In use a dial is turned until a needle matches an index seen in the finder. The shutter speed and aperture pairs can then be read. In low light the needle can be matched to one of a series of values a multiplication table is then used to give the correct reading. The meter was also known for a short while as the Helicon, that name was later used for a combined meter and rangefinder. Some versions have a baffle over the sensitive cell. Available with a foot to fit the accessory shoe of a camera.

The 1935 Zeiss-Ikon catalogue shows the Helios with only a DIN or Scheiner scale and only one row of apertures.

Similar to the previous entry.

Similar to the previous entry.

This is a Helios type photoelectric exposure meter combined with a rotating wedge rangefinder. The price in 1937 was £9/15/0.

The post-war Ikophot proved very popular and was made for several years. Variations of the dial layout exist and early post-war models were made in black plastic rather than the later cream. The cine speeds were added around 1957, prior to this only an index at 16 f.p.s. was shown.

On pre-war models as the reading is taken a dial is turned to align a mark with the meter needle, the shutter speed and aperture pairs can then be read. The meter has a cover over the cell that hinges down for low light levels. There are two corresponding scales on the dial.

On early post-war models the meter needle moves over a dial scaled 1 -16, that value is transferred to the calculator where the shutter speed and aperture pairs can be read.

The Ikophot Rapid uses a match needle system where a dial is turned until an index arm lines up to the needle. The shutter speed and aperture pairs can then be read.