Early meters were introduced for carbon and platinotype prints which were developed rather than being 'printed-out'. In use the carbon print is exposed in a printing frame to daylight, at the same time a test print on printing-out paper (POP) is exposed in the print meter which is placed next to the carbon print.

In the simplest form a small piece of POP was exposed until it matched a painted, standard, tint, a fresh piece of paper was then exposed. A normal negative required two or three 'tints', i.e. two or three exposures of the POP in the meter. The photographer judged the density of the negative and from experience how many tints were required. A problem with this form was the difficulty of estimating precisely when the standard tint had been matched. In Sawyer's meter a longer strip of paper was exposed through a graduated scale of opacities, each corresponding to a 'tint', the images on the test strip were compared to a painted standard tint. The operator still had to judge how many tints were required based on the density of the negative but it was easier to match how many tints had been reached and it was not necessary to move the paper during the exposure. In Burton's meter six small negatives were printed on the test strip, each negative varied in density corresponding to one tint. The operator first matched the density of the negative to be printed against one of the test images the exposure was stopped when the appropriate image was correctly printed.

With later bromide and other development papers the usual way of determining the exposure was to make a test strip by multi-exposure. This required no extra apparatus. Step wedges consisting of glass or celluloid sectioned into varying densities were produced, with these only one exposure need be made to produce a test strip. The difference between this type of meter and the earlier carbon meters is that the test strip is made first, prior to exposing the print. Densitometers where the density of the negative was read directly were used by dedicated amateurs but were the exception.

For daylight enlarging ordinary actinometers could be used to measure the strength of the light and after allowance for the degree of enlargement the exposure could be read on the meter. Watkins published details on using their meters for enlarging.

In the 1930s electric meters using the grease spot principle and other comparison types started to be produced. Later, meters using photo-electric cells, such as the Majus of the late 1930s, were introduced.

One of the most popular of the early meters. On some examples there is more elaborate engraving on the corners of the case. The price was around 6/-, briefly a solid silver model was advertised at 15/-.

This was designed by the editor of Miniature Camera Magazine in collaboration with the Research Department of Ilford. It was intended as an aid to classifying photographic paper. The wedge has 8 densities plus clear, the densities differ by a density of 0.3 thus each step in the test strip receives twice the exposure of the previous.

This was used to compare and categorise printing paper, the kit was supplied with cards on which to mount the finished test strips, a Contrast Scale could be held against the strip which would show the contrast rating of the paper.

This device uses the familiar grease spot principle to determine the exposure required when printing from a negative. The negative is placed against the screen between the two light sources (candles), the screen is then moved along the strip until the transmitted light through the negative matches the surrounding reflected light from the other light source. At this point a value which indicates the exposure required can be read from a scale. The scale has first to be calibrated by finding the correct exposure time for the printing papers to be used, a test negative is used for this. A successful print is made from the test negative, the test negative is then used in the photometer to find the scale value, the exposure time, for the successful print, is divided by the value to give a constant for this type of paper. For different negatives the constant is multiplied by the value found on the photometer, a further calculation involves the distance of the light if this is not fixed.

This is a rather cumbersome device to introduce in the 1920s. The inventor was Aubrey Leigh Price. This example appears to be unused.