The advent of digital point-and-shoot cameras in the 1990s through the 2010s with LCD viewfinder displays reduced the appeal of the SLR for the low end of the market, and in the 2010s and 2020s smartphones have taken this place.

These cameras were used at waist level; the ground glass screen was viewed directly, using a large hood to keep out extraneous light.

Medium format SLRs soon became common, at first larger box cameras and later "pocketable" models such as the Ihagee Vest-Pocket Exakta of 1933.

The Rectaflex was a 35 mm SLR camera with a focal plane shutter, interchangeable lenses, and a pentaprism eye-level finder.

Both were preceded by Alpa-Reflex, first presented to a wider public in April 1944 at the Swiss Trade Fair in Basel (Schweizer Mustermesse).

Highlights: From 1952 to 1960 the KW factory/VEB Pentacon also produced the Praktina, a system SLR camera for professionals and advanced amateurs with a bayonet mount and focal shutter, but production was closed, partly for political reasons.

The Pentamatic featured an automatic stop-down diaphragm (offered only with the Auto Yashinon 50mm/1.8 lens), instant-return mirror, a fixed pentaprism, and a mechanical focal-plane shutter with speeds of 1-1/1000 second, along with additional interchangeable lenses.

(Although this invention had been anticipated by the 1948 Gamma Duflex and 1954 Praktina FX-A which could be used with a semi-automatic diaphragm, which stopped down automatically, but had to be opened manually after the exposure.

[14]) The automatic diaphragm feature eliminated one downside to viewing with an SLR: the darkening of the viewfinder screen image when the photographer selected a small lens aperture.

When the shutter release is pressed the mirror flips up against the viewing screen, the diaphragm closes down (if automatic), the shutter opens and closes, the mirror returns to its 45-degree viewing position (on most or all 35 mm SLRs made since 1970) and the automatic diaphragm re-opens to full aperture.

In the later models pressing the shutter release moved the spring-loaded periscope out of the film path before the focal-plane shutter operated Minolta's first SLR, the SR-2, was introduced to the export market in the same year (in fact, at the same Philadelphia show as the Canon and Nikon products) but had been on sale in Japan since August 1958.

It featured interchangeable prisms and focusing screens; the camera had a depth-of-field preview button; the mirror had lock-up capability; it featured a large bayonet mount and a large lens release button; a single-stroke ratcheted film advance lever; a titanium-foil focal plane shutter; various types of flash synchronization; a rapid rewind lever; and a fully removable back.

Subsequent top-of-the-line Nikon models carried on the F series, which has as of 2005[update] reached the F6 (although this camera has a fixed pentaprism).

The camera featured a quick return mirror and an automatic diaphragm, and was introduced with an interchangeable black pentaprism housing.

These hand-held meters did not require any batteries and provided good analog readouts of shutter speeds, apertures, ASA (now referred to as 'ISO') and EV (exposure value).

In order for built-in light metering to be successful in SLR cameras, the use of Cadmium Sulfide Cells (CdS) was imperative.

Some early SLRs featured a built-in CdS meter, usually on the front left side of the top plate, as in the Minolta SR-7.

It had a more streamlined body, a better mirror-locking system, a top shutter speed of 1/2000 of a second and was introduced with its own proprietary, continually improving Photomic meter prism heads.

Other Miranda 35mm SLR cameras could be adapted to behind-the-lens capability through the use of a separate pentaprism which included coupled or non-coupled built-in CdS meters.

Maitani decreased the size and weight by totally redesigning the SLR from the ground up with unprecedented use of metallurgy, which included repositioning the shutter speed selector to the front of the lens mount, instead of a more conventional position on top of the body.

By 1974, the autoexposure SLR brands had aligned into two camps (shutter-priority: Canon, Konica, Miranda, Petri, Ricoh and Topcon; aperture-priority: Asahi Pentax, Chinon, Cosina, Fujica, Minolta, Nikkormat and Yashica) supposedly based on the superiority of their chosen mode.

(In reality, based on the limitations of the electronics of the time and the ease of adapting each brand's older mechanical designs to automation.)

With shutter-priority control, the camera would set the lens aperture after the photographer chose a shutter speed to freeze or blur motion.

Although the Minolta XD11 was the first SLR to offer both aperture-priority and shutter-priority modes in 1977, it was not until the next year that the A-1 came out with a microprocessor computer powerful enough to offer both of those modes and add the ability to automatically set both the shutter speed and lens aperture in a compromise exposure from light meter input.

It utilized an autofocus system based on sonar technology that gauges the camera-to-subject distance using ultrasonic sound waves.

Such "full frame" sensor digital SLRs (DSLRs) however gained early popularity with professional photographers who could both justify their initial high cost, and retain the use of their investment in expensive 35 mm film lenses.

In addition, the full-frame format is now found in Sony's MILC cameras and high-end fixed prime lens compacts, as well as Leica's M-mount digital rangefinders.

While twin-lens reflex cameras have been more numerous in the medium format film category, many medium-format SLRs had been (and some still are) produced.

The vast majority of SLRs now sold are digital models, even though their size, form factor, and other design elements remain derived from their 35 mm film predecessors.

The manufacturer's prism logo in gold on black with the factory initials ГОМЗ (GOMZ) is shown behind a circular magnifying window on the top left camera front.