Taylor-Hobson Ental II 4.25 inch f/4.5 ...

... Enjoying enlarger lenses as 100-th post here ...

Because of the missing focusing mechanism and diaphragm automatism, these lenses are really compact: the Ental II presented here has a focal length of 108mm, but it is smaller than my Pentax-K 28/2.8.

Usually built around a very simple optical formula, these lenses are very well corrected to offer high performances over a flat plane (they are meant for film printing). So, they are likely to reach a better level of sharpness and contrast from edge to edge of the image than the equivalent "standard" camera lenses. The cheapest ones usually have three or four elements, while the most sophisticated ones use optical schemes with five or six elements, and sometimes some apochromatic glass. These lenses are not famous for their speed, the fastest one seen has an f/stop of 2.8 wide open but, because of their usage domain, who needs faster ?

The optical scheme of the Ental II manufactured by Taylor-Hobson (now Cooke Optics Ltd.) should derive from the classic Zeiss Tessar design (lack of documentation here, correct me if i'm wrong) with four optical elements:



Most of these enlarger lenses are available with a standard M39x1 thread mount, which means that, for use on a bellow, an adapter ring is required most of the times. Unluckily, the Ental II used here has an M37 thread mount so, while waiting for an adapter from Hong-Kong, i just used a T2-to-M42 mount, with some adhesive tape around the base of the lens to reach the proper diameter.

The results speak by themselves:



The sample, shot at f/5.6 to have some depth of field, show a nice color saturation and contrast, as well as a good sharpness (feel free to display the full-res picture clicking here, and look at the reflections in the elephant's eye).

A series of close focusing pictures is available on my Flickr photostream here, while some "true macro" pictures are likely to be ready in the next few days, as soon as i can get a bit more spare time ...