User:Dsiviter/HF mount

HF-mount From Wikipedia, the free encyclopedia

The "HF" is said to stand for HeatFusion, an American manufacturer, who in 1995 made the first digital multi-spectral fusion goggle for the US Military. The lens mount was adapted to the HF1-mount thread with a simple adapter. Thus a retailer could stock a small number of expensive lenses that would fit a large number of camera brands using a selection of inexpensive adapters.

The original HF1 Mount was for a head mounted system called FusionWarrior. It has a fast four start thread that allows the user to quickly refocus with one hand. Later HF mounts were the HF2 and HF3 that evolved as larger format sensors evolved. However they all have a common four start fast thread for fine focusing with very short back focal distances.

The HF-mount connection is a solely mechanical specification. Electrical or mechanical connections (such as for autofocus) are generally not provided.

Applications include optical breadboard prototyping components, military head mounted night vision systems and optoelectronic systems for small UAVs. As a specialist mechanical interface, HF-mount allows components of various manufacturers to be interchanged and assembled.

The HF3-mount is the standard way to mount a lens to optoelectronic sensors that require small lightweight interfaces that have a fast thread for focusing. [edit] Adapters

Because the HF3-mount has a very short flange distance of 10mm and most 35mm and medium format cameras have longer flange distances, a simple mechanical adapter called a HF-T2 Ring is needed to adapt a HF-mount lens to any camera body without optical correction to achieve infinity focus.

An adapter ring has a female M36x0.75 metric thread on one side and a corresponding lens mount of the camera body.

The thickness of the external ring is equal to the difference of flange distance between HF-mount and corresponding lens mount in order to achieve infinity focus.

Other large format camera lenses have flange distance longer than 55mm. They can be attached to smaller format cameras with a combination of corresponding lens-to-HF-mount-adapter.