View source for Slide cube projector

{{Refimprove|date=December 2009}}

The  '''Slide Cube Projector''' is a [[slide projector]] and system, manufactured and marketed by [[Bell & Howell]], which was introduced in 1970 and marketed through the 1980s. The projector derived its name from its transparent cubical plastic slide storage [[Camera magazine|magazine]], approximately {{cvt|5.5|cm}} in each dimension (a bit larger than a standard [[135 film]] slide mount), that held 36 to 44 slides, depending on the mount thickness.<ref name=description>{{cite web | title=Bell and Howell 35mm Slide Cube Projector | publisher= Affordable Scanning| url=https://www.old-photo.com/pages/bell-and-howell-slide-cube-projector.htm | access-date=8 April 2024}}</ref> The magazine used a sliding lid to hold the slides in place. Unlike competing systems which used straight tray or [[carousel slide projector|carousel]] magazines, the slides in a Slide Cube are stacked on top of each other rather than stored in separate slots.

The system consisted of Slide Cubes and a projector designed to use them. Bell & Howell subsequently introduced a Slide Cube Projector II, with revised features, before discontinuing the system in the 1980s. Although Slide Cube Projectors are no longer manufactured, {{As of|2024|lc=y}} cubes, bulbs, a few replacement parts, and complete used projectors are available on the second-hand market.

==Design and operation==
When a cube is placed on the slide projector in the PRE-LOAD position, then slid into the LOAD position, its lid opens. As the advance trigger is activated, a sequence is initiated which starts by dropping a single slide into the slide advance mechanism, which uses a circular turntable with slide-size holes. The turntable has four distinct positions; in sequence, these are:
# LOAD
# PREVIEW
# PROJECTION
# RETURN
The turntable is thinner than a single slide, which allows just one slide at a time to drop from the cube into the LOAD position. The PREVIEW position allows the operator to check if the slide is loaded correctly before advancing into the PROJECTION position, where the image is projected onto the screen for viewing by the audience. The next position, RETURN, is available so the turntable can be reversed, allowing a slide in RETURN position to move back to PROJECTION, which gives the projector the capability to manually reverse the show by a single slide. After the RETURN position, the turntable finally rotates to the (RE)LOAD position, where the slide drops out of the turntable into a stack and another slide is taken from the cube. After the slides have been viewed, the operator presses a lever which lifts the slides back into the cube.<ref name=description/>

Most of the projectors use a 300&nbsp;watt 120&nbsp;V [[multifaceted reflector]] [[halogen lamp]] (ANSI code ELH) as a light source; early models use a 500&nbsp;W lamp without reflector (code CBA) instead. In addition to the on-projector controls, it could optionally be operated by a wired remote control, or the "Time Cube" automatic advancement accessory. The projector had an integrated handle, plastic lid or optional lid which incorporated additional cube storage. A sliding front foot or tilting lens adjustment were used to change the elevation of the projected image.<ref name=MurphyPM73/><ref>{{cite magazine |url=https://books.google.com/books?id=QtgDAAAAMBAJ&pg=PA50 |title=New Projector Shows Slides In a Cube |date=April 1970 |magazine=Popular Mechanics |page=50 |access-date=2 September 2024}}</ref> Several alternative projection lenses were offered.

Bell & Howell Slide Cubes were less expensive than trays and provided denser and cheaper storage capacity, with a book or drawer of 16 forty-slide cubes (640 slides) occupying the same space as a single round tray holding at most 140 slides.<ref name=MurphyPM73>{{cite magazine |url=https://books.google.com/books?id=GtUDAAAAMBAJ&pg=PA140 |title=Slide projectors get smarter all the time |first=Burt |last=Murphy |date=February 1973 |magazine=Popular Mechanics |access-date=2 September 2024 |pages=140–143}}</ref> Stack storage and preview facilitated editing of [[slideshow]]s; slides could be added to or removed from the show without having to move all of the remaining slides to fill the gap. Some tray-based projectors (e.g. some Kodak round-tray and Hähnel straight-tray slide projectors) also could use stack loaders to view a stack of slides, but did not allow addition or removal of slides, and did not have an associated storage system.

Drawbacks of the slide cube included the inability to go back by more than one slide, the fragility of the cubes, and the advancing turntable's tendency to jam if a slide mount was not perfect,<ref name=description/> interrupting slide shows and making the projectors challenging to operate.<ref>{{cite magazine |url=https://books.google.com/books?id=9i41hsvnbUYC&pg=PA32 |title=Letters: Projector's Lament |first=William R. |last=Grimes |page=32 |magazine=Popular Photography |date=December 1990 |access-date=2 September 2024}}</ref>

===Models===
{|class="wikitable sortable" style="font-size:90%;text-align:center;"
|+Bell & Howell Slide Cube Projector models
! rowspan=2 {{diagonal split header |Model{{efn|Model numbers are as written on the nameplate, or stamped on the bottom of the projector. The models which take CBA lamps also have the model number stamped in the metal lamp shield door.}} |Feature}}
! rowspan=2 | Series
! colspan=3 | Lens
! rowspan=2 | Focus
! rowspan=2 | Lamp
|-
! [[Focal length]] !! [[Aperture]] !! Tilt
|-
! 965Q
| rowspan=7 | Slide Cube{{efn|name=CubeO|Original Slide Cube projectors, {{circa|1970–1973}}, feature a silver ring around the projection lens mounting barrel and are finished in black plastic or woodgrain vinyl panels; lids are opaque woodgrain vinyl.}}
| || || {{yes C}} || Automatic
| CBA
|-
! 975Q
| || || {{yes C}} ||
| CBA
|-
! 977Q
| || || {{yes C}} ||
| CBA
|-
! 978Q
| || || {{yes C}} ||
| CBA
|-
! 981Q
| || || {{yes C}} || Automatic
| CBA
|-
! 982Q
| || || {{yes C}} ||
| CBA
|-
! 991 (early)
| || || {{yes C}} || Automatic
| CBA
|-
! 452
| rowspan=5 | Slide Cube (transitional){{efn|name=CubeT}}
| || || {{yes C}} ||
| ELH
|-
! 986
| 100&nbsp;mm || {{f/|2.8}} || {{yes C}} ||
| ELH
|-
! 987
| || || {{yes C}} ||
| ELH
|-
! 991 (late)
| || || {{yes C}} || Automatic
| ELH
|-
! 992
| || || {{yes C}} || Automatic
| ELH
|-
! RC55<br/>(857BH)
| rowspan=5 | Slide Cube (transitional),{{efn|name=CubeT|Slide Cube transitional projectors, {{circa|1974–1976}}, feature the projector model name on the front, a broad, colored ring around the projection lens mounting barrel, depending on if the lens tilts (chrome) or not (black), and are finished in woodgrain vinyl panels; lids are opaque woodgrain vinyl or black acrylic.}}<br/>Slide Cube II{{efn|name=Cube2|Slide Cube II projectors, {{circa|1977–1982}}, feature a black ring with a colored stripe around the projection lens mounting barrel matching the color of the model on the front nameplate and are finished in woodgrain vinyl panels; lids are translucent black acrylic.}}
| 100&nbsp;mm || {{f/|3.5}} || {{no X}} || Manual
| ELH
|-
! RF60<br/>(859B)
| 100&nbsp;mm || {{f/|3.5}} || {{no X}} || Remote
| ELH
|-
! AF70<br/>(861BH)
| 100&nbsp;mm || {{f/|3.5}} || {{no X}} || Automatic
| ELH
|-
! AF70Z<br/>(861Z, 861BHZ)
| 85–115&nbsp;mm || {{f/|3.5}} || {{no X}} || Automatic
| ELH
|-
! AF80<br/>(863BZ)
| 85–115&nbsp;mm || {{f/|3.5}} || {{no X}} || Automatic
| ELH
|-
! CP40
| rowspan=5 | Slide Cube II{{efn|name=Cube2}}
| 100&nbsp;mm || {{f/|3.5}} || {{no X}} || Manual
| ELH
|-
! RC50
| 100&nbsp;mm || {{f/|3.5}} || {{no X}} || Manual
| ELH
|-
! RF50
| 100&nbsp;mm || {{f/|3.5}} || {{no X}} || Remote
| ELH
|-
! AF66
| || || {{no X}} || Automatic
| ELH
|-
! AF72<br/>(861H)
| 100&nbsp;mm || {{f/|3.5}} || {{no X}} || Automatic
| ELH
|}

A version of the AF70 was sold by [[Sears]] as the Opticube (model 802).

===Lenses===
All Slide Cube projectors are compatible with any of the four available lenses. Lens appearance depends on age, with the earliest lenses featuring silver-colored finishes on the focusing (and zoom) ring, coordinating with the earliest Slide Cube projectors; lenses originally sold with the Slide Cube System II may be marked as ''Lumina II''.
* ''Lumina'' 64&nbsp;mm (2{{frac|2}}") {{f/|3.5}} for [[110 film]] slides
* ''Filmovara Lumina'' 85–115&nbsp;mm (3{{frac|2}}–4{{frac|2}}") {{f/|3.5}}
* ''Lumina'' 100&nbsp;mm (4") {{f/|2.8}}
* ''Lumina'' 100&nbsp;mm (4") {{f/|3.5}}

== See also ==
*[[Franke & Heidecke Rolleiscop]]

==Notes==
{{notelist}}

==References==
{{Reflist}}
===Patents===
* {{cite patent |country=US |status=Patent |number=3591275A |title=Slide Projector |invent1=Frank C Badalich |invent2=George F Krtous |assign=Bell & Howell Co. |fdate=June 10, 1968 |pubdate=July 6, 1971}}
* {{cite patent |country=US |status=Patent |number=3659934A |title=Slide Transport Device |invent1=Carl C Costanza |invent2=Frank W Betlejewski |invent3=Richard Frystak |invent4=Walter W Weber |assign=Bell & Howell Co. |fdate=September 23, 1969 |pubdate=May 2, 1972}}
* {{cite patent |country=US |status=Patent |number=3773413A |title=Slide Transport Device  |invent1=Carl C Costanza |invent3=Frank W Betlejewski |invent4=Richard Frystak |invent2=Walter W Weber |assign=Bell & Howell Co. |fdate=July 6, 1971 |pubdate=November 20, 1973}}
* {{cite patent |country=US |status=Patent |number=3782816A |title=Slide Return Mechanism |invent3=Carl C Costanza |invent1=Frank W Betlejewski |invent2=Richard Frystak |invent4=Walter W Weber |assign=Bell & Howell Co. |fdate=July 6, 1971 |pubdate=January 1, 1974}}
* {{cite patent |country=US |status=Patent |number=3926514A |title=Slide Projector Loading-Unloading Station  |invent1=Carl C Costanza |invent3=Frank W Betlejewski |invent4=Richard Frystak |invent2=Walter W Weber |assign=Bell & Howell Co. |fdate=July 6, 1971 |pubdate=December 16, 1975}}

==External links==
* {{cite magazine |url=https://books.google.com/books?id=m1UEAAAAMBAJ&pg=PA59-IA5 |title=The reviews are in. [advertisement] |date=May 1, 1970 |magazine=LIFE}}
* {{cite web |url=http://www.armory.com/~spcecdt/photo/slideCube/ |title=Slide Cubes |first=John |last=DuBois}}
* {{youtube |id=zgWZzONPZ_M |title=Projector AF70 Slide Cube}}, demonstrates projector turntable mechanism

{{DEFAULTSORT:Slide Cube Projector}}
[[Category:Slide projectors]]