Ollinger's Guide to Enlargers

Beseler 45 Series Enlargers


Beseler 45The Charles Beseler company began in 1868 making scientific and lab equipment, and began producing enlargers in 1953. Beseler is one of the two dominant manufacturers in the USA. Their enlargers (along with Omega) were frequently found in schools and rental labs; a great many students learned how to print on a Beseler enlarger. While not the least expensive, they are typically rugged, no-nonsense machines that are built to last.

Beseler has a naming scheme for most of their enlargers which describes the features of the machine. E.g. a 45MXC is a 4x5 enlarger chassis with a motorized colorhead and extra support truss.

I have a few of Instruction Manuals and brochures available for download. click for manual

Quick Comparison

Model Mfg Col. Type Head Focus Method Baseboard Price Notes
45AF Late 1950s Dual Rail Condenser Autofocus n/a $495 Modern Photography Test April 1959
45MX       Manual      
45MX-II 1981 - present Dual Rail Condenser Manual 25-1/2 x 30-3/8" Point-Light head $915; Dichro 45 $1,375; Dicrho 45S $825; Condenser $1,042; Dichro (computerized) $2,175 Motorized lamphouse elevation; tilting negative and lens stages for distortion control; point light source head available -- Dichro 45 colorhead reviewed Darkroom Magazine: July 1980 (Vol 2 #4)
CB7 1983 Triangular truss Condenser or diffusion Manual 21 x 25" Same heads as 45MX-II. Condenser $2,570; Dichro $3,585 Reviewed Darkroom Photography, Feb 1983 (Vol 5 #2)

Series Comments

The 45 series was Beseler's flagship for decades. The "ladder" chassis design was unique and identifiable. They were big, sturdy and well made, and were a favorite (along with Omega) of schools.

Model Comments


The following appeared in the now-defunct Modern Photography magazine, April 1959. It was written by Myron Matzkin.

Beseler 45AF (1959)Specifications: Beseler Model 4SAF Autofocus Enlarger. Negative size: 16mm to 4x5. Focusing: Autofocusing by parallelogram, wheel and cam system. Light source: 150-watt opal lamp. Construction: Steel and extruded aluminum with pyramid structure and obelisk frame. Other features: Single set of condensers for all lenses, concealed counterbalance for crank-controlled up and down movement, horizontal projection, glassless negative carriers and wheel-mounted variable contrast paper filters. Price: $495.

So we walked into the darkroom and there was this Beseler 45AF enlarger looking as solid and substantial as the Gantry cranes used for space rockets. "Test it," the man said, leaving us to our own devices. And then followed several pleasant days of print making in an attempt to test the Beseler on a strictly practical basis. The various frustrations that a wide variety of negatives can sneak into a darkroom bring out faults and virtues as no amount of dry run testing can.

We soon discovered that the appearance of strength and solidity engendered by the Beseler is real. In a darkroom close by a studio used for various other Modern Tests, a few doors that open and close regularly, and surrounded by other vibration causing operations, the Beseler proved amazingly solid. The impressive 1-3/8" thick baseboard and the obelisk-type frame standing 45 in. high combine to provide great rigidity and shock resistance.

But the autofocusing mechanism in the Beseler is the feature that makes enlarging easier--and more enjoyable. A wheel mounted on an axle supported by two parallel arms fitted to the lower lens bellows rides on a long cam. Once focused the lens remains focused for the negative no matter what change is made in the print size. As the wheel rides up and down the cam, the parallel arms raise and lower the lens stage, changing the distance between lens and negative, keeping the lens in focus for all enlargements.

A crank operates a cable and drum system that raises the enlarger to a maximum height of 59-1/2". And if you can't get a large enough print the normal way, it takes only a few seconds to loosen two screws behind the lens stage and swing the entire enlarger into position for horizontal projection.

One set of condensers does the job for all enlarging from 16mm to 4x5 with 50, 90, 101 and 135mm lenses. Cams, however, must be changed for each lens if you want to use the autofocus feature. Position of the condensers is changed to match the lens in use. Indicators on the frame show correct position for the condensers for each frame.

If we have a criticism of the Beseler it has to do with the negative carrier. We found that the small amount of play in the negative stage makes it possible to move the carrier sufficiently to change the corner to corner position of the image on the enlarging easel.

Illumination over an 8x10 sheet of enlarging paper proved extremely even. Also, after operating the enlarger for several hours (with prolonged "on" periods), we found that the lamp house was still cool enough to touch without danger of burning our fingers.

We liked the wheel arrangement for variable contrast paper filters. Just a flip of the wheel and the filter we wanted was in place--quick, neat and efficient.


The following is a review that appeared in the now-defunct Darkroom Photography magazine, Vol 5 #2, February 1983. It was written by Ed Rice.

The CB7 is back on the scene. A long-time favorite of scientific, educational, and institutional darkrooms, this sophisticated 4x5 enlarger from Beseler has been out of production for several years. Now, once again, you can order a CB7 if you're serious enough about darkroom work to need one.

At first glance, the CB7 looks something like Beseler's famous MCRX and MXII models. It has the same ultra-solid support frame, the same motorized carriage, and the same triangulated bracing (slightly modified for even greater sturdiness). But it also has some very interesting features not found on its cousins.

For example, across the front panel of the 2-1/2"-thick baseboard are a row of electrical controls. Using various switches you' can raise or lower the carriage and even focus the image; if you plug Beseler's #8177 timer into the system, another baseboard switch turns the lamphouse on or off for focusing, while a touch to the luminous "Expose" button initiates the exposure—all from the comfort of your enlarging stool! (With all the relevant controls right there on the baseboard, this enlarger would be excellent for a handicapped person confined to a wheelchair.) Across the rear of the baseboard are various sockets for cords running to and from the 8177 timer. You can use other timers, of course, but you may lose function on the baseboard focus and expose switches.

Power focus is the flashiest feature of the CB7. It may sound unnecessary, but you soon realize its value if you spend some time using it. When you have to crank out lots of prints of many different sizes and croppings, motorized focus is very nice—especially when making big blowups. Instead of going through some yogic contortion to reach the focus knob while stretching your eyeball to the grain-focus scope, you simply lean forward and touch a switch.

Actually, a pair of switches (coarse and fine) activate the focus motor. Additionally, there is a rheostat for governing fine focus speed. You can also focus manually with a knob if desired. Hitting the point of precise focus with the motor is admittedly tricky and takes practice; at lower elevations it may be preferable to use the power focus mainly for rough focusing, then change to the hand knob for final focus. Once the image is perfectly sharp, you can lock the lens stage in place, though it is not generally necessary.

A pair of safety switches on the focus motor shut it off when it reaches either limit of travel. (The carriage elevation motor has a similar cutout system). Another nice thing: when doing murals using Beseler's #8247 wall-projection mirror attachment, the power focus can be activated remotely using the #8253 Remote Focus Control, which plugs into a socket near the baseboard focus switches. A similar socket allows use of a remote foot switch, too.

The motorized lens stage as well as the negative and condenser stages are independently moveable (and locka-ble) along a 26-inch vertical track, allowing phenomenal adjustability. The lens stage can be as close as 4 inches from the condenser stage, or as far as 18 inches. More importantly, the main bellows draws up to 15 inches, making it possible to make 1:1 prints, or reductions down to about 60 percent, from the larger formats.

A linear scale indicates the proper condenser positions for 35mm, 6x6cm, 6x9cm, 3=1/4x4-1/4, and 4x5 formats; another scale shows relative height of the condenser stage along the track. Of course, there's also an elevation scale for overall carriage height, too. Prints up to 16x20 can be made right on the baseboard from 35mm; 20x24 is possible from 4x5 with a 135mm lens. For larger prints, the wooden portion of the baseboard may be removed and the image projected through the frame onto an easel underneath the enlarger. Or, the previously mentioned wall-projection mirror may be used for mural sizes.

Another feature of the CB7 that will appeal to serious printers is the ability to tilt both lens and negative stages with calibrated precision. Simply by turning a knob, the lens can be tilted as much as 15 degrees while the negative can be tilted up to 7V* degrees. These movements allow you to maintain sharp focus across the entire image while tilting the easel for perspective correction. The tiltability is in the left/right axis, but by rotating the negative carrier you can effectively correct in either axis. Unfortunately, when printing 35mm, the focusing bellows is so collapsed that the movement is limited; a recessed lensboard is available which would lessen this problem considerably.

Many other things are adjustable on this enlarger. For example, seven alignment checks are recommended following setup, and all but one of them may be adjusted if necessary with tools or shimming. The unit I tested was quite true and parallel right out of the box, so I didn't have to hassle with any of those. It's comforting to know that you can, though, in case anything ever gets out of whack during moving or general wear and tear. I did, however, have to fuss with the fit of the motorized lens stage on the focus track. It was initially too lose, allowing excessive play; just a bit too tight, however, and the motor bogged down. It's a tricky adjustment, but a necessary one.

The CB7 uses Beseler's standard 4-inch square lensboard series; they slip in and out quickly and securely for easy lens changing. A red filter swings into place under the lens for black-and-white work; a separate filter holder accepts drop-in variable contrast or special purpose filters.

The cam-activated negative stage opens smoothly with a lever, and may be locked open if desired. In use, however, a fair amount of light leaks out around the carrier, a problem that could be simply remedied with some sort of foam rubber seal (possibly weather-stripping).

Beseler's negative carriers are convenient to use, hinged in back and with locating pins that hold the film in line. There are also pins on the underside of the carriers to position them within the negative stage. The mounted slide carrier is especially nice, with spring clips that flatten the slide mount even if it's warped.

The conveyor-belt Negatrans carrier, available in 35mm and 120 versions, is great for production situations, allowing you to crank single negs, strips, or entire rolls through the enlarger—without removing the carrier. There's also the Negaflat carrier, which grips the edges of 4x5 sheet film, stretching it flat and tight as a drumhead. If you're the sort of 4x5 worker who shoots out to the very edges of the frame, you probably wouldn't like the Negaflat, though; its grippers do bite into the image area just slightly.

Beseler makes both a standard variable condenser head and a point light source for the CB7. (Compatible cold light heads can be obtained from other manufacturers, too). But the CB7's triple threat is completed when you install the Beseler Dichro 45 Computerized Colorhead (reviewed in Vol 3, #2, May 1981).

I worked with the CB7 as a standard black-and-white condenser enlarger and also got to check it out with the Dichro 45 plus the D.A.T.A. Module, a combination control console, timer, color analyzer, and magnetic card reader! Yep, with the D.A.T.A Module, you can record enlarger settings or analyzer programs on inexpensive magnetic cards, then recall them anytime.

The CB7 as a color enlarger is convenient and straightforward enough. But to really maximize the potential of the D.A.T.A. Module, you have to give yourself a crash course in darkroom computerization. In a production situation, this combination promises to be extremely handy. For example, a magnetic card could be assigned to each color image during testing and final printing, picking up printing and correction data at each step. The possibilities are mind-boggling. By the way, the Dichro 45 may be used with any standard timer instead of the D.A.T.A. Module if desired.

Production is the watchword with the CB7, whether it's used as a traditional black-and-white enlarger or an electronic color printing marvel. I can't imagine the weekend hobbyist really needing one, although if money is no object it would be a fine choice. But people who make prints day in and day out will find the CB7 a luxurious workhorse. Don't let the power focus fool you; this is not a lazy person's enlarger!