Some of the Iloca cameras were available with an in-built rangefinder, but many models were produced without any form of focussing aid at all. The latter group of cameras can still equipped with one of these useful devices by fitting an accessory rangefinder to the camera's acessory shoe. Even if there is no accessory shoe, you can still keep one of these rangefinders in your pocket.
There are many different brands available, and some are better than others. Here are some things to take into account when selecting an accessory rangefinder: ◙Does the focussing scale on the rangefinder match that of the camera? ie are they both calibrated in feet (or meters) and are the distance intervals on the rangefinder similar to those on the camera? ◙Are the primary and secondary images clearly visible (ie not cloudy or feint)? ◙ Does the focus wheel operate smoothly and do the two images snap crisply into a single image when the correct focussing distance is reached? ◙Does the rangefinder fit neatly on the camera's accessory shoe and does it clear the other controls? ie can the foot of the rangefinder be adjusted if necessary to allow for convenient placement on the camera? ◙ Is the rangefinder easy to calibrate if it goes out of adjustment?
These old rangefinders are generally more than accurate enough for most photographic situations that will be encountered with Iloca cameras. A typical rangefinder will have a range of around 3 feet (1 metre) to infinity. When you take into account the cameras depth of field, you should have little trouble focussing the camera under normal situations.
As with most things, you generally get what you pay for. In other words, better quality rangefinders usually produce the clearest images. However, age and condition will also play a part - it is quite likely that the optical and reflective surfaces on older rangefinders will have degraded to some degree.
A favourite is the Voigtländer. This device operates very smoothly, gives a nice clear image, is quite accurate and is easy to calibrate.