that focus point.

It is important to look through the viewfinder on the optical axis. Looking into the camera skewed will result in inaccurate focus. Comparing the viewfinder of a rangefinder with something else may make it easier to know it works.

Film prints always exclude some from the original negative when we fit it on a piece of paper and produce it with the exception of when prints include the film negative perforations for that special style of prints.
So, there is always a small edge lost when printing from a film negative. In digital photography, we keep it all, from edge to edge. 

Crop factor when focusing

 

When using a lens and focusing with a rangefinder camera we might feel it isn’t always precisely the frame we aimed for that comes in on the sensor (or film on a film camera). The most important factor influencing this is that the lens changes its angle of view when focussing. It works like this when the glass elements inside the lens move when the focus is changed; then the lens gets longer (i.e. a little more tele) as I focus closer. This way I have a smaller field of view at the closest focussing distance than at infinity for example.

There may be a maximum of 20% difference in the field of view leading to frame lines only being accurate at one ideal focussing distance. For the Leica M9, this is at 1 meter and for all other focusing distances, more of the image will be in the final picture captured than the frame lines actually show in the viewfinder. 

A guideline allows (on a 50mm lens) one frame line thickness outside the shown frame at around 3 m focal distance and three frame line thicknesses outside the frame at infinity focus. This a rough guideline, and in practical daily life and photography I am not concerned so much about this. I just crop a bit afterwards to correct lines or the horizon and therefore have just a bit more (5-10 %) in my picture than needed when shooting leaving room for small adjustments when needed.

Ensure that you can see the rangefinder patch properly when looking into the window of the camera. It is important to have a good match between the rangefinder window and your eye.