VI Photo Enlarger
|Vivitar VI enlarger
with condenser head
image by Bohdan Bobrowski (Image rights)
Vivitar decided to design their own enlarger that looked to solve the problem of heat reaching the negative, and a group of engineers in Inglewood, CA took on the task. Vivitar’s unique solution to the heat problem was to use a “dioptic light source”. The heat from the lamp was effectively insulated by using a "light pipe" made of glass which transmitted the light from the dichroic head to the negative. By having that "light pipe" there were 2 optical components and thus dioptic. The results were very good in regards to heat, but careful alignment was needed to avoid vignetting in larger negatives.
It was also provided with a condenser head for BW work, which has 2 fixed and 1 movable condenser to provide optimal light uniformity for 50 or 80mm lenses. It uses standard bulbs; which can be replaced with LED bulb for Black and White enlargements. A big drawback is the lack of a VC filter drawer, and thus these filters should be placed under the lens.
The enlarger itself is very tall, with a inclined column of about 1.1m allowing enlargements of 32X (768x1152mm) with a 50mm lens. The head moves smoothly, and can be tilted +/- 30° and resetting to the normal position is very easy.
The negative carriers were plastic, and had a groove to keep them flat and allow the user to rotate and align.
- Brochure in high quality by Peter D'Aprix 
- Modern Photography’s August 1978 review of the Vivitar VI enlarger
- Ollinger's Guide to Enlargers