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